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Burn fat while gaining muscle: Weight training for weight loss

Believe it or not, you can lose weight by gaining muscle. Here's how to do it.

Many people exercise with the specific goal of losing weight. Exercise is a great way to burn calories, so it can help you generate the calorie deficit necessary to lose body fat. However, when it comes to choosing the best type of exercise to lose weight, most people assume that you really have to focus on cardio. While cardio exercise such as running, cycling, rowing, swimming, and stair climbing can all be great ways to burn calories, it’s also possible to lose weight by lifting weights. If you tend to gravitate towards strength training more than cardio workouts but still want to lose weight, keep reading to learn how to lose weight by strength training.

Can you lose weight lifting weights?

lifting weights with spotter.

One of the top weight loss tips that any health and fitness expert will recommend is to incorporate exercise into your weight loss program. Most people assume that this means cardio exercise rather than strength training, as it’s somewhat counterintuitive that you can lose weight lifting weights. After all, the goal of strength training is often to build muscle mass, and if you’re increasing your muscle mass, your body weight will increase. 

However, this assumption does not take into account that as long as you follow a healthy, calorie-controlled diet and do the right type of strength training workouts, you can burn calories through weightlifting workouts and lose weight at the same time.

How lifting weights can help you lose weight

Lifting weights in the mirror.

Strength training can be a really effective form of exercise for fat loss and body recomposition. Here are the ways in which resistance training workouts can help you lose weight.

Lifting weights burns calories

Like any form of exercise, strength training burns calories because your muscles need energy to contract, which requires burning stored fuel (glycogen and adipose tissue) to generate ATP (cellular energy).

The number of calories you burn in a strength training workout depends on numerous factors, such as your body weight and composition, the intensity of the workout, the specific exercises you perform, and the duration or training volume of the workout. 

You will burn more calories if you have a larger body size and a higher percentage of lean body mass relative to fat mass. In terms of the structure of your workout, you will burn more calories if you lift heavier loads relative to your one-repetition maximum (1RM, or the most you could possibly lift for one full rep) and take less rest. This is because both of these changes increase the intensity of the workout and elevate your heart rate, which in turn will increase your energy expenditure.

Finally, as long as the intensity doesn’t drop, the longer your resistance training workout lasts, the more calories you will burn. 

Given the numerous factors at play, it’s difficult to give specific guidelines as to how many calories you will burn in a strength training workout. However, Harvard Health Publishing reports that 30 minutes of “vigorous weight lifting” burns 180 calories for a 125-pound person, 216 calories for a 155-pound person, and 252 calories for a 185-pound person.

Since “vigorous weightlifting” is difficult to quantify, you can also use metabolic equivalents (METs) for strength training activities to estimate the number of calories burned. METs represent the energy expenditure of a given activity compared to that of sitting quietly, which is equal to 1.0 MET. The Compendium of Physical Activities reports that circuit training at a moderate effort is 4.3 METs, while resistance training doing squats is equal to 5.0 METs. Circuit training with kettlebells and aerobic exercises with minimal rest is 8.0 METs. Using these METs values and the equation for energy expenditure, you can calculate the number of calories burned while strength training based on your body weight and the duration of your workout:

Calories Burned Per Minute = METs x 3.5 x (your body weight in kilograms) / 200

For example, if you weigh 185 pounds (84 kg) and do resistance training with squats:

5 METS x 3.5 x 84 / 200 = 7.35 calories per minute.

Then, if you do a 45-minute workout, you multiply the number of calories burned per minute by 45 minutes. So: 7.35 x 45 = 331 calories.

Although this is not a ton of calories, you could certainly burn more calories if you weigh more and increase the intensity of your workouts. Because you need to burn approximately 3,500 calories to lose one pound of fat, it would take about 10 strength training workouts (about two weeks, depending on workout frequency) for you to lose one pound of body fat if you make no additional changes to your diet.

Lifting weights builds muscle mass

One of the primary benefits of lifting weights is that it can increase lean body mass by stimulating myofibrillar protein synthesis (MPS), which increases the size of your muscle fibers by reinforcing them with new proteins. 

Because muscle tissue is metabolically active tissue, increasing your lean body mass can increase your basal metabolic rate, meaning that you will burn more calories throughout the day, even at rest. This will make it easier to create the calorie deficit necessary to lose weight.

Lifting weights can support healthy lifestyle choices

If you start engaging in a structured weight training for weight loss program, you might find that you’re more inclined to make healthy dietary choices to support your workout. Although this isn’t a given, many people find that they feel more motivated to eat nutritious foods and eliminate excessive sugar, alcohol, and processed foods once they start trying to optimize their physique through strength training workouts.

How to lose weight by lifting weights

A male athlete lifting a dumbbell in a gym.

The following tips can help when you begin lifting weights to lose weight:

  • Be mindful of your diet and try to maintain a calorie deficit.
  • Wear a heartrate monitor so you can gauge the intensity of your workouts.
  • Lift the heaviest weights you can handle with proper form for 8–12 reps.
  • Perform compound, multi-joint exercises.
  • Consider circuit training or performing strength training exercises back to back to keep your heartrate elevated.
  • Increase the frequency and duration of your strength training workouts. Aim for two to three sets of 8–15 exercises per workout, performing 8–12 reps per set.
  • Supplement with cardio training for improved weight loss results and better overall health.

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