Caffeine and Sports Performance

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Let’s be honest. Coffee and triathlon go hand in hand. The addiction to coffee probably kicked in around the same time that addiction to swim/bike/run did. In this article our Sports Dietitian, Margs talks about caffeine and the triathlete in general. She will be following this up with a more in-depth look into caffeine and the effects on performance in long course racing. 

Increasing athletic performance is a great desire of many athletes and coaches. From supplements to sports foods and drinks, there is a whole industry dedicated to developing products that help athletes gain that competitive edge over their opponents.

One well-known performance enhancer is caffeine.

Caffeine, a naturally occurring stimulant, enjoys widespread use and social acceptance around the world and also in competitive sport. Latte rides are commonplace in triathlon and many products used by triathletes during training and competition contain caffeine; ever wondered why cola is available at aid stations during long course events like Ironman?

Common dietary sources of caffeine include tea, chocolate, coffee, cola, and now also energy drinks and typically provide approximately between 30-200mg of caffeine per serve. The introduction of caffeine to sports foods and supplements has increased the opportunity for athletes to use caffeine as an ergogenic aid – an aid that helps to eliminate fatigue symptoms.

So, what effect does caffeine have on sports performance?

Caffeine is rapidly absorbed and transported around the body and has been shown to enhance performance in a variety of sports including endurance sports like triathlon. The way it does this is by decreasing the perception of fatigue or effort, enhancing the ability of muscles to contract, postponing fatigue, enhancing cognitive performance and the ability to concentrate, increasing alertness, wakefulness and feelings of “energy”, decreasing mental fatigue and quickening reaction times.  It was previously thought that caffeine also enhanced endurance performance by increasing the utilisation of fat as a fuel source thereby sparing glycogen. However, studies have now shown that this effect is short-lived and inconsistent among athletes. The main way caffeine appears to enhance endurance performance is through reducing an athletes’ perception of fatigue.

Studies have shown that the consumption of 100mg of caffeine (approximately one standard cup of coffee) immediately before 2.5 hours of cycling at 60% maximal effort significantly increased time-to-exhaustion in competitive cyclists (Glade, M., ‘Caffeine – Not just a stimulant’, Nutrition 26 (2010) 932-938). Furthermore, studies have shown that consuming about 150-200mg of caffeine before a 1500m run resulted in faster run times over 1500m (Goldstein, E. et al, ‘International society of sports nutrition position stand: caffeine and performance’, Journal of the International Society of Sports Nutrition 2010, 7:5).

But won’t caffeine cause dehydration?

Small to moderate doses of caffeine have been shown to have a minor effect on urine output and the overall hydration status in athletes who regularly consume caffeine. Additionally, caffeine-containing drinks like tea or coffee may, in fact, be a significant source of fluid in the everyday diet of some people.

Is caffeine consumption safe?

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