We have always known that strength training is good for us, but when it comes to weight loss it is a mode of exercise that has always been overshadowed by cardio. However, a recent review and meta-analysis, coming out of the University of New South Wales (UNSW), sheds light on the power of resistance training in managing fat mass (Wewege, et al., 2022).

The study looked at the findings from 58 research articles that used accurate measures in body composition (DEXA, MRI, and CT scans) to look at the effects of strength training on the fat mass of more than 3000 participants. The analysis showed that even without any intervention for cardio exercise or dietary intake, the participants experienced a positive effect on fat mass with an average decrease of 1.4%.

The research study at UNSW highlights that strength training alone can effect a positive change in fat mass. This is great news for people who don’t enjoy cardio exercise but are looking to lose weight. It is also a helpful nudge for those who don’t currently complete strength training because they don’t believe it helps with decreasing fat mass.

With all that being said, there are still some things to consider with the current findings:

• On average there was a decrease in body fat of 1.4% which equated to ~0.5kg loss in fat mass. The participants completed 45-60mins of strength training on 2.7 days of each week and the interventions all lasted longer than 4 weeks but were closer to 5 months – this is nearly half a year of consistent strength training to achieve a small change in body fat (remember that this intervention did not change diet and cardio exercise to assist with fat loss – all of the effects came from strength training alone).
• The participants had no prior strength training experience. The effect size for someone with previous strength training experience might not be as great.
• There was no dietary intervention. This is crucial to see changes in fat mass from strength training alone but because there was no dietary control it also leaves the door open for participants to unintentionally alter their normal diet while they are completing an exercise program.

These are not reasons to throw the baby out with the bathwater, as strength training was still shown to have a positive effect on body fat. Regular strength training is also a powerful tool for a myriad of other health benefits: bone mineral density; muscle mass; strength; basal metabolism. Now there are even more reasons to include strength training as part of your weekly routine, as it becomes another pillar, next to regular cardio and appropriate calorie intake, in the management of excess fat tissue.

References

Wewege, M. A., Desai, I., Honey, C., Coorie, B., Jones, M. D., Clifford, B. K., Leake, H. B., & Hagstrom, A. D. (2022). The Effect of Resistance Training in Healthy Adults on Body Fat Percentage, Fat Mass and Visceral Fat: A Systematic Review and Meta-Analysis. Sports medicine, 52(2), 287–300. https://doi.org/10.1007/s40279-021-01562-2