ABOUT THE EXERCISE PHYSIOLOGIST

Patrick Service, M.S., ACSM-EP^® is an Exercise Physiologist and founder of YOUTRAINFITNESS^® in Durham, North Carolina.  With 30+ years of professional experience in exercise and fitness, Patrick specializes in helping individuals safely begin and maintain exercise programs, including those using GLP-1 medications for weight management.

He developed the SERVICE™ GLP-1 Exercise Framework, an evidence-informed, four-phase conceptual framework designed to organize exercise considerations throughout different stages of GLP-1 treatment.

His approach emphasizes strength, muscle preservation, physical function, fitness, sustainable physical activity and collaboration with healthcare professionals.

Learn more about Patrick Service

NEW RESEARCH: RESISTANCE TRAINING DURING TIRZEPATIDE TREATMENT HELPS PRESERVE LEAN TISSUE AND IMPROVE STRENGTH

Weight loss is about more than the number on the scale. For people taking GLP-1 medications, protecting muscle, maintaining strength and supporting long-term physical health are important parts of a successful weight-management journey.

A newly published randomized controlled trial in Nature Medicine provides compelling evidence that resistance training can make an important difference during treatment with tirzepatide (Mounjaro).

The 40-week study, conducted by researchers at the University of Western Australia, found that participants who combined tirzepatide treatment with regular resistance training lost approximately 25% less lean tissue and significantly improved their muscle strength compared with participants who took the medication without structured resistance exercise.

These findings reinforce an important message: successful weight loss should focus on preserving strength and physical function, not simply reducing body weight.

WHAT DID THE NEW RESEARCH INVESTIGATE?

The study, titled Resistance exercise to attenuate lean mass loss during tirzepatide therapy for obesity: a randomized controlled trial, was published in Nature Medicine on November 9, 2026.

Researchers wanted to understand whether adding structured resistance exercise to tirzepatide treatment could help protect lean tissue and maintain muscle strength during significant weight loss.

The trial included 120 adults with overweight or obesity. Participants were between approximately 50 and 70 years of age and did not have type 2 diabetes.

All participants received tirzepatide treatment for 40 weeks. They were then assigned to one of two groups:

Group 1: Tirzepatide Without Structured Resistance Training

These participants received tirzepatide and continued their usual activities without participating in the structured resistance training program.

Group 2: Tirzepatide Combined With Resistance Training

These participants received tirzepatide while also completing three supervised resistance training sessions each week.

Both groups received general guidance on hydration, protein intake and dietary fiber.

The researchers measured changes in body weight, fat mass, lean tissue and muscle strength throughout the 40-week intervention.

WHAT WERE THE RESULTS AFTER 40 WEEKS?

The findings demonstrated that both groups experienced substantial weight loss. However, there were important differences in lean tissue preservation and strength.

1. Both Groups Experienced Significant Weight Loss

After 40 weeks:

• The tirzepatide-only group lost an average of 22.61 kg.
• The tirzepatide and resistance training group lost an average of 22.28 kg.

The addition of resistance training did not significantly change the amount of weight lost.

This is an important finding because it suggests that resistance exercise can support better body composition and physical function without compromising overall weight-loss results.

2. Resistance Training Helped Preserve Lean Tissue

One of the most important findings involved changes in lean soft tissue.

The tirzepatide-only group lost approximately 4.67 kg of total lean soft tissue.

The group combining tirzepatide with resistance training lost approximately 3.57 kg.

This represents approximately 25% less lean tissue loss in the resistance training group.

Although resistance exercise did not completely prevent lean tissue loss, it significantly reduced the amount lost.

It is important to understand that lean soft tissue includes more than skeletal muscle. It also includes other non-fat tissues, so these measurements should not be interpreted as direct measurements of muscle mass alone.

3. Resistance Training Improved Muscle Strength

Perhaps even more encouraging were the changes in muscle strength.

Participants who combined tirzepatide with resistance training experienced improvements in upper- and lower-body strength.

The researchers reported strength increases of approximately 10–18% across the muscle groups tested.

In contrast, participants taking tirzepatide without structured resistance training experienced strength reductions of approximately 6–9%.

These results demonstrate why maintaining strength should be an important consideration during significant weight loss.

Preserving physical function can support everyday activities, independence, mobility and healthy aging.

WHY DOES MUSCLE PRESERVATION MATTER DURING GLP-1 WEIGHT LOSS?

GLP-1 medications and related treatments have transformed the management of obesity and metabolic health.

Medications such as semaglutide and tirzepatide can produce substantial weight loss. However, weight loss does not consist exclusively of body fat.

Some lean tissue is also lost during significant weight reduction, regardless of whether weight loss occurs through medication, dietary changes or other interventions.

Skeletal muscle plays several important roles in the body:

• Strength and mobility: Muscle supports walking, lifting, balance and everyday physical activities.
• Metabolic health: Skeletal muscle is an important contributor to glucose regulation and metabolic function.
• Healthy aging: Maintaining muscle strength and physical function becomes increasingly important as we age.
• Independence: Preserving strength can help people remain active and independent throughout their lives.

For individuals experiencing significant weight loss while taking GLP-1 medications, resistance training offers an important strategy for supporting these aspects of health.

WHY RESISTANCE TRAINING SHOULD BE PART OF A GLP-1 WEIGHT-LOSS STRATEGY

The new research reinforces the value of incorporating resistance exercise into a comprehensive weight-management approach.

Resistance training involves working muscles against an external resistance or your own body weight.

Examples include:

• Resistance machines
• Dumbbells and free weights
• Resistance bands
• Squats and other body-weight exercises
• Progressive strength-training programs

The objective is to provide muscles with an appropriate training stimulus to help maintain or improve strength and physical function.

