DISEASES AND CONDITIONS

Athletic performance

March 22, 2017

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Athletic performance

Natural Standard Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Related Terms

  • Anabolic steroids, athlete, balance, energy boosters, energy drinks, energy enhancement, energy enhancers, exercise, exercise capacity, fall prevention, handgrip strength, isokinetic training, isometric training, isotonic training, muscle, muscle mass, muscle strength, physical endurance, physical strength, postural stability, posture, protein powder, protein shakes, testosterone, testosterone enhancement, weight control, weightlifting.

Background

  • Athletic performance, also called exercise performance, describes an individual's ability to use various muscles to stay physically fit.

  • Exercise is any form of physical activity that helps to promote overall health. Most movement of the body is considered beneficial, as long as it is done in moderation and at the skill level of the person. There are many ways for people to exercise including gardening, walking, sports activities, and dancing.

  • An individual's athletic performance can be measured in terms of cardiovascular endurance, muscular strength, and exercise capacity.

  • Cardiovascular endurance refers to the body's ability to efficiently use oxygen during aerobic activities such as jogging or biking. Individuals who have strong cardiovascular endurance have strong hearts and lungs. Their hearts are able to efficiently pump oxygen to the body's muscles.

  • Muscle strength refers to the amount of physical force an individual can exert at one time. This can be determined by how much weight a person can lift using certain muscles.

  • Exercise capacity, also called physical endurance, is the amount of uninterrupted physical exercise an individual can sustain.

  • Individuals in poor shape have an increased risk of developing many life-threatening health conditions including heart disease, high blood pressure, stroke, obesity, diabetes, osteoporosis, and cancer.

  • Individuals in poor shape are also more likely to have bad posture. When the muscles become tired, individuals tend to slouch putting extra pressure on the back and neck. As a result, poor posture may cause back and neck pain or muscle soreness. Regular exercise may help improve posture because it strengthens the muscles needed for good posture.

  • There is extensive scientific evidence suggesting that regular exercise offers major health benefits. According to the U.S. Centers for Disease Control and Prevention (CDC), the failure to exercise regularly is a significant precursor to heart disease, stroke, diabetes, and cancer. Exercising on a regular basis is one of the most inexpensive and easiest measures a person can take in order to reduce the risk and/or delay the onset of serious illnesses.

  • Regular exercise in the elderly may help prevent fall injuries. Falls are the leading cause of injury-related visits to emergency departments in the United States. They are also the number one cause of accidental deaths in patients older than 65 years. Exercise can help patients strengthen their muscles and improve their balance, which reduces the risk of accidental falls.

Maintaining and Improving Athletic Performance

  • General: Patients beginning an exercise program should choose activities that fit their levels of strength and endurance. Exercise that causes extreme pain or discomfort is considered by many experts as potentially harmful and it may even cause permanent damage to the body, especially to the joints, muscles, and tendons. The American Academy of Family Physicians recommends that patients choose exercise programs they will do consistently. They also recommend lower impact forms of exercise, such as walking or swimming, for pregnant patients and patients unable to handle more intense forms of exercise.

  • A qualified healthcare professional should be consulted before starting a new exercise plan. Exercise cautiously if pregnant, elderly, or with any longstanding medical conditions. Avoid high-impact forms of exercise with osteoporosis, nerve injuries, or if pregnant.

  • Nutrition: According to researchers, there is a connection between food consumption and athletic performance. Studies show that a poor diet almost always has a negative effect on an individual's athletic performance, regardless of how much they exercise. Individuals should consume a healthy diet that has sufficient amounts of calories, vitamins, minerals, and protein. The amount of calories needed depends on patient's age, size, gender, as well as the type and intensity of the physical activity being performed. The U.S. government issued a revised food pyramid in 2005 in an effort to help Americans live healthier. The new food pyramid provides 12 different models based on daily calorie needs, ranging from the 1,000-calorie diets for toddlers to 3,200-calorie diets for teenage boys.

  • Foods that are classified as complex carbohydrates are especially important for athletes because they provide energy, fiber, vitamins, and minerals. Examples of complex carbohydrates include pasta, whole grain bread, brown rice, whole grains, and bran. Oftentimes, athletes consume meals that are high in carbohydrates before they work out. This has been shown to improve an individual's athletic performance in endurance exercises that last longer than one hour. However, simple carbohydrates, such as sodas, white bread, jellies, and candies, are not recommended because they contain high amounts of calories and sugar, but little nutritional value. These food items may actually decrease an individual's performance before an athletic event.

  • Foods that contain protein are also important because they support the growth and repair of body tissues, including muscles. According to researchers, athletes only require slightly more protein than non-athletes. Also, according to the American Heart Association, most Americans already eat twice the amount of necessary protein. When an individual consumes more protein than the body needs, it is stored as fat.

  • In general, the Atkins diet™ is not recommended. This is a high-protein diet that involves restricting the amount of carbohydrates consumed. Patients considering this diet should consult their healthcare providers. Some medical experts question the health safety of the Atkins diet™ over the long term because the Atkins diet™ allows consumption of foods containing saturated fats and proteins without any restriction. Health concerns include the impact of large amounts of protein on kidney function, the impact of saturated fats on cholesterol and heart disease, and the potential for some types of cancers to develop from eating a diet low in complex carbohydrates, antioxidants, certain vitamins and minerals, and fiber.

  • Hydration is another essential nutrient for athletes. Water and other fluids help the body maintain proper body temperatures. As individuals sweat, their bodies lose water. Sweat is necessary to help keep the body cool. Individuals should drink plenty of water before, during, and after exercising. Individuals should avoid drinks that contain caffeine before exercising. Caffeine is a diuretic that promotes fluid loss.

  • Patients should be careful not to drink too much water because it may lead to overhydration, or hyponatremia, which may be life threatening. This occurs when the body consumes more water than it loses. When there is too much water in the body, there are low levels of salt in the blood. As a result, patients may experience swelling in the legs, shortness of breath, and enlarged organs and veins.

  • When individuals exercise, the body loses electrolytes, including sodium and potassium, in the blood. These electrolytes are needed to regulate bodily functions. Individuals who are participating in strenuous exercise that lasts longer than a couple hours may benefit from sports drinks. These drinks, such as Gatorade®, contain electrolytes to help replace the ones lost during exercise.

  • Regular exercise: Regular exercise can help patients improve or maintain muscle mass, physical endurance, balance, and postural stability. Exercise includes cardiovascular activities, such as running or walking, as well as weight training. All workouts should begin with a warm-up routine and end with a cool-down segment that includes stretching exercises. After completing a weight-training workout, wait 24-48 hours before lifting with the same muscles.

  • Because lifting weights increases muscle mass, this type of exercise may also improve an individual's postural stability. The American College of Sports Medicine recommends that patients perform one set of eight to ten exercises with eight to 12 repetitions of each exercise, two to three days per week in order to improve muscular strength, endurance, and flexibility. There are three main techniques used for muscle training: isometric, isotonic, and isokinetic.

