A 12-year study of 10,500 healthy men conducted at Harvard University and published in 2014 looked at which activity, from doing nothing, or virtually nothing, to weight training and aerobics had the biggest effect on body weight and waistlines.
It’s generally accepted that a combination of weights and aerobics has proven best for just about everything, from heart disease and diabetes to obesity and aging.
The Harvard study pinpointed the specific role of each form of exercise, although researchers in the United Kingdom were keen to urge effort over the differences between aerobic exercise and resistance exercise. The UK study said either is good, as long as the effort is high.
Looking at the Harvard study first, it’s notable that most previous studies tend to concentrate on specific groupings, whether it be people aged 50 and above, just overweight persons, people with diabetes and the like. Yet this study simply concentrated on average, healthy males.
The Harvard study found that substituting 20 minutes of weight training for any other activity had the strongest association with less increase in waistlines. Substituting 20 minutes of moderate to vigorous aerobic activity had the strongest association with less gain in body weight. It would be no surprise that those who increased their sedentary behaviors had the largest increase in waistline circumference and body weight.
Again, it would not be surprising that the study showed that long-term weight training is associated with less increase in waist size, while aerobic activity is associated with less gain in body weight.
As we age we suffer the loss of skeletal muscle mass, a process known as sarcopenia. So, measuring waist circumference is a better indicator of healthy body composition among older adults.
As the study leader said, “Engaging in resistance training or, ideally, combining it with aerobic exercise could help older adults lessen abdominal fat while increasing or preserving muscle mass.”
Quite simply, weight training builds and preserves muscle mass. This, in turn, increases metabolism, no matter how old you are, and this burns belly fat and contributes to healthy aging.
The reason weight training achieves the burning of more belly fat is because of the need to make a concerted effort.
Properly done, time efficient weight training done with effort causes greater Excess Post-exercise Oxygen Consumption than does aerobics. This difference in oxygen consumption can extend up to 48 hours after exercise.
Very important is that the after-workout energy burn is mostly fat. The calories burned during a weight training session are mainly carbohydrate, but those burned afterward are mostly fat.