Changing What Time You Exercise Can Help You Lose More Weight

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 exercise routine? Most of the time, the answer is influenced by our family’s schedule, our work schedule, and possibly even whether we are “larks” or “night owls.” However, over the last ten years, researchers have discovered that this question is considerably more important than these limitations. This is because new research indicates that the time of day (Exercise Time Of Day, ETOD) may affect the benefit of exercise.

Now, randomized controlled research indicates that ETOD affects exercise efficacy and also shows that these effects vary by type of exercise and between women and men. The findings have recently been published in the journal Frontiers in Physiology.

Lead researcher Dr Paul J Arciero, a professor in the Department of Health and Human Physiological Sciences at Skidmore College in Saratoga Springs, New York, USA, said: “Here we show for the first time that for women, morning exercise reduces abdominal fat and blood pressure, while evening exercise in women increases muscle strength, power, and upper-body 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, compared to morning exercise.”

New 12-week ‘multimodal’ training program

The researchers enlisted the help of 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.: 60 minutes of resistance training (R), sprint interval training (I), stretch training (S), or resistance training ( E), depending on the day of the week. Rest days were Wednesdays, Saturdays and Sundays. The participants followed a carefully developed diet plan that included 1.1-1.8 g of protein per kg of body weight each day.

Importantly, male and female participants were randomly assigned to one of two regimens: morning exercise only (60 minutes between 06:30 and 08:30) or evening training (between 18:00 and 20:00). . Those assigned to morning exercise ate breakfast immediately after exercise and three more meals at four-hour intervals. Those assigned to night exercise ate three meals at four-hour intervals before training, followed by one afterward.

At the beginning and end of the trial, the participants were thoroughly tested for their aerobic power, muscular endurance, flexibility, balance, upper and lower body strength and power, and jumping ability. Only 16% of the 56 enrolled participants dropped out during the course of the 12-week trial, solely because they were unable to adhere to this nutrition and exercise program.

In addition to changes in the participants’ physical and metabolic parameters, such as blood pressure, arterial stiffness, respiratory exchange rate, and body distribution and percentage of fat during the trial, the researchers also measured changes in blood biomarkers eg insulin, total and ‘good’ HDL cholesterol, C-reactive protein and IL-6. They also administered questionnaires to the participants, to quantify changes in mood and feelings of food satiety.

Clear overall benefits of the program

The researchers show that all participants improved in their overall health and performance over the course of the trial, regardless of their assignment to morning or evening exercise.

“Our study clearly demonstrates the benefits of both morning and evening multimodal exercise (RISE) for improving mood and cardiometabolic health, as well as physical performance outcomes in women and men,” said Arciero.

But crucially, they also show that ETOD determines the strength of improvements in physical performance, body composition, cardiometabolic health, and mood.

For example, all female participants reduced total body fat, abdominal and hip fat, and blood pressure during the test, but these improvements were greater in women who exercised in the morning. Only men who exercised at night showed a decrease in their total cholesterol to HDL ratio, blood pressure, respiratory exchange ratio, and carbohydrate oxidation, as fat became the preferred fuel source.

Different ETOD recommendations for women and men

“Based on our findings, women interested in reducing abdominal fat and blood pressure while increasing leg muscle strength should consider exercising in the morning. However, for women interested in gaining upper body muscular strength, power and endurance, as well as improving overall mood and food intake, evening exercise is the preferred option,” said Arciero.

“By contrast, 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 have shown that ETOD should be an important consideration for anyone, women and men, given its effects on strength and physiological exercise outcomes. But regardless of ETOD, regular exercise is essential to our health.”

Reference: “Morning exercise reduces abdominal fat and blood pressure in women; Nighttime 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.
DOI: 10.3389/fphys.2022.893783

The study was funded by Isagenix International, LLC.