With the popularity of 24/7 fitness centers and home gyms, one can seemingly get in an exercise session whenever convenient for their lifestyle.
While it’s good to get in the reps whenever you can, is there a specific time of day better suited for exercise? The answer, according to science, may be determined on what type of exercise you are performing. Whether you are a night owl or a morning person, we are all governed by our body clock, otherwise known as the Circadian clock or Circadian rhythm. Our Circadian clocks tell our brains when we should sleep, when it’s an optimal time to digest food, when to increase blood flow and when to decrease.
According to Satchin Panda, author of The Circadian Code, the Circadian rhythm is a 24-hour rhythm in which “almost every hormone, every brain chemical, every digestive enzyme and so on is pre-programmed to peak at a certain time of day and then tap out at another time of the day. It’s an in-built schedule for different programs to do different things at the optimal time, and these timing mechanisms are the Circadian rhythm.” (1)
Hormone production goes hand-in-hand with our Circadian rhythm.
This includes cortisol, a hormone that promotes fat storage and muscle breakdown, and melatonin, which helps prepare the body for sleep. Cortisol production is highest during the first two hours of waking. However, the testosterone hormone, key to muscle growth, also peaks in the morning. Since cortisol levels spike during any workout, a decision on what type of exercise to perform in the morning shouldn’t be based on cortisol production.
However, if you are looking to increase muscle building by lifting weights, there needs to be a certain amount of energy level for optimal performance. To achieve that energy level, it is recommended that you eat at least two meals prior to weightlifting.
Additionally, the Circadian rhythm also regulates body temperature, which changes throughout the day. A person’s body temperature is generally lowest in the hours just before and after awakening and highest in the late afternoon. The time for peak muscle development occurs near a person’s peak body temperature.
Conversely, if your goal is to lose weight, cardio exercise is best done in the morning on an empty stomach or immediately after ingesting a small amount of protein or a fat burner. After being asleep all night, the energy you have ready to burn for the cardio exercise is mostly in the form of stored fat.
So, the best time to do cardio is right when you wake up. This also helps boost your metabolism, which will help you burn more calories throughout the rest of the day than you would if you had worked out at night.
The best time for weightlifting, according to the Circadian rhythm, is in the afternoon. Testosterone is still high, you’ve had a chance to get in a couple of energy meals, and it is within two to three hours of your body’s peak temperature. The energy levels promote more strength, which leads to more muscle stimulation and growth.
While morning and afternoon workouts are optimal for peak performance and results, not everyone can exercise at those times. Perhaps your hometown gym isn’t open early or those times interfere with work or family obligations. In fact, some of the greatest male and female bodybuilders of all time have lifted early in the morning or throughout the evening as necessary due to schedules.
Remember, gains will be seen by doing the work no matter when it gets done. Consistency trumps all, but from a cellular and Circadian perspective, these are the times to maximize your gains.
By: Jon Johnson
- “How our body’s circadian clocks affect our health beyond sleep” – The Verge June 12, 2018.