While some people are up at the crack of dawn to lace up their running shoes, others can’t fathom a workout before noon. Finding the perfect time to exercise is as much about personal preference as it is physiology.The effect of training at a specific time of day: a review. Chtourou H, Souissi N. Journal of Strength and Conditioning Research / National Strength & Conditioning Association, 2012, Dec.;26(7):1533-4287. Exercise is supposed to feel good—but if muscles are tight in the morning or working out too late disrupts sleep, it can feel counterproductive.
Plenty of people tout the benefits of early morning sweat sessions, but if you can’t fit in a workout before noon, don’t sweat it. Research suggests the body could adapt to regular gym dates, so if we hit the weight room every day at 4 p.m., eventually we might perform better at that time than at any other time of day.The effect of training at a specific time of day: a review. Chtourou H, Souissi N. Journal of Strength and Conditioning Research / National Strength & Conditioning Association, 2012, Dec.;26(7):1533-4287. These findings are similar to earlier research, which suggests that sticking to a specific workout time can result in better performance, higher oxygen consumption, and lower perceived exhaustion.Temporal specificity in adaptations to high-intensity exercise training. Hill DW, Leiferman JA, Lynch NA. Medicine and Science in Sports and Exercise, 1998, Jun.;30(3):0195-9131. But scheduling a workout is more complicated than choosing a number on the clock.
Your body’s core temperature is an important factor in determining the quality of exercise. A cold body leaves muscles stiff, inefficient, and susceptible to sprains, whereas higher body temperatures leave muscles more flexible. Body temperature typically increases throughout the day, so muscle strength and endurance may peak in the late afternoon, when body temperature is highest.Different effects of heat exposure upon exercise performance in the morning and afternoon. Racinais S. Scandinavian Journal of Medicine & Science in Sports, 2011, Feb.;20 Suppl 3():1600-0838. The afternoon is also when reaction time is quickest and heart rate and blood pressure are lowest, all of which combine to improve performance and reduce the overall likelihood of injury.
It’s sometimes easier to keep a morning workout routine consistent. Afternoon and evening workouts are more likely to conflict with other responsibilities as the day progresses. Plus a full day’s work can take a serious toll on willpower—which can overcome any gym-goer’s best intentions.
In the end, it’s most important to find a realistic, consistent workout schedule, no matter what the time. If working out in the morning is best for your schedule, just make sure to warm up muscles that might be cold and tight from sleep. And to keep afternoon workouts consistent, treat them as unbreakable appointments, find a workout buddy, and keep a gym bag in the car or office to minimize excuses.