No, we’re not pitchmen, for Starbucks, but if you’re looking for an energy boost in the gym, coffee can be a tempting workout partner. `There are numerous performance benefits [to caffeine],’ says Eric Sternlicht, Ph.D., a nutrition and exercise consultant (www.simplyfit.com) and the author of “Fuel Up”. `It increases the strength of muscle contractions, both with your skeletal muscle and your heart muscle. It increases endurance, and it increases the relative contribution of fat [to energy expenditure], so you’ll burn more fat relative to carbohydrates at any exercise intensity.’
But here’s the catch: The effect diminishes over time. Many people think, Oh, wow its great. I’m going to burn more tht by drinking a cup of coffee, or two or three,'” says Sternlicht. You build a tolerance quite quickly Within a few weeks, you’re not getting that same benefit.” If you are a regular coffee drinker, you can counteract this by abstaining from drinking coffee for two weeks-a good idea if you have an upcoming competition or even a long car ride. A six- to eight- ounce cup of coffee has SD to 250 milligrams of caffeine, depending on how strongly it’s brewed.