What Is Chrono-Exercise & Can It Help You Achieve Your Goals Faster?
The time of day you choose to exercise plays a more prominent role in the efficacy of a workout than previously thought, according to a 2023 study published in the scholarly journal Sports Medicine and Health Science. Chrono-exercise, or chrono-activity, describes a new discipline of research that investigates the connection between exercise and the body's biological clock. In another 2023 study — this one published in the European Journal of Preventive Cardiology — researchers also observed greater health benefits for those who exercised in the morning. They noted a lower risk of cardiovascular disease and stroke in participants who exercised in the morning (between 8 a.m. and 11 a.m.) compared to those who exercised at night (between 12 p.m. and 6 a.m.).
The Sports Medicine and Health Science article also found that working out between certain hours of the day enhances the effects of exercise, depending on your fitness goal. For instance, women who exercise in the morning could potentially lose more abdominal fat, while the opposite is true for men. On the other hand, women who perform strength training workouts in the evening could experience greater muscle gains than in the morning, per a 2022 study published in the Frontiers in Physiology. Therefore, the secret to reaching your health goals quicker and more efficiently may just involve scheduling your workout to align with your biological clock — who knew?
What is our biological clock?
The circadian rhythm, or biological clock, refers to a natural process responsible for the sleep-wake cycle and other crucial physiological patterns that occur within 24 hours, per Healthline. Chrono-exercise focuses on incorporating exercise in a way that doesn't interrupt the circadian rhythm. Instead, it coincides with the different stages of these cyclical patterns. "The concept is based on the understanding that our bodies have natural biological rhythms that influence various physiological processes, including metabolism, hormone levels, body temperature, and cognitive function," nutritionist and personal trainer Mary Sabat explains to The Zoe Report.
The fluctuations in hormones such as cortisol remain an ongoing topic of interest in chrono-exercise research due to its role in energy metabolism, the sleep-wake cycle, and your body's stress response (via the Cleveland Clinic). Your body produces peak levels of cortisol in the morning to help you wake up. "By exercising in the morning, when cortisol levels are higher, you can potentially harness the cortisol-induced energy boost to enhance your workout," Sabat tells The Zoe Report.
Exceptions to the rule
There is an overwhelming amount of conflicting information in terms of finding the "best" time to exercise. Although the concept of chrono-exercise is biologically inclined, there's no guarantee that it will work for everyone, as it doesn't account for different lifestyles. "People's natural sleep-wake cycles, or chronotypes, differ significantly," psychiatrist and sleep expert Chester Wu, M.D., tells The Zoe Report. "Some people are early risers, others are night owls, and most fall somewhere in between. These chronotypes can influence energy levels, performance, and preference for exercise at different times of the day."
Switching up your workout routine may also be difficult for those who work or have personal responsibilities that may prevent them from exercising during the recommended time slots. For instance, if you follow the concept of chrono-exercise and want to lose weight, you should exercise in the morning sometime after 8 a.m. and no later than noon. However, most adults work during these hours. In this case, it's nearly impossible to adhere to chrono-exercise, so you should continue with whatever routine works best for your chronotype, current sleep schedule, and lifestyle.
When to exercise for weight loss
Exercising in the morning allows you to take advantage of the spike in cortisol to help fuel your workout. According to chrono-exercise research published in Sports Medicine and Health Science, it can also help one lose weight. What's more, morning workouts can be a safer option for those with Type 1 diabetes, as researchers noted a lower risk of blood sugar drops at night after exercising earlier in the day. This observation supports findings from the study published in the European Journal of Preventive Cardiology, which suggests that exercise performed between the hours of 8 a.m. and 11 a.m. is better for heart health.
A 2019 study published in the International Journal of Obesity also observed how the participants who exercised before noon lost more weight compared to those who exercised later than 3 p.m. However, these studies didn't account for factors such as exercise frequency, diet, and health conditions, which can all greatly affect weight loss progress. That said, implementing the appropriate lifestyle changes and incorporating cardio exercise into your morning workout are great steps to help you reach your goal.
How to increase muscle gains
For those focusing on muscle strength, try rearranging your workout schedule to exercise in the evening. A 2022 study published in the Frontiers in Physiology delved further into the discipline of chrono-exercise to discover the benefits of evening workouts for both men and women over a period of 12 weeks. According to the study's researchers, evening workouts increase muscle gains for women, specifically. The experiment also revealed an increase in upper-body muscle strength and endurance. If you're looking to increase your booty gains, however, you may want to stick with a morning routine, as researchers found that morning workouts produced greater lower-body gains than evening workouts. The ideal routine, therefore, would involve cardio and lower-body exercises between 8 a.m. to 11 a.m., followed by upper-body strength training between 6 p.m. to 8 p.m.
The research on chrono-exercise is ongoing and doesn't always consider individual chronotypes and realistic workout schedules. However, experimenting with chrono-exercise might be worth it to see if it helps you reach your fitness goals faster than your current routine.