What worries you more, drinking too much coffee or too little? Now, this may seem trivial at first glance, but there’s nothing trivial about sporting performance. You pour hours of effort into training so why would you flippantly pour your coffee when it’s time to shine?
Firstly, it is important to understand that we are not dealing in absolutes and there isn’t a magical caffeine dose for all. Everybody has a different tolerance to caffeine, so be warned if you see a blanket statement giving advice on this. "It depends on..." should be the prefix for most answers in sports science. The correct dose of caffeine for you depends on several variables:
your training goals,
your genotype and
your experience with caffeine.
Guidelines either prescribe a quantity of 200mg or between 6 - 9mg/kg of body weight of caffeine to improve performance. Numbers such as this have become almost dogma with ill-informed recommendations continuing to regurgitate these figures. One of the leading researchers into caffeine consumption, Dr. Lawrence Spreit, notes himself that in the early days of research they would deliberately give subjects a large dose (9 mg/kg) so that they could be sure to see a result.
"And see results we did." (Spreit)
Outside of a lab setting, this is highly impractical. For example, I weigh 96kgs, which would equate to 864mg of caffeine or nearly 7 bottles of The Strongest!! This a massive dose and I would not recommend it to anyone, no matter how into your coffee you are.
More recent research has focused on lower doses of caffeine. If we specifically look at research in endurance sport, positive effects have been shown in doses as low as 1.5mg/kg. What is interesting is that doses beyond 3mg/kg seem negligible. The ‘More is better’ approach is not standing true.
This was researched further in 2008 by Jenkins in a study that provided 1, 2 & 3 mg/kg of caffeine to well-trained cyclists 1 hour prior to a 20 minute cycle and a 15 minute all out test. 1 mg/kg did not provide a significant improvement but there was a 4% and 3% improvement in work done in the 2mg/kg & 3mg/kg tests respectively. I encourage you to calculate what a 4% improvement in your chosen sport would look like.
This is good news for endurance athletes, as doses between 6 & 9 mg/kg are more likely to produce negative effects such as the ‘shakes’ or an inability to concentrate. So, that provides insight into the ideal caffeine dose for endurance sports, but what about more strength/power- based activities?
We pride ourselves on providing you with unbiased information at Power press, so we will be the first to say that evidence backing strength improvements is not as unequivocal as it is behind endurance performance. However, there are a number of studies that indicate a possible advantage in the use of caffeine.
A 2017 study looked at whether strength and power could be improved upon with caffeine ingestion. Lower body strength assessment was via 1RM back squat and upper body power was inferred from a seated medicine ball throw. Improvements in 1RM squat (+2.8%) and throw (+4.3%) were found alongside a 7% reduction in rating of perceived exertion.
However, the study also measured 1RM bench press and did not find any significant improvement, which is peculiar considering the improvements in upper body power. Interestingly, a meta-analysis (a method of combining studies and their results to get a birds eye view of the research available) conducted at Georgia State University, collated 27 studies that looked at muscular strength.
This indicated that caffeine had a significant effect on knee extensor muscles ~+7%. Considering that lower body pushing strength (squatting) is required in 99% of sporting movements, this is massively encouraging.