A: You know instinctively that the best time to train is whenever you feel most energetic and can fit it into your schedule. Individual differences regarding the best time of day to train come from the fact that each person has a slightly different chronobiology, meaning circadian rhythms. Research reveals some noteworthy ideas:
• For muscle building, because men’s testosterone is generally highest in the morning and gradually declines over the course of the day, morning may be the best time for men to lift. In addition, the male testosterone response to training appears to be greater in the morning than later in the day.
• For fat loss there’s evidence that trainees experience a greater afterburn, or “EPOC”—excess postexercise oxygen consumption—if they work out in the evening around 6 p.m. Higher EPOC means the body burns more calories during the recovery period.
• For endurance training, studies show that time of day doesn’t matter much for performance, but of course individual experiences will differ.
• Regarding performance that relies on the anaerobic system, such as strength training, studies suggest that strength performance is significantly greater in the midafternoon and early evening. The effect is most pronounced when it comes to power production—when you need to produce maximal force at a fast speed.
• For sprint training, competing or working out in the midafternoon and early evening tends to produce faster times. Having greater strength and speed later in the day is likely due to the fact that your body temperature increases as the day progresses, leading to enhanced muscle function and flexibility.
Editor’s note: Charles Poliquin is recognized as one of the world’s most suc-cessful strength coaches, having coached Olympic med-alists in 12 different sports, including the U.S. women’s track-and-field team for the 2000 Olympics. He’s spent years researching European journals (he’s fluent in English, French and German) and speaking with other coaches and scientists in his quest to optimize training methods. For more on his books, seminars and methods, visit www.CharlesPoliquin.com. Also, see his ad on the opposite page. IM