It's True: Exercising Really is Harder in the Morning
Have you ever had more trouble exercising in the morning than in the afternoon? If so, you are not alone. It turns out that it really is harder to exercise in the morning than later in the day. Most world records for athletes were broken in the late afternoon. And those that exercise later in the day get more benefit out of it. Gina Kolata of The New York Times investigates:
But, it turns out, a small group of researchers has studied the question of exercise performance and time of day, even doing studies of heart rates. And not only are performances better in the late afternoon and early evening, but, contrary to what exercise physiologists would predict, heart rates are also higher for the same effort.
One recent study, by the late Thomas Reilly and his colleagues at the Research Institute for Sport and Exercise Sciences at Liverpool John Moores University in England, found that people's maximum heart rates and sub-maximal heart rates were lower in the morning but that their perception of how hard they were working was the same in the morning as it was later in the day.
Dr. Reilly and his colleague Jim Waterhouse, in a review published this year, also noted that athletes' best performances, including world records, were typically set in the late afternoon or early evening.
Greg Atkinson, also at Liverpool John Moores University, said that some researchers, noticing that heart rates during exercise were lower in the morning, reasoned the way I did -- that people must be more efficient in the morning. It would mean that exercise was easier in the morning. Of course, it seemed harder to me, but I could have been deluding myself. Not really, Dr. Atkinson said. It actually is harder to exercise in the morning.
"Most components (strength, power, speed) of athletic performance are worst in the early hours of the morning," he wrote in an e-mail message. “Ratings of perceived exertion during exercise have generally been found to be highest in the early morning."
If you exercise later in the day, your muscles are more flexible and stronger and your heart and lungs are more efficient, said Michael H. Smolensky, an expert in chronobiology, the study of the body clock.
Of course, if the only way you can get your exercise in is to do it early in the morning, that's perfectly fine. It just may feel more difficult than if you did it later in the day. This study was based on regular exercisers who exercised vigorously at least three times a week.