On Ozempic, Wegovy, or Mounjaro? Don’t Just Lose Weight — Protect Your Muscle, Back, Knees, and Metabolism

By Dr. John Mishock, PT, DPT, DC 

 

 

Weight-loss medications such as Ozempic, Wegovy, and Mounjaro have changed the conversation around obesity, diabetes, and long-term health. For many people, these medications can be life-changing. They can help reduce appetite, improve blood sugar control, and support meaningful weight loss when prescribed and monitored appropriately. But here is the part that does not get talked about enough: losing weight is not the same thing as getting healthier.

Why Weight Loss Isn’t the Same as Health

The goal should never be simply to make the number on the scale go down. The real goal is to lose excess fat while protecting muscle, strength, joint health, posture, balance, and metabolism. This is where physical therapy, chiropractic care, strength training, and movement-based healthcare become essential.

What the Research Actually Shows About Muscle Loss

Research from major weight-loss medication trials shows impressive results. In the STEP 1 trial, semaglutide 2.4 mg led to significant weight reduction in adults with overweight or obesity (Wilding, et al., New England Journal of Medicine, 2021). Body-composition analysis also showed reductions in total fat mass and visceral fat, with improvement in lean-mass-to-fat-mass ratio (Wilding, et al., Journal of the Endocrine Society, 2021). More recently, body-composition data from the SURMOUNT-1 trial found that tirzepatide produced major weight loss, with roughly 75% of weight lost coming from fat mass and about 25% from lean mass (Look, et al., Diabetes, Obesity and Metabolism, 2025).

That matters because lean mass is not “extra weight.” Lean mass includes muscle, connective tissue, water, and other metabolically active tissue. Muscle is one of the body’s most important organs for glucose control, balance, mobility, posture, and long-term independence. When someone loses weight too quickly without strength training, adequate protein, and proper movement, they may look thinner but become weaker, less stable, and more prone to back pain, knee pain, falls, fatigue, and metabolic slowdown.

Why Lean Muscle Matters More Than the Scale

A major review in Advances in Nutrition concluded that weight-loss therapy should include adequate protein and increased physical activity, especially resistance exercise, to help maintain muscle mass, muscle strength, and physical function (Cava, et al., Advances in Nutrition, 2017). The same review found that both endurance and resistance exercise help preserve muscle during weight loss, but resistance training is especially important for improving strength.

This is especially important for people over 40, 50, and 60. As we age, we naturally lose muscle mass and power. Add rapid weight loss on top of that, and the risk of weakness increases. A clinical trial in older adults with obesity found that weight loss combined with both aerobic and resistance exercise produced the best improvements in physical function compared with weight loss alone or either exercise mode alone (Villareal, et al., New England Journal of Medicine, 2017).

How Weight Loss Affects Joints, Back, and Movement

The knees also deserve attention. Weight loss can significantly reduce stress through the knee joints. One well-known study found that each pound of body weight lost reduced knee-joint load by approximately four pounds per step in overweight and obese adults with knee osteoarthritis (Messier, et al., Arthritis & Rheumatism, 2005).

That is great news. But weight loss alone does not automatically correct poor mechanics, weak hips, limited ankle mobility, poor balance, or painful movement patterns. Those issues need to be assessed and trained.

The same is true for the spine. Losing weight may reduce mechanical load, but it does not automatically restore core strength, hip mobility, glute strength, spinal stability, or posture. Patients who lose weight but do not rebuild strength may still struggle with low back pain, sciatica-like symptoms, arthritis pain, or difficulty returning to walking, golf, pickleball, running, or exercise. This is why patients taking GLP-1 medications should consider seeing a physical therapist first — or at least early — before pain, weakness, or loss of function becomes a problem.

Why Physical Therapy Should Be Part of a GLP-1 Plan

Physical therapy is not only for injury recovery. It is preventive healthcare. It helps patients build the strength, mobility, balance, and confidence needed to make weight loss functional.

There is also strong evidence that early physical therapy can improve outcomes and reduce unnecessary healthcare utilization for low back pain. A large study of insurance claims found that patients who saw a physical therapist first for low back pain had lower odds of receiving opioids, advanced imaging, and emergency department care (Frogner, et al., Health Services Research, 2018). Another study found that early, guideline-adherent physical therapy for low back pain was associated with lower use of imaging, injections, surgery, opioids, and lower back-pain-related costs (Childs, et al., BMC Health Services Research, 2015).

The 4 Pillars of Protecting Your Body During Weight Loss

A smart GLP-1 plan should include four pillars:

1. Protect muscle. Strength training two to three days per week is critical. This does not mean bodybuilding. It means progressive, safe exercises for the hips, legs, core, back, shoulders, and posture.

2. Second, protect joints. As weight drops, patients need to retrain how they walk, squat, climb stairs, lift, and move. Less weight on the joints is helpful, but better mechanics are what make the improvement last.

3. Third, protect metabolism. Adequate protein, resistance exercise, and regular movement help preserve lean tissue and support long-term weight maintenance.

4. Fourth, protect function. The true measure of success is not just the scale. It is being able to walk farther, climb stairs easier, get off the floor, play with grandchildren, return to golf, avoid knee surgery, reduce back pain, and live with more energy.

The Real Goal Isn’t the Scale

Ozempic, Wegovy, and Mounjaro may help patients lose weight. But physical therapy and chiropractic care help patients use that weight loss to become stronger, healthier, and more resilient.

So if you are on one of these medications, do not just ask, “How much weight did I lose?”

Ask the better question: “Am I losing fat while protecting my muscle, my joints, my back, and my future?”

That is the real win. And that is why trying physical therapy first — or early — may be one of the smartest decisions you make during your weight-loss journey.

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We can help!

If pain is limiting you from doing the activities you enjoy, give Mishock Physical Therapy a call: locations in Gilbertsville (610-327-2600), Skippack (610-584-1400), Phoenixville (610-933-3371), Boyertown (610- 845-5000), Limerick (484-948-2800)  at www.mishockpt.com or request your appointment by clicking here.

Dr. Mishock is one of only a few clinicians with doctorate-level degrees in both physical therapy and chiropractic in the state of Pennsylvania. He has also authored two books; “Fundamental Training Principles: Essential Knowledge for Building the Elite Athlete”, “The Rubber Arm; Using Science to Increase Pitch Control, Improve Velocity, and Prevent Elbow and Shoulder Injury” both can be bought on Amazon or train2playsports.com.