The research intervention involved three supervised resistance training sessions each week. The program was progressive and individualized, with training intensity increasing over time.

This is an important distinction: the findings came from a structured, supervised exercise program, not simply occasional physical activity.

Exercise programs should be adapted to an individual’s abilities, health status, experience and medical considerations.

WHAT DOES THIS RESEARCH MEAN FOR PEOPLE TAKING GLP-1 MEDICATIONS?

The findings provide valuable information for individuals taking medications such as Mounjaro, Wegovy and other GLP-1-based treatments.

While medication can play an important role in weight management, it should not be viewed as the only component of a successful long-term health strategy.

A comprehensive approach should also consider:

1. Maintaining adequate nutrition and protein intake.
2. Incorporating appropriate resistance training.
3. Monitoring strength and physical function.
4. Supporting healthy movement habits.
5. Developing sustainable lifestyle behaviors that continue beyond active weight-loss treatment.

Patients should discuss their individual exercise and nutrition needs with their healthcare providers, particularly when starting a new exercise program or managing other health conditions.

How the Research Supports the SERVICE™ GLP-1 Exercise Framework

At YOUTRAINFITNESS^®, we believe that successful weight management should extend beyond losing pounds.

Our SERVICE™ glp-1 Exercise Framework provides an educational approach to understanding the importance of muscle preservation, strength development and long-term physical health during GLP-1-assisted weight loss.

The framework is built around four important phases:

BUILD

Develop a foundation of strength, movement skills and physical conditioning.

PRESERVE

Prioritize muscle preservation and maintain strength during significant weight loss.

PREPARE

Develop sustainable exercise habits and physical capabilities that support long-term health.

MAINTAIN

Continue prioritizing strength, movement and healthy lifestyle behaviors beyond the initial weight-loss phase.

The new Nature Medicine research provides valuable scientific support for the importance of resistance exercise during tirzepatide treatment.

Its findings reinforce the importance of looking beyond the scale and considering what happens to lean tissue, muscle strength and physical function during weight loss.

The SERVICE™ GLP-1 Exercise Framework translates these important educational principles into a practical conversation about supporting people throughout their weight-management journey.

IMPORTANT LIMITATION OF RESEARCH

Although these findings are encouraging, it is important to understand what the study does and does not demonstrate.

Several considerations should be kept in mind:

• The study involved 120 participants, primarily middle-aged and older adults between approximately 50 and 70 years of age.
• Participants received tirzepatide specifically. The findings should not automatically be assumed to apply identically to every GLP-1 medication.
• The intervention lasted 40 weeks, so longer-term outcomes require further research.
• Resistance training was supervised, individualized and performed three times per week. Results may differ with less structured exercise programs.
• Resistance training reduced, but did not eliminate, lean tissue loss.
• Lean soft tissue measurements are not equivalent to direct measurements of skeletal muscle mass.

The study provides strong evidence supporting the role of resistance exercise during tirzepatide-assisted weight loss, but it does not establish that every individual will experience identical results.

Further research will help clarify how different exercise approaches can best support people taking weight-management medications.

THE TAKEAWAY: WEIGHT LOSS SHOULD BE ABOUT MORE THAN THE SCALE

The new Nature Medicine study reinforces an important message for healthcare professionals, fitness professionals and individuals using GLP-1 medications.

Losing weight is one part of the journey. Maintaining strength, preserving lean tissue and supporting long-term physical function are equally important considerations.

The evidence demonstrates that combining tirzepatide treatment with structured resistance training can reduce lean tissue loss and improve muscle strength during significant weight reduction.

At YOUTRAINFITNESS^®, we believe education and appropriate exercise guidance should be important parts of the GLP-1 weight-management conversation.

Our SERVICE™ GLP-1 Exercise Framework and educational workshops help healthcare and fitness professionals better understand the importance of muscle preservation and resistance training during GLP-1-assisted weight loss.

Because the goal should not simply be to lose weight. It should be to build a stronger, healthier body along the way.

LEARN MORE ABOUT THE ROLE OF EXERCISE DURING GLP-1 TREATMENT

YOUTRAINFITNESS^® offers educational workshops designed to help healthcare and fitness professionals understand the relationship between GLP-1 medications, muscle preservation, resistance training and long-term health.

Explore our educational workshop:

PROTECT YOUR MUSCLES WHILE LOSING WEIGHT ON GLP-1 MEDICATIONS →

REGISTRATION NOW OPEN!

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ORIGINAL RESEARCH AND ADDITIONAL READING

Primary scientific publication:

Green, D.J., et al. (2026). Resistance exercise to attenuate lean mass loss during tirzepatide therapy for obesity: a randomized controlled trial. Nature Medicine.

https://www.nature.com/articles/s41591-026-04752-5

Additional news coverage:

News.com.au: New research reveals surprising effects of resistance training on GLP-1 users.

https://www.news.com.au/lifestyle/health/diet/new-research-reveals-effects-of-resistance-training-on-people-taking-glp1-drugs/news-story/220400f757560c0679ae58ec96874dab

Educational disclaimer: This article is intended for educational and informational purposes only. It is not medical advice and should not replace individualized guidance from a qualified healthcare professional. Individuals taking GLP-1 medications should consult their healthcare providers before making changes to their exercise or nutrition programs.

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Learn More About GLP-1 Exercise

For more detailed information about exercising while taking GLP-1 medications, visit our:

This resource center provides additional educational information about GLP-1 exercise, strength training, muscle preservation, progression, and related topics.

Exercise Physiology Services in Durham, NC

This GLP-1 exercise program is part of our Exercise Physiology Services in Durham, NC.

Link: Certified Exercise Physiologist in Durham NC