W hen it comes to resistance training, the general popula- tion can be divided into three categories: diehard muscle- heads, ambivalent folks who episodically lift between ex- tended sabbaticals, and diehard haters convinced dumbbells are perfectly named. A 2018 study in Medicine & Science in Sports & Exercise offers new information for all three groups. Lifting as little as once or twice a week for less than an hour in total is linked to a 40 to 70 percent reduction in cardiovascular disease events and deaths from any cause. Even better, such benefits come regardless of whether you get any aerobic exercise, let alone the oft-recommended 150 min- utes of moderate or 75 minutes of vigorous activity each week. “Until recently, resistance exercise has been understudied by the research community,” says DC Lee, a co-author of the study, an as- sociate professor of kinesiology at Iowa State University, and a longtime weightlifter. Most of the work that has been done has fo- cused on bone health, muscle function, and quality of life in old age. Lee and his colleagues are among the first to look past the mus- culoskeletal system to metabolic effects of resistance exercise. In two earlier studies published in Mayo Clinic Proceedings, they showed how lifting weights for less than an hour each week lowers the risk of diabetes and high cholesterol. For their 2018 study, they focused on resistance exercise and cardio- vascular disease–related problems and mortality by analyzing data from 12,591 individuals who had at least two clinical examinations at the Cooper Clinic in Dallas. Ranging in age from 18 to 89 at their first visit, the patients were assessed on a host of parameters, from BMI and blood pressure to glucose and cholesterol levels to lifestyle factors such as smoking, drinking, and exercise including resistance training. Although resistance training can take many forms—from stretch bands to heavy construction work—the investigators fo- cused on free weights and weight machines. Not surprisingly, most of the participants, like most Americans, availed themselves of neither option. Among those who did, the investigators divided them according to frequency (one, two, three, or four or more ses- sions per week) and total minutes each week (less than an hour, between one and two hours, and over two hours). “We then fol- lowed them for 5.4 years to assess all [cardiovascular disease] events and 10.5 years for all-cause deaths,” Lee says. Statistical analysis revealed a clear, U-shaped association be- tween quantity of resistance training and both cardiovascular dis- ease health and overall mortality. The greatest benefits went to those who took a modest to moderate approach to resistance training—once to thrice weekly and for less than an hour in total. Those in the highest category didn’t enjoy any additional benefits from their greater commitment—in fact, they fared little better than those who didn’t lift at all. As for why too much resistance training might be counterpro- ductive, Lee cites a 2013 meta-analysis in the British Journal of Sports Medicine that offers some possible mechanisms. Years of in- tense resistance training, for instance, can increase “arterial stiff- ness” and stimulate mild cardiac hypertrophy, or a thickening of the heart walls, both of which could set the stage for future cardiovas- cular disease problems. Another possibility: In people with undiag- nosed or untreated hypertension, the temporary but normal blood pressure spikes that occur during heavy lifts could be dangerous. Not that gym rats need panic. “In our study, we did not find any statistically harmful effects from doing higher levels of [resistance training],” Lee says. But the study design also didn’t look at mea- sures of intensity, such as high versus low weights and number of reps and sets. Until more is known, overly enthusiastic muscle- heads might want to consider a nod to moderation, in particular, substituting a bit more aerobic exercise for a bit less resistance training. “Although the data is limited,” Lee says, “most studies do indicate some additive benefits from doing both.” As for those who haven’t yet made any regular lifting a habit, Lee suggests those are the people with the most to gain. “Most benefits from any exercise, including [resistance training], go to those who start or add even a small amount of it,” he says. “You don’t have to spend loads of time lifting weights—just a couple sets once a week and for as little as five minutes can be effective.” Lee recommends two other keys to success. First, make sure to learn and use proper form to avoid injury. And second, join a gym. In a previous study, Lee and colleagues found that access to free weights and exercise machines—along with the social camarade- rie of fellow lifters—significantly increase the odds of sticking to the program.—JIM THORNTON Lift Up, My Heart CHECK-UP Research finds modest doses of resistance exercises do wonders for cardiovascular health and longevity The information in this department is not intended to be a substitute for professional or medical advice on personal health matters. For personal medical advice, or if you’re concerned about a medical condition or injury, see your health care provider for evaluation and care. HEALTHY SWIMMER BigStock/Parilov 14 usms.org