Why I Now Prescribe Weightlifting Alongside Weight-Loss Drugs and Surgery

If you have followed my recent articles on medications like bimagrumab and apitegromab, you already know that muscle loss during rapid weight loss is one of the biggest concerns I discuss with patients starting GLP-1 therapy or recovering from bariatric surgery. A comprehensive 2026 review pulling together the evidence on resistance training in people with obesity reinforces something we can act on today, without waiting for any new drug: structured resistance exercise is one of the most effective tools we already have to make weight loss higher quality, not just faster.

Why "how much weight" is the wrong question

When patients ask me how much weight they should expect to lose, I try to redirect the conversation toward what kind of weight they lose. Rapid weight loss — from calorie restriction, medication, or surgery — typically comes from a mix of fat and lean tissue, and depending on the method and pace, lean mass (mostly muscle) can account for a meaningful share of the total, sometimes 25% or more of weight lost. Muscle is not just about strength and appearance; it is your body's primary site of glucose disposal, a major driver of resting metabolic rate, and a key determinant of physical function and fall risk as we age. Losing large amounts of muscle alongside fat can blunt some of the metabolic benefit of weight loss and set patients up for frailty later, particularly older adults and those losing weight quickly on high-dose incretin therapy.

What the evidence shows

The recent evidence synthesis on resistance training and weight loss draws on multiple randomized trials and systematic reviews and reaches a consistent conclusion: adding structured resistance exercise to a weight-loss program — whether diet-based, medication-based, or post-surgical — preserves significantly more lean mass than diet or medication alone, without meaningfully slowing fat loss. In several trials, combining resistance training with aerobic exercise produced the best overall body-composition outcomes, improving not just muscle preservation but also strength, physical function, and markers of cardiometabolic health such as blood pressure and lipid profile. Importantly, this benefit does not require elite-level training: supervised programs using standard resistance machines or even bodyweight and resistance-band exercises, performed two to three times weekly, have shown measurable benefit in adults with obesity, including those with additional cardiometabolic risk factors.

Why this matters even more in the GLP-1 era

This evidence arrives at a particularly relevant moment. As more patients achieve large, rapid weight losses with tirzepatide, semaglutide, and newer agents, the absolute amount of muscle at risk of being lost alongside fat has grown — simply because more weight is coming off, faster, than was typical with lifestyle intervention alone. Several pharmaceutical companies are, as I have discussed previously, now developing muscle-preserving add-on drugs specifically to address this. But resistance training is available today, requires no prescription, has an excellent long-term safety record, and — unlike an add-on medication — comes with its own independent benefits for mood, bone density, and long-term functional independence.

What I actually recommend

For patients starting a GLP-1 or dual-agonist medication, or preparing for bariatric surgery, I now routinely discuss resistance training as part of the treatment plan, not an optional extra. A reasonable starting target is two to three sessions per week of structured resistance exercise — working the major muscle groups (legs, back, chest, shoulders, core) — combined with adequate dietary protein intake to give the body the raw material it needs to preserve muscle during a calorie deficit. This does not need to happen in a gym with heavy free weights from day one; resistance bands, bodyweight exercises, and supervised sessions with a physiotherapist or qualified trainer are all reasonable starting points, particularly for patients with joint disease or mobility limitations related to their weight. If you are on a weight-loss medication or considering surgery, ask your care team to help you build this into your plan from the start, rather than as an afterthought once weight loss has already begun.

Source: Systematic evidence synthesis on resistance training for weight-loss quality and cardiometabolic health in adults with obesity, Frontiers in Endocrinology (2025–2026).