Weight training trumps cardio in battle of the bulge: study

A new study suggests weight training may be more important for weight control than aerobic exercise such as running. (holbox/shutterstock.com)

Weight training helped protect against expanding waistlines for healthy men in a new study at the Harvard School of Public Health, whereas those who skipped barbells for exercise that was strictly aerobic saw less impressive results.

"This study underscores the importance of weight training in reducing abdominal obesity, especially among the elderly," says senior study author Frank Hu, a professor of nutrition and epidemiology at HSPH. "To maintain a healthy weight and waistline, it is critical to incorporate weight training with aerobic exercise."

The research team selected participants who represented a wide range of sizes with varying body mass index (BMI). They followed their sample of 10,500 healthy US men aged 40 or over for a total of 12 years, starting in 1996 and ending in 2008.

To assess how to control age-related belly fat, the research team collected data on participants' physical activity, body weight and waist circumference, the latter being the most important for lead author Rania Mekary, a researcher in HSPH's Department of Nutrition.

"Because aging is associated with sarcopenia, the loss of skeletal muscle mass, relying on body weight alone is insufficient for the study of healthy aging," she says. "Measuring waist circumference is a better indicator of healthy body composition among older adults."

Participants who upped their moderate to vigorous aerobic exercise by 20 minutes per day reduced the gain on their waistlines by 0.33 cm whereas those who did the same with weight training reduced the gain by 0.67 cm.

Optimum results were seen in those who combined weight training and aerobic activity, and those who increased sedentary behaviors had a larger gain.

"Engaging in resistance training or, ideally, combining it with aerobic exercise could help older adults lessen abdominal fat while increasing or preserving muscle mass," says Dr. Mekary.

The study was published in the journal Obesity.