|You don't necessarily have to bring fresh beans to the gym. A simple Nescafé instant coffee will serve the purpose, study shows. And it's going to work better than equal doses of straight caffeine.|
Against that background it is only logical that Darren L. Richardson and Neil D. Clarke from the Department of Applied Sciences and at the Faculty of Health and Life Sciences of the Coventry University in the UK wanted to expand on the previously reported results by Trexler et al. (2015 | previously mentioned at the SuppVersity).
Trexler et al. found that coffee improved leg press 1-RM performance to a greater extent than caffeine, while both coffee and caffeine attenuated the reduction in total work performed compared with placebo. Accordingly, Richardson and Clarke started their research, which was a randomised, latin-square, crossover, placebo-controlled trial, in which each subject attended the strength and conditioning suite on six occasions, with the hypothesis that the ingestion of coffee would exhibit at least some advantages over a equally dosed caffeine "placebo".
|Figure 1: Graphical illustration of the experimental protocol on all five test occasions (Richardson. 2016).|
"Trials were performed within half an hour on separate days to ensure an accurate comparison of strength and to limit strength fluctuations due to the effects of circadian variation (Duncan. 2011). Trials were separated by at least two days in order to allow recovery and to ensure complete caffeine washout. As caffeine has a highly variable half-life in healthy individuals of between 1.5-9 hours (Syed. 2005) subjects were instructed to avoid caffeine ingestion for a minimum of 12 hours and strenuous exercise for 24 hours prior to each trial to avoid fatigue (Beaven. 2013).The actual exercise protocol consisted of squats and bench presses at 60% 1-RM until failure. Each subject performed the exercise protocol following the ingestion of...
- 0.15 g/kg caffeinated coffee (COF; 3.4g per 100g coffee = 5.1g/kg body weight),
- 0.15 g/kg decaffeinated coffee (DEC; 5mg caffeine per kg coffee = almost zero),
- 0.15 g/kg decaffeinated coffee plus 5 mg/kg anhydrous caffeine (D+C),
- 5 mg/kg anhydrous caffeine (CAF), or
- a placebo (PLA; 5 mg·kg-1 maltodextrin from MyProtein, Manchester, UK).