Supplements for Athletes: A Nutritional Edge

Originally posted on HVMN and authored by Brady Holmer on July 17, 2019

Athletes need to eat.

The importance of nutrition for athletic performance has been known since the Ancient Greek Olympics. Athletes ate dried figs for muscle health and stamina and used products like deer liver and lion heart to impart bravery, speed and strength. One olympic runner even won several races following a carnivore diet.

Table of Contents

Intro to Supplements

Supplements for Endurance

Sodium Bicarbonate

Beta-Alanine

Caffeine

Nitrates (Beetroot Juice)

Exogenous Ketones

Ashwagandha

Supplements for Recovery

Supplements for Muscle Growth, Strength, and Power

Creatine Monohydrate (Creatine)

Beta-hydroxy-beta-methylbutyrate (HMB)

Supplements for Bone and Joint Health

Glucosamine and Chondroitin

Supplements for Cognitive Performance

Caffeine and L-Theanine

Bacopa Monnieri

Do You Need to Supplement?

Sports nutrition is much more advanced now. In addition to whole foods, sports supplements are commonly consumed by athletes hoping to gain an edge and boost performance above and beyond what a training program and diet can do on their own.

Intro to Supplements

All athletes hope to maximize training adaptations and maintain health throughout hard training cycles, and dietary supplements can help. While proper diet should come first, some athletes may fail to get sufficient nutrition through food alone. Supplements may be a great way to support general health and wellness.

Certain dietary supplements have both nutritional and ergogenic potential, meaning they can provide performance benefits beyond those gained from food alone.

Dietary supplements are categorized as foods, products intended to supplement the diet above and beyond general nutrition obtained from food. Supplements must contain a “dietary ingredient” such as vitamin, mineral, herb, botanical, amino acid, enzyme, metabolite, or various concentrations of these substances.1 Supplements often come in soft gel, liquid, powder, or capsule form and are intended for oral ingestion.

An ergogenic aid (ergogenic supplement) on the other hand, is a supplement ingested with the goal of boosting performance in an athletic event. Not all supplements are ergogenic aids, but all ergogenic aids are supplements. Ergogenic supplements are intended to enhance energy utilization and energy production, improve control and efficiency and therefore improve athletic performance during competition and training.

As an athlete, certain supplements may play a role in helping you meet macro and micronutrient goals. Ergogenic aids may allow you to train harder, adapt quicker, and recover better while promoting general health.

Why should athletes supplement? Individuals undergoing training sometimes have special needs.

Exercise stresses metabolic pathways where vitamins, minerals, and other micronutrients are essential, increasing an athlete’s needs. Supplementing could help avoid particular nutrient deficiencies and even prevent unwanted weight loss.2

Female athletes may be at a higher risk for such deficiencies. It has been observed that iron, vitamin D, and calcium deficiencies are higher in women.3 This may predispose them to stress fractures and other health issues in addition to limiting athletic performance.

Training and competition also compromise the immune system, predisposing athletes to a greater risk of illness, infection, and lost training time. An all-around healthy diet helps, but supplementing with certain micronutrients might bolster your ability to fight of pesky infections while training hard.

Supplements for Endurance

Aerobic performance is crucial for endurance athletes competing in events from the 5k up to the marathon and beyond. Certain supplements have been shown to boost performance in aerobic endurance events when added to a training regimen or taken before a race.

Sodium Bicarbonate

High-intensity exercise leads to a buildup of acidic ions which may impair performance. Our body deals with this through a “buffer” system that maintains pH. Bicarbonate is our body’s primary buffer.

Since our bicarbonate stores are limited, supplementing with sodium bicarbonate (baking soda) has been proposed as a way to benefit performance during high-intensity exercise when the need to buffer acidic ions is high.

