Supplements for Endurance and Muscle Building: What does research evidence show?

Introduction: Supplements for Endurance and Muscle Building

Countless supplements for endurance and muscle building are now available everywhere with labels and advertisements boasting to provided athletic performance enhancement. Most are not backed by evidence-based research and are advertised through the media while promoting false benefits. The majority are not regulated by the FDA, are not clear on a standardized content of ingredients, and may not contain what the label states. The following information on supplements for endurance and muscle building is a collection of various studies showing some degree of efficacy seen in quality designed research. Some of the supplements for endurance and muscle building backed by evidence based research for improvement of athletic performance include caffeine, nitrates, creatine, and protein sources.

General Concerns of Supplements:

Caution is advised when taking supplements for endurance and muscle building to boost athletic performance. The best approach is to obtain approval from a physician prior to starting any substance. Many supplements for endurance and muscle building have been associated with severe adverse reactions. An example includes a case of a bodybuilder who appeared to be in good health with no prior tobacco use or history of major medical problems suffered from an ischemic stroke (occurs when an artery to the brain is blocked). Prior to the stoke, the bodybuilder took one supplement (dose 2 capsules) containing MaHuang extract (20 mg ephedra alkaloids), 200 mg caffeine, 100 mgL-carnitine, and 200 mcg chromium. A second supplement contained 6000mg creatine monohydrate, 1000 mg taurine,100 mg inosine, and 5 mg coenzyme Q10 per scoop. Additionally, 40–60 mg ephedra alkaloids, 400–600 mg caffeine, and 6000 mgcreatine monohydrate were taken daily for 6 weeks prior to having the stroke. (1)

Caffeine for Endurance Training:

Caffeine is a supplement used for endurance and prolonged time to exhaustion in cycling which may work by conserving potassium. Researchers examined the effects of caffeine on athletic performance, including oxygen uptake, also known as VO2 max; oxygen deficit; and certain substances that are by-products of exercise. The researchers evaluated six trained cyclists who exercised to a level beyond aerobic capacity—the ability of the body to utilize oxygen—following consumption of 5 mg per kilogram of body weight of caffeine. There was a significant increase in exercise endurance of 14.8% and the ability of the athletes to exceed aerobic capacity by 6.5%; however, no change was observed for maximum oxygen uptake. Blood potassium levels were tested as a measure of metabolic efficiency and found to be decreased after caffeine consumption and prior to exercise by 13.4%, leading the researchers to suggest the possibility that caffeine had a conserving effect on potassium, thereby prolonging time to fatigue. (2)

Caffeine equivalent to about a cup of coffee improved performance by about 3% in a 60 minute cycling time trial. Investigator had 12 well-trained, regular caffeine users undertake 4 separate cycling trials. Subjects consumed either a measured caffeine dose or a placebo (caffeine withdrawal) for 4 days before a 60 minute cycle time trial. On the caffeine trial, subjects were provided with 1.5 mg of caffeine per kilogram body weight, which equalled about 120 mg of caffeine. On the withdrawal trial, subjects received a placebo tablet to ensure they were blinded to the intervention. Then, on the actual day of the exercise cycle time trial, subjects consumed either a placebo or a 3 mg per kilogram dose of caffeine 90 minutes before the start of the trial. Results found that regardless if subjects withdrew from caffeine or had caffeine daily for the 4 days leading into the cycle time trial, having a 3 mg per kilogram dose of caffeine 90 minutes before the trial, improved exercise performance by about 3%. (3)

In a randomized, double-blind study with 10 moderately trained male athletes, it was found that caffeine ingestion may improve performance when athletes are both fresh and fatigued. Compared to placebo participants, individuals taking a 6mg/kg dose of caffeine 60 min before completing an 80-min (4 × 20 min) simulated team-game reported increased total time by 2.3%, reactive agility by 3.9%, movement time by 2.7%, decision time by 9.3%, and decision-making accuracy by 3.8% compared to placebo. However, the results were not significant. (4)

Caffeine or sodium bicarb enhanced cycling performance but combining both did not result in further benefit. Ten well-trained cyclists (mean age, 24.2 yr) participated in this double-blind, crossover study that involved four 3-km cycling time-trial (TT) on a laboratory-based cycle ergometer performed on separate days. Before each TT, participants took either 3 mg/kg body mass (BM) of caffeine (CAFF), 0.3 g per kilogram of sodium bicarbonate (SB), a combination of the two (CAFF+SB), or a placebo (PLAC). Findings indicate that when taken individually, both CAFF and SB enhance high-intensity cycling TT. However, the effect on enhancing physical performance of these 2 popular supplements when taken together was not additive. (5)

