Exercising Longer May Boost Weight Loss, Meta-Analysis Shows

TOPLINE:

Aerobic exercise shows a linear relationship with weight loss, with 30 minutes of weekly exercise linked to reduced body weight, waist circumference, and body fat in adults who were overweight or had obesity.

METHODOLOGY:

• Researchers conducted a meta-analysis of randomized clinical trials to investigate the association of varying intensities and durations of aerobic exercise with adiposity measures in adults with obesity or who were overweight.
• Overall, 116 randomized clinical trials that spanned across North America, Asia, Europe, Australia, South America, and Africa and involved 6880 adults (mean age, 46 years; 61% women) were included.
• The trials were required to have intervention durations of at least 8 weeks; all trials used supervised aerobic exercise, such as walking or running, while the control groups remained sedentary or continued usual activities.
• The intensity of exercise was defined as: Light (40%-55% maximum heart rate), moderate (55%-70% maximum heart rate), and vigorous (70%-90% maximum heart rate).
• The primary outcomes were body weight changes and adverse events; the secondary outcomes included changes in waist circumference, quality-of-life scores, and reduction in medications like antihypertensives.

TAKEAWAY:

• Every 30 minutes of aerobic exercise per week was associated with a 1.14 lb reduction in body weight (certainty of evidence, moderate).
• Every 30 minutes of aerobic exercise per week was also associated with lower waist circumference (mean difference, −0.56 cm; 95% CI, −0.67 to −0.45), body fat percentage (mean difference, −0.37%; 95% CI, −0.43 to −0.31), and body fat mass (mean difference, −0.20 kg; 95% CI, −0.32 to −0.08), along with reduced visceral and subcutaneous adipose tissue.
• A dose-response meta-analysis revealed that body fat percentage improved most significantly with 150 minutes of aerobic exercise per week, while body weight and waist circumference decreased linearly with increasing duration of aerobic exercise at 300 min/wk at different intensities.
• Adverse events with aerobic exercise were mostly mild or moderate musculoskeletal symptoms.

IN PRACTICE:

“Point-specific estimates for different aerobic exercise duration and intensity can help patients and healthcare professionals select the optimal aerobic exercise duration and intensity according to their weight loss goals,” the authors wrote.

SOURCE:

The study was led by Ahmad Jayedi, PhD, of the Department of Epidemiology and Biostatistics in the School of Public Health at the Imperial College London, London, England. It was published online on December 26, 2024, in JAMA Network Open.

LIMITATIONS:

High heterogeneity was present in the data. Only one trial included measures of health-related quality of life, and two studies included measures of medication use. Dietary habits and smoking status of participants were not included in studies, so any potential effects were not risk adjusted for.

DISCLOSURES:

No funding sources were reported. The authors reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.