Strength training while losing weight on a GLP-1 medication

Many patients starting a GLP-1 medication have never lifted a weight. Resistance training can be started at home, with bodyweight exercises, a backpack or resistance bands.

Why does resistance training matter during medical weight loss?

A GLP-1 medication such as Mounjaro, Wegovy or Foundayo reduces appetite and food intake, which creates a calorie deficit. Larger calorie deficits can increase the amount of lean tissue lost alongside body fat. Resistance training places a load on muscle, which helps the body to keep it during a calorie deficit.

A study in the International Journal of Obesity measured a decrease in resting metabolic rate of around 101 calories a day in adults who lost around 8 kg over a year. It attributed roughly 60% of that decrease to the loss of energy-expending tissue and roughly 40% to metabolic adaptation. One finding from the study is often reported in reverse. The researchers found no significant association between skeletal muscle loss and the reduction in resting metabolic rate, meaning that preserving muscle does not prevent this decline. Preserving muscle remains important for strength, physical function and maintaining a healthier body composition. Our article on muscle loss on a GLP-1 medication covers muscle loss during treatment in more detail.

What do the studies show?

A retrospective study of 304 adults on a calorie-restricted diet, published in Frontiers in Endocrinology, found that resistance training produced the greatest reduction in fat mass and was the only form of exercise associated with an increase in fat-free mass. The aerobic-only and no-exercise groups in that study did not show the same protection of lean tissue. The study was retrospective, so it shows an association and cannot prove cause and effect.

A review in the journal Nutrients concluded that higher protein intakes help protect fat-free mass and skeletal muscle mass during weight loss, either on their own or together with exercise. A retrospective study of 267 patients on a very low calorie formula diet, published in Nutrients in 2024, found no significant difference in lean mass loss over 12 weeks between around 1.0 g and around 1.5 g of protein per kg of body weight. The evidence therefore supports resistance training and adequate protein together.

How often, and how much?

Aim for muscle-strengthening exercise at least twice a week, alongside regular aerobic activity. US physical activity guidelines recommend 150–300 minutes of moderate-intensity activity weekly. Two sessions a week covering the main movement patterns is a reasonable starting point during weight loss. Two to three sessions a week can help preserve muscle.

A session does not need to be long. Twenty to thirty minutes covering the main movement patterns, with enough effort that the last few repetitions of each exercise feel hard, can be enough for a beginner.

Where do you start if you have never trained?

Compound movements

Compound movements use several joints and muscle groups at once, which makes them an efficient use of a short session. A beginner session covers six patterns, each of which can be done at home:

• Squat: a chair squat or bodyweight squat
• Hinge: a hip hinge with a backpack or a kettlebell
• Push: a wall or incline push-up
• Pull: a band row or a doorframe row
• Carry: walking with a loaded bag in each hand
• Core: a plank held for a comfortable time

Two or three sets of eight to twelve repetitions of each, twice a week, can form a full programme for the first months. Your lifestyle coach can adapt the exercises to any joint problem or previous injury.

Progressive overload without a gym

Muscle adapts to a demand that increases gradually. Without a gym, the demand increases by adding repetitions, adding a set, slowing the movement, or adding weight to a backpack or using a heavier band. Outdoor training is difficult during the hotter months in the UAE, and home-based sessions avoid the heat.

How do you train when your appetite and energy are low?

Reduced appetite is an intended effect of the medication. Lower energy can follow, particularly in the first few days at a new dose. Training with nausea on an empty stomach can be difficult, and these adjustments can help:

• Train on the days furthest from your injection day if side effects cluster after it
• Eat a protein-containing meal or snack two to three hours before a session
• Keep sessions to twenty to thirty minutes on low-energy days
• Drink water before and during the session
• Use a lighter weight on low-energy days

If side effects persist beyond the first two weeks at a dose, raise it at your follow-up. Your endocrinologist can adjust the pace of dose increases and, where needed, prescribe medication to help manage these side effects.

Is walking enough?

Walking is valuable for health. It contributes to the 150 to 300 minutes of aerobic activity the guidelines advise, supports cardiovascular health and blood sugar control, and is easy to maintain on a low-energy day. Walking does not place muscle under the same load as resistance training. In the study above, aerobic exercise alone was not associated with a comparable increase in fat-free mass. Walking therefore complements strength sessions.

How do protein and training work together?

Adequate protein and resistance training can help preserve muscle while you lose weight. General guidance such as the International Society of Sports Nutrition suggests roughly 1.2 to 1.6 g of protein per kg of body weight per day for people losing weight. Endocare’s lifestyle coaches will personalise that figure from your body composition analysis. They will also help you adjust your usual meals to reach it with practical swaps.

In the formula diet study above, lean mass fell in both protein groups during a very large calorie deficit. Protein alone may therefore not be enough to protect muscle, and resistance training remains important alongside it.

How does Endocare track whether it is working?

At Endocare, body composition analysis is included free of charge at every consultation. Body composition analysis estimates body fat, muscle mass and body water. Repeated measurements help your endocrinologist understand how your body is changing beyond the number on the scale. Where repeated measurements show weight falling while skeletal muscle mass holds steady, the loss is likely to be mostly body fat. Where they show muscle mass falling alongside body fat, your endocrinologist and lifestyle coach will review your protein intake, your training and the rate of weight loss.

Muscle beneath the skin may also influence how an area looks as weight comes off, which is one of the factors covered in our article on loose skin after weight loss.

Frequently asked questions

Should I lift weights while on a GLP-1?

Yes, where your endocrinologist has no reason to advise otherwise. Resistance training was the only form of exercise associated with an increase in fat-free mass during calorie restriction in a study of 304 adults.

How often should I train?

We recommend two sessions a week to start, in line with the Physical Activity Guidelines for Americans, which advise muscle-strengthening activity on at least two days each week. Two to three sessions a week can help preserve muscle during weight loss.

Is walking enough?

Walking is valuable for general health. It does not load muscle in the way resistance training does, so on its own it is not enough to help preserve muscle during weight loss. The two complement each other.

What if I have no energy?

We recommend a shorter session on low-energy days, a protein-containing meal two to three hours beforehand, and training on the days furthest from your injection if side effects cluster after it. If low energy persists beyond the first two weeks at a dose, raise it with your endocrinologist.

Do I need a gym?

A gym is not necessary. Bodyweight versions of the six movement patterns, a backpack, resistance bands or a pair of adjustable dumbbells allow steady progress at home. Training at home also avoids the summer heat in the UAE.

How will I know if it is working?

Body composition analysis at your monthly follow-up estimates skeletal muscle mass and body fat percentage, and repeated measurements help show whether training is helping to preserve muscle. You may also notice your strength improving from week to week.