Exercising has increasingly become popular with people looking to be fit and others lose weight. The fitness sector is expected to generate close to $80 billion in revenue this year. Although exercise has many benefits such as reduced diabetes risk and enhanced cardiovascular health there has been debate regarding its efficacy in weight loss.
Exercise may not be offering weight loss benefits
The debate revolves around the constrained total energy usage hypothesis, suggesting that exercise does not lead to significant calorie burning as the body compensates by reducing post-workout calorie use. Therefore, exercise may not aid weight loss despite its numerous health benefits.
However, obesity researchers dispute the hypothesis due to its reliance on observational research instead of randomized controlled trials (RCTs), which are considered the scientific evidence’s gold standard. RCTs have shown a positive correlation between exercise and weight loss, but the overall verdict remains mixed based on available evidence.
Proponent of the hypothesis emphasize the need to systematically review available evidence from RCTs. For instance a 2021 review of 100+ physical activity studies on weight loss in adults established that supervised exercise routine can lead to weight loss even if it is high-intensity interval training or aerobics.
Exercise doesn’t prevent regaining weight after dieting
Surprisingly this is not straightforward. Although the expectation is that extra physical exertion should help prevent regaining weight after lose, the results from randomized controlled trials from the 2021 review indicated otherwise. The study found that engaging in six to 12 months of resistance training or aerobic exercise, or both after dieting didn’t effectively prevent weight regain in adults.
In the 2021 review there was only one RCT on weight maintenance which offered objective compliance data which meant a trainer supervised the exercise sessions. The compliance rate for this exercise program, where participants had to exercise two to three times per week for a year, was 64%. Despite this effort, women in the RCT still regained the same amount of weight as those in the control group who did not participate in the exercise program.
