Obesity

What's the best time of day to exercise for optimal metabolic outcomes?

June 20, 2024

According to new research from Spain, people with overweight or obesity should exercise in the evening to best manage their blood sugar. These findings, published in the Obesity Society’s flagship journal, Obesity, show that moderate to vigorous physical activity (MVPA) during the evening appears to have a beneficial effect on glucose levels in sedentary adults with overweight/obesity and metabolic impairments. The results add to the growing field of research examining the ideal time to exercise for maximum benefit; however, conclusions on exercise timing and outcomes vary. In one study published last September (also in the journal Obesity), researchers found that people who tend to exercise early in the morning tend to have healthier eating habits and lower weight.

When is the optimal time of day to exercise for adults with overweight/obesity and metabolic impairments?

• In the most recent study, Antonio Clavero-Jimeno, predoctoral researcher at the University of Granada, and his colleagues recruited 186 adults from the EXTREME project, a multicenter randomized controlled trial conducted in Granada and Pamplona that studied the efficacy and feasibility of time-restricted eating on visceral adipose tissue, body composition, and cardiometabolic risk factors in adults with overweight and obesity.
• Participants were aged 30-60 years, had a BMI between 25-40 kg/m^2, were inactive for >3 months prior to the study, and had at least one metabolic impairment (eg, type 2 diabetes, hypertension).
• MVPA and glucose patterns were monitored over a 14-day period using a wearable fitness tracker and a continuous glucose-monitoring device, respectively.
• Completing >50% of total MVPA during the evening was associated with lower 24-hour, diurnal, and nocturnal mean glucose levels compared with being inactive.

Does the diurnal pattern of exercise affect BMI or waist circumference?

• Tongyu Ma of Franklin Pierce University’s Health Sciences Department and colleagues gathered their cross-sectional data from 5,285 participants in the National Health and Nutrition Examination Survey (NHANES), all of whom were in the habit of daily MVPA.
• Investigators measured the diurnal pattern of MVPA in three clusters – morning, midday, and evening.
• Individuals with a diurnal pattern of at least 150 minutes of morning exercise tended to have a lower BMI and waist circumference than those in the afternoon or evening clusters who did the same amount of cardio.

Authors in both studies point out the limitations, including whether the findings can be extrapolated to other populations, and conclude that ultimately any exercise is better than none.

Sources:

Clavero-Jimeno A, et al. (2024, June 10). Obesity (Silver Spring). Impact of lifestyle moderate-to-vigorous physical activity timing on glycemic control in sedentary adults with overweight/obesity and metabolic impairments. https://pubmed.ncbi.nlm.nih.gov/38853594/

Ma T, et al. (2023, October). Obesity (Silver Spring). The diurnal pattern of moderate-to-vigorous physical activity and obesity: a cross-sectional analysis. https://pubmed.ncbi.nlm.nih.gov/37661938/