Hey, night owls: Aim to finish your workout at least three hours before turning in to ensure smooth sailing into Slumberland. Breaking a sweat too close to bedtime might sabotage your sleep because cardio boosts blood flow, which can energize you and make it harder for your body to relax and doze off. Try to exercise no later than the early evening to give your body enough time to cool down and, well, get sleepy. Sources: National Sleep Foundation and American Council on Exercise
