For two years, Steph Gaudreau gave up her daily cup of coffee. She switched to large mugs of herbal tea – not because caffeine was affecting her sleep or making her anxious, but to gain an edge in cross-country mountain bike racing.
Hoping to enhance the effect of caffeine as a performance aid, Gaudreau, who lives in San Diego, drank a cup of coffee on race day as she warmed up. Once that pre-race caffeine boost hit, Gaudreau, now a nutritional therapy practitioner and strength coach, said she felt a sense of euphoria, which helped her feel focused and mentally prepared for her race. The strategy paid off. In 2010, she took first place in a regional amateur biking race called the Kenda Cup.
Caffeine is the most widely consumed psychoactive substance in the world and one of the best-studied. Scientists have been looking at caffeine’s effect on athletics since the 1900s. Although there is still some disagreement as to the exact mechanism by which caffeine consumption affects exercise performance, and whether taking a break from it until game day can give you an edge, scientists agree that a cup of coffee before working out can improve performance, whether you’re playing for the NBA or just running through your neighbourhood.
Caffeine enhances the ability of muscles to contract at a greater rate and thus would conceivably create greater power.
However, it’s important to be aware of the potential downsides of caffeine consumption and to know how best to use it to your advantage when working out.
Gaudreau wasn’t imagining the effect of her pre-race cup of coffee. There’s a good consensus among scientists that caffeine gives an exercising edge, whether it’s running a marathon, lifting weights or playing soccer, said Nanci Guest, a dietitian, coach and researcher at the University of Toronto who led a comprehensive review in 2021 of caffeine and exercise.
Whether consumed via coffee, a workout supplement or an energy drink, caffeine tends to improve performance by an average of 2 per cent to 5 per cent, said Brad Schoenfeld, a professor of exercise science at the Lehman College in the New York City borough of the Bronx and director of the school’s human performance and fitness program. Although caffeine moderately improves anaerobic activities (intense, shorter workouts), such as weightlifting, sprinting and high-intensity interval training, it appears to show the most benefit with aerobic efforts (less-intense, longer exercises), such as swimming, cycling and jogging.
For instance, a 2020 analysis of multiple studies about the effect of caffeine on rowing performance found that competitive rowers improved their time on a 2,000m row by about four seconds when using caffeine.
“It takes a lot of work to drop your 2,000m row if you’ve been training for a couple of years,” said Mike Nelson, an associate professor at the Carrick Institute for Clinical Neuroscience. “But if you said, ‘Hey, just take this supplement and we can decrease your time instantly by four seconds,’ I’m going to take the supplement.”
This response to caffeine varies from person to person, depending on factors such as genetics, sex, hormonal activity and even diet. Some see performance improvement above 5 per cent, while others experience almost none.
“There’s fast metabolisers of caffeine and slow metabolisers of caffeine,” Nelson said.
Some studies have shown that caffeine also helps our muscles produce more force. Our body needs calcium to initiate muscle contractions, and caffeine helps mobilise calcium ions so they have greater interaction with the filaments that induce muscle fibre contractions.
“Caffeine enhances the ability for muscles to contract at a greater rate and thus would conceivably create greater power,” Schoenfeld said.
It may take some experimentation to find the right dose for you because people metabolise caffeine differently.
Caffeine’s influence on our nervous system starts with adenosine, a neurotransmitter that binds to specific receptors and makes us feel drowsy. Caffeine binds to those same receptors, blocking the adenosine from working.
“When caffeine blocks that receptor, the result is a stimulating effect,” Guest said. This, in turn, releases other hormones such as dopamine and epinephrine, which are related to mood, focus and alertness.