Even if you walk daily, you might control your weight better by practicing weightlifting at least twice per week, according to new research. In a study published in the journal Obesity, people who did the recommended amount of aerobic exercise (150 minutes or more per week of an activity like walking) were 28% less likely to be obese. Those who did the recommended amount of muscle-strengthening exercise (two or more sessions of weightlifting per week) were 30% less likely to be obese. But people who did the recommended amount of both forms of exercise had the lowest odds of obesity — they were 50% less likely to be obese.
The Australian study was the first to analyze associations between aerobic exercise, muscle-strengthening exercise and obesity in such a large sample of adults (1.7 million people). “Up until 2008, physical activity guidelines [including World Health Organization guidelines and the Physical Activity Guidelines for Americans] exclusively recommended aerobic exercise — it is only within the last decade that muscle-strengthening exercise has been included in physical activity guidelines,” says study author Jason Bennie, PhD, a senior research fellow at the University of Southern Queensland in Australia.
“I believe resistance training and aerobic exercise work at different mechanisms at the muscular cellular level, like taking two different medications,” says Dr. Tim Church, MPH, PhD, professor of preventive medicine at Pennington Biomedical Research Center at Louisiana State University. You may build more muscle from the combined exercise regimen, which could be a contributing factor.
“There is some clinical evidence that doing both muscle-strengthening and aerobic exercise may result in an increased muscle mass, which leads to increased metabolic rate and/or total energy expenditure,” Bennie says.
OTHER HEALTH BENEFITS
People who walked on a treadmill for roughly 110 minutes each week and did muscle-strengthening exercises with weights twice a week for about 15 minutes each were able to lose about 3.7 pounds and lower their A1C numbers (which measures someone’s average blood sugar levels over the previous 3-month period) by 0.3 to 0.4 over a 9-month period. When people only did one type of exercise (aerobic or muscle-strengthening), the impact on A1C wasn’t as great.