Caffeine improved cycling performance time in a surrounding temperature of 12°C but not in a 33°C temperature. The effects of ambient temperature (12°C and 33°C) on how caffeine affects performance during endurance cycling exercise were examined. Male cyclists (N = 11) completed four exercise trials. After cycling continuously for 90 minutes (15-minutes alternating intensities of ~60 and ~71% max oxygen consumption [VO2max]) in either a warm (~33°C, ~41% RH) or cool (~12°C, ~60% RH) environment, participants completed a 15-minute performance trial. Participants ingested 3 mg/kg of caffeine or placebo in capsules 60 minutes prior to exercise and after 45 minutes of exercise. Prior to, and at every 15 minutes of exercise, individuals drank water in equal volumes so that independent of ambient temperature were dehydrated less than 1% at the end of exercise (there was greater fluid intake in the 33°C condition compared to the 12°C condition). Total work accumulated during the performance trial was greater in 12°C than 33°C. Independent of temperature, caffeine increased performance time when compared to placebo. However, compared to placebo, caffeine increased performance time in the 12°C but not in the 33°C condition. Within the 12°C trial, significant differences between caffeine and placebo occurred from 0-5 minutes and 5-10 minutes, but not 10-15 minutes. (6)

Beet Juice for Endurance Training:

Beet juice is one of the recently popular supplements used for endurance and muscle building. Beet juice at a dose of 0.5 liters per day reduced oxygen consumption, reduced blood pressure, increased time to failure, and improved time trials.

In a double-blind, randomized, cross-over fashion, researchers gave 9 active males 0.5 L/day (17 ounces) of beetroot juice (BRJ) (~6.2 mmol nitrate; brand: Beet it) or nitrate-depleted beetroot juice as placebo (PL) for 6 days (10 day washout). Walking/ running tests on days 4 and 5 were performed, and knee-extensions were performed on day 6. Results indicate that plasma nitrite increased significantly in the BRJ group compared to PL (105%). Systolic blood pressure decreased 4% in the BRJ (BRJ: 124 mmHg, PL: 129 mmHg), while diastolic blood pressure and mean arterial pressure did not change. Additionally, BRJ reduced VO2 (oxygen consumption) during the baseline walking by ~12%, as well as during the last 30 seconds of moderate-intensity running by ~7%. Pulmonary VO2 response was also reduced by ~4%, and the oxygen cost of running 1 km by ~6%. During severe-intensity exercise, BRJ again reduced VO2 during walking, by ~14% compared to PL. BRJ increased time to failure by ~15% (BRJ: 8.7 min vs PL: 7.5 min). At failure, VO2 was ~6% lower in the BRJ group. Knee-extensions were used to measure phosphocreatine concentration which is depleted following an intense work out. Task to failure was longer after the 6 days of BRJ consumption compared to PL: BRJ: 8.5 min, PL: 8.2 min. In summary, this study established that the nitrate in beetroot juice has positive effects on exercise. As nitrite concentration increased, systolic blood pressure decreased, the oxygen cost of walking, moderate-intensity, and severe-intensity running was reduced, and the time to failure in severe-intensity running and the incremental knee-extensions was extended. (8)

The Department of Human Movement Sciences of Maastricht University Medical Centre, Maastricht, The Netherlands tested the hypothesis that 6 days of nitrate ingestion in the form of beetroot juice could improve time-trial performance in trained cyclists. The study was a double-blind, repeated-measures crossover design. Cyclists took about 0.5 liters per day of beetroot juice for 6 days. According to the study, the beetroot juice was reported to reduce pulmonary oxygen uptake and increase tolerance of highly intensive work rates. Nitrate ingestion helped athletes improve 2.8% and 2.7% in the 4 and 16.1 -km time trials, respectively. (9)

Beet Juice Helps Athletes Lift More Weight

A beet juice supplement may help athletes lift more weight according to Mosher et al (32). The authors for this research gave a nitrate rich beet juice supplement to 12 men active in weight training between the ages of 19-23. The nitrate containing product named “Beet IT Sport” was given to the subjects at a dose of 70 ml with 400 mg of nitrate or a blackcurrant placebo. The subjects lifted weight for multiple repetitions after the beet juice supplement at 60% of their 1 repetition maximum on a “Smith Machine” for as many times as they could for 3 sets with 2 minutes if rest between each set. There was similar amounts of physicial exertion in both groups. The following results were obtained from taking the beet juice product:

Table adapted from Mosher et al (32)

The athletes were able to lift weight with higher repetitions and 18.9% more weight with the beet juice supplement when compared to placebo. The authors described that a beverage containing beet juice may increase exercise tolerance and performance but longer term studies are needed.