  • Isometric muscle training is the contraction of a muscle against an immovable force. For instance, muscles will flex and hold a stationary position when an individual pushes against a wall. This weight training technique involves no weight and very little equipment. Isometric exercise is primarily used in physiotherapy and rehabilitation following an injury.

  • Isotonic muscle training involves muscle contractions where tension is equal throughout the range of motion. Isotonic exercise strengthens the muscles in the entire range of motion while improving joint mobility. Isotonic muscle training is usually done with dumbbells, barbells, or elastic resistance bands.

  • Isokinetic muscle training is a type of contraction where the speed of movement is fixed and resistance varies with the force exerted. In other words, the harder an individual pushes or pulls, the more resistance is felt. This method is mostly used for sports training or rehabilitation following an injury. This form of training usually requires the use of a machine.

  • Balance may be improved with the use of physio balls, also called exercise balls. Individuals usually sit on these inflatable balls to perform sit-ups and lift arm weights. Patients can work many body areas, including the back, thighs, and buttocks. Sitting or lying on these balls forces individuals to use core muscles, including the abdominal muscles. At first, patients may feel like the ball is unstable underneath their weight. However, as muscles mass increases and balance is improved, it will become easier to use.

  • Cardiovascular training helps to improve an individual's physical endurance. The American College of Sports Medicine recommends that individuals engage in 20 to 60 minutes of continuous or intermittent (bouts of at least 10 minutes) aerobic activity at 55-90% maximum heart rate or at 40-85% maximum oxygen uptake three to five days per week to increase cardio-respiratory fitness.

  • Posture awareness: In addition to regular exercise, posture awareness may help patients improve their postures. This can help prevent neck and back pain as well as sore muscles, which are often caused by poor posture. Individuals can practice good posture in front of the mirror. When standing, a patient's weight should mostly be on the balls of the feet, which are shoulder-width apart. The back should be straight and the shoulders should be upright. The arms should hang naturally down the sides of the body. Do not lock the knees. The head should be square on top of the neck and spine, not pushed forward. Patients can test their standing posture by standing against the wall. The shoulders, buttocks, and back of the head should touch the wall.

  • Ergonomic furniture: Maintaining good posture when standing or sitting for prolonged periods is an important part of staying fit. Individuals should sit in furniture that promotes good posture. For instance, individuals can purchase chairs that have adjustable back supports. Footrests, portable back supports, or even a small pillow can be added to chairs to improve posture.

  • When sitting, the back of the head should be aligned with the back of the chair. The shoulders should be upright. Do not slouch or lean forward. Office chairs should be adjusted so that the arms can comfortably bend at 75-90 degree angles. The knees should be even with the hips. Keep both feet on the floor.

  • Supportive footwear: Wearing comfortable and supportive footwear may help improve posture. Avoid wearing high-healed shoes because they affect the body's center of gravity, which changes the alignment of the body.

Fall Prevention

  • General: Individuals who are in poor physical shape are more likely to accidentally fall and hurt themselves. Accidental falls can lead to serious injuries such as hip fractures or even death. The elderly have the greatest risk of falling and hurting themselves. This is because muscle strength and coordination lessen over time. As a result, people tend to lose mobility, agility, and flexibility as they age. Increasing one's athletic performance may help prevent falling and minimize injuries. In addition to regular exercise, patients are encouraged to regularly visit their eye doctors, make the home safer, and use assisted mobility devices, if needed.

  • Regular exercise: Regular exercise can help build muscle strength and balance, which may help reduce a patient's likelihood of falling. There are many ways for people to exercise including gardening, walking, sports activities, and dancing. The type of exercise is not as important as a consistent exercise schedule. The U.S. Centers for Disease Control and Prevention (CDC) recommends that individuals engage in 30 minutes of moderate activity on all or most days of the week.

  • A qualified healthcare professional should be consulted before starting a new exercise plan. Patients beginning an exercise program should choose activities that fit their levels of strength and endurance. Avoid high-impact forms of exercise with osteoporosis, nerve injuries, or if pregnant.

  • Assisted mobility devices: Some individuals, especially the elderly, may require assisted mobility devices to help them walk. This may include a cane, walker, wheelchair, or mobilized chair. Individuals should talk to their healthcare providers to determine the best options for them.

  • Eye exam: Individuals, especially the elderly, should have their vision checked annually. Most elderly people suffer from varying degrees of vision loss and it may lead to an increased risk of falling.

  • Making the home safer: Patients should move things that they may trip over, such as shoes, clothes, and books. Remove throw rugs or apply double-sided tape to the bottom of such rugs to prevent them from sliding. Patients should keep most or all of their items in areas that do not require the use of a step stool. Grab bars can be installed in the shower and near the toilet. Use a non-slip bath mat in the shower or tub. Install proper lighting inside the home. Handrails and lights should be installed on the staircases of the home. Consider installing a ramp into the home if there are steps to the front door. Wear rubber-soled slippers that do not slip when walking around the home.

Supplements and Enhancers

  • Energy boosters: Energy drinks, or energy boosters, are beverages that contain stimulants, vitamins, and/or minerals. Common ingredients include caffeine, guarana extracts, taurine, ginseng, maltodextrin, inositol, carnitine, creatine, and Ginkgo biloba. Energy drinks may contain as much as 80 milligrams of caffeine, the equivalent of one cup of coffee. Many also contain high levels of sugar or glucose. There are many different types of energy drinks. Some examples include Adrenaline Rush®, Red Bull®, Sprint®, Monster®, Diesel®, and Venom®. Most energy drinks contain some combination of B vitamins, which are thought to help the body convert sugar into energy.

  • Few studies have evaluated the safety or efficacy of energy drinks. Most scientific studies have investigated the role of energy drinks in obesity. Research suggests that energy drinks high in sugar lead to weight gain. Energy drinks act as diuretics and may potentially cause dehydration. Drink plenty of water after consuming energy drinks.

  • Because energy drinks contain stimulants, they may potentially interact with alcohol, a common depressant. Theoretically, the combination could lead to cardiopulmonary or cardiovascular failure. Two people died in Sweden after consuming Red Bull® and vodka. However, it is unclear whether the energy drink was the cause.

  • Avoid consuming energy drinks in excess, mixing them with alcohol, or using them during or immediately before or after rigorous physical activities. The National Collegiate Athletic Association (NCAA) and other professional sports leagues have banned certain energy drinks, such as Red Bull®, due to potential health risks. Avoid energy drinks that contain high levels of caffeine with heart disease, high blood pressure, and insomnia.

  • Protein powder: Protein powder is a powdered and refined protein intensive dietary supplement used by fitness enthusiasts and muscle builders who are trying to increase muscle bulk and strength. These powders can be mixed with a liquid for consumption as a protein shake, sprinkled on top of cereal, mixed with soups, or cooked into baked goods. Protein is necessary in the diet because of its role in muscle and tissue structure and function. Some examples of protein-rich foods include meats, fish, dairy products, dried beans and peas, and tofu. Protein powders are usually made from one of four basic sources: whey (from milk), egg, soy, or rice. Protein powders may be made from just one of these sources or may be a combination.

