I'm Sarah Bernier Olin, a stress reduction and meditation expert. It's good to squeeze in a workout every day, but what about breaking a sweat right before bedtime -- will that sabotage your sleep? Turns out, this is an unproven "myth." A Cardio workout does increase blood flow and raise core body temperature. But for most people, it doesn't create sleep problems -- even if you exercise an hour before bedtime! So, go ahead and exercise whenever it works for your schedule. If you have trouble falling asleep, try tensing and then relaxing specific muscle groups starting at your head and moving down your body, avoiding light from computer screens and phones, or sleeping with a new pillow. It's all about a relaxing routine that makes you feel like sleeping.