Bicarbonate supplementation can augment training capacity. Athletes who consumed sodium bicarbonate prior to intense intermittent exercise (think HIIT) experienced a 23% performance boost and a lower levels of perceived exertion.4 Faster performance times following bicarbonate ingestion have been shown in well-trained endurance athletes during a 3km cycling time trial.5

Sodium bicarbonate may even enhance long-term training adaptations. Taking sodium bicarbonate prior to HIIT resulted in a higher post-exercise signal for the genesis of mitochondria, our body’s energy producing powerhouses for aerobic exercise.6

When considering how to take the supplement, for acute dosing pre-exercise, take 300 mg/kg of sodium bicarbonate 1 - 2 hours before an activity. Ingest sodium bicarbonate with sufficient water to prevent gastrointestinal issues. A liter or more is recommended.

Chronic sodium bicarbonate loading is also a strategy used to accumulate and maintain sodium bicarbonate stores. A dose of 300 mg/kg body weight per day or 500 mg/kg divided into two daily doses can load bicarbonate stores.

Beta-Alanine

Beta-alanine is a substance naturally produced in the liver. We need beta-alanine to synthesize carnosine, which is necessary for proper skeletal muscle function. Food sources of beta alanine include meat, fish and poultry.

Beta alanine benefits performance by increasing production of natural proton buffers, preventing the accumulation of acidic ions during exercise that lead to fatigue. There is also evidence to suggest beta alanine can help reduce oxidative stress associated with muscle damage and perhaps reduce muscles soreness. Endurance athletes can benefit from beta-alanine supplementation by improving their ability to exercise at a high intensity for longer. Studies show time trial performance improves after beta alanine supplementation.7

Six weeks of beta alanine supplementation paired with high intensity interval training led to greater improvement in V02 max and time to exhaustion compared to a training regimen alone.8 Women who supplemented with beta alanine for 28 days increased their exercise threshold by 13.9% and time to exhaustion by 2.5%.9

There doesn’t seem to be an upper limit for carnosine in our body, suggesting that supplementing with beta alanine can boost stores above normal. In trained athletes, 4 - 10 weeks of supplementation has been shown to significantly increase muscle carnosine stores.10 A dose of 4 - 6 grams daily divided into equal doses of 2 grams for a minimum of two weeks can boost muscle carnosine stores by 20% - 30% and an additional 40% - 60% after four weeks of continued supplementation.

Caffeine

Caffeine is the drug of choice for most Americans. Endurance athletes have long known about, and believed in, the ergogenic benefits of caffeine on performance.

Caffeine is metabolized in the liver and within 45 minutes, levels begin to rise in the blood. Peak caffeine concentration appears around 60 minutes post ingestion.

Exactly how caffeine boosts performance is highly debated, but two hypotheses dominate.

Caffeine blocks the binding of a sleep-promoting molecule in the brain called adenosine, and therefore has a stimulating effect on the central nervous system. This action likely benefits performance by reducing perceptions of fatigue. In one study, caffeine ingested before a cycling time trial nearly doubled the levels of pain-reducing beta endorphins in the brain.11 No pain, more gain.

Caffeine may also shift substrate utilization during endurance exercise, lowering reliance on glycogen and carbohydrate for energy and increasing fat oxidation. This would theoretically boost endurance during moderate-intensity exercise by conserving energy stores and sparing muscle glycogen.

Caffeine is proven to be ergogenic for endurance athletes. Various studies on athletic performance have reported that pre-exercise caffeine ingestion leads to improved cycling time trial performance by 4% - 5%, increases time to exhaustion, and augments work capacity in runners.12,13,14

Caffeine intake after exercise may even boost recovery. When consumed with a post-workout carbohydrate source, caffeine enhanced muscle glycogen resynthesis by 66% in trained athletes.15

High doses of caffeine aren't required. A dose of 3mg/kg - 6 mg/kg is effective. For a 150lb athlete, this is about 200 - 400 milligrams of caffeine. The ideal time to ingest caffeine is 60 minutes before exercise but, ingestion 15 - 30 minutes prior has also been shown to enhance athletic performance.

However, caffeine comes with a caveat. There are non-responders to caffeine, where the substance actually can make performance worse.16

Nitrates (Beetroot Juice)

Nitric oxide is the molecule in our body primarily responsible for relaxing blood vessels and increasing blood flow, making it critically important to endurance exercise performance.