  • A study from Ohio State University, Columbus compared the effects of consumption of soy and whey protein bars in athletes. Researchers found that both the soy and whey groups showed a gain in lean body mass. However, the whey group, but not the soy group, showed a potentially harmful post-training effect on two antioxidant-related parameters. This led the researchers to conclude that soy and whey protein bars both promoted exercise training-induced lean body mass gain, but the soy had the added benefit of preserving two aspects of antioxidant function.

  • Recent studies involving whey powders have focused on its effects on muscle mass and resistance training in elderly males. Subjects who took whey protein powder immediately after exercise achieved positive results (less muscle wasting), while those who took the formula two hours or more after exercise had no significant change.

  • The consumption of too much protein may be unhealthy. Protein is broken down in the body by the kidneys. If a person has kidney problems, the consumption of protein may need to be limited. The daily recommended consumption of protein is based on a patient's weight, age, and activity level.

  • Testosterone enhancement: Testosterone enhancement is the illegal use of anabolic steroids to boost athletic performance. Anabolic steroids are male sex hormones, collectively known as androgens. Although these drugs may be prescribed for certain health conditions, such as hormonal disorders, it is illegal to use them without prescription. Many athletes illegally take these hormones to build more muscle and endurance than would normally be possible. Because anabolic steroids offer athletes an unfair advantage, they are banned by all major sporting organizations. Athletes are regularly screened for steroids in professional sports.

  • The most popular steroid used is called testosterone. This man-made chemical imitates the effects of the male hormones that are naturally produced in the body. Testosterone and other anabolic steroids that are used to increase muscle mass are taken by mouth or self-injected. Athletes often take multiple anabolic steroids.

  • Anabolic steroids may have significant adverse effects. In men, shrinking of the testicles, reduced sperm count, infertility, baldness, development of breasts, and increased risk for prostate cancer have been reported. In women, growth of facial hair, male-pattern baldness, menstrual irregularity, enlargement of the clitoris, and a deepened voice have been reported. In children, prematurely halted growth has been reported.

  • There is widespread evidence that the use of testosterone and other anabolic steroids may have permanent harmful effects on the body. Anabolic steroids have been linked to many health conditions including liver tumors, cancer, high blood pressure, increased bad cholesterol (LDL), and kidney tumors. Psychiatric side effects may include extreme irritability, delusions, paranoia, unabated jealousy, and impaired judgment stemming from feelings of invincibility.

  • Individuals who share needles to inject steroids have an increased risk of developing infectious diseases, including hepatitis C and HIV/AIDS.

Integrative Therapies

  • Strong scientific evidence:

  • Creatine: Several high-quality studies have shown increased muscle mass and muscle strength with the use of creatine. Future studies should take into account the effect of different individual fitness levels of study subjects.

  • Avoid if allergic to creatine or with diuretics (like hydrochlorothiazide, furosemide (Lasix®)). Use caution with asthma, diabetes, gout, kidney, liver or muscle problems, stroke or a history of these conditions. Avoid dehydration. Avoid if pregnant or breastfeeding.

  • Unclear or conflicting scientific evidence:

  • Acupressure, shiatsu: During acupressure, finger pressure is applied to specific acupoints on the body to help promote relaxation and wellness. Preliminary research reports that ear acupressure may reduce muscle fatigue and lactic acid production in the muscles, thereby possibly improving athletic performance. Additional research is necessary before a firm conclusion can be drawn.

  • With proper training, acupressure appears to be safe. No serious long-term complications have been reported, according to scientific data. Hand nerve injury and herpes zoster ("shingles") cases have been reported after shiatsu massage. Forceful acupressure may cause bruising.

  • Acupuncture: It is unclear if acupuncture can improve muscular performance, muscle strength, or heart rate recovery after exercise. Additional research is needed to determine if acupuncture is an effective therapy for exercise performance.

  • Needles must be sterile in order to avoid disease transmission. Avoid with valvular heart disease, infections, bleeding disorders, medical conditions of unknown origin, neurological disorders or if taking anticoagulants. Avoid on areas that have received radiation therapy and during pregnancy. Avoid electroacupuncture with irregular heartbeat or in patients with pacemakers. Use cautiously with pulmonary disease (like asthma or emphysema). Use cautiously in elderly or medically compromised patients, diabetics or with a history of seizures.

  • Alexander technique: The Alexander technique is an educational program that teaches movement patterns and postures. The technique is used to improve coordination and balance, reduce tension, relieve pain, alleviate fatigue, improve medical conditions, and promote well-being. Limited research suggests that functional reach performance may be improved through Alexander technique instruction, particularly in people older than 65 years. Better quality evidence is needed before a firm conclusion can be drawn.

  • The Alexander technique has also been suggested as a way to improve postural development in children. The long-term effects of such instruction are unknown.

  • No serious side effects have been reported with the Alexander technique. It has been suggested that the technique may be less effective in patients with learning disabilities or mental illnesses. The Alexander technique has been used safely in pregnant women.

  • Androstenediol: Androgen prohormones are widely promoted for their effects on building lean body mass, reducing body fat, and enhancing physical endurance due to their androgenic effects. Androstenediol and other prohormones have been shown to increase testosterone and estradiol levels in humans. However, significant improvements in muscle mass and athletic performance have not been observed in clinical studies.

  • Use cautiously in patients taking estrogenic or androgenic agents. Use cautiously in patients with low serum levels of high density lipoprotein (HDL). Caution is advised when purchasing androstenediols. Avoid in patients with estrogen or testosterone dependent cancers. Avoid use in pregnant or lactating women, and children. Sales of androstenediols and other pro-androgen hormones without a prescription are prohibited in the United States.

  • Aspartic acid: According to secondary reports, aspartate salts may enhance aerobic performance in humans. Theoretically, aspartate salts may reduce the accumulation of ammonia during aerobic exercise, thus potentially reducing the purported fatigue-inducing effects of ammonia. Further clinical trials are required before recommendations can be made for the use of aspartic acid for athletic performance enhancement.

  • Use cautiously in patients with high protein intakes. Use cautiously in patients with gastrointestinal concerns. Use cautiously in patients with liver damage, gout, or kidney damage. Use cautiously in patients with osteoporosis.

  • Astaxanthin: Astaxanthin may be found in microalgae, yeast, salmon, trout, krill, shrimp, crayfish, crustaceans, and the feathers of some birds. Astaxanthin may have positive effects on muscle strength, but better-quality studies are needed before a conclusion can be made.

  • Avoid if allergic or hypersensitive to astaxanthin or related carotenoids, including canthaxanthin. Use cautiously if taking 5-alpha-reductase inhibitors, hypertensive agents, asthma medications, drugs that are broken down by the liver, menopause agents, birth control pills, immunosuppressants, or with drugs used to treat Helicobacter pylori infections. Use cautiously with high blood pressure, parathyroid disorders, or osteoporosis. Avoid with hormone-sensitive conditions or immune system disorders. Avoid with previous experience of visual changes while taking astaxanthin and with low eosinophil levels. Avoid if pregnant or breastfeeding.

