GLP-1 Receptor Agonists: What Strength and Conditioning Professionals Need to Know
When a strength and conditioning client is using GPL-1s, the opportunity as a coach is not simply to support weight loss, but to ensure that the process results in improved health, preserved function and long-term physical resilience.
Written by Hannah Witt
GLP-1 receptor agonists are a rapidly expanding class of medications used in the treatment of type 2 diabetes and obesity. They’re designed to mimic the gut-derived hormone GLP-1 and regulate appetite, glucose metabolism and satiety. While their primary mechanism for weight loss is a sustained reduction in energy intake, the resulting rapid and often substantial weight loss is not tissue-specific and can include meaningful reductions in lean muscle mass alongside fat mass.
For strength and conditioning professionals, this creates a critical training challenge: how to preserve muscle quantity, quality and neuromuscular function in a context of pharmacologically driven energy deficit.
This article outlines the physiological mechanisms behind GLP-1 receptor agonists and examines current evidence on their relationship with lean mass loss. It also provides a practical training and nutrition framework to help coaches protect performance, metabolic health and long-term functional capacity in clients using these medications.
What Are GLP-1 Receptor Agonists?
Before discussing the training implications of GLP-1 receptor agonist use, it is important to understand what these medications are and how they produce weight loss. A foundational understanding of their physiological effects provides critical context for the muscle preservation strategies that strength and conditioning professionals must implement.
GLP-1 receptor agonists are a class of medications that mimic the function of GLP-1, a gut hormone released by enteroendocrine cells after food ingestion. This hormone regulates glucose metabolism and satiety, making it a key focus for both diabetes and obesity treatment (Reiss et al., 2025).
These medications are available in both tablet and injectable forms. Oral medications often require stricter scheduling, such as administration 30 minutes before eating, whereas injectable forms are typically administered once weekly with fewer food-timing restrictions.
By mimicking endogenous GLP-1, these medications stimulate insulin secretion, inhibit glucagon release, slow gastric emptying and reduce caloric intake. Their effect on weight loss is driven primarily through reduced energy intake rather than increased energy expenditure (Reiss et al., 2025).
Why Muscle Loss Occurs During GLP-1-Induced Weight Loss
While the appetite-suppressing effects of GLP-1 receptor agonists are largely responsible for their effectiveness as weight-loss medications, they also create an important consideration for coaches: Reductions in body mass do not occur exclusively from fat tissue. As body weight decreases, lean tissue can also be lost, making muscle preservation a primary concern during pharmacologically assisted weight loss.
Weight loss, particularly when it occurs rapidly, is inherently nondiscriminatory. As a result, GLP-1 receptor agonist therapy often leads to reductions in lean mass alongside fat mass. Studies evaluating these changes have frequently used DEXA scans, which provide useful but imperfect measurements because they combine muscle tissue with other components such as bone, organs and body water.
While concerns have emerged regarding the potential adverse effects of GLP-1-induced weight loss on muscle quantity and function, contemporary evidence paints a more nuanced picture. MRI-based studies suggest that skeletal muscle changes may be adaptive rather than pathological. In many cases, reductions in muscle volume appear proportionate to the individual’s age, disease status and total amount of weight lost (Linge et al., 2024).
Whether these muscular adaptations ultimately prove beneficial or detrimental depends largely on how the individual trains throughout the weight-loss process. This is where strength and conditioning professionals play a critical role.
Why Resistance Training Matters
Strength training and resistance exercise are essential components of preserving muscle mass during GLP-1 receptor agonist-induced weight loss. These interventions serve as the primary stimulus for protecting lean tissue and neuromuscular function despite the energy deficit created by these medications.
Energy restriction naturally downregulates the mTORC1 pathway responsible for muscle protein synthesis while simultaneously upregulating the AMPK/FoxO pathway associated with muscle protein breakdown. Resistance training provides the direct, non-pharmacological stimulus needed to reactivate anabolic signaling and mitigate catabolic muscle loss (Sancho-Haro et al., 2026).
During pharmacological weight loss, the body may adapt to carrying less mass by reducing muscle tissue that is no longer required to support previous loading demands. Consistent resistance training helps counteract this adaptation by maintaining mechanical loading on both muscle and skeletal tissue.
Importantly, the goal is not simply to preserve muscle volume. The emphasis should be on maintaining muscle quality, including force production, insulin sensitivity, functional strength and metabolic resilience. This distinction is especially relevant because obesity is frequently associated with reduced muscle quality, including myosteatosis, which contributes to weakness and impaired mobility.
Preserving high-quality muscle tissue helps support long-term physical performance while minimizing reductions in resting energy expenditure that commonly accompany weight loss (Linge et al., 2024).
Training and Nutrition Strategies for Clients Using GLP-1 Receptor Agonists
Understanding the physiological challenges associated with GLP-1-induced weight loss is only the first step. The next challenge is translating this knowledge into practical coaching strategies that preserve muscle mass, support metabolic health and help clients achieve sustainable outcomes.
When managing an athlete or client using GLP-1 receptor agonists, the primary objective is to ensure that weight loss remains adaptive rather than maladaptive by aggressively protecting muscle quantity, composition and function. Pharmacologic weight loss can result in lean mass losses comprising 20% to 50% of total body weight lost, making structured resistance training and precision nutrition nonnegotiable components of the training plan (Linge et al., 2024).
As a strength and performance coach, here are several areas to focus on when working with clients on GLP-1s:
1. Prioritize Resistance Training for Mechanical Loading
Because the body adapts to carrying less mass by catabolizing muscle tissue, resistance training remains the most effective intervention for preserving skeletal integrity and lean mass. Training should emphasize force production, functional strength, and progressive overload rather than simply accumulating training volume.
