Morning, noon, or night?  When is the best time of day to exercise? Some find that exercising first thing in the morning keeps them energized all day long. These early birds know that getting it out of the way is their best guarantee they'll exercise at all.  Others head to the gym right after work as an extension of their workday. It also provides a nice transition between work and home life.  Still others work out on the night shift; taking advantage of quiet streets and empty gyms. Which group is best off?

Afternoon Athletes

Phyllis Zee, M.D., a neurologist at Northwestern University says late afternoon or early evening is our most productive and beneficial workout time because of circadian rhythms. Circadian rhythms are the body's internal timing mechanism that controls sleep patterns, blood pressure, body temperature, moods and more.  Zee's study says late afternoon provides peak exercise performance because that's when circadian rhythms naturally elevate our body temperature.  Warmer muscles along with smoother pulmonary function, oxygen exchange and blood flow all function better for exercise later in the day.