As an athlete there is a good chance that you are more likely to be taking dietary supplements as compared with the general population (1). The primary motivation for this is enhancing performance and recovery from exercise. There are a number of natural supplements which are actually proven to enhance performance, with caffeine and beetroot the most popular right now. We will also look at some other popular supplements such as bee pollen and fish oil where the science is still not as clear. And to make life simple, we have put together a handy guide on how to use these supplements to get the most benefit.
Caffeine is a naturally occurring stimulant found in over 60 different plant species, however it is actually classified as a drug because it does not have any nutritional value. Caffeine is currently allowed, however did you know this breaking news…?
WADA looks set in 2017 to add caffeine to its list of banned substances. Caffeine is currently on WADA’s monitoring program, to determine whether athletes are using the substance with the intent of enhancing performance (6).
Currently, about 75% of all athletes consume some form of caffeine before competition (5). Caffeine was previously a WADA-prohibited substance but then removed in 2003 to prevent athletes from testing positive for drinking cola or coffee. The threshold for caffeine then was equivalent to about 4 cups of coffee.
In September, WADA is likely to issue a three-month notice that caffeine will be added to the Prohibited List in 2018. This decision depends on if they find it has it has the potential to enhance performance; it poses a health risk to athletes; and it violates ‘the spirit of sport’.
How does Caffeine work?
Caffeine appears to be most effective in endurance activities, including running and cycling. There hasn’t been any clear effect shown on high-intensity exercise (2,4). Caffeine affects your central nervous system, resulting in vasodilation (expanding blood vessels) and lipolysis (breaking down fat), so the end result is an improvement in your body’s fuel utilisation and sparing of your precious muscle glycogen stores (2, 4). . Caffeine also helps to decrease your perception of effort during exercise and aid activities requiring your concentration (2)
Dosage and timing of Caffeine intake
Most studies show that caffeine will have a performance enhancing effect at a dose of 400-600mg of caffeine, which is equivalent to approximately 4-6 cups of coffee. Importantly, the timing of intake – either before or during an event – doesn’t seem to matter. Having all your caffeine in one go, or spreading it out will give you the same effect (2). It’s also important to note that taking caffeinated ‘defizzed’ soft drinks during races will have a dose much less than is shown to have a positive effect on your performance.
Tolerance to Caffeine
It is really common for athletes to go ‘cold turkey’ on caffeine in the week leading up to a race, with the aim to get the most out of the caffeine effect on race day. Well guess what? You don’t need to! Recent research suggests that regular use of caffeine does not reduce the performance effects of pre-exercise caffeine supplementation, provided the dose you take before exercise is higher than your regular intake (5). Having said that, it has been recognised for some time that the effect of caffeine is more pronounced in non-users of caffeine versus regular users (5)
Side effects of Caffeine
Most people are familiar with the ‘coffee shakes’, including an increased heart rate, sleeplessness, irritability and increased anxiety. And there is the problem of needing to urinate more during a race for some!
Be mindful that caffeine is prohibited when used in combination with some other substances such as Ephedrine, which is a stimulant found in many diet supplements to increase energy, decrease appetite and increase metabolism without exercise. Caffeine/ephedrine combinations have led to serious side effects including serious heart arrhythmias and death. Use of ephedrine products and elevated levels of urinary caffeine are prohibited by WADA (7).
Beetroot juice is one of the richest sources of nitrate, which exerts a number of positive effects on the human body, and has been used for medicinal purposes since ancient times. The more recent spotlight on beetroot juice for exercise performance took exercise scientists, athletes and the medical fraternity by surprise. What looked like another passing fad started to be backed by rigorous and credible scientific research (10, 11, 12).
Beetroot Guidelines from the AIS
Beetroot juice is a Group A supplement as classified by the AIS, which means it enhances sports performance is backed by scientific evidence.
How does Beetroot Juice work?
Beetroot juice is one of the richest sources of nitrate and this has a number of effects on the human body such as:
- Allowing you to exercise at greater intensity with less effort
- Dilating blood vessels so that more blood can pass through them
- Making cells more efficient so that your body has more oxygen available to burn energy for longer.
Dosage and timing of intake
The peak effect of nitric oxide occurs 2-3 hours after intake, so research suggests you should consume it 90 minutes before your athletic effort, and at a dose of 300-400mg (9,13). However, some studies are suggesting that much larger doses of nitrate taken over longer periods are required to shift your blood nitrite levels. So, drinking beetroot juice every day for up to a week before an event might be a preferred approach.