Creatine Increases Strength for Resistance Training:

Creatine is one of the commonly used supplements for endurance and muscle building, However, creatine has only been shown to improve strength but not endurance: Based on creatine supplementation information available from 1966 to July 1999, a majority of supplement regimes include a loading dose of 20 to 30 grams divided in 4 equal doses for 5 to 7 days, followed by a 2 gram per day maintenance dose. While creatine may enhance the performance of high-intensity, short-duration exercise, it is not useful in endurance sports. (10)

Creatine improved strength. Researchers reviewed 16 creatine and weight lifting studies into one analysis of creatine’s effect on strength and power in healthy adults. The maximum lifted weight difference between the placebo group and the creatine groups differed by 6.85 kg. The creatine group was also able to bench press 9.76 kg more than the placebo group. However, there was no difference in cycle ergometer or isokinetic dynamometer performance. The creatine group was able to lift more weight than the placebo group in every study. The evidence of using creatine supplementation with resistance training showed improved performance in young men, however they could not find enough evidence for improved performance in older individuals or women or for other types strength and power exercises. Further study of the effect of using creatine supplementation is needed. (11)

Creatine supplementation safely promotes better muscle strength and hypertrophy than resistance training alone in adults aged 55-82 years according to a review by Dalbo et al. Muscle hypertrophy is an increase in the size of a muscle through an increase in the size of cells. Creatine supplementation should therefore be strongly considered as a safe, inexpensive and effective nutritional intervention to help slow the rate of muscle deterioration with age, particularly when consumed in conjunction with a resistance training regimen. (12)

Leg strength, endurance, average power, and lean muscle increased in older men (average age, 70.4 years) after taking creatine (Cr) supplementation of 0.3 g/kg(-1) body weight for the first 5 days and then 0.07 g/kg(-1) body weight. Compared to placebo, participants taking Cr experienced significantly greater increases in lean mass (3.3 kg vs 1.3 kg), leg press (50.1 kg vs 31.3kg),  knee extension endurance (21 reps vs 14 reps), and average power (26.7 watts vs 18 watts). (23)

Creatine (Cr) supplementation (0.35 g/kg of fat-free mass) for 3 days significantly increased body mass (+0.9 kg), thigh muscle volume (+6.6%) and sprint performance (total work during the first sprint and peak power during sprints 2 to 6) in this study that included 20 athletes (50% male). Enhanced performace was greater for men than women during the first sprint but in later sprints women experienced a greater effect. (24)

Researchers suggest that creatine (Cr) may increase bone density by improving muscle size and strength. For 12 weeks, participants (n=29 men, aged 71 years) were randomized to received creatine (0.3 g/kg creatine for 5 days and then 0.07 g/kg) or placebo in addition to resistance training. Results showed a 0.5% and 1% increase in whole-body and leg bone density, respectively. Arms bone mineral contents increased significantly in the Cr group by 3.2 % (vs a non-significant increase of 1.0% with placebo). (25)

Creatine adverse effects: This supplement should only be considered under a physician’s direction. Kidney function will require to be evaluated prior to taking creatine and should be monitored during use. Reports have linked creatine to weight gain, cramping, dehydration, diarrhea, and dizziness and may decrease renal function. In short-term trials creatine appears to well tolerated. Therefore, individuals should carefully weigh the benefits and risks of using creatine supplement, including possible renal dysfunction. (14)

Creatine and Whey Protein for Lean Mass and Strength

Creatine and whey protein increased lean tissue mass and strength gains over whey protein alone and placebo. Whey protein increased lean tissue mass and strength gains over placebo. Research suggests that combining whey and creatine may offer benefits for enhancing the effects of resistance training. Thirty-six men were randomly assigned to supplementation with whey protein (1.2 g/kg/day), whey protein and creatine monohydrate (0.1 g/kg/day), or placebo (1.2 g/kg/day maltodextrin) for 6 weeks. Results indicated that men who supplemented with whey and creatine demonstrated greater gains in lean tissue mass and bench press strength, compared with men who supplemented with whey alone or with placebo. The group taking whey protein without creatine also showed better strength gains than the placebo group. (13)

Protein and Resistance Training:

Protein is one of the supplements for endurance and muscle building, but is used in higher amounts by athletes compared to non-athletes. Adequate amounts of protein may be consumed as a supplement, or part of a diet, It was found that consuming protein soon after doing resistance exercise promotes muscular hypertrophy. This appears to provide important amino acids needed for repair and growth of muscle tissue when the body needs it the most. Protein should be consumed in amounts equal to 1-2 grams per kilogram of bodyweight based on the frequency and intensity of resistance training. The relationship between post-exercise consumption of protein on muscle was reviewed by Phillips SM. An adequate protein source is needed to maximize muscle protein production leading to anabolism (building of muscle). Leucine rich foods such as whey protein are better at promoting muscle protein production. Additionally, milk proteins and principally whey protein show an advantage soy and casein protein in promoting hypertrophy. Therefore, evidence suggests a benefit in early post-exercise consumption of whey protein or dairy-based protein to promote muscle protein production, net muscle protein growth and hypertrophy. (15)