2. Implement a Protein-First Nutrition Model
GLP-1 therapy often reduces appetite, which can make adequate protein intake difficult. Prioritizing approximately 25-30 grams of protein per meal can help attenuate muscle loss and maintain metabolic resilience. Following a protein-first eating sequence—protein, vegetables, then starches—may further support blood glucose regulation and satiety (Linge et al., 2024).
3. Utilize Metabolic Efficiency Training (MET)
Metabolic Efficiency Training, developed by Bob Seebohar, MS, RD, CSSD, CSCS, METS II, is a system of nutrition and exercise strategies designed to improve the body’s ability to utilize stored fuel. Emphasizing zone 1 and zone 2 aerobic exercise can improve fat oxidation, enhance mitochondrial function and reduce dependence on supplemental carbohydrate intake during training.
4. Establish a Comprehensive Baseline
Before implementing major nutritional or training interventions, athletes should complete foundational assessments, including blood work and metabolic efficiency testing. These assessments provide coaches with an individualized blueprint from which to make informed decisions.
Sample Weekly Training Structure
The following schedule balances the anabolic stimulus needed to preserve muscle with the aerobic training required for metabolic health while allowing sufficient recovery for adaptation.
| Day | Focus | Activity Details |
|---|---|---|
| Monday | Resistance Training (RT) | Full-body compound movements (squats, presses, rows) to maintain mechanical loading |
| Tuesday | Aerobic Base | Low-intensity (zone 2) cardio (walking, cycling, or swimming) to support fat oxidation |
| Wednesday | Resistance Training (RT) | Full-body focus; emphasize progressive overload to stimulate muscle protein synthesis |
| Thursday | Recovery/Mobility | Active recovery (yoga, Pilates, or light stretching) to manage inflammation and support gut health |
| Friday | Metabolic Strength | Circuit-style strength training or full-body compound movements |
| Saturday | Long Endurance | Lower-intensity, steady-state aerobic activity (zone 1-2) to support insulin sensitivity |
| Sunday | Full Rest | Total recovery to allow for adaptation and hormonal balance |
While a structured weekly schedule provides an effective starting point, successful implementation ultimately depends on individualization. Medication tolerance, training history, recovery capacity and overall health status should continually influence exercise prescription and progression.
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Key Coaching Considerations
Monitor training intensity carefully. If digestive symptoms occur, consider reducing intensity before reducing volume, as high-intensity exercise can exacerbate gastrointestinal distress.
Track functional outcomes rather than relying exclusively on body weight. Measures such as grip strength, chair-stand performance, movement quality and overall mobility provide valuable insight into whether weight loss remains high quality.
Prioritize long-term health markers, including blood lipids, hormonal status and metabolic health, over short-term performance outcomes during the initial phases of medication use.
Conclusion
As the use of GLP-1 receptor agonists continues to increase among both clinical and athletic populations, strength and conditioning professionals are more likely to encounter clients using these medications. The opportunity for coaches is not simply to support weight loss, but to ensure that the process results in improved health, preserved function and long-term physical resilience.
Ultimately, GLP-1 receptor agonist therapy creates a unique physiological context where rapid changes in body composition, appetite and energy availability can significantly influence training tolerance and adaptation. For strength and conditioning professionals, the priority is not only to design effective programs, but to do so within an appropriate medical framework.
Coaches should always ensure clients have been cleared for exercise by a qualified healthcare provider, remain aware of potential side effects that may affect performance or recovery and be prepared to adjust training variables in response to changes in appetite, gastrointestinal tolerance and fatigue.
When applied thoughtfully, resistance training and structured conditioning can meaningfully protect lean mass and function during pharmacologically induced weight loss; however, this programming should be integrated with careful monitoring and interdisciplinary collaboration. As this area of practice continues to evolve, practitioners are encouraged to stay evidence-informed, prioritize athlete safety above performance outcomes and work closely with medical professionals to ensure each client’s training plan supports both health and long-term adaptation.
References
Linge, J., Birkenfeld, A. L., & Neeland, I. J. (2024). Muscle mass and glucagon-like peptide-1 receptor agonists: Adaptive or maladaptive response to weight loss? Circulation, 150(16). https://doi.org/10.1161/CIRCULATIONAHA.124.067676
Reiss, A. B., Gulkarov, S., Lau, R., Klek, S. P., Srivastava, A., Renna, H. A., & De Leon, J. (2025). Weight Reduction with GLP-1 Agonists and Paths for Discontinuation While Maintaining Weight Loss. Biomolecules, 15(3), 408. https://doi.org/10.3390/biom15030408
Sancho-Haro, E., Muñoz-López, M., Baz-Valle, E., Villanueva-Tobaldo, C. V., Tornero-Aguilera, J. F., López-Gil, J. F., … & Clemente-Suárez, V. J. (2026). Optimizing Weight Loss in the GLP-1 Era: Preserving Muscle Mass, Function and Metabolic Health Through Precision Nutrition and Resistance Training. Pharmaceuticals.
Seebohar, B. (n.d.). Metabolic efficiency training. eNRG Performance. https://www.enrgperformance.com/metabolic-efficiency-training
Hannah Witt is a UESCA Certified Running Coach, endurance athlete, and content creator with a background in Human Biology and competitive collegiate running. Still actively training at a high level with 80+ mile weeks, she is passionate about helping runners pursue long-term performance through thoughtful training, injury prevention, strength work, and sustainable fueling practices. Through her coaching, Instagram platform, and YouTube interview series, The Performance Collective, Hannah aims to create an education-based support network that makes evidence-informed endurance training more approachable, empowering, and community-driven for runners of all levels, while also advocating strongly for animal welfare and rescue.
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