Why preserving muscle—not simply losing pounds—may become one of the most important advances in Exercise Oncology.
The arrival of highly effective GLP-1 medications and next-generation obesity treatments has transformed how physicians think about weight management. New drugs such as semaglutide, tirzepatide, and investigational multi-receptor therapies can produce levels of weight loss once achievable only through bariatric surgery. Yet a recent commentary by diabetes and obesity expert Dr. Robert Gabbay argues that medicine has reached a pivotal moment: the conversation should no longer focus on “How much weight can we lose?” but rather, “How do we improve health while preserving muscle?”
For cancer patients and survivors, this shift could not be more important.
Cancer Patients Face a Different Challenge
Many individuals diagnosed with cancer experience changes in body composition long before they notice changes on the scale. Chemotherapy, radiation therapy, surgery, endocrine therapy, immunotherapy, chronic inflammation, inactivity, poor nutrition, and aging all contribute to the progressive loss of skeletal muscle—a condition known as sarcopenia.
Unlike obesity alone, sarcopenia directly affects how patients live, function, and respond to treatment.
Research has consistently shown that reduced muscle mass is associated with:
- Increased chemotherapy toxicity
- Greater postoperative complications
- Reduced tolerance of cancer treatments
- More fatigue and physical disability
- Loss of independence
- Poorer quality of life
- Increased all-cause and cancer-specific mortality
In Exercise Oncology, preserving muscle has become just as important as treating the cancer itself.
Not All Weight Loss Is Healthy Weight Loss
One of the most important observations highlighted by Dr. Gabbay is that 25–40% of rapid weight loss may come from lean body mass rather than body fat.
That statistic should capture the attention of every oncologist.
Many cancer survivors are now candidates for GLP-1 medications because of obesity, diabetes, cardiovascular disease, or metabolic syndrome. While these medications offer tremendous health benefits, they also raise an important clinical question:
Can patients lose fat while preserving the muscle they need to fight cancer and maintain independence?
The answer increasingly appears to depend on whether structured exercise and proper nutrition accompany medical therapy.
Exercise Oncology Provides the Missing Piece
Exercise Oncology was built around the principle that muscle is medicine.
Decades of research now demonstrate that appropriately prescribed exercise can:
- Preserve skeletal muscle during treatment
- Increase muscular strength
- Reduce cancer-related fatigue
- Improve balance and mobility
- Enhance treatment tolerance
- Improve insulin sensitivity
- Reduce inflammation
- Improve quality of life
- Potentially improve long-term survival
Among all forms of exercise, progressive resistance training remains the most effective strategy for protecting lean body mass. When combined with aerobic exercise and adequate dietary protein, resistance exercise becomes a powerful countermeasure against treatment-related sarcopenia.
For patients receiving GLP-1 medications, these interventions become even more important.
Precision Medicine Should Include Precision Exercise
Dr. Gabbay argues that obesity medicine is moving toward individualized treatment rather than one-size-fits-all prescribing. The same philosophy has guided Exercise Oncology for years.
Every cancer patient differs in:
- Cancer diagnosis and stage
- Age and frailty
- Treatment regimen
- Nutritional status
- Functional capacity
- Existing muscle mass
- Medical comorbidities
- Personal goals
Exercise prescriptions should be individualized just as carefully as chemotherapy or targeted therapies. The most successful programs combine physician oversight with exercise physiologists, physical therapists, dietitians, behavioral health professionals, and rehabilitation specialists working together to create personalized care plans.
Body Composition Is More Important Than Body Weight
Traditional medicine has relied heavily on body weight and body mass index (BMI). However, these measurements tell only part of the story.
Two patients with identical BMIs may have dramatically different proportions of muscle and fat. One may be physically strong and metabolically healthy, while the other has severe sarcopenia hidden beneath excess body fat—a condition known as sarcopenic obesity.
Future cancer care should routinely assess:
- Skeletal muscle mass
- Grip strength
- Functional performance
- Walking speed
- Balance
- Physical activity levels
- Nutritional status
These measurements provide a far more meaningful picture of overall health than the number on a scale.
A New Direction for Cancer Research
Dr. Gabbay also highlights the need for studies that focus on specific patient populations rather than relying solely on average trial results. He advocates for innovative “basket trials” that evaluate multiple high-risk groups simultaneously.
This concept has relevance in oncology.
Future studies should examine how exercise, nutrition, body composition monitoring, and metabolic therapies—including GLP-1–based medications—work together in patients undergoing chemotherapy, immunotherapy, endocrine therapy, or long-term survivorship. Such research could help define best practices for preventing sarcopenia while optimizing metabolic health.
The Future of Cancer Care
The next generation of cancer care will not be measured simply by pounds lost or tumors removed.
Success will increasingly be defined by whether patients maintain strength, preserve muscle, remain independent, tolerate treatment, and enjoy a higher quality of life throughout survivorship.
Exercise Oncology is uniquely positioned to lead this transformation. By integrating precision exercise, nutritional counseling, body composition assessment, rehabilitation, and evidence-based metabolic therapies, clinicians can move beyond weight loss alone toward comprehensive health restoration.
For cancer survivors, preserving muscle is not merely a fitness goal—it is an essential component of modern cancer medicine.
Call to Action
At CancerFitness.org, we believe that every cancer patient deserves a treatment plan that protects both life and function. Whether you are newly diagnosed, undergoing active treatment, or living years beyond cancer, maintaining muscle should be a central part of your care. Ask your oncology team about supervised exercise, resistance training, nutritional support, and body composition assessments. Together, these evidence-based strategies can help you tolerate treatment better, recover faster, and build a stronger future. In the era of precision medicine, preserving muscle is one of the most powerful prescriptions we have.
Reference: Dr. Bob’s Reflections: Moving Beyond the Weight Loss Olympics. 6/22/2026