How much protein is required by athletes? According to Phillips SM, evidence suggests that among atheletes, the recommended daily allowance (RDA) for protein intake should be higher than non-athletes. Leucine, an essential amino acid, and possibly the other branched-chain amino acids, stimulate muscle protein synthesis. Protein intakes ranging between 1.3-1.8 g per kilogram per day consumed as 3-4 isonitrogenous meals, diets containing soybean or animal by-product, will maximize muscle protein production. These recommendations might be dependent on athlete training status. Experienced athletes require less, while during periods of high frequency/intensity training more protein should be consumed. Additionally, during periods of energy restriction to promote fat loss, high protein intake of 1.8-2.0 grams per kilogram per day may help prevent lean muscle mass loss. (16)

Both soy and whey protein supplementation during resistance training increased lean tissue mass and strength over sugar placebo. Candow DG, et al studied whey protein or soy protein in combination with resistance exercise in 27 untrained healthy subjects (18 female, 9 male) age 18 to 35 years. Participants were randomly assigned (double blind) to supplement with whey protein, soy protein or placebo for 6 weeks. Lean tissue mass, strength, and an indicator of myofibrillar protein catabolism were measured before and after training. Results showed that both soy and whey protein supplementation during resistance training increased lean tissue mass and strength over placebo with equal calorie diet and resistance training (P < 0.05). (17)

Tyler A et al expressed that dietary amino acids increase skeletal muscle protein synthesis, an effect that is enhanced by prior resistance exercise. The author stated that timing of and type of protein intake may affect the formation of proteins for muscle growth. It appears that consumption of approximately 20–25 grams of a rapidly absorbed protein with a high percentage of essential amino acids may be optimal to stimulate muscle protein synthesis after resistance exercise in young healthy individuals. According to Tyler A et al, whey or bovine milk appear to be the best food source to achieve this and explained that protein intake, not only immediately after, but up to ~24 hours following exercise should be carefully considered as a dietary strategy to maximally stimulate exercise-induced muscle protein synthesis. (18)

Whey protein and a resistance training program reduced cholesterol. Overweight hypercholesterolemic men with serum cholesterol >200 mg/dl were randomly divided into 3 groups (placebo (n = 9), soy (n = 9) or whey (n = 10) supplementation) and participated in supervised resistance training for 12 weeks. Total serum cholesterol decreased significantly (average=5.8%) for all groups (mean reduction = 12.6 mg/dL), with no differences among groups. Specifically, total cholesterol reduction was 10.4 mg/dL for placebo, 11.2 mg/dL for soy, and 15.9 mg/dL for whey. Participation in a 12 week resistance exercise training program significantly reduced serum cholesterol, increased strength, and improved body composition in overweight, hypercholesterolemic men. Whey protein improved cholesterol a small amount more than placebo or soy protein but additional added benefit from protein (soy or whey) supplementation was not otherwise seen in this study group. (19)

Protein in Foods:

A reference for protein in foods is available at United States Department of Agriculture. Review the protein content in thousands of foods.

Protein containing foods may be accessed at: http://www.choosemyplate.gov/food-groups/protein-foods.html#

Protein in vegetarian foods may be accessed at: http://vegetariannutrition.net/docs/Protein-Vegetarian-Nutrition.pdf   (20)

Caffeine for Muscle Contraction Velocity:

Caffeine was found to increase short duration muscle contraction and muscle fiber conduction velocity in 14 male volunteers in a double-blind study using placebo or caffeine (6mg/kg). Measure of muscular function such as maximal voluntary isometric contractions, evoked maximal twitch, and maximal isokinetic contractions during elbow flexion were assessed. Mechanical and electromyographic signals from the biceps brachi muscles were recorded, and changes in the muscle-force velocity relationship and muscle fiber were evaluated. The toque-angular velocity curve improved after caffeine supplementation with an 8.7% increase in muscle conduction velocity. Caffeine was believed to improve motor unit muscle recruitment. (7)

Coenzyme Q10 and Athletic Performance:

Coenzyme Q10 improved athletic performance in only 1 out of 5 studies reviewed in a study by the Australian Sports Commission, Supplements and sports foods, Burke and Deakin. This review included a parallel group design study by Bonetti et al in which 28 recreational cyclists received 100 mg/d CoQ10 and performed incremental cycling test with an increase of 50 W/minutes until exhaustion. Supplementation increased levels of CoQ10 levels, but aerobic power did not improve. In a crossover study, Nielsen et al administered 100 mg/d for 6 weeks (plus vitamins E, C) to 7 male triathletes. VO2 testing to exhaustion was performed. Results showed no effect on maximal oxygen uptake or muscle energy metabolism. In another parallel group study of 18 men, Malm et al. administered 120 mg/d for 22 days as follows: days 2–9: usual activity; days 11–14: 2/d anaerobic training; and days 15–22: recovery. At the end of the study, the placebo and Q10 group both improved performance of repeated sprint test after training, but only the placebo group held this improvement during recovery to day 20. During anaerobic training, the placebo group achieved higher average power, and greater improvement in latter intervals. Neither group saw a change in VO2 max outcomes or in oxygen use during submaximal cycling. In a parallel group study of 18 male cyclists and triathletes, Weston et al. administered 1 mg/kg/d for 28 days. Base on data on the cycling incremental test to exhaustion, CoQ10 did not enhance performance compared with placebo group. In a parallel group study, Ylikoski and colleagues analyzed data on 25 national-level cross-country skiers taking 90 mg/d of CoQ10 for 6 weeks and found an improvement in VO2 max with coenzyme Q10 supplementation and an increase in aerobic and anaerobic thresholds. Of all the studies reviewed only 1 of the 5 studies showed an improvement in athletic performance with CoQ10 supplementation. (21)

Studies have evaluated coenzyme Q10 for it’s role in the possible enhancement of exercise performance but results have been mixed. According to 6 trials, coenzyme Q10 (CoQ10) resulted in improvement of exercise capacity but 5 different trials showed no benefit of CoQ10 on exercise capacity. (22)

Garlic for Muscle Damage and Exercise Recovery:

Garlic use has shown evidence in reducing exercise-induced muscle damage. Researchers reported that administration of 80 mg of allicin (a component of garlic), increased muscle anti-oxidant levels and reduced exercise-induced muscle damage.  Participants received either allicin or placebo for 2 weeks before and 2 days after a downhill treadmill run. Compared to placebo, Allicin reduced plasma creatine kinase (CK) (including CK-MM, muscle-specific), lactate dehydrogenase (LDH) and IL-6, and alleviated muscle soreness. Total anti-oxidant levels were also significantly higher with allicin supplementation. (26)

Citrulline malate and Resistance Training:

Citrulline is a non-essential amino acid which has previously been found to increase arginine in the body which converts to nitric oxide leading to dilation of blood vessels. Researchers examined the effects of citrulline malate (CM) on the performance of flat barbell bench presses in a randomized, double-blind, 2-period crossover study. Forty-one men each performed 2 consecutive training sessions of 16 sets of chest training. Each subject was given 8 grams of citrulline malate and a similar looking placebo, but randomly on either the first or second training session. Results show that when the subjects were using the citrulline malate they were able to perform more repetitions in the later sets (52.92% more repetitions), and also had significantly less reported muscle soreness—a decrease of 40% in muscle soreness at 24 hours and 48 hours after the training session. The only reported side effect was stomach discomfort experience by 14.63% of men. This study shows that CM may be beneficial to men in intensive high level training. (27)

Ashwagandha for Competitive Sports

Shweta et al (28) tested 40 Indian cyclist athletes competing at the state level for the effect of Ashwagandha upon exercise performance. Half of the athletes were randomized to take 500 mg of aqueous Ashwagandha extract twice daily for 8 weeks. The other half was randomized to a starch pill. Exercise performance improved in the treatment group with an increase of 13% in VO2 max from a baseline of 46 mL/kg/min to 52 m/kg/min. The placebo group showed no improvement in VO2 max over baseline after placebo. After 8 weeks, the time to exhaustion improved from 15.79 min to 16.93 min in the Ashwagandha treatment group and improved minimally, 0.02 min in the placebo group.

Grandhi A et al (29) studied the swimming time of mice that took either Ginseng or Ashwagandha. Both of the herbal agents led to improvements on swimming time, but the Ashwagandha group was noted to increase their body size more than the Ginseng group.

Ashwagandha for Resistance Training and Power Lifting

Wankhede S et al (30) performed an 8 week randomized, double-blind placebo-controlled trial with Ashwagandha. The study included 57 men between 18 and 57 years old who were given 300 mg of Ashwagandha root extract twice daily or a starch placebo. The 2 groups were tested for their 1 repetition maximum in the bench press and the leg extension. The Ashwagandha group showed a significant average increase in strength of 46 kg compared to 26.4 kg in the control group. The additional benefits of the Ashwagandha group over the placebo group included larger arms and chest size, lower creatine kinase levels, and lower body fat percentage.

Pycnogenol for Endurance Training

Summary: Supplements for Endurance and Muscle Building

• Most supplements marketed for “performance enhancements” are not backed by evidence-based research and are advertised through the media while promoting false benefits. The majority of these are not regulated by the FDA, and are not clear on a standardized content of ingredients. They also may not contain what the label states. Caution is advised when taking supplements for athletic performance. Obtain approval from a physician prior to starting any substance.

