From today’s New York Times, Gina Kolata stumbled upon the discovery that athletes may spend less effort on a workout than they would at night. She asks, “Are athletes more efficient in the morning?”
“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.”