Dietary nitrates, found in green leafy vegetables and beetroot juice, can be directly converted to nitric oxide under conditions of low oxygen as an “alternate” source of nitric oxide. Plasma nitrate concentration has been linked to aerobic exercise capacity in humans.

Supplementation with nitrates often involves consumption of beetroot juice or sodium nitrate. Both are shown to improve exercise efficiency by lowering the oxygen cost of submaximal exercise.17,18 Nitrates can boost your running and cycling economy.

Beetroot consumption has been shown to improve performance in a variety of activities including four-kilometer and 16-kilometer cycling time trials and a five-kilometer run.19,20 Endurance athletes who consumed beetroot prior to exercise also ran faster in the last 1.8k of the time trial.

Since low oxygen availability is a limiting factor for nitric oxide production, supplementing with nitrates may become more beneficial during high-intensity training and races that occur near maximum capacity.

A dosing regimen of 2 - 6 days (up to 15 days) with sodium nitrate or beetroot juice containing around 5mM - 9mM of supplementary nitrates leads to levels shown to enhance performance.

An acute dose of .5L beetroot juice (containing 6.2mM nitrates) taken 2 - 3 hours before exercise will lead to peak nitrate concentrations in the body.

Exogenous Ketones

Nutritional ketosis may have the ability to unlock your potential as an endurance athlete.

The advantages of using exogenous ketones to achieve a state of ketosis for endurance performance are now being realized. Ketones provide an excellent fuel source for the body during prolonged exercise.

Supplementing with H.V.M.N. Ketone can enhance endurance exercise performance. This is achieved through a switch in fuel preference–a lower reliance on carbohydrate and stored glycogen and enhanced muscle fat and ketone oxidation. Ketones have been shown to contribute 16% - 18% of total energy production when taken exogenously before exercise. This lowers lactate production and spares muscle glycogen, both limiting factors in prolonged endurance activity.

Cyclists who consumed a ketone ester along with carbohydrate performed 2% - 3% better compared to when they only consumed carbohydrates.21

If you’re involved in endurance activities where fuel storage might limit performance, exogenous ketones act as a high-quality superfuel to boost your performance.

Ingest one serving of H.V.M.N. Ketone containing 25g BHB monoester 30 minutes prior to exercise along with your usual pre-workout fuel of carbohydrates, caffeine, or hydration beverage.

For recovery, one serving of H.V.M.N. Ketone ingested 30 minutes post-exercise with usual nutrition such as a meal or shake can enhance replenishment of muscle glycogen.22

Ashwagandha

An herbal supplement popular in Ayurvedic and indigenous medical systems, Ashwagandha has been used for its proposed cognitive enhancement properties. However, the applications to physical performance are now being realized and explored.

In a single blind placebo controlled study of 40 college-aged students, Ashwagandhda supplementation (500 mg/day for eight weeks) led to an increase in maximal oxygen consumption (V02 max) and faster sprint ability.23 Supplementing for 8 - 12 weeks with 300mg Ashwagandha also led to improvements in max aerobic capacity.24 These studies provide evidence that aerobic endurance may be enhanced following supplementation with this herb.

Rise, H.V.M.N.’s daily nootropic for memory, contains 250 milligrams of pure, high-quality Ashwagandha extract. Take two capsules per day along with some form of dietary fat such as eggs, nuts, or fish oil. Rise can also be combined with Kado, H.V.M.N.’s Omega-3 fatty acid supplement.

2 - 12 weeks of supplementation is the time needed for performance improvements to appear.

Supplements for Recovery

Training hard means nothing if you don’t properly recover. The time between workouts is when the body soaks up adaptations to make you faster and stronger. Certain supplements may help with mitigating damage during training so you can recover quicker and get back to training sooner.

We’ve got you covered. Here’s an entire post dedicated to recovery supplements for athletes, from BCAAs to CBD.

Supplements for Muscle Growth, Strength, and Power

It’s not just bodybuilders who need to build muscle.

Runners, triathletes, team sport athletes, and anyone looking to build muscle mass can benefit from certain supplements that may increase training capacity. The increased training ability can promote greater muscle mass and strength gains when paired with resistance exercise.

Creatine Monohydrate (Creatine)

Caffeine is the drug of choice for most Americans. Endurance athletes have long known about, and believed in, the ergogenic benefits of caffeine on performance.b

Caffeine is metabolized in the liver and within 45 minutes, levels begin to rise in the blood. Peak caffeine concentration appears around 60 minutes post ingestion.

Exactly how caffeine boosts performance is highly debated, but two hypotheses dominate.

Caffeine blocks the binding of a sleep-promoting molecule in the brain called adenosine, and therefore has a stimulating effect on the central nervous system. This action likely benefits performance by reducing perceptions of fatigue. In one study, caffeine ingested before a cycling time trial nearly doubled the levels of pain-reducing beta endorphins in the brain.11 No pain, more gain.

Caffeine may also shift substrate utilization during endurance exercise, lowering reliance on glycogen and carbohydrate for energy and increasing fat oxidation. This would theoretically boost endurance during moderate-intensity exercise by conserving energy stores and sparing muscle glycogen.

Caffeine is proven to be ergogenic for endurance athletes. Various studies on athletic performance have reported that pre-exercise caffeine ingestion leads to improved cycling time trial performance by 4% - 5%, increases time to exhaustion, and augments work capacity in runners.12,13,14

Caffeine intake after exercise may even boost recovery. When consumed with a post-workout carbohydrate source, caffeine enhanced muscle glycogen resynthesis by 66% in trained athletes.15

High doses of caffeine aren't required. A dose of 3mg/kg - 6 mg/kg is effective. For a 150lb athlete, this is about 200 - 400 milligrams of caffeine. The ideal time to ingest caffeine is 60 minutes before exercise but, ingestion 15 - 30 minutes prior has also been shown to enhance athletic performance.

However, caffeine comes with a caveat. There are non-responders to caffeine, where the substance actually can make performance worse.16

Nitrates (Beetroot Juice)

Nitric oxide is the molecule in our body primarily responsible for relaxing blood vessels and increasing blood flow, making it critically important to endurance exercise performance.

Dietary nitrates, found in green leafy vegetables and beetroot juice, can be directly converted to nitric oxide under conditions of low oxygen as an “alternate” source of nitric oxide. Plasma nitrate concentration has been linked to aerobic exercise capacity in humans.

Supplementation with nitrates often involves consumption of beetroot juice or sodium nitrate. Both are shown to improve exercise efficiency by lowering the oxygen cost of submaximal exercise.17,18 Nitrates can boost your running and cycling economy.

Beetroot consumption has been shown to improve performance in a variety of activities including four-kilometer and 16-kilometer cycling time trials and a five-kilometer run.19,20 Endurance athletes who consumed beetroot prior to exercise also ran faster in the last 1.8k of the time trial.

Since low oxygen availability is a limiting factor for nitric oxide production, supplementing with nitrates may become more beneficial during high-intensity training and races that occur near maximum capacity.

A dosing regimen of 2 - 6 days (up to 15 days) with sodium nitrate or beetroot juice containing around 5mM - 9mM of supplementary nitrates leads to levels shown to enhance performance.

An acute dose of .5L beetroot juice (containing 6.2mM nitrates) taken 2 - 3 hours before exercise will lead to peak nitrate concentrations in the body.

Exogenous Ketones

Nutritional ketosis may have the ability to unlock your potential as an endurance athlete.

The advantages of using exogenous ketones to achieve a state of ketosis for endurance performance are now being realized. Ketones provide an excellent fuel source for the body during prolonged exercise.

Supplementing with H.V.M.N. Ketone can enhance endurance exercise performance. This is achieved through a switch in fuel preference–a lower reliance on carbohydrate and stored glycogen and enhanced muscle fat and ketone oxidation. Ketones have been shown to contribute 16% - 18% of total energy production when taken exogenously before exercise. This lowers lactate production and spares muscle glycogen, both limiting factors in prolonged endurance activity.

