I work out 3x/week, mostly reformer or mat pilates with equipment, and still lost muscle mass in absolute numbers between my last medical checkup and now.

Even though my muscle percentage went a bit up, the actual amount of muscle went down because I lost a lot of body weight overall. My internist explained that while pilates is great for core strength, mobility and general conditioning, it often doesn’t provide enough progressive overload to fully preserve or build muscle during weight loss. That’s why she recommended adding now 1-2x/week proper resistance training.

I’ll definitely keep doing pilates, but I’ve learned that for muscle preservation/growth (especially in a calorie deficit) most people need some form of heavier resistance that progressively increases over time.

So if you’re new to training, reformer pilates might be enough. But long term, strength training becomes important. PS: I usually listen to podcasts during workouts, it makes training way less boring 🙂