The burning sensation many people feel during a workout is often seen as a sign that the exercise is working. But according to physical therapist Shannon Ritchey, DPT, that feeling is not a reliable indicator of muscle growth or strength gains.
Ritchey, a doctor of physical therapy and founder of Evlo Fitness, explained on the mindbodygreen podcast that chasing the burn can actually slow down progress. She said the sensation is widely misunderstood in the fitness world.
The burn is caused by a buildup of hydrogen ions in the muscle, a byproduct of metabolic stress when the muscle works under fatigue. It is a chemical signal, not a signal that muscle is growing. Muscle growth, she said, comes from mechanical tension and how close a person gets to muscular failure, meaning the point where another rep cannot be completed with good form.
Many people stop a set when they feel the burn, not when the muscle is truly fatigued. This can mean the muscle has not been stimulated enough to grow. Stopping because of discomfort rather than failure may limit results.
Ritchey noted that the fitness industry often links discomfort with results, leading to workouts designed to maximize burn and exhaustion. But high-rep, burn-heavy routines often use lighter weights that do not provide enough mechanical tension for muscle growth. These workouts can cause fatigue without clear strength benefits, leaving people sore and frustrated despite consistent effort.
Instead of asking if a movement burns, Ritchey advises asking if you are training close to failure. Muscle can be built with six reps or 30 reps, as long as the set brings you near the point where another rep is not possible with good form. The key is effort at the end of the set, not the burn itself.
Strength training may look less intense from the outside than it feels internally. The last few reps demand focus and control, not speed or drama. When training is structured this way, it becomes more efficient. Intentional loading, adequate recovery, and enough effort to signal change are more important than endless volume or constant soreness.
For those used to using burn as a measure of a good workout, shifting focus can feel uncomfortable. Ritchey suggests choosing weights that make the final reps genuinely challenging, focusing on form and control, paying attention to whether you stop due to fatigue or discomfort, and allowing rest and recovery for muscles to adapt.
This approach supports strength and sustainability over time, rather than constant exhaustion. The burn has been oversold as a sign of effectiveness. Muscle growth comes from intentional effort, smart loading, and recovery, not from chasing discomfort. When pain is no longer equated with progress, workouts become less about punishment and more about purpose, which changes what the body can do over the long term.
