“This study looks at the effects of caffeine on muscle pain during high-intensity exercise as a function of habitual caffeine use,” Motl said. “No one has examined that before. What we saw is something we didn’t expect: caffeine-naive individuals and habitual users have the same amount of reduction in pain during exercise after caffeine [consumption].”
This and other studies by Motl could wind up encouraging not only intense-exercise enthusiasts but average people who may be seeking to increase their physical activity in order to improve their health.
Motl, a former competitive cyclist, said he used to drink coffee with his teammates before long-distance training rides.
“The notion was that caffeine was helping us train harder ... to push ourselves a little harder,” he said. They and many other athletes knew it helped, but not why – though some speculated, erroneously, that it facilitated the metabolism of fat.
“I think intuitively a lot of people are taking caffeine before a workout, and they don’t realize the actual benefit they’re experiencing,” Motl said. “That is, they’re experiencing less pain during the workout. … They can push themselves harder. It doesn’t hurt as much.”
Over the course of several years, the professor has performed a number of studies on the links between caffeine intake, spinal reflexes and physical activity.
“Caffeine works on the adenosine neuromodulatory system in the brain and spinal cord,” Motl said, “and this system is heavily involved in nociception [pain perception] and pain processing.”
Since he knew caffeine interferes with adenosine’s action, he conjectured that it could mitigate pain. His other work, on variables such as exercise intensity, dose of caffeine, anxiety sensitivity and gender, supports that conclusion.