For many athletes, caffeine is a double-edged sword.
It can improve performance, but can also make you feel like you're dragging. If you're a regular consumer, it's important to understand the impact the drug has on your training.
Research on Performance
Most people who have consumed a significant amount of caffeine know it can provide a boost for mental alertness. It gives your brain a perk.
Studies have shown there are physical benefits to caffeine, too. It helps rowers go further, badminton players jump higher, cyclists go faster, and volleyball players hit the ball harder and jump higher. Additionally, could the effect of caffeine be any more obvious than in Serena William's comeback after ordering a mid-match espresso in the 2015 Hopman Cup?
Some experts such as Mark Glaister estimate caffeine can give a performance advantage of 1.5 to 5 percent. In terms of personal records and racing, that can be very significant.
"Of all the legal supplements an athlete could take, it has the biggest effect on performance," Glaister says.
Dosage and Timing
Although the mechanism isn't completely understood, many believe caffeine suppresses pain and increases the frequency or size of neural transmissions. According to Glaister, it also helps with bursts of activity that last longer than one minute.
Athletes see benefits with doses of 3 to 6 milligrams per kilogram of body weight. For example, a 70-kilogram athlete (approximately 154 pounds) would need 210 to 420 milligrams of caffeine. In this day of strong, gourmet coffee, this amount isn't as much as it seems. Most dark, strongly brewed cups of coffee have at least 200 milligrams of caffeine.
As for timing, it takes 30 to 60 minutes for caffeine levels to peak in the body, but you can start to feel effects as quickly as 15 minutes. For shorter sessions of 2 hours or less, one dose before training should work. For extremely long sessions, athletes may continue to take 50 percent of their initial dose every two hours for prolonged benefits.