Some people meditate after exercising. Just lie down and imagine their body relaxing, from toes headwards. (Facial muscles are rather confusing, though.) Concentrate also on even breathing - on the count of four, begin exhaling for four 'beats', then hold your breath for four more, then take a prolonged breath, etc. (You can be more comfortable with three at first.) Idon't know about reducing the need for sleep, but it does bring calm and is easier to do for longer than seven minutes (AFA I remember).