Weight loss drugs don’t replace training, they make it even more important.

Weight loss medications like GLP-1 agonists are powerful tools. They reduce appetite, make it easier to eat less, and can help people lose a meaningful amount of bodyweight.

But the scale doesn’t care where that weight comes from. Both fat and muscle (and, as a result, fitness and performance) all tend to trend down together unless you actively interject.

That’s where training comes in.

When calories drop—whether from dieting, medication, or both—your body looks for ways to conserve energy. Muscle tissue is metabolically expensive, so without a strong signal to keep it, your body will happily shed it.

Resistance training is that signal. It tells your body: this tissue is necessary, let’s keep it.

Research consistently shows that people who lift weights during weight loss retain significantly more lean mass than those who rely on diet alone. And lean mass isn’t just about aesthetics. It’s tied to strength, bone density, metabolic health, balance, and the ability to both shovel two feet of snow today and live independently in the future.

Training also preserves fitness and performance (i.e. strength, power, work capacity, coordination, and overall tissue resilience).

Losing weight without training often results in being lighter, but also weaker and less capable.

Weight loss is one of the biggest and most influential levers we can pull for improving health markers and you won’t likely find many people who are generally pro-weight loss than myself.

It makes stairs easier, groceries lighter, injuries less likely, and daily life more enjoyable. It helps maintain resting metabolism and can make weight maintenance after medication easier.

If you’re using (or thinking about using) a weight loss medication, think of it as reducing friction. They’ll make weight loss simpler, less aggravating, and more certain (which is, after all, what most of us are after).

Your training routine, though, will shape the outcome.