Strength Training for Weight Loss: Why Lifting Weights Helps

By the Medsmingle Team · Updated 13 November 2026

Most weight loss comes from eating fewer calories, but strength training helps make sure the weight you lose is fat rather than muscle. In older adults with obesity, adding resistance training to a lower-calorie diet prevented about 93% of the muscle loss that dieting alone caused. US guidelines recommend muscle-strengthening activity on at least 2 days a week.

Why muscle matters when you lose weight

When you cut calories, some of the weight you lose can be muscle rather than fat. Holding on to muscle helps you stay strong for everyday tasks, which matters more as you get older.

What the research shows

A 2018 review of six randomized trials in older adults with obesity compared calorie restriction with and without resistance training. Adding resistance training prevented about 93.5% of the lean (muscle) mass lost through dieting alone. Fat loss and total weight loss were about the same either way, so strength training changed what kind of weight people lost, not how much.

Does strength training burn fat?

It burns calories, but on its own it isn’t the main driver of weight loss. The CDC notes that most weight loss comes from eating fewer calories, and that you’d need a high amount of physical activity to lose weight without changing your diet. Strength training works best alongside a calorie deficit. See how to set yours in our guide to calorie deficits.

How much should you do?

• Muscle strengthening: at least 2 days a week, working all the major muscle groups: legs, hips, back, chest, abdomen, shoulders and arms.
• Aerobic activity: 150 to 300 minutes of moderate activity, such as brisk walking, each week.
• Move more and sit less through the day.

To keep weight off, you may need more than these minimums. The amount varies a lot from person to person.

Sets and reps, explained

Doing an exercise 8 to 12 times in a row (8 to 12 repetitions, or “reps”) counts as one set. Aim for at least one set of each exercise; two or three sets give even more benefit. Each set should be hard enough that you’d struggle to do another rep without help.

It doesn’t have to mean a gym. Lifting weights, resistance bands, body-weight exercises such as push-ups or sit-ups, digging in the garden and some yoga poses all count.

How to start

• Begin with your own body weight: squats, wall push-ups, lunges and step-ups.
• Move on to resistance bands, dumbbells or gym machines.
• Choose a weight you can lift with good form, and increase it slowly as the exercise gets easier.
• Combine strength sessions with walking. Our guide to walking for weight loss shows how to build up.
• Eat enough protein to support your muscles. See how much protein for weight loss you need.

A simple starter routine

Twice a week, for example on Monday and Thursday, do one set of 8 to 12 reps of each: squats, lunges, wall push-ups and a resistance-band row. Together they work most of your major muscle groups. Add a second set, then a third, as you get stronger.

Stay safe

If you have heart disease, joint problems or another long-term condition, or you haven’t been active for a while, talk to your doctor before starting. Start light, and stop if you feel chest pain, dizziness or sharp pain.

Frequently asked questions

Is cardio or strength training better for weight loss?

Both have a place. US guidelines recommend aerobic activity and muscle strengthening every week, and strength training helps protect your muscle while you lose weight.

Can I do strength training at home?

Yes. Body-weight exercises such as squats and push-ups count, and so do resistance bands.

Why am I not losing weight even though I exercise?

Most weight loss comes from eating fewer calories, so look at your diet as well. If your weight has stopped moving for several weeks, read about the weight-loss plateau.

How many days a week should I lift weights?

At least 2 days a week, working all your major muscle groups, with 8 to 12 reps in each set.

Sources

• Resistance training prevents muscle loss induced by caloric restriction in obese elderly individuals: a systematic review and meta-analysis, Sardeli AV et al., Nutrients (2018)
• Top 10 Things to Know About the Physical Activity Guidelines for Americans, US Department of Health and Human Services
• What Counts as Physical Activity for Adults, Centers for Disease Control and Prevention (CDC)
• Physical Activity and Your Weight and Health, CDC

This article is for general information only and isn’t a substitute for advice from a doctor or pharmacist. Don’t start, stop or change a medicine without talking to a qualified healthcare professional.