Your muscles do their best work around 6 p.m
. You can jump a little higher, pump a little faster, swing more powerfully. Your core temperature is its hottest, your joints their supplest, your nerve conduction its fastest, your muscular blood flow its strongest. Testosterone (women have this competition-enhancing hormone too) is more responsive to exercise in the early evening. Evening resistance training may even lead to stronger muscles than morning workouts
, says a study in Chronobiology International
. Avoid late-night workouts
, however. They may throw off your body clock—and your muscles, like the rest of you, don't perform well without sleep.