A popular sports and strength supplement being extensively used since the early 90s is creatine. Is coffee a diuretic? Does creatine hold water in the muscles? There has been a lot of controversy and confusion about whether creatine and caffeine be combined for a better ergogenic effect. Some earlier studies suggested that creatine and caffeine oppose each other, primarily because coffee is a diuretic and creatine has a property of holding water in the muscles.
This entire confusion actually stems from a single study, published in the Journal of Applied Physiology in 1996, by a team of Belgian researchers led by K. Vandenberghe. The study involved two groups, one consuming both creatine and caffeine together, and one consuming creatine alone. The results showed that the creatine-only group experienced modest improvements in overall performance during bouts of intermittent exercise, but there was no improvement seen in the group taking both creatine and caffeine. But there were a number of issues with the study. Firstly, the study only looked at overall training performance and did not examine the actual creatine uptake into the muscles. Just because, one group performed better only on caffeine, that does not mean, in any way that caffeine was negating the effects of creatine in the other group. The second issue was that there is no study after this single study, which proved the same.
So, is coffee a diuretic? To understand the confusion, it has been already proven in a number of studies and is part of my book on coffee that caffeine is a very weak diuretic, and these properties of creatine and caffeine have nothing to do with their effectiveness as an ergogenic aid. The later studies have negated these controversies and shown that creatine and caffeine combined can be a good ergogenic aid.
A 2002 study in the journal, Medicine, and Science in Sports and Exercise, by a research team from UK led by M. Doherty, took fourteen male subjects, who did a high intensity running workout on a treadmill. These runners were given a mixture of creatine and caffeine. The study concluded that the combination of creatine and caffeine can be more ergogenic than either of them taken alone.
A 2010 study in the journal Nutrition Research, by D.H. Fukuda and researchers, investigated the effects of a pre-workout supplement containing creatine, caffeine and amino acids, on aerobic and anaerobic performance. Researchers saw that participants who took the pre-workout combination showed an improvement in anaerobic power, but no effect on aerobic power.
A 2011 study in the European Journal of Applied Physiology, by a team of Taiwanese researchers led by C. L. Lee, investigated the effect of acute caffeine ingestion on intermittent high-intensity sprint performance after 5 days of creatine loading, on 12 active men. The study determined that caffeine ingestion after creatine supplementation augmented the high-intensity sprint performance.
A December 2017 study, in the Journal of Exercise Physiology, by a team of Brazilian researchers, gave 6mg/kg caffeine and 3 grams of creatine to 16 male athletes. The results showed that caffeine potentiates the effects of creatine during resistance training. So, combining caffeine with creatine for a workout could be a better performance booster than only creatine or caffeine.
So, all those who want to mix their aromatic coffee with creatine powder or capsules can safely and effectively do it, anytime they want.