  • Astragalus: Astragalus is frequently combined with other herbs in traditional Chinese medicine (TCM). Western herbalists began using astragalus in the 1800s as an ingredient in various tonics. Few human studies have investigated the effect of astragalus-containing products in athletes. Preliminary evidence from two combination studies using Chinese herbal formulas has shown positive results. However, further research is needed before a firm conclusion can be made for the use of this therapy for athletic performance enhancement.

  • Avoid if allergic to astragalus, peas, or any related plants. Avoid with a history of Quillaja bark-induced asthma. Avoid if taking aspirin, aspirin products, or herbs or supplements with similar effects. Avoid with inflammation, fever, stroke, organ transplant, or autoimmune diseases. Stop use two weeks before and immediately after surgery/dental/diagnostic procedures with a risk of bleeding. Use cautiously with bleeding disorders, diabetes, high blood pressure, lipid disorders, or kidney disorders. Use cautiously if taking blood-thinners, blood sugar drugs, diuretics, or herbs or supplements with similar effects. Avoid if pregnant or breastfeeding.

  • Bee pollen: Bee pollen is considered a highly nutritious food because it contains a balance of vitamins, minerals, proteins, carbohydrates, fats, enzymes, and essential amino acids. Early evidence suggests that bee pollen does not enhance athletic performance. However, further research is needed before a firm conclusion can be made.

  • Avoid if allergic or hypersensitive to bee pollen or other bee products. Avoid with liver disease or bleeding disorders. Bee pollen may contain mycotoxins, such as ochratoxin A, which can cause potentially serious reactions. Avoid if pregnant or breastfeeding due to a lack of scientific data.

  • Bovine colostrum: Bovine colostrum is the pre-milk fluid produced from cow mammary glands during the first two to four days after birth. Bovine colostrum provides nutrients that help the offspring grow and fight against disease and infection. Although the results of current human studies conflict with one another, bovine colostrum may improve exercise performance. Additional study is needed in this area to reach a firm conclusion.

  • Avoid if allergic or hypersensitive to dairy products. Use bovine colostrum cautiously because toxic compounds, such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), and dichlordiphenyldichloroethylene (DDE), have been found in human colostrum and breast milk. Thus, it is possible that these agents may be found in bovine colostrum. Avoid with cancer or if at risk for cancer. Use cautiously with immune system disorders or with hardening of the arteries. Use cautiously if taking medications to treat diarrhea, (e.g. Imodium®), insulin, or central nervous system stimulants (e.g. amphetamines, caffeine). Avoid if pregnant or breastfeeding.

  • Choline: Choline is an essential amino acid that is produced in the body and consumed in foods. The largest dietary source of choline is egg yolk. Choline may also be found in high amounts in liver, peanuts, fish, milk, brewer's yeast, wheat germ, soy beans, bottle gourd fruit, fenugreek leaves, shepherd's purse herb, Brazil nuts, dandelion flowers, poppy seeds, mung and other beans, a variety of meats, and vegetables such as cabbage and cauliflower. There is a lack of sufficient evidence for the use of choline for changing body composition and specifically, for changing lean muscle mass.

  • Avoid if allergic or hypersensitive to choline, lecithin, or phosphatidylcholine. Use cautiously with kidney or liver disorders or trimethylaminuria. Use cautiously with a history of depression. If pregnant or breastfeeding, it is generally safe to consume choline within the recommended adequate intake (AI) parameters; supplementation outside of dietary intake is usually not necessary if a healthy diet is consumed.

  • Coenzyme Q10: Coenzyme Q10 (CoQ10) is produced by the human body. It is needed for the basic functioning of cells. CoQ10 levels decrease with age. Research is conflicting as to whether or not CoQ10 can help improve exercise performance. Further research is needed.

  • Currently, there have not been any reports of allergic reactions associated with CoQ10 supplements, although rash and itching have been reported rarely. Stop use two weeks before and immediately after surgery/dental/diagnostic procedures with bleeding risk. Use cautiously with a history of blood clots, diabetes, high blood pressure, heart attack, or stroke. Use cautiously if taking anticoagulants (blood thinners) or antiplatelet drugs (such as warfarin), blood pressure drugs, blood sugar drugs, cholesterol drugs, or thyroid drugs. Avoid if pregnant or breastfeeding.

  • Cordyceps: Cordyceps is a type of parasitic fungi. Cordyceps has been used as a tonic food in China and Tibet and it has also been used as a food supplement and tonic beverage. It is also an ingredient in soups and other foods used traditionally in Chinese medicine for thousands of years, helping debilitated patients recover from illness. In 1993, two female Chinese athletes, who admitted using cordyceps supplements, beat the world records in the track and field competition at the Stuttgart World Championships for the 1,500-, 3,000-, and 10,000-meter races. However, there is insufficient evidence from conflicting controlled clinical trials to recommend for or against the use of cordyceps for exercise performance enhancement. More studies are needed in this area.

  • Avoid if allergic or hypersensitive to cordyceps, mold, or fungi. Use cautiously with diabetes, bleeding disorders, or prostate conditions. Use cautiously if taking anticoagulants, immunosuppressants, hormonal replacement therapy, or birth control pills. Avoid with myelogenous type cancers. Avoid if pregnant or breastfeeding.

  • Creatine: It has been suggested that creatine may help improve athletic performance or endurance by increasing time to fatigue (possibly by shortening muscle recovery periods). Creatine has been studied for athletic performance enhancement for cyclists, females, high-intensity endurance athletes, rowers, runners, sprinters, and swimmers. However, the results of research evaluating these claims are mixed. Findings from different studies disagree with each other, and most studies do not support the use of creatine to enhance sustained aerobic activities.

  • Avoid if allergic to creatine or if taking diuretics. Use cautiously with asthma, diabetes, gout, kidney, liver problems, muscle problems, stroke, or with a history of these conditions. Avoid dehydration while taking creatine. Avoid if pregnant or breastfeeding.

  • Feldenkrais Method®: It has been suggested that the Feldenkrais Method® may help improve unstable balance problems or function, but there is little available research. There is also not enough scientific evidence to assess the effects of Feldenkrais on physical functioning and physical rehabilitation.

  • There is currently a lack of available scientific studies or reports of safety of the Feldenkrais Method®.

  • Focusing: Focusing is a method of psychotherapy that involves being aware of one's feelings surrounding a particular issue and understanding the meaning behind words or images conveyed by those feelings. It has been suggested that psychomotor intervention may be effective for reducing the risk of falls in the elderly. Focusing strategies have not yet been demonstrated to significantly reduce the risk of falling in healthy, physically active older adults. More studies are needed to examine various focusing strategies in older adults with different levels of physical activity.

  • Side effect reporting is rare, but patients should consult with a qualified healthcare practitioner before making decisions about medical conditions and practices. Individuals with severe emotional difficulties should not abandon proven medical and psychological therapies but rather choose focusing as a possible adjunct.

  • Garcinia: Garcinia cambogia is an extremely small purple fruit that is naturally found in India and Southeast Asia. Hydroxycitric acid, a constituent in garcinia, may increase fat metabolism and enhance exercise performance. Additional study is needed to confirm these results.