Cyclists who consumed a ketone ester along with carbohydrate performed 2% - 3% better compared to when they only consumed carbohydrates.21

If you’re involved in endurance activities where fuel storage might limit performance, exogenous ketones act as a high-quality superfuel to boost your performance.

Ingest one serving of H.V.M.N. Ketone containing 25g BHB monoester 30 minutes prior to exercise along with your usual pre-workout fuel of carbohydrates, caffeine, or hydration beverage.

For recovery, one serving of H.V.M.N. Ketone ingested 30 minutes post-exercise with usual nutrition such as a meal or shake can enhance replenishment of muscle glycogen.22

Ashwagandha

An herbal supplement popular in Ayurvedic and indigenous medical systems, Ashwagandha has been used for its proposed cognitive enhancement properties. However, the applications to physical performance are now being realized and explored.

In a single blind placebo controlled study of 40 college-aged students, Ashwagandhda supplementation (500 mg/day for eight weeks) led to an increase in maximal oxygen consumption (V02 max) and faster sprint ability.23 Supplementing for 8 - 12 weeks with 300mg Ashwagandha also led to improvements in max aerobic capacity.24 These studies provide evidence that aerobic endurance may be enhanced following supplementation with this herb.

Rise, H.V.M.N.’s daily nootropic for memory, contains 250 milligrams of pure, high-quality Ashwagandha extract. Take two capsules per day along with some form of dietary fat such as eggs, nuts, or fish oil. Rise can also be combined with Kado, H.V.M.N.’s Omega-3 fatty acid supplement.

2 - 12 weeks of supplementation is the time needed for performance improvements to appear.

Supplements for Recovery

Training hard means nothing if you don’t properly recover. The time between workouts is when the body soaks up adaptations to make you faster and stronger. Certain supplements may help with mitigating damage during training so you can recover quicker and get back to training sooner.

We’ve got you covered. Here’s an entire post dedicated to recovery supplements for athletes, from BCAAs to CBD.

Supplements for Muscle Growth, Strength, and Power

It’s not just bodybuilders who need to build muscle.

Runners, triathletes, team sport athletes, and anyone looking to build muscle mass can benefit from certain supplements that may increase training capacity. The increased training ability can promote greater muscle mass and strength gains when paired with resistance exercise.

Creatine Monohydrate (Creatine)

Creatine is one of the most popular and scientifically-supported sports supplements available to athletes. Studies show it clearly increases levels of creatine in the muscle, improves performance, and promotes long term adaptations to training.25

While creatine can be adequately consumed in the diet (sources include red meat), achieving greater levels by supplementing can saturate your stores. Creatine is necessary to form phosphocreatine (PCr) , which is broken down during high intensity exercise to produce ATP. Phosphocreatine supplies are limited, and creatine monohydrate supplementation may increase the time before PCr depletion occurs.

The theory behind creatine supplementation: it allows you to train harder.

Creatine monohydrate supplementation for 3 - 4 days resulted in a 3.7% boost in peak anaerobic cycling power, a 6.6% increase in ankle torque production, and greater anaerobic energy production in a group of males and females.26 Creatine supplementation for 12 weeks during resistance exercise training resulted in greater improvements in fat free mass compared to protein supplements.27 Forget the whey protein, creatine is where it’s at.

There is also evidence to suggest creatine supplementation enhances the rise in satellite cells and myonuclei in skeletal muscle following resistance exercise, indicating a greater signal for muscle protein synthesis needed for muscle mass gains.28

A normal diet contains about 1 - 2 grams of creatine per day. Supplementing can increase stores up to 20% - 40% above normal.

Creatine supplementation often involves an initial loading dose of five grams taken four times per day for 5 - 7 days to fully saturate creatine stores.

After creatine loading, a maintenance dose of 3 - 5 grams per day will keep muscle creatine stores elevated. Consuming creatine with carbohydrate or protein can promote greater retention, so taking this supplement with a meal is recommended if you want to get the most out of supplementation.

