Personal trainers are working with more clients than ever before who are on GLP-1 medications, including Ozempic, Wegovy, Mounjaro, and similar brands. This has left many personal trainers wondering how GLP-1s will impact their training plans.
This guide explains GLP-1 medications, what they change in the body, and how understanding them impacts a coach's approach to training and nutrition without going outside of their scope of practice.
Heather Hamilton
MS, ACSM-CEP, ACE-CPT, RYT 200
What Are GLP-1 Medications?
GLP-1 medications are prescription drugs that mimic the effects of GLP-1, a hormone released by the small intestine after eating. This hormone helps regulate blood sugar by signaling the pancreas to release insulin when glucose levels rise. It also helps you feel full by acting on appetite centers in the brain and slows how quickly food leaves the stomach. Unlike natural GLP-1, which breaks down within minutes, GLP-1 medications remain active in the body for hours or even days, providing longer-lasting effects on blood sugar control and appetite.
GLP-1 medications are most taken as injections, although some are available in pill form. Healthcare providers monitor a person's response to the medication and adjust the dosage when needed. Personal trainers should not provide advice about medications, dosing, or treatment decisions, as these should be managed by a qualified medical professional.
However, understanding how GLP-1 medications work can help trainers better support their clients.
Originally developed to help manage type 2 diabetes, GLP-1 medications are now widely used for weight management under brand names such as Ozempic, Wegovy, Mounjaro, and Zepbound. About one in five adults who have been told they are overweight or obese have used or are currently using a GLP-1 medication. As their popularity continues to grow, personal trainers are increasingly likely to work with clients taking these medications.
The effect on each person's appetite varies because individuals respond differently to GLP-1 medications based on genetics or how quickly their bodies process them.
How GLP-1s Affect Appetite and Metabolism
GLP-1 medications slow the rate at which food leaves the stomach and influence appetite centers in the brain. Many clients feel full sooner, stay satisfied longer, and think about food less often, leading to a significant reduction in calorie intake.
Lower calorie intake can make it harder to maintain lean muscle mass during weight loss. To support muscle retention, clients taking GLP-1 medications should generally consume 0.5 to 0.7 grams of protein per pound of body weight, with higher amounts often needed for those who train regularly. Reduced appetite can also make it challenging to meet protein needs, so clients may need to pay closer attention to their daily protein intake.
Common Brand Names and How They Differ
Ozempic and Wegovy both use semaglutide, a medication that activates the GLP-1 pathway alone. Mounjaro and Zepbound use tirzepatide, which activates both the GLP-1 pathway and a second hormone pathway called GIP, or glucose-dependent insulinotropic polypeptide. GIP works alongside GLP-1 to regulate blood sugar and appetite, so activating both pathways at once tends to produce a stronger combined effect than activating GLP-1 alone.
For personal trainers, it's important to understand that clients taking semaglutide or tirzepatide may not have the same experience, even when their goals and starting points are similar. Tirzepatide is often associated with greater weight loss and broader metabolic effects, while semaglutide has a longer research history supporting cardiovascular health benefits. As a result, clients may experience different rates of weight loss, appetite changes, energy levels, and side effects.
Personal trainers should monitor each client's response individually and adjust exercise programming, recovery strategies, and nutrition recommendations accordingly.
What This Means for Coaching Approach
Expect lower energy availability, especially in the first weeks after a dose increase. Clients may need more recovery time between sessions and may undereat simply because they aren’t hungry.
Digestive side effects are common among clients taking GLP-1 medications, especially during the first few weeks of treatment or after a dosage increase. Nausea, diarrhea, and feeling overly full can all affect workout performance, energy levels, and exercise tolerance.
A quick check-in at the start of each session about recent dose changes and how the client is feeling can provide valuable context for the day's workout. This helps personal trainers make informed adjustments to intensity, exercise selection, or recovery rather than guessing why a client may be struggling with a routine that normally feels manageable.
Timing matters when working with clients taking GLP-1 medications. If a client recently increased their dose, expect workouts to feel different for a week or two. During that adjustment period, it often makes sense to scale back intensity and focus on movement quality, strength maintenance, and consistency. Trying to push through nausea, low energy, or digestive discomfort rarely leads to a great workout experience. Once side effects ease and the client feels more like themselves, they can typically return to their normal training progression.
