Losing just 5% to 10% of your body weight can improve your health if you are overweight. For a 150 pound person, that can be as little as 7.5 pounds. For a 200 pound person, it would be just 10 pounds.
But losing weight can be difficult. While there is recent research that challenges some of the old thinking about weight loss, the most common way to think about weight loss is that it requires a calorie deficit: you need to use up more calories than you consume in order to lose weight.
30 minutes of lifting weights will burn about 100 calories for the average 150-pound person. A 200-pound person will use up about 150 calories in the same amount of time. A Snickers bar contains over 200 calories. So if we look at the question with simple math, it looks like resistance training can’t be a big part of weight loss — it just doesn’t use up enough calories, right?
It’s not that simple
While much of the research on the subject shows that moderate exercise alone, without changing what you eat, will not usually lead to significant weight loss, it’s actually more complicated than that.
Resistance training is also called strength training. It is a type of exercise using weights, bands, or even your own body weight to increase resistance to movement. This causes your muscles to work harder.
One benefit of resistance training for weight loss is the “after-burn effect.” The official name for this is excess post-exercise oxygen consumption (EPOC). This means that muscles use more energy while we’re doing resistance training — but they also continue to use more energy after we finish. This is part of the process of muscle recovery.
Depending on the intensity of a workout, this effect can continue for hours or even days. In fact, there is evidence that regular strength training boosts resting metabolism over time. While it can take a year to see this kind of change, it can cause your body to use more calories on a regular basis.
Strength training also builds muscles, literally making them larger as they gain strength through regular resistance training. This process also boosts metabolism. Over time, regular strength training changes your metabolism and causes you to use more calories even when you are resting.
That’s why the fact that a 30-minute workout uses fewer calories than the number of calories in a candy bar is not the most important fact about resistance training and weight loss.
Resistance training can also strengthen bones and joints, an extra benefit. The same experts who recommend 150 minutes of cardio each week also suggest two strength training sessions each week as part of your regular exercise plan.
Getting started with resistance training
If you have not previously tried strength training or you have health concerns, talk with your doctor about how to get started safely. You might receive a referral to a physical therapist.
As a general rule, you should begin with a weight that allows you to lift 10 times with proper form. This could be soup cans, dumbbells, a kettlebell, or just the weight of your own body. For example, push-ups or push-aways from a wall let you use your own body weight to strengthen your arms, while squats or pliés work your legs.
Repeat your set of 10 lifts three times.
You can alternate upper body work on one day with lower body work the next day. You can also do both upper and lower body work on the same day, and then take a day off to let your muscles recover before your next session.
Over time, work your way up to heavier weights and more repetitions.