I squeeze in my workouts first thing. Good or bad?
ANSWER In a word, good! Circadian rhythms – not a lesser-known Sean Paul track, but the physiological processes that govern your sleep/wake cycles – determine how effective your workouts are, according to 2016 research. The study, published in Cell Metabolism, found muscle function peaks during daylight hours when you’re most awake, which would suggest that bright mornings trump dark nights in the workout stakes. “It’s correct to say that muscles are affected by circadian rhythms,” says Claire Stewart, professor of molecular physiology at Liverpool John Moores University in the UK. But she’s not sold on the daylightfits-all idea. “These circadian rhythms are more intelligent than that. If you exercise at the same time each day, your body anticipates this and knows to adapt, which could mean generating more muscle,” she explains. The upshot? With consistency, you can tailor your circadian rhythms to your schedule. So, the best time to work out is the one that you actually stick to.