How do I keep my muscle while losing weight? Strength training and exercise on a GLP-1

Any way you lose a lot of weight, some of it is lean tissue, not just fat. About 25 to 30% of the weight lost can be lean mass, which includes water, organs and muscle, not only muscle. That's similar whether the weight comes off with a GLP-1 or through dieting alone. The medication isn't the problem; losing weight is the part that costs lean tissue. So anyone losing weight needs a plan to protect it.

Three tools protect your muscle

• Protein: eat at least your daily minimum (see How much protein do I need, and how do I hit it every day?).
• Strength training: this gives your body a reason to keep muscle. Without it, your body lets muscle go, and protein alone isn't enough.
• Creatine monohydrate, 5 g a day: supports strength and muscle, and helps keep lean mass during weight loss (see Which supplements does Belle recommend, and is creatine safe?).

You don't need a gym. A simple plan of strength work plus daily steps protects your metabolism and improves results.

Strength training: 2 to 3 days a week, 30 to 45 minutes

• Pick one setup: full body each session, upper and lower days, or push, pull, legs (chest and shoulders, back and arms, then legs).
• Starter moves: squats or sit-to-stands ×10 to 12, push-ups (incline if needed) ×8 to 12, hip hinges ×10 to 12, rows ×10 to 12, plank for 20 to 40 seconds. Do 2 to 3 sets.
• What matters more than the setup:
• Progressive overload: add a little weight, a few reps, or a set over time.
• Train close to failure: the last few reps of each set should feel truly hard. Easy workouts don't send the signal to keep muscle.
• Consistency: the best plan is the one you'll repeat.

Daily steps

Find your baseline, then add about 1,000 steps a week until you're at 8 to 10k most days. Everyday movement outside workouts (walking, chores, standing) burns more each day than planned exercise, and it protects your metabolism.

A 5 to 10 minute walk after meals is one of the most useful habits on a GLP-1. It lowers blood sugar for hours and eases digestion.

Cardio (optional, 2 to 3 days): 20 to 30 minutes at a pace where you can still talk in full sentences: a brisk walk, cycling, the elliptical, or swimming.

Mobility (daily, 5 to 10 min): hips, hamstrings, chest and shoulders. It improves posture and reduces aches as you get more active.

During dose increases: keep workouts lighter for 24 to 72 hours after an increase. If you feel nausea or fatigue, swap intensity for gentle walking or mobility and return to normal within a few days.

Fuel your workouts: your protein minimum, 2 to 3 L of fluids, electrolytes on hot or sweaty days, and 7 to 9 hours of sleep.

Do all three (protein, strength training, and daily movement) and you'll keep far more muscle, feel stronger, and usually keep the weight off better.