  • Avoid if allergic or hypersensitive to Garcinia cambogia. Use cautiously with a history of diabetes, rhabdomyolysis (breakdown of skeletal muscle), or with HMG-CoA reductase inhibitors ("statins"). Avoid with Alzheimer's disease. Avoid if pregnant or breastfeeding.

  • Ginkgo biloba: Ginkgo biloba has been used to treat many medical conditions for thousands of years. Today, it is one of the top selling herbs in the United States. Ginkgo biloba is used to treat numerous conditions, many of which are under scientific investigation. Limited available human study has evaluated the effects of Ginkgo biloba in chronic cochleovestibular disorders, which may cause patients to have unstable balance. Further trials are needed.

  • Avoid if allergic or hypersensitive to members of the Ginkgoaceae family. If allergic to mango rind, sumac, poison ivy, poison oak, or cashews, then allergy to ginkgo is possible. Avoid with blood-thinners (such as warfarin) due to an increased risk of bleeding. Ginkgo biloba should be stopped two weeks before and immediately after surgical procedures. Ginkgo biloba seeds are toxic and should be avoided. Skin irritation and itching may also occur due to Ginkgo biloba allergies. Do not use Ginkgo biloba in supplemental doses if pregnant or breastfeeding.

  • Ginseng: Athletes commonly use ginseng with the intention of improving stamina. However, it remains unclear if ginseng taken by mouth significantly affects exercise performance. Numerous studies have been published in this area, with mixed results. Better studies are necessary before a clear conclusion can be reached.

  • Avoid ginseng with a known allergy to plants in the Araliaceae family. There has been a report of a serious life-threatening skin reaction, possibly caused by contaminants in ginseng formulations.

  • Glucosamine: Glucosamine is a natural compound that is found in healthy cartilage. Glucosamine has been given to athletes with acute knee injuries. Although glucosamine did not improve pain, it did help improve flexibility. Additional research is needed to better understand the role of glucosamine for rehabilitation after knee injury.

  • Avoid if allergic or hypersensitive to shellfish or iodine. Some reports suggest a link between glucosamine/chondroitin products and asthma. Use cautiously with diabetes or with a history of bleeding disorders. Avoid if pregnant or breastfeeding.

  • Hellerwork: Hellerwork is a form of deep tissue bodywork and movement therapy. Proponents claim that hellerwork can relieve respiratory conditions and problems related to muscle tension and stress. It has also been used to treat sports injuries, carpal tunnel syndrome, and back and neck pain. Studies have evaluated hellerwork for potential benefits in balance and posture. However, further research is warranted.

  • Hellerwork should not be used as the sole therapeutic approach to disease and it should not delay the time to speak with a healthcare provider about a potentially severe condition. In theory, hellerwork may make some existing symptoms worse. Deep-tissue massage is not advisable in some conditions. Speak with a qualified healthcare professional before starting treatment.

  • Use cautiously with psychosis or bipolar disorder because hellerwork may cause the release of suppressed memories of severe emotional anguish. Use cautiously with bleeding disorders, bone or joint disorders, major diseases of the internal organs (especially the kidneys, liver or intestines), or after recent abdominal surgery. Use cautiously if taking blood thinners. Use cautiously in women who are menstruating. Avoid with recent musculoskeletal injury (such as broken bones), osteoporosis, disease of the spine or vertebral disks, skin damage or wounds, trauma, or major surgery. Avoid if pregnant or breastfeeding.

  • Kiwi: The kiwi fruit comes from China, but it is now produced in New Zealand, the United States, Italy, South Africa, and Chile. Kiwi is rich in vitamins C and E, serotonin, and potassium. According to recent studies, the fruit has antioxidant activity. Limited available study suggests that a kiwi-containing drink has beneficial effects on energy enhancement. However, further studies are needed to support these claims.

  • Avoid if allergic or hypersensitive to kiwi, latex, birch pollen, banana, chestnut, fig, flour, melon, poppy seeds, rye grain, sesame seeds, or related substances. Kiwi is generally considered safe when taken in amounts naturally found in foods. Use cautiously with anti-platelet drugs, such as aspirin, cilostazol, or clopidogrel. Use cautiously with hormone therapies or serotonergic drugs. Avoid if pregnant or breastfeeding because human studies have not tested its safety in supplemental doses. The amount found in foods appears to be safe in most people.

  • L-carnitine: L-carnitine is an amino acid that is produced in the muscles and liver. Overall, the data is mixed in terms of the benefits of L-carnitine for exercise performance.

  • Avoid with a known allergy or hypersensitivity to carnitine. Use cautiously with peripheral vascular disease, high blood pressure, alcohol-induced liver cirrhosis, or diabetes. Use cautiously in low birth weight infants and individuals on hemodialysis. Use cautiously if taking anticoagulants (blood thinners), beta-blockers, or calcium channel blockers. Avoid if pregnant or breastfeeding.

  • Magnet therapy: Magnetic fields play an important role in Western medicine. Static magnets have been used to increase athletic performance, but firm evidence is lacking. Additional study is needed.

  • Avoid with implantable medical devices, such as heart pacemakers, defibrillators, insulin pumps, or hepatic artery infusion pumps. Avoid with myasthenia gravis or bleeding disorders. Avoid if pregnant or breastfeeding. Magnet therapy is not advised as the sole treatment for potentially serious medical conditions and should not delay the time to diagnosis a condition. It should not replace treatment with more proven methods. Patients are advised to discuss magnet therapy with their qualified healthcare providers before starting treatment.

  • Massage: Various forms of massage have been practiced for thousands of years to promote well-being, relaxation, pain reduction, stress relief, musculoskeletal injury healing, sleep enhancement, and quality of life. A common goal of therapy is to "help the body heal itself." There is insufficient evidence to determine whether or not practicing massage helps improve handgrip strength, exercise recovery, or rehabilitation of the elderly.

  • Avoid with bleeding disorders or low platelet counts. Avoid if taking blood-thinning medications, such as heparin or warfarin. Areas should not be massaged where there are fractures, weakened bones from osteoporosis or cancer, open/healing skin wounds, skin infections, recent surgery, or blood clots. Use cautiously with a history of physical abuse or if pregnant or breastfeeding. Massage should not be used as a substitute for more proven therapies for medical conditions. Massage should not cause pain to the client.

  • Meditation: Meditation (in the form of Tai Chi or Qi gong) may help to improve balance in healthy elderly people. More research is needed to understand the specific effects of meditation on balance.

  • Use cautiously with underlying mental illnesses. People with psychiatric disorders should consult with their primary mental healthcare professional(s) before starting a program of meditation, and should explore how meditation may or may not fit in with their current treatment plan. Avoid with risk of seizures. The practice of meditation should not delay the time to diagnosis or treatment with more proven techniques or therapies, and should not be used as the sole approach to illnesses.

  • Pantothenic acid (vitamin B5): Pantothenic acid (vitamin B5) is found in many foods, including, meats, liver, kidney, fish/shellfish, chicken, vegetables, legumes, yeast, eggs, and milk. Pantothenic acid is essential to all life. It remains unclear whether or not pantothenic acid can improve athletic performance. Further research is needed.

