Strong muscles never sleep. While strength training doesn’t burn as many calories as the same amount of time you jog or swim, it does appear to have a bigger after-burn. Technically called “excess post-exercise oxygen consumption,” it is the extra calories you burn after an exercise session as your body returns to its normal state. Generally, the higher the intensity and the lengthier the workout, the longer this excess calorie burn lasts. That means the more strength training you do, the more calories you can burn even after you put the weights down. One study found that on non- exercise days following strength training, participants burned an average of extra 240 calories a day through everyday activities— significantly higher than on days following cardio.

Other studies confirm that strength training can increase your metabolic rate (the rate at which your body converts energy stored to working energy) by up to 15%. This means you burn more calories, even while you’re sitting or sleeping.

Like muscle mass, bone strength starts to decline earlier than you might imagine, slipping at an average rate of 1% per year after age 40—and even more steeply for menopausal women, who can lose up to 20% of bone mass in five to seven years in that phase of life. You can lose a fair amount of bone density and still remain in the normal range, but if bone loss occurs at a steeper rate, it can cause your bones to become weak and porous—a condition known as osteoporosis. Many studies have shown that weight-bearing exercise—defined as any exercise in which your body supports its own weight and works against gravity—can play a role in slowing bone loss. Several studies show it can even build a small amount of bone. Activities that put stress on bones stimulate extra deposits of calcium and nudge bone-forming cells into action. The tugging and pushing on bone that occur during strength and power training provide the stress. The result is stronger, denser bones. Walking or running protects only the bones in your lower body, including hips.

By contrast, a well-rounded strength training program that works out all the major muscle groups, can benefit practically all of your bones. Of particular interest, it targets bones of the hips, spine, and wrists, which, along with the ribs, are the sites most likely to fracture. 

While aerobic exercise provides more protection against diabetes than strength training does, the best protection comes when you do both types of exercise. According to an analysis done by the Harvard University of more than 32,000 men, who did 150 minutes of cardio a week, reduced their risk of developing type 2 diabetes by 52%. Those who did an equal amount of strength training cut their risk by 34%. But doing both cardio and strength training for the same duration – 150 minutes a week – reduced their risk by 59%. Similar research in women showed a 30% to 40% reduction. When diabetes does develop, strength training can help control it. One study of older adults with type 2 diabetes found that four months of strength training improved blood sugar control so much that 70% of the volunteers were able to reduce their dosage of diabetes medicine.

Strong muscles support and protect your joints, easing pain and stiffness and reducing your risk of developing osteoarthritis. Strength training may also enhance range of motion in many joints, so you’ll be able to bend and reach with greater ease. If you do develop osteoarthritis, strength training can ease pain and improve quality of life.

There are various other diseases like depression, side effects of cancer medicines, fibromyalgia, lyme etc where patients can benefit from strength training.

It’s time you make some investments in dumbbells. Having said that, you still need to do your cardio as aerobic activity is good for your heart, lowers your blood pressure, helps manage diabetes, leads to sound sleep, and results in better immune function and sharper mental function. Apart from strength training, a well rounded program should include aerobic activity, and flexibility & balance exercises. 150 minutes of aerobic cardio, 2-3 sessions of strength training (30-40 minutes each), dynamic stretching to warm up and static stretching to cool down, plus a few single leg exercises for balance, is an ideal weekly routine.