Beta-hydroxy-beta-methylbutyrate (HMB)

Not to be confused with the ketone beta-hydroxy-butyrate (BHB), HMB is a metabolite of the branched-chain amino acid leucine. Bodybuilders and power athletes supplement with HMB to enhance muscle growth and body composition.

HMB stabilizes muscle structure and lessens protein breakdown.29 HMB supplementation significantly lowers markers of muscle damage and proteolysis following 2 - 6 weeks of supplementation.30 This is accompanied by greater muscle strength and improved body composition after a resistance training program.

Studies on resistance exercise and HMB observed increases in bench press lift by 55%, gains in muscle mass, and decreased body fat after four weeks.31,30

If you’re looking to supplement, HMB commonly comes in capsule form. 1.5 - 3 grams per day. This should be split into daily doses of one gram taken at breakfast, lunch or pre-exercise, and bedtime over a period of 3 - 6 weeks to effectively enhance athletic performance.

Supplements for Bone and Joint Health

Pounding out miles and pumping iron takes a toll on your bones, tendons, and joints. Some supplements have been shown to promote strong bones and cushy cartilage. This may enhance your athletic longevity.

Glucosamine and Chondroitin

Glucosamine is derived from shellfish. It’s often sold as a joint health supplement alongside chondroitin, due to the known additive effects on collagen synthesis, cartilage degradation, and osteoarthritis symptoms.

Doses as high as 3,000 milligrams may slow the degradation of joints in athletes involved in high impact sports. Glucosamine supplementation significantly lowered markers of collagen breakdown in soccer players.32 Three grams of glucosamine per day for three months reduced markers of collagen degradation in bicycle racers.33 The effect was dose-dependent; more was better in these two studies.

If you're looking to go right to the source, think about adding a collagen supplement into your recovery regimen. H.V.M.N.'s Keto Collagen+ is the choice to make; not only is it packed with grass-fed, bovine collagen peptides, it also has three essential co-factors for helping your body's natural collagen production. Plus, with a base of our MCT Oil Powder, you'll also be getting all those healthy, ketogenic fats (with 0 net carbs).

Glucosamine comes in capsules, salts, and even chews. Athletes should take 300 - 500 milligrams three times/day with food (for daily dose of 900 - 1500 milligrams).

Supplements for Cognitive Performance

Training and competition require you to be at the top of your mental game. These supplements may help you get there.

Caffeine and L-Theanine

Caffeine is great for concentration, attention, and focus, but may cause jittery feelings and anxiety. L-theanine is an amino acid that can reduce heart rate, blood pressure, and promote “zen state” alpha brain waves.

Taken together, these compounds may prime the nervous system, providing balance for the brain and extreme athletic concentration. That’s why H.V.M.N. combined them in Sprint, our nootropic for energy and focus.

Combined, caffeine and L-theanine have been shown to elevate visual attention performance, improve reaction time, boost working memory, and promote ratings of alertness.34,35

Consume caffeine + L-theanine 60 minutes before a workout, competition, or cognitively demanding task. Most studies use 80 - 100 milligrams of L-theanine and 50 milligrams of caffeine (a dose typically found in tea).

Bacopa Monnieri

Bacopa Monnieri is an herbal supplement known for its medicinal properties and has been used traditionally as treatment for certain mental conditions. The cognitive-enhancing effects are a topic of recent interest. Bacopa Monnieri gives a boost to your central nervous system by raising antioxidant activity in the brain, increasing neuronal density, and reducing beta amyloid.

Bacopa Monnieri is also a key ingredient in Rise, H.V.M.N.’s daily nootropic for memory.

Studies have shown that 90 days of bacopa monnieri supplementation improved performance in working memory, information processing speed, and anxiety.36,37 These benefits are likely to enhance any athlete’s ability to perform under high-stakes conditions where nerves must be calmed and decisions made quickly.

A dose of 300 - 400 milligrams per day for 12 weeks can result in the benefits listed above.

Do You Need to Supplement?

Obviously, no athlete needs to experiment with all supplements on the sports nutrition market.