• Caffeine used by athletes without any medical problems may result in a small benefit in endurance sports when even a small time improvement can be important. The dose range of caffeine used in studies was 1.5 – 5 mg per kilogram and greater benefit was seen in especially colder compared to warmer surrounding temperatures. Caffeine intake up to 300 mg per day is generally safe for healthy adults. Older patients or those with hypertension, cardiovascular disease, or cerebrovascular disease, avoid more than 1-2 cups of caffeinated beverages per day. Caffeine intake is generally recognized as safe by the FDA and AMA but can be dangerous with adverse effects such as high bp, stroke, and arrythmias reported. See adverse effects below. If more than 1-2 cups of caffeinated beverages are consumed per day, it is prudent to seek physician and/or pharmacist approval of caffeine consumption with any medications or supplements. Please see caffeine section for more detail.

• Beet juice taken in the amount of 0.5 liters (17 ounces) for 6 – 9 days prior reduced oxygen requirements as measured by VO2 max and increased time to failure in endurance athletes. Beet root juice may reduce blood pressure. Beet juice increases plasma nitrate levels and dangerous drop in blood pressure may occur if taken with other nitrate medications such as sublingual nitroglycerin, nitroglycerin paste, nitroglycerin patches, Imdur, Isordil, and Viagra.

• Beet juice concentrate containing nitrates at a dose of 400 mg taken daily for 6 days allowed athletes to lift weight with a higher number of repetitions and 18.9% more weight than a blackcurrant placebo (32).

• Creatine enhances muscle strength and hypertrophy in resistance training. Creatine has been taken at a dose of 0.1 mg per kilogram or as a loading dose of 20 to 30 grams divided in 4 equal doses for 5 to 7 days, followed by a 2 gram per day maintenance dose. Adverse effects may be more frequent with the loading regimen. Both regimens result in significant improvement of muscle strength and hypertrophy in younger and older adults. Lean muscle increased in older men even at the average age of 70.4 years in one study after taking creatine for 3 days Creatine significantly increased body mass, thigh muscle volume, and sprint performance. Creatine may increase bone density by improving muscle size and strength. Creatine should only be considered under a physician’s direction. Kidney function will require to be evaluated prior to taking creatine and should be monitored during use. Reports have linked creatine to weight gain, cramping, dehydration, diarrhea, and dizziness and may decrease renal function. In short-term trials creatine appears to well tolerated. Therefore, individuals should carefully weigh the benefits and risks of using creatine supplement, including possible renal dysfunction.

• Whey, casein, and soy protein each contribute to muscle growth and hypertrophy when taken along with resistance training. Whey is superior in this regard and may reduce cholesterol a small amount more than resistance training alone. Whey protein and creatine taken together have additive effects to muscle growth.

• High dose caffeine contributed to improved performance by allowing better muscle contraction velocity but safety has not been studied.

• Coenzyme Q10 improved athletic performance in only 1 out of 5 studies in a review by the Australian Sports Commission. Coenzyme Q10 improved exercise capacity in 6 out of 11 studies reviewed by Rosenfeldt F, et al. The is supplement is safe and would not cause harm if tried for this purpose but is not likely to result in benefit unless the athlete is malnourished or undergoing prolonged strenuous exercise.

• Garlic use has shown evidence in reducing exercise-induced muscle damage with reductions in creatine kinase over placebo (26).

• 8 grams of citrulline malate given to male subjects resulted in performance of 52.92% more repetitions in later sets and a decrease of 40% in muscle soreness at 24 hours and 48 hours after the training session. Stomach discomfort was the only adverse effect reported in 14.63%.

• Ashwagandha for Competitive Sports: Shweta et al (28) found performance improved in an Ashwagandha group over placebo with an increase of 13% in VO2 max. After 8 weeks, the time to exhaustion improved from 15.79 min to 16.93 min in the Pycnogenol group and minimally in the placebo group. Grandhi A et al (29) studied the swimming time of mice that took either Ginseng or Ashwagandha. Both herbal agents led to improvements on swimming time, but the Ashwagandha group also increase body size more. Wankhede S et al (30) found that 300 mg of Ashwagandha root extract twice daily increased the amount of weight lifted by 46 kg compared to 26.4 kg. The Ashwagandha group also developed larger arms, larger chest size, lower creatine kinase, and lower body fat percentage compared to placebo.

• Pycnogenol for Endurance Training: Vinciguerra G et al (31) found that Pycnogenol at a dose of 50 mg twice daily improved 2 mile running time, amount of push-ups, and amount of sit-ups. A higher dose of 50 mg 3 times daily with meals for a triatholon. The triatholon was completed by the Pycnogenol group by an average of 89 min and 4 seconds vs 96 min, 5 sec on average by the controls. The control group improved their time by 4 min, 36 sec and the Pycnogenol group improved their time by 10 in, 48 sec on average. There were no side effects from Pycnogenol.

