Strength training during weight loss: what does the research say?

In weight loss the aim is often lower fat mass. The body also consists of fat-free mass, which includes muscles. Researchers have examined whether strength training alongside dietary change can affect the loss of fat-free mass, fat mass and muscle strength [1][2].

This article reports what two reviews found. It is not a training programme and does not take a position on which diet suits the individual.

The review included 25 randomised studies of adults aged 18 to 65 with a body mass index of 25 or more. The studies compared diet-based weight loss combined with strength training with diet-based weight loss alone [1].

Total body weight was about the same in the groups, with a mean difference of 0.32 kg. Strength training protected against the loss of fat-free mass, with moderate certainty in the assessment, and gave a larger loss of fat mass, with high certainty. Muscle strength increased more in the group with strength training, but the certainty of this finding is low [1].

A review from 2021 gathered 12 systematic reviews and 149 studies on exercise in adults with overweight or obesity. Here strength training reduced the loss of fat-free mass during weight loss, with a mean difference of 0.8 kg [2].

The finding rests on a single systematic review, and the authors regard the evidence as limited [2].

The general recommendations for adults are strength training at least twice a week, with exercises for the large muscle groups [3]. The training can be done with weights, in machines, with body weight or with elastic bands, and regularity is regarded as the most important thing [3].

The recommendations apply to adults in general and are not drawn up specifically for people who are losing weight. The reviews above do not describe a particular programme that is best during weight loss either [1][2].

The meta-analysis found no effect of strength training on other cardiometabolic markers [1]. The studies do not say anything about the lasting effects of strength training during weight loss either, or about how much training it takes to see a difference.

Observational studies have linked strength training to a lower risk of disease and early death, with the strongest association at 30 to 60 minutes a week [4]. These are associations in groups of people, and they do not show that the training is the cause [4].

If you are unsure how to get started with strength training, a physiotherapist can map your needs and challenges and, together with you, make a plan that suits you. At Dr.Dropin, personal training and follow-up is also offered to those undergoing medical weight loss. You can read more on the page about physiotherapy during weight loss.

Do you lose muscle mass when you lose weight?

The reviews examine precisely the loss of fat-free mass, which includes muscle mass. In the 2025 meta-analysis, strength training protected against this loss, with moderate certainty in the assessment [1].

Does strength training give faster weight loss?

In the meta-analysis the change in total body weight was about the same with and without strength training. The group that did strength training did, however, have a larger loss of fat mass [1].

How often should I do strength training?

The general recommendations for adults are at least twice a week, with exercises for the large muscle groups [3].

Do I have to train at a gym?

No. The training can be done with weights, in machines, with body weight or with elastic bands. The most important thing is to train regularly [3].

The page about physiotherapy during weight loss describes how the follow-up works. You can find more articles in the overview of articles.

This article was written by Dr.Dropin Fysikalske and is based on the sources listed below. It gives general information and does not replace an examination by a healthcare professional.

The websites were accessed and read on 22 October 2026.

1. Binmahfoz A, Dighriri A, Gray C, Gray SR. Effect of resistance exercise on body composition, muscle strength and cardiometabolic health during dietary weight loss in people living with overweight or obesity: a systematic review and meta-analysis. BMJ Open Sport Exerc Med. 2025;11(3):e002363. doi:10.1136/bmjsem-2024-002363. Link

2. Bellicha A, van Baak MA, Battista F, et al. Effect of exercise training on weight loss, body composition changes, and weight maintenance in adults with overweight or obesity: an overview of 12 systematic reviews and 149 studies. Obes Rev. 2021. doi:10.1111/obr.13256. Link

3. Belander O. Styrketrening - viktig for helse og funksjonsevne (Strength training: important for health and functional ability). Tidsskr Nor Legeforen. 2026;146. Published 12 October 2026. Link

4. Johannessen T. Styrketrening gir lavere risiko for sykdom og død (Strength training gives lower risk of disease and death). NHI.no. Published and last updated 20 October 2022. Link