GLP-1 Medications and Fitness: What You Need to Know (and Why Strength Training Matters)

Coach Cass
Dec 13, 2025
3 min read

GLP-1 medications have become one of the most talked-about topics in health and fitness today. From social media to mainstream news, they’re often framed as a fast and effortless solution for weight loss.

But like most things in health, the full picture is more nuanced.

At Rx Performance, we believe in informed decisions, sustainable results, and long-term health. This article aims to help you understand what GLP-1s are, what they do, and most importantly, how training plays a critical role if you’re using them.

What Are GLP-1 Medications?

GLP-1 (glucagon-like peptide-1) medications were originally developed to help manage type 2 diabetes. They work by:

Increasing feelings of fullness
Slowing gastric emptying
Reducing appetite and food intake
Improving blood sugar regulation

Because of these effects, GLP-1s are now widely prescribed for obesity treatment as well.

Why Are More People Turning to GLP-1s?

Many people consider GLP-1s because they appear to offer:

Rapid weight loss
Reduced hunger and cravings
An alternative to traditional dieting

For individuals who have struggled with obesity, metabolic conditions, or repeated dieting cycles, GLP-1s can feel like a breakthrough.

And it’s important to say this clearly: GLP-1s are not “bad.”

In fact, the World Health Organization (WHO) now recognizes GLP-1s as a valid medical treatment for obesity.

But there’s an important condition attached.

What the WHO Actually Recommends

The WHO recommends GLP-1 medications only when they are combined with lifestyle interventions, including:

A healthy, balanced diet
Regular physical activity
Strength or resistance training

Why? Because weight loss alone is not the goal.

Preserving muscle mass and functional strength is critical for long-term health.

The Risk People Often Miss: Muscle Loss

One of the lesser-discussed side effects of GLP-1 use is loss of lean muscle mass.

This can happen due to:

Significant calorie reduction
Lower protein intake from appetite suppression
Reduced training intensity or activity levels
Lack of resistance training

Without strength training, weight loss can come from both fat and muscle. Losing muscle may lead to:

Slower metabolism
Reduced strength and energy
Increased injury risk
Poor long-term weight maintenance

This is why relying on medication alone is rarely enough.

Why Strength Training Is Non-Negotiable

Strength training sends a clear signal to your body:

“This muscle is needed. Keep it.”

When paired with GLP-1s, resistance training helps:

Preserve lean muscle mass
Support metabolic health
Improve insulin sensitivity
Maintain strength, bone density, and confidence
Create sustainable, long-term results

According to WHO physical activity guidelines, adults should aim for:

150–300 minutes of moderate activity per week or
75–150 minutes of vigorous activity, plus
At least 2 days of strength training per week

A Note From the Fitness Industry: Fear, Reality, and a Better Way Forward

It would be disingenuous to say that the rise of GLP-1 medications hasn’t caused concern within the fitness industry.

In Singapore, GLP-1s often cost about the same as a monthly gym membership. To many gyms and coaches, they can look like a “shortcut” — a fast track to weight loss without the long, often uncomfortable journey of training, lifestyle change, and habit-building.

From the outside, it’s easy to see why some might view GLP-1s as competition.

But at Rx Performance, we believe that mindset misses the bigger picture.

Weight loss alone is not health.

Medication alone is not resilience.

And muscle, strength, and confidence cannot be injected.

Rather than seeing GLP-1s as a threat, we see them as a potential partner, one that, when used responsibly and combined with coaching, can help clients finally move forward after years of frustration.

For some people, GLP-1s lower the barrier to entry. They reduce appetite, improve metabolic markers, and create enough breathing room for individuals to begin exercising consistently. That’s where coaching becomes even more important — not less.

Our role as coaches is not to compete with medication, but to: