Strength training on GLP-1 treatment: why it matters and how to start

Why muscle is part of the conversation

When your weight goes down, it isn’t only fat that goes: some lean mass goes too, which includes muscle, water, organs and bone. This happens with any way of losing weight, and in the studies of semaglutide and tirzepatide, the share of lean mass in the weight lost was similar to the others.

What changes on treatment is appetite. With less hunger, meals get smaller and protein falls short without you noticing. That combination is where muscle loss matters most.

Two pillars: the signal and the building material

Strength training is the signal: it’s what tells your body to hold on to muscle. Protein is the building material, and it helps to spread it across the day’s meals, starting your plate with it when you’re not very hungry.

Your protein goal is the one you set with the people who care for you, and if you have kidney disease, you need a goal of your own, decided with your care team.

How much per week

There are two references. The World Health Organization recommends muscle-strengthening exercise at least twice a week. The joint advisory on nutrition in GLP-1 treatment, from four American nutrition and obesity societies, suggests three times.

Along with strength training, the reference is at least 150 minutes of moderate aerobic activity a week. And a daily walk also helps your bowels when you’re constipated.

How to start

Your starting point is what you can do today, not what the recommendations ask for down the road.

• Pick two or three days a week for strength training, and start with what your body can handle right now.
• On training days, include protein in your meals and drink water throughout the day: exercise calls for more water.
• When you’re not very hungry, a meal or snack with protein still helps, especially when you feel tired.
• On a day when you feel weak or tired, rest or train lightly, and get back to your usual routine when your energy returns.
• If you feel dizzy, sit or lie down until it passes, and get up slowly.