Content overview: “Does Muscle Turn Into Fat If You Stop Working Out? Expert Debunks Gym Myth”. The Guardian Lifestyle Oct 12, 2026 • 7:00 AM 1 views Many gym-goers worry that taking a break from exercise will cause hard-earned muscle to turn into fat, but muscle physiology expert Prof Leigh Breen from the University of Leicester says this is a myth. He explains that muscle and fat are completely different tissues with no biochemical process that converts one into the other.
What actually happens during a training hiatus is a loss of muscle mass and a potential gain in fat, often due to reduced activity and unchanged eating habits. This can make muscles feel softer or less toned, leading to the misconception that they have transformed into fat. Understanding the real changes can help people manage their fitness expectations and avoid unnecessary frustration when returning to the gym. The full version stays on the original page, which this listing opens directly.