*FOR DEMONSTRATION ONLY*
When is the best time to exercise, according to science? That all depends. If you're looking to lose weight, morning may be best. Multiple studies have shown that "fasted training" -- that is, exercising before eating breakfast -- is better than "fed training" for controlling appetite and improving glucose tolerance and insulin sensitivity. Exercising late in the day can also interfere with sleep, whereas there's evidence to support a link between morning workouts and a good night's rest. For most of us, morning may also be the best time for maintaining a consistent workout schedule, since most last-minute obligations pop up in the evening. But if you trust yourself to stay consistent, the evening has plenty of benefits too. Your core body temperature raises throughout the day, and since warmer muscles are more flexible and at less risk of injury, that makes evening a great time for higher-intensity exercise. Testosterone levels are higher later in the day, too, which is why strength training and resistance exercises are most effective in the afternoon and evening, both for women and men. And the stress hormone cortisol, which makes you store fat and reduce muscle, is highest in the morning and ramps down throughout the day. One study also showed that 6 p.m. workouts were better than 6 a.m. workouts for boosting energy and focus.