  • Avoid if allergic or hypersensitive to pantothenic acid or dexpanthenol. Avoid with gastrointestinal blockage. Pantothenic acid is generally considered safe in pregnant and breastfeeding women when taken at recommended doses.

  • Papain: In a controlled trial, patients taking a combination of proteases had faster recovery of contractile function and less delayed-onset muscle soreness than those taking the placebo. Although the results are intriguing, more study using papain as a monotherapy is needed to observe its effects for exercise recovery.

  • Use cautiously in patients sensitive to papain. Use cautiously in patients being treated for prostatitis. Use Wobenzym®, which contains papain, cautiously, especially in those with bleeding disorders or taking anticoagulants or antiplatelets. Use cautiously as an adjuvant to radiation therapy. Avoid in patients with gastroesophageal reflux disease. Avoid in patients using immunosuppressive therapy.

  • Physical therapy: The goal of physical therapy is to improve mobility, restore function, reduce pain, and prevent further injury. Many techniques are used, including exercises, stretches, traction, electrical stimulation, and massage. Early study of individually tailored programs of physical therapy in the home appear promising for the reduction of falls in elderly women. More research is warranted in this area before a firm conclusion can be made.

  • Physical therapy has been used with biofeedback training to enhance strength in patients with foot drop, which is a birth disorder where the foot is twisted out of shape or position. It has also been used in elderly patients recuperating from acute illnesses. Well-designed studies are needed before a conclusion can be made for its benefits as a strength enhancer.

  • Patients with chronic vestibular disorders typically have complaints of unsteadiness, imbalance, and/or motion intolerance. Various types of rehabilitation have been tried, although vestibular rehabilitation, a specific approach to physical therapy aimed at reducing dizziness and imbalance, has been used the most. Results are generally positive, but more well-designed studies are needed.

  • Not all physical therapy programs are suited for everyone and patients should discuss their medical history with their qualified healthcare professionals before beginning any treatments. Based on the available literature, physical therapy appears generally safe when practiced by a qualified physical therapist. Physical therapy may aggravate pre-existing conditions. Persistent pain and fractures of unknown origin have been reported. Physical therapy may increase the duration of pain or cause limitation of motion. Pain and anxiety may occur during the rehabilitation of patients with burns. Both morning stiffness and bone erosion have been reported in physical therapy literature, although causality is unclear. Erectile dysfunction has also been reported. Physical therapy has been used safely during pregnancy. However, all therapies during pregnancy and breastfeeding should be discussed with a licensed obstetrician/gynecologist before initiation.

  • Qi gong: Qi gong is a type of traditional Chinese medicine (TCM) that is thought to be at least 4,000 years old. It is traditionally used for spiritual enlightenment, medical care, and self-defense. Medical Qi gong can involve internal or external techniques and it often includes five steps: meditation, cleansing, recharging/strengthening, circulating, and dispersing qi. Each step includes specific exercises, meditations, and sounds. Cardiac rehabilitation programs are designed to improve heart health through activities, such as monitored exercise, and they are often recommended for individuals with heart failure or after a heart attack. Qi gong may help strengthen the heart muscle in terms of improving physical activity, balance, and coordination. Further research is needed to confirm these findings.

  • Qi gong is generally considered to be safe in most people when learned from a qualified instructor. Use cautiously with psychiatric disorders. In cases of potentially serious conditions, Qi gong should not be used as the only treatment instead of more proven therapies and it should not delay the time it takes to see an appropriate healthcare provider.

  • Rhodiola: Limited human study of rhodiola for exercise performance enhancement is promising; however, better studies are needed before a conclusion can be made.

  • Avoid if allergic or sensitive to rhodiola. Use cautiously in people with diabetes, cardiovascular disease, or neurological or psychiatric disorders. Rhodiola is not recommended for use during pregnancy or breastfeeding.

  • Selenium: The anti-oxidant effects of selenium have been suggested to improve physical endurance. However, the available evidence suggests that selenium supplementation does not affect physical performance or endurance training.

  • Avoid if allergic or hypersensitive to products containing selenium. Avoid with a history of non-melanoma skin cancer. Selenium is generally regarded as safe for pregnant or breastfeeding women. However, animal research reports that large doses of selenium may lead to birth defects.

  • Siberian ginseng: Siberian ginseng is traditionally used for exercise performance enhancement, due to its supposed beneficial effects on cardiorespiratory fitness, fat metabolism, and endurance performance. Further study in well-designed trials is still required.

  • Use cautiously in patients with blood pressure disorders, bleeding disorders, diabetes, autoimmune disorders, psychiatric disorders, or impaired gastrointestinal function. Avoid in children or pregnant and lactating women. Avoid in patients with a known allergy/hypersensitivity to Eleutherococcus senticosus, its constituents, related products, or members of the Araliaceae family.

  • Soy: Soy has been investigated as a source of protein with potential for exercise performance enhancement. In general, research findings suggest soy protein is better than no protein but is unlikely to be superior to other sources of protein. Further research is required in this field.

  • Avoid if allergic to soy. Breathing problems and rash may occur in sensitive people. Soy, as a part of the regular diet, is traditionally considered to be safe during pregnancy and breastfeeding, but there is limited scientific data. The effects of high doses of soy or soy isoflavones in humans are not clear, and therefore are not recommended. People who experience intestinal irritation (colitis) from cow's milk may experience intestinal damage or diarrhea from soy. The use of soy is often discouraged in patients with hormone-sensitive cancers, such as breast, ovarian, or uterine cancer. Other hormone-sensitive conditions, such as endometriosis, may also be worsened. Patients taking blood-thinning drugs like warfarin should check with their doctors and/or pharmacists before taking soy supplements.

  • Tai chi: Tai chi is a system of movements and positions believed to have developed in 12th Century China. Tai chi techniques aim to address the body and mind as an interconnected system and they are traditionally believed to have mental and physical health benefits to improve posture, balance, flexibility, and strength. Preliminary research suggests that tai chi practice may improve balance and strength. These benefits may be similar to other forms of exercise. Additional research is necessary before a firm conclusion can be reached.

  • Several studies suggest that tai chi may improve exercise capacity. In particular, a benefit has been reported with the classical Yang style.

  • Several studies have also examined the effects of regular tai chi practice on falling risk in the elderly. Results are not consistent and many studies have been poorly designed. It is not clear if tai chi is safer or more effective than other forms of exercise in older individuals. Better research is needed before a conclusion can be made for the use of tai chi for elderly fall prevention.

  • Avoid with severe osteoporosis or joint problems, acute back pain, sprains, or fractures. Avoid during active infections, right after a meal, or when very tired. Some believe that visualization of energy flow below the waist during menstruation may increase menstrual bleeding. Straining downwards or holding low postures should be avoided during pregnancy and by people with inguinal hernias. Some tai chi practitioners believe that practicing for too long or using too much intention may direct the flow of chi (qi) inappropriately, possibly resulting in physical or emotional illness. Tai chi should not be used as a substitute for more proven therapies for potentially serious conditions. Advancing too quickly while studying tai chi may increase the risk of injury.

