Exercise
What exercise can and cannot do for weight loss — and where it matters most.
Quick read · 2 min
- •Exercise alone produces modest weight loss (~1.6 kg at 6 months in meta-analyses)
- •Where exercise matters most: metabolic health, muscle preservation, cardiovascular fitness, and mental health
- •Resistance training is especially important during weight loss to preserve lean mass
- •Combined with diet or medication, exercise significantly improves outcomes and body composition
Based on clinical trials · No rankings · Every claim linked to source
Last reviewed: April 2026
Exercise for weight loss
What randomised trials show about aerobic exercise for fat loss — the dose required, and why diet plus exercise outperforms either alone.
Exercise for metabolic health
How exercise improves insulin sensitivity, blood pressure, and lipid profiles independently of weight loss.
Resistance training & muscle preservation
On GLP-1 drugs, approximately 25–40% of weight lost comes from lean mass. Resistance training is the most effective counter-strategy.
Types of exercise — what works
Aerobic, resistance, HIIT, and combined training — what each does and when to prioritise each approach.
Next step most people take
If you're taking weight loss medication
Exercise shifts from "a way to lose weight" to "the way to protect your body while losing weight." GLP-1 and dual agonist drugs produce significant weight loss, but approximately 25–40% of that loss comes from lean mass — muscle, bone density, organ tissue — not just fat.
Resistance training is the single most effective counter. Across clinical trials, it consistently preserves lean mass during rapid weight loss, regardless of how the weight loss is achieved. This is not lifestyle advice — it is one of the most well-supported findings in the entire field.
If you are on a GLP-1 or similar medication and doing no resistance training, you are likely losing more muscle than necessary. See the full evidence on muscle preservation →
When to reconsider
If exercise and diet changes have not achieved the results you are looking for, prescription medications may be worth discussing with your doctor. See all prescription options →