Activities like walking and lifting weights were both tied to a healthier weight, but combining the two may have the most benefits.
To stave off obesity, we might want to both stride and lift, according to an important, large-scale new study of how different types of exercise affect the incidence of obesity in America.
The study, which involved health records for almost 1.7 million men and women, indicates that people who exercise in almost any way are less likely to be obese than those who are sedentary. But the study also finds that the odds of being normal weight are greatest for those who complete both aerobic exercise and weight training, at least occasionally.
Obesity is one of the world’s most pressing health concerns. My colleague Jane Brody wrote recently about a new study showing that within a decade, half of all Americans may be obese. These soaring obesity rates are worrying in large part since the condition is linked to a range of other serious health concerns, including Type 2 diabetes, heart disease, arthritis, dementia and premature death.
Despite obesity’s prevalence and morbidity, though, its causes remain poorly understood. We know that nutrition and energy imbalance play outsize roles. But exercise and inactivity are involved as well, although their contributions are muddled. Exercise does not seem, for instance, to be very effective at helping most overweight people to drop pounds, probably because exercise tends to make people hungry.
More helpfully, exercise does seem to help many people avoid packing on pounds in the first place. In some past studies, adults who frequently walked or completed other physical activities were less prone to becoming obese during middle age than people who were sedentary.
But most of those studies involved relatively small groups of people or specific populations, such as female nurses or older men. In many of those studies, only relatively large amounts of exercise, such as an hour or more a day of walking, were tied to maintaining a healthy weight. And almost none examined the potential role of weight training in obesity prevention, leaving many questions unexplored about just how much and what kinds of exercise might correlate with the likelihood of obesity.