Specific activities require different energy systems, which might not benefit from having more of this and less of that. Adding something new to training doesn’t always translate to improved capabilities or a personal record.

If you’re prone to a certain deficiency due to diet or training, consider supplements specific to your needs. Ask yourself: is the supplement worth the cost? Is there enough evidence to support taking a particular supplement for your sport or overall health? Ultimately, it might take a bit of experimenting with supplements to find what works for you. Do your research, find high quality products and let results be your guide.

Scientific Citations

1.Kerksick CM, Wilborn CD, Roberts MD, et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr. 2018;15(1):38.

2.Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. Journal of the American Dietetic Association 2009; 109 (3), 509-527

3.Mcclung JP, Gaffney-stomberg E, Lee JJ. Female athletes: a population at risk of vitamin and mineral deficiencies affecting health and performance. J Trace Elem Med Biol. 2014;28(4):388-92.

4.Marriott M, Krustrup P, Mohr M. Ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise. J Int Soc Sports Nutr. 2015;12:13.

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;22(3):175-83.

6.Percival ME, Martin BJ, Gillen JB, et al. Sodium bicarbonate ingestion augments the increase in PGC-1α mRNA expression during recovery from intense interval exercise in human skeletal muscle. J Appl Physiol. 2015;119(11):1303-12.

7.Baguet A, Bourgois J, Vanhee L, Achten E, Derave W. Important role of muscle carnosine in rowing performance. J Appl Physiol. 2010;109(4):1096-101.

8.Smith AE, Walter AA, Graef JL, et al. Effects of beta-alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial. J Int Soc Sports Nutr. 2009;6:5.

9.Stout JR, Cramer JT, Zoeller RF, et al. Effects of beta-alanine supplementation on the onset of neuromuscular fatigue and ventilatory threshold in women. Amino Acids. 2007;32(3):381-6.

10.Trexler ET, Smith-Ryan AE, Stout JR, Hoffman JR, Wilborn CD, Sale C, Kreider RB, Jäger R, Earnest CP, Bannock L, Campbell B, Kalman D, Ziegenfuss TN, Antonio J. International society of sports nutrition position stand: Beta-Alanine. J Int Soc Sports Nutr. 2015; 12: 30

11.Laurent D, Schneider KE, Prusaczyk WK, et al. Effects of caffeine on muscle glycogen utilization and the neuroendocrine axis during exercise. J Clin Endocrinol Metab. 2000;85(6):2170-5.

12.McNaughton LR, Lovell RJ, Siegler J, Midgley AW, Moore L, Bentley DJ. The Effects of Caffeine Ingestion on Time Trial Cycling Performance. International Journal of Sports Physiology and Performance 2008 3:2, 157-163

13.Pasman WJ, Van baak MA, Jeukendrup AE, De haan A. The effect of different dosages of caffeine on endurance performance time. Int J Sports Med. 1995;16(4):225-30.

14.Graham TE, Hibbert E, Sathasivam P. Metabolic and exercise endurance effects of coffee and caffeine ingestion. J Appl Physiol. 1998;85(3):883-9.

15.Pedersen DJ, Lessard SJ, Coffey VG, et al. High rates of muscle glycogen resynthesis after exhaustive exercise when carbohydrate is coingested with caffeine. J Appl Physiol. 2008;105(1):7-13.

16.Guest N, Corey P, Vescovi J, El-Sohemy A. Caffeine, CYP1A2 Genotype, and Endurance Performance in Athletes. Med Sci Sports Exerc. 2018 Aug;50(8):1570-1578

17.Bailey SJ, Winyard P, Vanhatalo A, et al. Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. J Appl Physiol. 2009;107(4):1144-55.

18.Larsen FJ, Weitzberg E, Lundberg JO, Ekblom B. Effects of dietary nitrate on oxygen cost during exercise. Acta Physiol (Oxf). 2007;191(1):59-66.

19.Murphy M, Eliot K, Heuertz RM, Weiss E. Whole beetroot consumption acutely improves running performance. J Acad Nutr Diet. 2012;112(4):548-52.