• Please see resistance training and aerobic exercise sections.

References for Supplements for Endurance and Muscle Building

1.Vahedi K, Domigo V, Amarenco P, Bousser MG. Ischaemic stroke in a sportsman who consumed MaHuang extract and creatine monohydrate for body building. J Neurol Neurosurg Psychiatry. 2000 Jan;68(1):112-3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1760579/pdf/v068p00112.pdf

2.Simmonds MJ, Minahan CL, Sabapathy S. Caffeine improves supramaximal cycling but not the rate of anaerobic energy release. Eur J Appl Physiol. 2010 May;109(2):287-95. http://www.ncbi.nlm.nih.gov/pubmed?term=20082092

3.Irwin C, Desbrow B, Ellis A, O’Keeffe B, Grant G, Leveritt M. Caffeine withdrawal and high-intensity endurance cycling performance. J Sports Sci. 2011 Mar;29(5):509-15. http://www.ncbi.nlm.nih.gov/pubmed/21279864

4.Duvnjak-Zaknich DM, Dawson BT, Wallman KE, Henry G. Effect of caffeine on reactive agility time when fresh and fatigued. Med Sci Sports Exerc. 2011 Aug;43(8):1523-30. http://www.ncbi.nlm.nih.gov/pubmed?term=21266929

5.Kilding AE, Overton C, Gleave J. Effects of caffeine, sodium bicarbonate, and their combined ingestion on high-intensity cycling performance. Int J Sport Nutr Exerc Metab. 2012 Jun;22(3):175-83. http://www.ncbi.nlm.nih.gov/pubmed/22693238

6.Ganio MS, Johnson EC, Klau JF, Anderson JM, Casa DJ, Maresh CM, Volek JS, Armstrong LE. Effect of ambient temperature on caffeine ergogenicity during endurance exercise. Eur J Appl Physiol. 2011 Jun;111(6):1135-46. http://www.ncbi.nlm.nih.gov/pubmed/21120518

7.Bazzucchi I, Felici F, Montini M, Figura F, Sacchetti M. Caffeine improves neuromuscular function during maximal dynamic exercise. Muscle Nerve. 2011 Jun;43(6):839-44. http://www.ncbi.nlm.nih.gov/pubmed?term=21488053

8.Lansley, K., Winyard, P., Fulford, J., Vanhatalo, A., Bailey, S., Blackwell, J., DiMenna, F., Gilchrist, M., Benjamin, N., & Jones, A. Dietary nitrate supplementation reduces the O2 cost of walking and running: a placebo-controlled study. Journal of Applied Physiology. 2010. http://jap.physiology.org/content/110/3/591.long

9.“Nitrate supplementation’s improvement of 10-km time-trial performance in trained cyclists.” Department of Human Movement Sciences, Maastricht University Medical Centre, Maastricht, The Netherlands. Int J Sport Nutr Exerc Metab. 2012 Feb;22(1):64-71.  http://www.ncbi.nlm.nih.gov/pubmed/22248502

10.Graham AS, Hatton RC. Creatine: a review of efficacy and safety. J Am Pharm Assoc (Wash). 1999 Nov-Dec;39(6):803-10; quiz 875-7. http://www.ncbi.nlm.nih.gov/pubmed/10609446

11.Dempsey RL, Mazzone MF, Meurer LN. Does oral creatine supplementation improve strength? A meta-analysis. J Fam Pract. 2002 Nov;51(11):945-51. http://www.ncbi.nlm.nih.gov/pubmed/12485548

12.Dalbo VJ, Roberts MD, Lockwood CM, Tucker PS, Kreider RB, Kerksick CM. The effects of age on skeletal muscle and the phosphocreatine energy system: can creatine supplementation help older adults. Dyn Med. 2009 Dec 24;8:6. http://www.ncbi.nlm.nih.gov/pubmed/20034396

13.Burke DG, Chilibeck PD, Davidson KS, et al. The effect of whey protein supplementation with and without creatine monohydrate combined with resistance training on lean tissue mass and muscle strength. Int J Sport Nutr Exerc Metab. 2001 Sep;11(3):349-64. http://www.ncbi.nlm.nih.gov/pubmed/11591884

14.Graham AS, Hatton RC. Creatine: a review of efficacy and safety. J Am Pharm Assoc (Wash). 1999 Nov-Dec;39(6):803-10; quiz 875-7.

