Caffeine, at least, is not a placebo, there is ample evidence showing that it improves workout performance. https://www.google.com/search?ix=sea&sourceid=chrom

Caffeine, at least, is not a placebo, there is ample evidence showing that it improves workout performance. https://www.google.com/search?ix=sea&sourceid=chrome&ie=UTF-8&q=caffeine+workout+study https://www.google.com/search?ix=sea&sourceid=chrome&#38...