# The first randomised trial of lifting weights on a GLP-1 drug

> Source: https://peptidewellnessusa.com/news/tirzepatide-resistance-training-rct-november-2026/
> News · Research · November 2026
> By PeptideWellness Editorial Team · Updated November 11, 2026 · 3 min read

Everyone in the trial lost about 22 kg. The half who lifted weights three times a week lost 3.57 kg of lean tissue instead of 4.67 kg, and got stronger rather than weaker. It is the first randomised test of the advice every clinic gives.

Every weight-loss clinic tells patients on these drugs to do resistance training. Until this week that advice rested on trials of people losing weight by other means, and on the arithmetic of what happens to muscle when anyone loses 20 kilograms fast.

On November 9, 2026, *Nature Medicine* published the trial that tested it directly [1]. One hundred and twenty adults with overweight or obesity were put on tirzepatide, most of them titrated up to 15 mg a week, and randomised either to supervised resistance training three times a week or to carry on as usual. The trial ran 40 weeks. Attendance in the training arm was 91 percent, which is high enough that the result is about the exercise rather than about whether people can be made to do it.

## What the trial found

**Weight loss was the same in both arms.** Tirzepatide alone: 22.61 kg. Tirzepatide plus training: 22.28 kg. The difference was not significant [1]. Nobody lost more weight by lifting.

**Fat loss was the same.** 17.19 kg against 17.98 kg, again not significant, with the confidence interval running from 2.14 kg in favour of training to 0.60 kg against it [1].

**Lean tissue is where the arms separated.** The drug-only group lost 4.67 kg of total lean soft tissue; the training group lost 3.57 kg. The difference, 1.09 kg, was significant, and the same pattern held for arm and leg tissue specifically: 3.55 kg against 2.92 kg [1].

**Strength moved in opposite directions.** On tirzepatide alone, every measure fell: bench press down 4.09 kg, lat pulldown down 4.42 kg, knee extension down 4.42 kg. With training, every measure rose: up 4.68 kg, 8.58 kg and 5.88 kg [1].

That last pair of lines is the part a patient can feel. Roughly a quarter of the lean-tissue loss was prevented, which is real but partial; the change in what the body can actually do is the larger finding.

## How it fits what we already reported

In August we [went through the evidence](https://peptidewellnessusa.com/news/glp-1-muscle-loss-nestle-august-2026/) behind Nestlé's plan to sell protein products to GLP-1 users. The meta-analysis at the centre of that piece pooled 20 trials and 15,782 participants, and put lean tissue at 25.4 percent of the weight lost on tirzepatide, against 17.5 percent when weight was lost through lifestyle plus resistance training [2].

This trial lands close to that. Lean tissue was about 20.6 percent of the weight lost in the drug-only arm and about 16.0 percent with training added. The direction and the rough size both hold up, and now they hold up inside a single randomised comparison in people taking the drug.

What has changed in our August report is one sentence: the first trial of this combination in GLP-1 patients is no longer "running now". [LEAN-PREP](https://clinicaltrials.gov/study/NCT06885736) is still running, and it tests protein as well as training, but the training question has an answer [3].

## What it does not show

The trial was open-label: everyone knew which arm they were in, and strength tests are effort-dependent. It ran in Australia, in one programme, for 40 weeks, and three of its authors declare fees from Eli Lilly, which makes tirzepatide [1].

It also says nothing about the peptides sold for exactly this worry. A clinic offering sermorelin, ipamorelin or CJC-1295 "to protect muscle on a GLP-1" is selling something no trial has tested: searching PubMed on November 11, 2026 for any clinical trial of a growth-hormone secretagogue given alongside semaglutide or tirzepatide returns nothing at all [4]. The intervention with the randomised evidence is the one that costs a gym membership.

## References

1. [Green DJ, et al. Resistance exercise to attenuate lean mass loss during tirzepatide therapy for obesity: a randomized controlled trial. *Nat Med.* 2026. PMID 43003902. Trial registration ACTRN12623001236684.](https://pubmed.ncbi.nlm.nih.gov/43003902/)
2. [Lean-mass share of weight lost by intervention, meta-analysis of 20 randomised trials, as cited in our August report.](https://pubmed.ncbi.nlm.nih.gov/41877354/)
3. [ClinicalTrials.gov — LEAN-PREP, NCT06885736.](https://clinicaltrials.gov/study/NCT06885736)
4. [PubMed search, November 11, 2026: (tesamorelin OR sermorelin OR ipamorelin OR "CJC-1295" OR "growth hormone secretagogue") AND (semaglutide OR tirzepatide OR "GLP-1") AND clinical trialpt — no records.](https://pubmed.ncbi.nlm.nih.gov/)

> Editorial note: Informational only — not medical advice. Whether to start a resistance-training programme, and how, is a question for a clinician who knows your history.