It's all a big scam
Deborah Cohen, an investigations editor at the BMJ who was involved in the project and wrote a summary of the findings, recalls a study in which volunteers who fasted overnight were divided into two groups, one whose members were given a sports drink containing water, salts and sugar and another whose members received water. “People who were given the sports drink fared better,” she says. “Well, no [inappropriate word removed].” If you haven’t had any food in 12 hours and then you get a bit of sugar, of course you’ll perform better than the people still running on empty. But to say that this means the sports drink is superior to whatever a normal person would consume leading up to or during exercise just isn’t generalizable, she says. “Who starves themselves overnight and then goes to perform some exercise?” And yet the BMJ investigation found that this type of study design is surprisingly common among tests of nutritional products.
Cohen says, that studies using plain water for the control group found that the sports drink had positive effects, while the ones that used taste-matched placebos didn’t.
When Heneghan’s and Cohen’s reports came out, some sports science experts blasted it as unnecessarily rigid, because they set their standards based on the conventions of clinical medicine rather than sports science, where, for instance, small sample sizes are common.
You can also forget those pee charts that look like paint swatches for urine, and ignore anyone who says that yellow pee is a sign that you need to drink more water.