For the first time, scientists have shown that the best time of day to exercise varies with gender and training goals.
When should I fit into my regular exercise routine? Most of the time the response is affected by our family schedule, our working hours, and perhaps even if we are a “larks” or a “night owl”. However, over the past 10 years, researchers have discovered that this question is far more important than these limitations. This is because new research suggests that time of day (time of day exercise, ETOD) may influence how beneficial exercise is.
Now, randomized controlled research indicates that ETOD affects the effectiveness of exercise, and also shows that these effects differ across types of exercise and between women and men. The results were recently published in the journal Frontiers in Physiology.
“Here we show for the first time that for women, exercise in the morning reduces belly fat and blood pressure, said lead researcher Dr. Paul J. Arceiro, professor in the Department of Health and Human Physiological Sciences at Skidmore College in Saratoga Springs, New York, USA. Whereas in women, evening exercise increases upper body muscle tone, strength and endurance, and improves overall mood and food satiety.”
“We also show that for men, evening exercise lowers blood pressure, heart disease risk, fatigue, and burns more fat, compared to morning exercise.”
New 12-week “Multimedia” training program
The researchers recruited 30 women and 26 men. All were between 25 and 55 years old, healthy, physically active, non-smokers and of normal weight. They were trained by trainers for 12 weeks, using the RISE program originally designed by Arciero et al: either 60 minutes of resistance training (R), quick interval training (I), exercise (S), or endurance training ( E), depending on the day of the week. The rest days were Wednesday, Saturday and Sunday. Participants followed a carefully developed diet plan that included 1.1-1.8 grams of protein per kilogram of body weight each day.
Importantly, female and male participants were randomly assigned to one of two regimens: morning exercise only (60 min between 06:30 and 08:30) or evening training (between 18:00 and 20:00). Those assigned to exercise in the morning ate breakfast immediately after exercise, and three more meals every four hours. Those assigned to the night workout ate three meals at four-hour intervals before training, followed by another meal afterward.
At the beginning and end of the experiment, participants were comprehensively assessed for their aerobic strength, muscular endurance, flexibility, balance, upper and lower body strength, and jumping ability. Only 16% of the 56 participants enrolled had dropped out during the 12-week trial period, exclusively because they were unable to stick to this nutrition and exercise schedule.
Besides changes in participants’ physical and metabolic parameters such as blood pressure, arterial stiffness, respiratory exchange ratio, somatic distribution and percentage of lipids over the course of the trial, the researchers also measured changes in relevant blood biomarkers, for example, insulin, total and high lipoprotein cholesterol. “Good” HDL, C-reactive protein, and interleukin-6. They also gave participants questionnaires to determine changes in mood and feelings of fullness from food.
Survey the overall benefits of the program
The researchers showed that all participants improved in general health and performance over the course of 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) for improving cardiovascular health and mood health, as well as physical performance outcomes in women and men,” Archero said.
But more importantly, they also show that ETOD determines the strength of improvements in physical performance, body composition, cardiovascular health, and mood.
For example, all female participants reduced total body fat, abdominal and hip fat, and blood pressure during the trial, but these improvements were greater in the women who exercised in the morning. The men who exercised only showed reductions in total HDL cholesterol, blood pressure, respiratory exchange ratio and carbohydrate oxidation, with fat becoming the preferred fuel source.
Different ETOD recommendations for women and men
“Based on our findings, women interested in reducing belly fat and blood pressure, while at the same time increasing leg muscle strength, should consider exercising in the morning. However, women interested in gaining upper body muscle tone, strength and and stamina, in addition to improving mood and eating, evening exercise is the preferred option,” Arcero said.
“Conversely, evening exercise is ideal for men interested in improving heart and metabolic health, as well as emotional well-being.”
Second author Stephen J. Ives, associate professor at Skidmore College, concluded: “We’ve shown that ETOD should be an important consideration for anyone, women and men, due to its impact on the strength of exercise physiological outcomes. But regardless of ETOD, regular exercise is essential to our health.”
Reference: “Morning exercise reduces belly fat and blood pressure in women. Evening exercise increases muscle performance in women and lowers blood pressure in men” by Paul J. Arcero 1, Stephen J. Ives, Alex E. Mohr, Nathaniel Robinson, Daniela Escudero, Jake Robinson, Kayla Rose, Olivia Minicucci, Gabriel O’Brien, Catherine Curran, Vincent J Miller, Feng He, Chelsea Norton, Maya Paul, Caitlin Sheridan, Sheridan Bird, Jessica Senn Doodar, Katie Instrom, Daquimbay Hoyt, Heather Mack, and Aliyah Yard, May 31, 2022, Available here. Frontiers in Physiology.
DOI: 10.3389 / fphys.2022.893783
The study was funded by Isagenix International, LLC.