20.Lansley KE, Winyard PG, Bailey SJ, et al. Acute dietary nitrate supplementation improves cycling time trial performance. Med Sci Sports Exerc. 2011;43(6):1125-31

.21.Cox, P.J., Kirk, T., Ashmore, T., Willerton, K., Evans, R., Smith, A., Murray, Andrew J., Stubbs, B., West, J., McLure, Stewart W., et al. (2016). Nutritional Ketosis Alters Fuel Preference and Thereby Endurance Performance in Athletes. Cell Metabolism 24, 1-13.

22.Holdsworth, D.A., Cox, P.J., Kirk, T., Stradling, H., Impey, S.G., and Clarke, K. (2017). A Ketone Ester Drink Increases Postexercise Muscle Glycogen Synthesis in Humans. Med Sci Sports Exerc.

23.Sandhu JS, Shah B, Shenoy S, Chauhan S, Lavekar GS, Padhi MM. Effects of Withania somnifera (Ashwagandha) and Terminalia arjuna (Arjuna) on physical performance and cardiorespiratory endurance in healthy young adults. Int J Ayurveda Res. 2010;1(3):144-9.

24.Choudhary B, Shetty A, Langade DG. Efficacy of Ashwagandha (Withania somnifera [L.] Dunal) in improving cardiorespiratory endurance in healthy athletic adults. Ayu. 2015;36(1):63-8.

25.Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition 2017; (14). 18.

26.Tarnopolsky MA, Maclennan DP. Creatine monohydrate supplementation enhances high-intensity exercise performance in males and females. Int J Sport Nutr Exerc Metab. 2000;10(4):452-63.

27.Kerksick CM, Rasmussen C, Lancaster S, et al. Impact of differing protein sources and a creatine containing nutritional formula after 12 weeks of resistance training. Nutrition. 2007;23(9):647-56.

28.Olsen S, Aagaard P, Kadi F, et al. Creatine supplementation augments the increase in satellite cell and myonuclei number in human skeletal muscle induced by strength training. J Physiol (Lond). 2006;573(Pt 2):525-34.

29.Wilson GJ, Wilson JM, Manninen AH. Effects of beta-hydroxy-beta-methylbutyrate (HMB) on exercise performance and body composition across varying levels of age, sex, and training experience: A review. Nutr Metab (Lond). 2008;5:1.

30.Nissen S, Sharp R, Ray M, et al. Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training. J Appl Physiol. 1996;81(5):2095-104.

31.Panton LB, Rathmache JA, Baier S, Nissen S. Nutritional supplementation of the leucine metabolite β-hydroxy-β-methylbutyrate (hmb) during resistance training. Nutrition 2000; (16), 9, 734-739

32.Yoshimura M, Sakamoto K, Tsuruta A, et al. Evaluation of the effect of glucosamine administration on biomarkers for cartilage and bone metabolism in soccer players. Int J Mol Med. 2009;24(4):487-94.

33.Momomura R, Naito K, Igarashi M, et al. Evaluation of the effect of glucosamine administration on biomarkers of cartilage and bone metabolism in bicycle racers. Mol Med Rep. 2013;7(3):742-6.

34.Higashiyama A, Htay HH, Ozeki M, Junej LR, Kapoor MP. Effects of l-theanine on attention and reaction time response. Journal of Functional Foods 2011; (3) 3, 171-178.

35.Haskell, C. (2008) The effects of l-theanine, caffeine and their combination on cognition and mood. Biological Psychology Volume 77, Issue 2, February 2008, Pages 113-122

36.Stough C, Downey LA, Lloyd J, et al. Examining the nootropic effects of a special extract of Bacopa monniera on human cognitive functioning: 90 day double-blind placebo-controlled randomized trial. Phytother Res. 2008;22(12):1629-34.

37.Stough C, Lloyd J, Clarke J, et al. The chronic effects of an extract of Bacopa monniera (Brahmi) on cognitive function in healthy human subjects. Psychopharmacology (Berl). 2001;156(4):481-4.