  • Taurine: Energy drinks containing taurine, along with other ingredients, such as caffeine and glucuronolactone, have been available for about a decade. Overall these drinks have been suggested to decrease sleepiness associated with driving, increase concentration, mood, and memory, and positively affect well-being and vitality. Further study is required to examine the effect of taurine alone.

  • Taurine is an amino acid and it is unlikely that there are allergies related to this constituent. However, allergies may occur from multi-ingredient products that contain taurine. Use cautiously in patients with high cholesterol, low blood pressure, coagulation disorders, potential for mania, or epilepsy. Avoid consumption of energy drinks containing taurine, caffeine, glucuronolactone, B vitamins, and other ingredients, then consuming alcohol or exercising. Use cautiously if pregnant or breastfeeding.

  • Thiamin: Thiamin (also spelled "thiamine") is a water-soluble B vitamin. It is also known as vitamin B1 or aneurine. Thiamin is involved in nervous system and muscle functioning, enzyme processes, and the breakdown of carbohydrates and production of hydrochloric acid (which is needed for digestion). There is very little thiamin stored in the body and depletion can occur quickly. Severe chronic thiamin deficiency can cause potentially serious complications involving the nervous system/brain, muscles, heart, and gastrointestinal system. It remains unclear whether or not thiamin can help improve athletic performance.

  • Thiamin is generally considered safe and relatively nontoxic, even at high doses. Avoid if allergic or hypersensitive to thiamin. Thiamin appears safe if pregnant or breastfeeding. The U.S. recommended daily allowance (RDA) for pregnant or breastfeeding women is 1.4 milligrams taken by mouth.

  • Tribulus: Tribulus terrestris is a ground-hugging plant with spiny fruit that grows in tropical and sub-tropical climates. Tribulus terrestris has a long history of use in folk medicine. Traditionally, it has been used for a variety of reproductive conditions, such as infertility and impotence, as well as for muscle strength and general health. Preliminary studies indicate that tribulus may enhance body composition or exercise performance in males who undergo resistance training. More information is needed before a firm recommendation can be made.

  • Avoid if allergic/hypersensitive to Tribulus terrestris or members of the Zygophyllaceae family. Use cautiously with enlarged prostate, prostate cancer, or diabetes. Use cautiously if taking steroids or blood pressure medications, such as beta-blockers, calcium channel blockers, or digoxin. Avoid if pregnant or breastfeeding.

  • Vitamin C: Vitamin C may prevent endurance exercise-induced lipid peroxidation and muscle damage in healthy people. More research is needed to better understand the effects of vitamin C on exercise recovery.

  • Avoid if allergic or sensitive to vitamin C product ingredients. Vitamin C is generally considered safe in amounts found in foods. Vitamin C supplements are also generally considered safe in most individuals if taken in recommended doses. Large doses (greater than 2 grams) may cause diarrhea and gastrointestinal upset. Avoid high doses of vitamin C with glucose 6-phosphate dehydrogenase deficiency, kidney disorders or stones, cirrhosis (inflammation of the liver), gout, or paroxysmal nocturnal hemoglobinuria (bleeding disorder). Vitamin C intake from food is generally considered safe if pregnant or breastfeeding.

  • Vitamin D: Vitamin D is found in many foods, including fish, eggs, fortified milk, and cod liver oil. The sun also helps the body produce vitamin D. It has been suggested that vitamin D may help the body maintain strong bones, which may help prevent accidental falls. However, further research is needed to confirm the effectiveness of vitamin D for fall prevention.

  • Avoid if allergic or hypersensitive to vitamin D or any of its components. Vitamin D is generally well-tolerated in recommended doses. Doses higher than recommended may cause toxic effects. Individuals with overactive thyroids, kidney disease, sarcoidosis, tuberculosis, or histoplasmosis have an increased risk of experiencing toxic effects. Vitamin D is generally considered safe for pregnant women. It may be necessary to give infants vitamin D supplements along with breast milk. The recommended intake of vitamin D for normal infants, children, and adolescents is 200 IU daily.

  • Yoga: Yoga is an ancient system of relaxation, exercise, and healing with origins in Indian philosophy. Yoga has been described as "the union of mind, body, and spirit," which addresses physical, mental, intellectual, emotional, and spiritual dimensions towards an overall harmonious state of being. Healthy individuals with the desire to achieve relaxation, fitness, and a healthy lifestyle often practice yoga. Preliminary studies in humans report that yoga may improve human reaction time, arousal, information processing, exercise performance, and concentration. Early research also suggests that yoga may improve physical posture in children. Better-designed studies are needed before a conclusion can be drawn.

  • Yoga is generally considered to be safe in healthy individuals when practiced appropriately. Avoid some inverted poses with disc disease of the spine, fragile or atherosclerotic neck arteries, risk for blood clots, extremely high or low blood pressure, glaucoma, detachment of the retina, ear problems, severe osteoporosis, or cervical spondylitis. Certain yoga breathing techniques should be avoided in people with heart or lung disease. Use cautiously with a history of psychotic disorders. Yoga techniques are believed to be safe during pregnancy and breastfeeding when practiced under the guidance of expert instruction (the popular Lamaze techniques are based on yogic breathing). However, poses that put pressure on the uterus, such as abdominal twists, should be avoided in pregnancy.

  • Zinc: Zinc formulations have been used since ancient Egyptian times to enhance wound healing. Zinc may improve exercise performance in athletes with low serum zinc or zinc deficiencies. Additional evidence is needed before a recommendation can be made.

  • Zinc is generally considered safe when taken at the recommended dosages. Avoid zinc chloride since studies have not been done on its safety or effectiveness. While zinc appears safe during pregnancy in amounts lower than the established upper intake level, caution should be used because studies cannot rule out the possibility of harm to the fetus.

  • Fair negative scientific evidence:

  • Arginine: L-arginine is an amino acid that helps maintain the body's fluid balance (urea, creatinine). It also aids in wound healing, hair growth, sperm production (spermatogenesis), blood vessel relaxation (vasodilation), and fights infection. Currently available studies conclude that arginine supplementation does not improve exercise performance.

  • Avoid if allergic to arginine. Avoid with a history of stroke, liver disease, or kidney disease. Use cautiously if taking blood-thinning drugs (such as warfarin or heparin), blood pressure drugs, or herbs or supplements with similar effects. Check blood potassium levels. Avoid if pregnant or breastfeeding.

  • Boron: Boron is an element that is found around the world. It has elements that border between metals and non-metals. Boron can enter the body through the skin, lungs, or mouth. Preliminary evidence suggests that boron does not improve muscle mass by increasing testosterone levels and may not be effective as a bodybuilding aid.

  • Avoid if allergic or sensitive to boron, boric acid, borax, citrate, aspartate, or glycinate. Avoid with a history of diabetes, seizure disorder, kidney disease, liver disease, depression, anxiety, high blood pressure, skin rash, anemia, asthma, or chronic obstructive pulmonary disease (COPD). Avoid with hormone-sensitive conditions, such as breast cancer or prostate cancer. Avoid if pregnant or breastfeeding.

  • Choline: Research has shown that choline may not be effective for improvement of sports performance for endurance sports.

