"Equal to or substantially better than steroids … and it's not illegal."This is the sort of claim you see in spam email subject lines, not in discussions of mammalian thermoregulation. Even the man making the statement, Stanford biology researcher Dennis Grahn, seems bemused. "We really stumbled on this by accident," he said. "We wanted to get a model for studying heat dissipation."
But for more than a decade now, Grahn and biology Professor H. Craig Heller have been pursuing a serendipitous find: by taking advantage of specialized heat-transfer veins in the palms of hands, they can rapidly cool athletes' core temperatures – and dramatically improve exercise recovery and performance.
But the glove's effects on athletic performance didn't become apparent until the researchers began using the glove to cool a member of the lab – the confessed "gym rat" and frequent coauthor Vinh Cao – between sets of pull-ups. The glove seemed to nearly erase his muscle fatigue; after multiple rounds, cooling allowed him to do just as many pull-ups as he did the first time around. So the researchers started cooling him after every other set of pull-ups.
"Then in the next six weeks he went from doing 180 pull-ups total to over 620," said Heller. "That was a rate of physical performance improvement that was just unprecedented."
The researchers applied the cooling method to other types of exercise – bench press, running, cycling. In every case, rates of gain in recovery were dramatic, without any evidence of the body being damaged by overwork – hence the "better than steroids" claim. Versions of the glove have since been adopted by the Stanford football and track and field teams, as well as other college athletics programs, the San Francisco 49ers, the Oakland Raiders and Manchester United soccer club.