If you’re already working out with weights, keep reading so you can feel smug about all the benefits you’re getting. If you haven’t ventured into the weight room, here’s some extra incentive to do so.

It won’t even take that much time. You can get a solid strength workout in 20 to 30 minutes, and the American College of Sports Medicine says you only need two to three sessions a week. You don’t have to make a special trip to the gym either. Just cut back a little on the cardio to make room for strength training.

Here are five really good reasons to do so:

TO PROTECT YOUR BONES

Strength training is one of the best ways to maintain or increase bone density. Maybe you’re thinking, “I already jog or walk. Isn’t that enough?” It might be—for the lower half of your body.
But what about the rest of you? Working out with weights encourages bone to become denser and stronger. Here’s why: During strength training, muscles exert force on bones that stimulates new growth. A well-rounded strength program applies good stress to the bones of your hips, spine, arms, and wrists (common fracture sites in people with osteoporosis). The best possible time to build dense bones is before you reach age 35. But it certainly isn’t too late for women in their 50s and 60s. You can learn more from my post “Six ways to save your bones,” which lists the top six exercises for building strong, sexy bones.

TO METABOLIZE SUGAR BETTER

Researchers have done fascinating studies on the plusses of regular strength training for diabetics. The more healthy muscle tissue they have, the better their bodies handle blood sugar and manage insulin. But you don’t have to be diabetic to benefit. Studies on healthy men showed that they improved too. Subjects who performed regular strength training and put on a little muscle had significantly reduced blood insulin concentrations after consuming a good-sized dose of glucose. This makes a lot of sense. Glucose—blood sugar—is your muscles’ fuel. You build muscle, you need more blood sugar to feed it. And that brings me to point No. 3.

TO BURN MORE CALORIES ALL DAY LONG

The word metabolism is tossed around a lot, but what does it really mean? The simple answer is that metabolism equals the energy it takes to exist—to run all the bodily processes necessary to keep you alive. The energy cost, or number of calories, required for you to breathe, digest food, pump blood, and so on is your basal metabolic rate. Your daily activity also has an energy cost, and we’ll touch on that in the next section. I know that some of us females are terrified of gaining muscle, but we shouldn’t be. First, unless we’re taking steroids or human growth hormone, we’re not going to look like men. Second, unless our body fat is extremely low, we’re not going to display much muscle definition. But muscle is your friend, not least because the more you have, the more calories you burn all the time, even when you’re asleep or stretched out on the couch. In my report “Build a Faster Metabolism,” I explain it all in detail, while comparing hypothetical twins. One exercises regularly, and the other is sedentary. The active one has 11.5 pounds more lean muscle mass than her sister (and looks a hell of a lot better in a pair of shorts). The leaner twin has a basal metabolic rate that’s 115 calories higher than the couch potato, and that doesn’t even take into account how many more calories the active one burns every day through exercise. Over a year, 115 calories a day amounts to the energy equivalent of 12 pounds. Pretty significant, yeah? 

TO BURN MORE CALORIES AFTER A WORKOUT

Exercise of any kind is an essential weapon in our fat-burning arsenal. But did you know that you continue burning extra calories even after you’ve hopped off the treadmill or put away your bike? We’re talking about a phenomenon called excess post-exercise oxygen consumption, or EPOC. On days when you do cardio, your calorie burn is slightly elevated for up to several hours after you finish. But when you perform high-intensity strength training, your EPOC is even greater. As trainer and fat-loss expert Tom Venuto puts it in his book Burn the Fat, Feed the Muscle, “studies have shown increases in metabolic rate of as much as 4 to 7 percent over a 24-hour period from resistance training… . For someone with an expenditure of 2,500 calories per day, that could add up to 100-175 extra calories burned after your weight-training workout is over.” You can see how quickly adding even two strength-training sessions per week could boost your fat-loss results.

TO CREATE A BETTER SHAPE

Even if you’re not especially motivated by the idea of building strong bones or processing glucose better, I’ll bet you care how your butt looks in a pair of tight jeans. Ladies, nothing in this world can improve your shape like working out with weights. Want a firm and curvy rear end, lean legs, and shapely shoulders? Cardio can’t deliver them, but weights can. I know we tend to get anxious about the scale. But if you gained 10 pounds of muscle and lost 10 pounds of fat, your appearance would be significantly improved—even though the needle on the scale hadn’t budged. You’d be smaller, and your clothes would fit better because the 10 pounds of fat you burned were much bulkier than 10 pounds of lean, lovely muscle. Of course, it won’t happen overnight. For most women, adding muscle is a slow process. But while you’re patiently lifting weights to gain all their unique benefits, you might find you fall in love with the iron.

http://shesafitchick.com/2012/01/five-reasons-strength-training/