  • Avoid if allergic/hypersensitive to choline, lecithin, or phosphatidylcholine. Use cautiously with kidney disorder, liver disorders, or trimethylaminuria. Use cautiously with a history of depression. If pregnant or breastfeeding, it seems generally safe to consume choline within the recommended adequate intake (AI) parameters; supplementation outside of dietary intake is usually not necessary if a healthy diet is consumed.

  • Creatine: Data on effectiveness of creatine in endurance exercise are mixed. Most studies have had small sample sizes and short follow-up periods. Most do not support its use to enhance sustained aerobic activities. For increased endurance during aerobic exercise, the majority of studies failed to demonstrate benefit.

  • Avoid if allergic to creatine or with diuretics (such as hydrochlorothiazide or furosemide). Use cautiously with asthma, diabetes, gout, kidney problems, liver problems, muscle problems, stroke, or with a history of these conditions. Avoid dehydration. Avoid if pregnant or breastfeeding.

  • DHEA: DHEA (Dehydroepiandrosterone) is a hormone that is produced by the adrenal glands. Based on the available studies, it remains unclear whether or not DHEA can be used to improve muscle strength. Although most evidence in this area is negative, further research is necessary to draw a firm conclusion.

  • Avoid if allergic to DHEA. Avoid with a history of seizures. Use with cautiously with adrenal or thyroid disorders. Use cautiously if taking anticoagulants or drugs, herbs, or supplements for diabetes, heart disease, seizures, or stroke. Stop use two weeks before and immediately after surgery/dental/diagnostic procedures with bleeding risk. Avoid if pregnant or breastfeeding.

  • Gamma oryzanol: Gamma oryzanol occurs in rice bran oil and has been extracted from corn and barley oils as well. Gamma oryzanol is frequently sold as a bodybuilding aid, specifically to increase testosterone levels, stimulate the release of endorphins (pain-relieving substances made in the body), and promote the growth of lean muscle tissue. However, scientific support in humans for these claims is currently lacking. Additional study is needed to establish gamma oryzanol's effect on bodybuilding.

  • Avoid if allergic/hypersensitive to gamma oryzanol, its components, or rice bran oil. Use cautiously if taking anticoagulants (blood thinners), central nervous system (CNS) suppressants, growth hormone, drugs or herbs that alter blood sugar levels, immunomodulators, luteinizing hormone or luteinizing hormone-releasing hormone, prolactin, cholesterol-lowering or thyroid drugs, herbs, or supplements. Use cautiously with diabetes, hypothyroidism, hypoglycemia, hyperglycemia, or high cholesterol. Avoid if pregnant or breastfeeding.

  • Magnesium: Magnesium (Mg) is a cofactor to more than 325 enzymatic reactions; therefore, Mg deficiency has many physiological and exercise performance implications. Some experts suspect that Mg status may be marginal in many individuals, especially athletes. Low dietary intakes, which are found in many female athletes, coupled with increased urinary losses with exercise, may result in Mg deficiency. To date, there is insufficient evidence that Mg supplementation can improve athletic performance; however, it may reduce the stress response to exercise.

  • Use cautiously in patients with bleeding disorders, or in those taking anticoagulants or antiplatelet agents. Use cautiously in patients taking antidiabetic or antihypertensive agents or antibiotics. Use intravenous magnesium sulfate with extreme caution in patients with eclampsia. Avoid in patients with atrioventricular heart block. Avoid in patients with renal failure or severe renal disease.

  • Pantethine: Pantethine is a natural compound. It is the active form of pantothenic acid. Preliminary study does not suggest that pantethine is helpful in athletic performance. These preliminary negative results cannot be confirmed without more studies.

  • Avoid if allergic or hypersensitive to pantethine or any component of the formulation. Use with cautiously with bleeding disorders. Avoid if pregnant or breastfeeding.

  • Phosphates, phosphorus: Phosphorus is a mineral found in many foods, such as milk, cheese, dried beans, peas, nuts, and peanut butter. Phosphate is the most common form of phosphorus. Phosphorus plays an important role in the formation of bones and teeth. Several studies report that taking phosphates by mouth does not improve exercise performance.

  • Avoid if allergic or hypersensitive to any ingredients in phosphorus/phosphate preparations. Use phosphorus/phosphate salts cautiously with kidney or liver disease, heart failure, unstable angina (chest pain), recent heart surgery, hyperphosphatemia (high phosphate blood level), hypocalcemia (low calcium blood level), hypokalemia (low potassium blood level), hypernatremia (high sodium blood level), Addison's disease, intestinal obstruction or ileus, bowel perforation, severe chronic constipation, acute colitis, toxic megacolon, hypomotility syndrome, hypothyroidism, scleroderma, or gastric retention. Avoid sodium phosphate enemas with congenital or abnormalities of the intestine. Too much phosphorus may cause serious or life-threatening toxicity.

  • Vitamin D: Oral cholecalciferol does not appear to increase muscle strength or improve physical performance in healthy older men who are not vitamin D deficient.

  • Avoid if allergic or hypersensitive to vitamin D or any of its components. Vitamin D is generally well tolerated in recommended doses. Doses higher than recommended may cause toxic effects. Individuals with overactive thyroids, kidney disease, sarcoidosis, tuberculosis, or histoplasmosis have a higher risk of experiencing toxic effects. Vitamin D is generally considered safe for pregnant women. It may be necessary to give infants vitamin D supplements along with breast milk. The recommended intake of vitamin D for normal infants, children, and adolescents is 200 IU daily.

Author Information

  • This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  1. Box W et al. Soy intake plus moderate weight resistance exercise: effects on serum concentrations of lipid peroxides in young adult women. J Sports Med Phys Fitness. 2005 Dec;45(4):524-8. View Abstract.

  2. Centers for Disease Control and Prevention. www.cdc.gov.

  3. Komi PV, Viitasalo JT, Rauramaa R, et al. Effect of isometric strength training of mechanical, electrical, and metabolic aspects of muscle function. European Journal of Applied Physiology and Occupational Physiology. 1978 Dec 15;40(1):45-55. 15 May 2006 View Abstract.

  4. Mezei O, Li Y, Mullen E, et al. Dietary isoflavone supplementation modulates lipid metabolism via PPAR alpha dependent and independent mechanisms. Physiol Genomics. Feb 28, 2006. View Abstract.

  5. National Collegiate Athletic Association (NCAA). www.ncaa.org.

  6. Natural Standard: The Authority on Integrative Medicine. www.naturalstandard.com.

  7. Rush E, Schulz S, Obolonkin V, et al. Are energy drinks contributing to the obesity epidemic? Asia Pac J Clin Nutr. 2006;15(2):242-4. View Abstract.

  8. Torres N, Torre-Villalvazo I, Tovar AR. Regulation of lipid metabolism by soy protein and its implication in diseases mediated by lipid disorders. J Nutr Biochem. 2006 Jun;17(6):365-73. View Abstract.

  9. U.S. Food and Drug Administration (FDA). www.fda.gov.

Copyright © 2013 Natural Standard (www.naturalstandard.com)

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.

Updated:  

March 22, 2017