You know that by hitting the treadmill before work and walking your dog every evening, you likely have less risk of type 2 diabetes than your buddy who's glued to the couch watching 'SportsCenter' nightly and is even too lazy to join you for golf. The connection between aerobic exercise and diabetes risk has long been established: Regular workouts equal less chance of disease. But until recently, weight training's role in staving off type 2 was murky at best.

Now, after studying 32,000 men over 18 years, Harvard scientists believe that lifting weights – independent of cardio – significantly lowers diabetes risk. In fact, they found that guys who weight-trained at least 30 minutes a day, five days a week, cut their chances by 34 percent. And the men in the study who weight-trained and did cardio regularly were a whopping 59 percent less likely to develop diabetes.

"One thing is clear: Combining weight training with aerobic exercise is the best way to improve glycemic control and reduce risk of type 2 diabetes," says Jose Antonio, professor of exercise science at Nova Southeastern University and CEO of the nonprofit International Society of Sports Nutrition.

The reason the hybrid strategy works is because each type of exercise is so different (kind of the way it feels when you're doing them in the gym, too). "Both types of exercise produce such disparate adaptations," Antonio explains. "Weight training, i.e., contracting skeletal muscles, results in larger and more powerful muscle fibers and helps promote the uptake of glucose into cells to be used for energy, while aerobic exercise improves mitochondrial volume density and fat burning capacity." Translation? "All of these improvements in body composition are key to optimal health and lower disease risk," says Antonio.

The scientists on the Harvard team concur that an aerobic–weight training combo is best, but they point out that many men don't have time to do both, or else struggle to stick with a regular cardio plan. If either scenario is the case for you – or your buddy – know that running, swimming, and paddling aside, pumping iron also does the body some serious long-term good.