15.Phillips SM. The science of muscle hypertrophy: making dietary protein count. Proc Nutr Soc. 2011 Feb;70(1):100-3. http://www.ncbi.nlm.nih.gov/pubmed/21092368

16.Phillips SM, Van Loon LJ. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci. 2011;29 Suppl 1:S29-38. http://www.ncbi.nlm.nih.gov/pubmed/22150425

17.Candow DG, Burke NC, Smith-Palmer T, Burke DG, Candow DG, Burke NC, Burke DG. Effect of whey and soy protein supplementation combined with resistance training in young adults. Int J Sport Nutr Exerc Metab 2006 June; 16(3):233-244. http://www.ncbi.nlm.nih.gov/pubmed/16948480

18.Tyler A Churchward-Venne, Nicholas A Burd, and Stuart M Phillips. Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism. Nutrition & Metabolism 2012 May;9(1):40. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3464665/

19.Denysschen CA, Burton HW, Horvath PJ, Leddy JJ, Browne RW. Resistance training with soy vs whey protein supplements in hyperlipidemic males. J Int Soc Sports Nutr. 2009 Mar 11;6:8. http://www.ncbi.nlm.nih.gov/pubmed/19284589

20.Nutritive Value of Foods, United States Department of Agriculture, Agricultural Research Service, Home and Garden Bulletin Number 72. May be accessed at: https://www.ars.usda.gov/SP2UserFiles/Place/12354500/Data/SR25/nutrlist/sr25w203.pdf and http://www.nal.usda.gov/fnic/foodcomp/Data/HG72/hg72_2002.pdf

21.Australian Sports Commission. Supplements and sports foods, Burke and Deakin (eds). Clinical Sports Nutrition, 4th ED, McGraw Hill, Sydney 2010. http://www.ausport.gov.au/

22.Rosenfeldt F, Hilton D, Pepe S, Krum H. Systematic review of effect of coenzyme Q10 in physical exercise, hypertension and heart failure. Biofactors. 2003;18(1-4):91-100. http://www.ncbi.nlm.nih.gov/pubmed/14695924

23.Chrusch MJ, Chilibeck PD, Chad KE, Davison KS, Burke DG. Creatine supplementation combined with resistance training in older men. Med Sci Sports Exerc. 2001 Dec;33(12):2111-7. http://www.ncbi.nlm.nih.gov/pubmed/11740307

24.Ziegenfuss TN, Rogers M, Lowery L, Mullins N, Mendel R, Antonio J, Lemon P. Effect of creatine loading on anaerobic performance and skeletal muscle volume in NCAA Division I athletes. Nutrition. 2002 May;18(5):397-402. http://www.ncbi.nlm.nih.gov/pubmed/11985944

25.Chilibeck PD, Chrusch MJ, Chad KE, et al. Creatine monohydrate and resistance training increase bone mineral content and density in older men. J Nutr Health Aging. 2005 Sep-Oct;9(5):352-3. http://www.ncbi.nlm.nih.gov/pubmed/16222402

26.Su QS, Tian Y, Zhang JG, Zhang H. Effects of allicin supplementation on plasma markers of exercise-induced muscle damage, IL-6 and antioxidant capacity. Eur J Appl Physiol. 2008 Jun;103(3):275-83. http://www.ncbi.nlm.nih.gov/pubmed/18305954

27.Pérez-Guisado J, Jakeman PM. Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. J Strength Cond Res. 2010 May;24(5):1215-22. http://www.ncbi.nlm.nih.gov/pubmed/20386132

28.Shweta Shenoy, Udesh Chaskar, Jaspal S. Sandhu, and Madan Mohan Paadhi. Effects of eight-week supplementation of Ashwagandha on cardiorespiratory endurance in elite Indian cyclists. J Ayurveda Integr Med. 2012 Oct-Dec; 3(4): 209–214. https://www.ncbi.nlm.nih.gov/pubmed/23326093

29.Grandhi A, Mujumdar AM, Patwardhan B. J A comparative pharmacological investigation of Ashwagandha and Ginseng. Ethnopharmacol. 1994 Dec;44(3):131-5. https://www.ncbi.nlm.nih.gov/pubmed/7898119

30.Wankhede S, Langade D, Joshi K, Sinha SR, Bhattacharyya S. Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial. J Int Soc Sports Nutr. 2015 Nov 25;12:43. https://www.ncbi.nlm.nih.gov/pubmed/26609282

31.Vinciguerra G, Belcaro G, Bonanni E, Cesarone MR, Rotondi V, Ledda A, Hosoi M, Dugall M, Cacchio M, Cornelli U. Evaluation of the effects of supplementation with Pycnogenol® on fitness in normal subjects with the Army Physical Fitness Test and in performances of athletes in the 100-minute triathlon. J Sports Med Phys Fitness. 2013 Dec;53(6):644-54. https://www.ncbi.nlm.nih.gov/pubmed/24247188

32.Mosher SL, Sparks SA, Williams EL, Bentley DJ, Mc Naughton LR. Ingestion of a Nitric Oxide Enhancing Supplement Improves Resistance Exercise Performance. J Strength Cond Res. 2016 Dec;30(12):3520-3524. https://www.ncbi.nlm.nih.gov/pubmed/27050244