Side effects of Beetroot Juice
Some people report gut discomfort and temporary pink-coloured urine when using beetroot juice. Some athletes have tried using synthetic nitrites (ie the drug amyl nitrite) instead of beetroot, however they are very potent and can lead to fatal cardiovascular collapse if taken in excessive quantities (14). Overdosing with these supplements can be fatal. Best avoid the chemicals, and stick with your natural nitrates!
What about combining Beetroot and Caffeine?
This is where is gets tricky – combining the two supplements may actually decrease the effects of beetroot juice on cardiorespiratory performance – this is an area that needs more research to better understand the impact of combining your supplements.
So what about the Bee pollen craze?
It’s becoming more common to see bee pollen in sports bars and nutrition products. Bee pollen is a natural source of the plant chemical quercetin, which is potent antioxidant that is widely used for fighting inflammation and allergies. There are some small scale studies giving and early indication that quercetin may also increase muscle building and muscle endurance but large scale testing is need to supports these claims (15). So there’s no harm in using bee pollen but don’t believe the hype just yet!
Fish oil helps everything right?
Fish oil has been studied extensively, and some studies show improved exercise performance in athletes due to the omega-3 polyunsaturated fatty acids (PUFAs). These fatty acids improve blood vessel function and blood flow during exercise, reducing inflammation, and increase the provision of energy from fat.
However, there are many studies which have not reported the benefits of fish oil, and much work is needed to be done to appreciate the types of fish oils that are best, and also the best dose and timing of fish oil supplementation. Again, be wary of misleading claims, as although the health benefits of fish oils have been proven, there is a tendency to stretch the application of some of these supplements to sports performance.
- Knapik JJ, et al. 2016. Prevalence of dietary supplement use by athletes: Systematic review and meta-analysis. Sports Medicine, 46: 103-123. Accessed June 2017 at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4697915/
- Keisler BD and Armsey TD, 2006. Caffeine as an ergogenic aid. Current Sports Medicine Reports, 5(4): 215-219. Accessed June 2017 at: http://ow.ly/U4sy30clf6k
- Burke L, Desbrow B and Spriet L, 2013. Caffeine for Sports Performance. Human Kinetics.
- Applegate E, 1999. Effective nutritional ergogenic aids. International Journal of Sport Nutrition, 9: 229-239. Accessed June 2017 at: http://ow.ly/JRJl30cL5GG
- Pickering C, 2017. Does regular caffeine use reduce its performance enhancing effects. HMMR Media. Accessed June 2013 at: http://ow.ly/8zRO30cL7ph
- Payne M, 2017 (March 8). Caffeine could be headed to World Anti-Doping Agency’s prohibited substance list. The Washington Post. Accessed June 2017 at:
- Ahrendt DM, 2001. Ergogenic aids: Counseling the athlete. American Family Physician, 63(5): 913-922. Accessed June 2017 at: http://www.aafp.org/afp/2001/0301/p913.html
- History of beetroot – Historical uses of beetroots. Vegetable Facts. Accessed June 2017 at: http://www.vegetablefacts.net/vegetable-history/beetroot-history/
- Sports Dietitians Australia. Nitrate Fact Sheet. Accessed June 2017 at: http://ow.ly/HcX730clfOC
- Burke L, 2013. To beet or not to beet? Journal of Applied Physiology, 115: 311-312. Accessed June 2017 at: http://jap.physiology.org/content/jap/115/3/311.full.pdf
- Bailey et al. 2009. Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercises in humans. Journal of Applied Physiology, 107: 1144-1155. Accessed June 2017 at: http://jap.physiology.org/content/jap/107/4/1144.full.pdf
- Hoon et al., 2013. The effect of nitrate supplementation on exercise performance in healthy individuals: A systematic review and meta-analysis. International Journal Sports Nutrition and Exercise and Metabolism, 23: 522-532. . Accessed June 2017 at:
- Dominguez et al 2017. Effects of beetroot juice supplementation on cardiorespiratory endurance in athletes. A systematic review. Nutrients, 9(1): 43. Accessed June 2017 at: http://ow.ly/1SmX30clfSz
- Coleman E 2012. Rep the benefits of beetroot juice: Evidence suggests it improves heart health and athletic performance. Today’s Dietitian 14(2): 48. Accessed June 2017 at: http://www.todaysdietitian.com/newarchives/020612p48.shtml
- Bee pollen for athletes. Bee Hub. Accessed June 2017 at: http://www.beepollenhub.com/bee-pollen-for-athletes/
- Mickleborough TD, 2013. Omega-3 polyunsaturated fatty acids in physical performance optimization. International Journal of Sports Nutrition and Exercise Metabolism, 23: 83-96. Accessed June 2017 at: http://ow.ly/DlF730cLkXo