Strength training does more than build muscle; it is the top choice for fat loss and raising basal metabolic rate.

When many people first start working out, they usually choose cardio such as running, swimming, or jump rope. Their goal is clear: lose fat, reshape their body, and get healthier. Strength training often is not part of the plan. The reason is that many people believe strength training is only for building muscle and has little to do with fat loss. But as they learn more about fitness, the truth turns out to be that strength training is the first choice for fat loss.

Strength training can raise metabolism. Research shows that regular strength training can increase basal metabolic rate—the rate at which the body uses energy while awake and at complete rest, free from the effects of muscle activity, environmental temperature, food, and mental stress—by 6.8% to 7.8%. That is because muscle burns more calories than fat. Each pound of muscle burns about 6 kcal a day, while each pound of fat burns only about 2 kcal. This means that if you add 5 pounds of muscle, you burn 30 more kcal a day, or 10,950 kcal a year.

Resting metabolic rate—the energy used to maintain normal body functions and internal stability, plus the energy used by sympathetic nervous system activity—is a measure similar to basal metabolic rate. After a period of strength training, resting metabolic rate rises significantly, so the body keeps burning more calories even if you sit still all day. A study of adults over 65 found that after 26 weeks of strength training, resting metabolic rate increased by 7%, equal to burning about 100 more kcal a day.

Strength training also promotes fat burning. The University of New South Wales in Australia published an article that included a research finding: strength training alone can reduce total body fat by about 1.4%, similar to the amount of fat that might be lost through aerobic exercise alone. This is because strength training stimulates growth hormone release.

Growth hormone is an important metabolic regulating hormone and can raise basal metabolic rate by 15% to 20%. Even more surprising, when high-intensity interval training (HIIT) is combined with strength training, growth hormone secretion can rise by as much as 450% in the 24 hours after training, and fat is burning at a furious rate.

Strength training can prevent muscle loss. During fat loss, skipping strength training can easily lead to muscle loss, which lowers basal metabolic rate, weakens fat-loss results, and can even cause a plateau. So if raising basal metabolic rate and growth hormone secretion sets the upper limit of the body’s calorie burning, preventing muscle loss protects the lower limit.

Once seen as a training method only for building muscle, strength training is now a powerful tool for fat loss. Compared with aerobic training alone, it has a higher ceiling, more room for variation, is more interesting, and produces more lasting fat-loss results.

Finally, if you have been doing aerobic exercise for a while and fat loss has started to plateau, try adding strength training. You may get results you did not expect.