One of the most valuable ways personal trainers can support clients on GLP-1 medications is by helping them preserve lean muscle mass. Resistance training and adequate protein intake should remain priorities throughout the weight-loss process. Since appetite suppression can make eating enough protein challenging, practical strategies often work better than simply providing a daily target.
Encourage clients to include protein earlier in the day, keep convenient options like protein shakes or Greek yogurt on hand, and look for simple ways to spread protein intake across meals and snacks.
Regular check-ins can also make a big difference. Asking about appetite, energy levels, hydration, and any digestive symptoms at the start of a session helps trainers understand how a client is feeling that day and whether adjustments are needed. These conversations can improve workout quality, support recovery, and help clients stay consistent and safe as they adapt to their medication.
Staying in Scope of Practice
A personal trainer can coach training, movement, and general nutrition education. They cannot advise on medication dosing, side-effect management, or whether a client should start, stop, or switch a prescription.
When a client raises a medical question, the right move is a direct, professional redirect to their prescribing provider, paired with the coaching support that's within a trainer's lane. Something as simple as "That's a great question for your doctor, and in the meantime, here's how we can adjust your training to support how you're feeling." This keeps the relationship supportive without overstepping.
Supporting Clients Using GLP-1s
Help clients get better results and position yourself as the personal trainer they trust to guide them through the GLP-1 journey.
As more clients turn to GLP-1 medications for weight loss, trainers who understand how to train, coach, and support them effectively will have a clear advantage. NASM's Understanding Weight Loss Medications (GLP-1s) course equips fitness, wellness, and nutrition professionals with practical strategies to help clients preserve muscle, manage side effects, build sustainable habits, and maintain results long-term.
Go beyond the basics with evidence-based guidance, real-world coaching applications, and the confidence to support one of the fastest-growing client populations in fitness. As the landscape evolves, this knowledge can help you deliver better outcomes, build stronger client relationships, and grow your value as a coach.
GLP-1 Medications Frequently Asked Questions
What do GLP-1 medications do?
GLP-1 medications mimic a gut hormone that slows digestion and reduces appetite, which leads to lower calorie intake and, over time, weight loss. The appetite suppression is often more pronounced and longer lasting than what most clients have experienced with diet changes alone.
Are Ozempic and Wegovy the same drug?
Ozempic and Wegovy contain the same active ingredient, semaglutide, but are approved and dosed differently for diabetes versus weight management. Mounjaro and Zepbound, by contrast, use tirzepatide, a related but distinct medication that acts on an additional hormone pathway.
Can personal trainers give advice about GLP-1 dosing?
Dosing and medication management should always go through the client's prescribing provider. A trainer's role is to support training and general nutrition education around whatever the client's care team has decided.
Why do GLP-1 clients need more protein?
Reduced appetite lowers overall protein intake, which puts muscle at risk if protein isn't prioritized alongside resistance training. Clinical guidance recommends 0.5 to 0.7 grams of protein per pound of body weight during treatment, above what's typically recommended for the general population.
Should training change for a client on a GLP-1 medication?
Adjust volume and recovery around energy availability, particularly following dose increases, when gastrointestinal side effects and fatigue tend to peak. Checking in specifically about recent dose changes at the start of a session, rather than assuming a client's capacity is unchanged week to week, is one of the simplest ways to program around this variability. Emphasize resistance training two to four times weekly throughout treatment to protect lean mass.
Should a trainer ask clients directly whether they're on a GLP-1 medication?
Ask about GLP-1s the same way they ask about any other prescription, rather than singling it out or assuming based on appearance. Framing it as routine, "Are you currently taking any medications I should know about for programming purposes?" keeps the conversation professional and avoids putting a client in an uncomfortable position.
What happens if a client stops taking a GLP-1 medication?
Appetite and hunger cues typically return, often leading to weight regain if training and nutrition habits aren't maintained independently of the medication. Research following clients after treatment discontinuation has found that those who continued structured exercise, particularly resistance training, retained more of their results than those who relied on the medication alone. Building durable training habits during treatment is vital, since those habits are what carry a client through if or when they stop the medication.
