The scale drops and you're delighted — but the question the scale never answers: what exactly did you lose?
The uncomfortable truth
When losing weight through diet alone, the literature indicates that 20–30% of the weight lost comes from fat-free mass (mostly muscle) without an exercise intervention[1]. A recent network meta-analysis of exercise modalities during caloric restriction found that only groups incorporating resistance training preserved or gained lean mass, while aerobic training alone was accompanied by significant lean-mass loss[1].
— without resistance training
muscle in the network analysis
for preserving muscle
And for those over fifty in particular
A systematic review and meta-analysis in older adults with obesity concluded that resistance training prevents the muscle loss caused by caloric restriction[2] — the most consequential point here: muscle lost after sixty does not come back easily, and with it goes balance and independence.
And what about weights for women?
A meta-analysis in postmenopausal and older women found that resistance training programmes improve muscle mass[3] — no "bulking", no masculine appearance, just protection against frailty and falls.
The practical prescription
- Two to three sessions a week is enough: not five days in the gym.
- Don't exceed a 500 kcal daily deficit: a severe deficit eats muscle however much you train[1].
- Protein is a mandatory partner: review your protein numbers — resistance without protein is half a solution.
- Start with body weight: squats, push-ups, stair climbing — no membership needed on day one.