For the first time, scientists show that the best time of day to exercise varies by gender and training goals.
When should I fit into my regular workout routine? Most of the time, the answer is influenced by our family’s schedule, our work hours and maybe even if we are “larks” or “night owls”. However, over the past decade, researchers have discovered that this issue is considerably more important than these limitations. Indeed, new research indicates that the time of day (Exercise Time Of Day, ETOD) can affect the benefits of exercise.
Now, randomized controlled research indicates that ETOD has an impact on exercise efficiency, and it also demonstrates that these effects vary across exercise types and between women and men. The results were recently published in the journal Frontiers in physiology.
Lead researcher Dr Paul J Arciero, Professor in the Department of Health Sciences and Human Physiology at Skidmore College in Saratoga Springs, NY, USA, said: “Here we show for the first time that for women, exercising in the morning reduces belly fat. and blood pressure, while evening exercise in women increases upper body muscle strength, power and endurance, and improves overall mood and nutritional satiety.
“We also show that for men, evening exercise reduces blood pressure, heart disease risk and feelings of fatigue, and burns more fat than morning exercise.”
New 12-week “multimodal” training program
The researchers enlisted the help of 30 women and 26 men. They were all between the ages of 25 and 55, in good health, physically active, non-smokers and of normal weight. They were trained by coaches for 12 weeks, using the RISE program originally designed by Arciero et al. : either 60 min of resistance training (R), sprint interval training (I), stretching training (S) or endurance training (E), depending on the day of the week. Days off were Wednesdays, Saturdays and Sundays. The participants followed a carefully crafted diet that included 1.1 to 1.8 g of protein per kg of body weight each day.
Importantly, female and male participants were randomly assigned to one of two regimens: morning exercise only (60 minutes between 6:30 a.m. and 8:30 a.m.) or evening training (between 6:00 p.m. and 8:00 p.m.) . Those assigned to morning exercise ate breakfast immediately after exercise and three more meals four hours apart. Those assigned to nighttime exercise ate three meals four hours apart before the workout, followed by another after.
At the start and end of the trial, participants were thoroughly assessed for aerobic power, muscular endurance, flexibility, balance, upper and lower body strength and power, and ability to skip. Only 16% of the 56 enrolled participants dropped out during the 12-week trial, exclusively because they were unable to stick to this nutrition and exercise program.
In addition to changes in participants’ physical and metabolic parameters, such as blood pressure, arterial stiffness, respiratory exchange rate, body distribution, and fat percentage during the trial, researchers also measured changes relevant blood biomarkers, eg insulin, total and “good” HDL cholesterol, C-reactive protein and IL-6. They also administered questionnaires to the participants, to quantify mood changes and feelings of food satiety.
Clear overall program benefits
The researchers show that all participants improved their overall health and performance during the trial, regardless of whether they were assigned to morning or evening exercise.
“Our study clearly demonstrates the benefits of morning and evening multimodal exercise (RISE) to improve mood and cardiometabolic health, as well as exercise performance in women and men,” Arciero said.
Importantly, they also show that ETOD determines the strength of improvements in exercise performance, body composition, cardiometabolic health, and mood.
For example, all participants reduced their total body fat, abdominal and hip fat, and blood pressure during the trial, but these improvements were greater in women who exercised in the morning. Only men exercising in the evening showed a decrease in their ratio of total cholesterol to HDL, blood pressure, respiratory exchange rate, and carbohydrate oxidation, as fat became the fuel source favourite.
Different ETOD recommendations for women and men
“Based on our findings, women interested in reducing belly fat and blood pressure, while increasing leg muscle power, should consider exercising in the morning. However, women interested in gaining strength , power and endurance in the upper body muscles, as well as improving overall mood and food intake, evening exercise is the preferred choice,” Arciero said.
“Conversely, evening exercise is ideal for men who want to improve their heart and metabolic health, as well as their emotional well-being.”
Second author, Stephen J Ives, Associate Professor at Skidmore College, concluded, “We have shown that ETOD should be an important consideration for all, women and men, given its effects on the strength of physiological outcomes of the ‘exercise. But regardless of ETOD, regular exercise is essential for our health.
Reference: “Morning exercise reduces abdominal fat and blood pressure in women; Evening Exercise Increases Muscle Performance in Women and Lowers Blood Pressure in Men” by Paul J. Arciero1, Stephen J. Ives, Alex E. Mohr, Nathaniel Robinson, Daniela Escudero, Jake Robinson, Kayla Rose, Olivia Minicucci, Gabriel O’Brien, Kathryn Curran, Vincent J. Miller, Feng He, Chelsea Norton, Maia Paul, Caitlin Sheridan, Sheriden Beard, Jessica Centore, Monique Dudar, Katy Ehnstrom, Dakembay Hoyte, Heather Mak and Aaliyah Yarde, May 31 2022, Frontiers in physiology.
The study was funded by Isagenix International, LLC.