Caffeine as an Ergogenic Aid for Strength & Power?
For some time now caffeine has been known to be an ergogenic aid (a substance that enhances performance) in aerobic activities. While the initial mechanism of action was thought to be the increased reliance upon fat as an energy source (since caffeine is known to increase fatty acid availability), it was later discovered that caffeine’s performance benefits largely come from its action on the central nervous system. That is, caffeine has been shown to decrease ratings of perceived exertion (you feel as though you are not working as hard as you actually are, allowing you to push harder) in aerobic activities. So, athletes participating in aerobic activities should consider caffeine consumption to allow them to train slightly harder, and perform slightly better. Effects are small (don’t expect a HUGE increase in performance); but, as we all know sometimes small differences can make what ends up being a big difference in outcomes.
There was been more question and inconsistencies when looking at the research on caffeine’s effects on anaerobic performance. A recent meta-analysis attempted to provide some clarification on this important question. In their examination of the effects of caffeine on muscle strength and power, here is what Grgic and colleagues (2018) found. First, they noted that following caffeine consumption there were acute increases in maximal upper body strength. Results for lower body strength were inconsistent, though two studies did show an increase in isometric lower body strength, but other studies did not show an increase in lower body dynamic strength. The reasoning behind these disparities is not yet fully known and further studies are necessary. As for power, the meta-analysis supports the benefit of caffeine consumption for increasing muscle power as expressed by vertical jump height (a common measurement of power). In fact, the benefit of caffeine consumption was of the same magnitude as that seen with 4 weeks of plyometric training. Additionally, the article noted previous studies have shown improvements on the Windgate test as another measure of power output following caffeine consumption.
The results also indicated that training status of the athlete did not matter, that both trained and untrained individuals experienced similar results. This is contrasted with some previous studies on mostly aerobic performance where trained individuals experienced a greater benefit compared with untrained individuals. Finally, while male athletes seemed to exhibit greater strength gains compared with male athletes, caution should be used in these findings since the studies done on females are limited and very small in sample size. Further studies are needed before we can make more confident claims regarding sex differences and benefits of caffeine consumption.
The article noted that most of the studies demonstrate a benefit of caffeine consumption when taken in pill form; authors noted that further studies are needed to understand if the benefits extend to caffeine consumed in liquid or gel form.
So what does this mean? This meta-analysis indicates caffeine may improve training ability and performance for upper body muscle strength and power output. The study did not note how much caffeine is necessary for benefit, though previous research indicates about 3 mg per kg of body weight is likely sufficient (so, if you weigh 70 kg, you would want to consume 210 mg of caffeine). It is important to note that adverse effects of caffeine are seen at doses greater than 6 mg per kg of body weight and so it is highly discouraged to take amounts great than this. Caffeine peaks in the body 30 to 60 minutes after consumption and thus should be consumed accordingly before exercise. Because caffeine has a half-life of 5 hours, it is advised to avoid taking it later in the day to avoid problems sleeping that night.
Caffeine really is one of the few substances that has been found to have an ergogenic effect, let alone in a variety of contexts (aerobic performance, HIIT, and strength activities). At the very least I recommend giving it a try and seeing how it impacts your training and performance. And as always, never try it on the day of a big event (like, the Open…) since you’ll want to practice with it in training first. You just never know how your body will respond to your first time of taking something!
Grgic J, Trexler ET, Lazinica B, and Pedisic Z. Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis. Journal of the International Society of Sports Nutrition. 2018; 15(1).