When planning an effective workout, take frequency, intensity, time and type into consideration, according to the FITT principle—a method that establishes the guidelines that should be used in a fitness plan.
Regarding the time component of the FITT principle, remember humans are cyclical beings. Our circadian rhythm helps regulate hormones that affect bodily functions like our sleep/wake cycle, energy levels, hunger, body temperature, breathing capacity and energy stores.
Timing your workout to your circadian rhythm can mean increased coordination, improved energy metabolism and better sleep. Think of it this way: If you’re getting up before sunrise to exercise but you’re not typically an early riser, your body may feel a little sluggish, slow to react and weaker than if you exercise at a later hour.
Ultimately, though, it comes down to preference or what your daily schedule looks like. Some people prefer to work out in the morning, while others hit the gym after work and still reap the same benefits.
Benefits of Morning Workouts
Early workouts often lead to fewer distractions and increased productivity throughout the day, says Mark Brisby, a sports medicine doctor of chiropractic and owner of The Training Room in Santa Barbara, California.
In a study of 51 healthy adolescents, those who ran 30 minutes in the morning three days a week reported improved sleep quality, mood and concentration during the day, as well as decreased daytime sleepiness, compared to the control group (who did not engage in any running).
Research considering the effects of circadian cortisol—the usual fluctuation of your body’s cortisol level—on habit formation shows that cortisol plays an important and well-documented role in developing and maintaining a healthy habit. Since you tend to have a higher concentration of cortisol in the morning, exercising at this time might help make working out a stronger habit. Indeed, morning exercisers in a 2017 study in Health Psychology achieved consistency with a stretching routine nearly 50 days sooner than those who stretched in the evening.
Research also suggests morning workouts can curb appetite throughout the day. A small study from Brigham Young University compared food intake and brain responses to food images in a group of 35 women. Those who completed 45 minutes of moderate-intensity exercise in the morning had a lower response to food images and didn’t consume extra calories during the day to make up for the calories burned during exercise.
Drawbacks of Morning Workouts
One of the biggest drawbacks to morning workouts involves sacrificing sleep. Sleep debt—the difference between the amount of sleep you need versus the amount of quality sleep you actually get—is associated with an increase in catabolic hormones, which break down muscle, and a decrease in anabolic hormones, which build muscle. This negatively affects muscle adaptation and recovery after exercise.
Some say exercising first thing in the morning, before you can talk yourself out of it, is a good strategy, but Brisby disagrees. Having a nervous system primed and ready to perform is essential, he says—especially when completing complicated movements like agility drills and powerlifting.
Brisby also notes that eating before exercising—something you might skip if you’re trying to squeeze in a workout before work or other obligations—is important in order to avoid depleting energy stores during your workout. He suggests allowing enough time to eat a simple meal in the morning, such as a hard-boiled egg or serving of yogurt, to help you power through your workouts. Overeating can make you feel sluggish and full, though, so keep portions small.
Ideally, save high-intensity and neurologically demanding exercise for a mid-morning session or an hour or two after you wake up, Brisby suggests. This timing allows you to not only have a small meal before your workout, but also to be more alert and neurologically prepared for a challenging workout, promoting better focus, coordination and, ultimately, a better workout experience.
Benefits of Night Workouts
When it comes to exercising in the evenings, the most significant benefit is that most people have more time. This can lead to better focus, longer workouts and better exercise adherence if you’re working out with friends or participating in an exercise class. Evening exercise can also be a great way to de-stress, boost endorphins and leave your workday behind you.
Contrary to popular belief, new research on high-intensity exercise and sleep in men shows high-intensity exercise doesn’t affect sleep or appetite if performed in the early evening. There’s also evidence that engaging in low-intensity exercise in the evening can actually improve sleep quality in older adults, which may be a helpful way to get better rest without medications.
Evening workouts can also help you maximize your workout performance. When looking at anaerobic output, such as peak power and jump performance, some studies show evening workouts yield better results. A 2020 review looked at 44 studies that examined the time of day differences on short-duration maximal exercise. All but two found better performance outcomes in the afternoon. This difference may be due to a better ability to concentrate, more fuel reserves from eating during the day and/or more time to warm up before exercising.
Drawbacks of Night Workouts
If you struggle to get a good night’s sleep, intense workouts right before bed may be problematic. A 2019 study found exercising vigorously less than an hour before bedtime can increase arousal, delay sleep and disturb sleep quality. To avoid this reaction, aim to work out in the early evening to give your body ample time to unwind before bedtime.
Overall, it all comes down to how well you perform mentally and physically in the evenings and what time you go to bed. If you’re naturally a morning person, forcing yourself to exercise in the evening and delaying bedtime may not work for you. Meanwhile, others might find they only have time to exercise after their young children go to bed, so if that’s the time that keeps you consistent, it’s much better than not working out at all. While there are some drawbacks to evening workouts, any activity you perform consistently is your best choice.
Which Is Best?
There are benefits to morning and evening workouts, and experts agree whatever time you can find to exercise is better than not working out at all. Morning exercise may have an edge when it comes to benefits like fewer distractions, increased productivity throughout the day and habit formation, but evening exercise might be better if you’re looking to improve your performance.