The burning sensation felt during exercise is often seen as a sign of a productive workout, but a physical therapist says this belief can be misleading. Shannon Ritchey, a Doctor of Physical Therapy, personal trainer, and founder of Evlo Fitness, explained on the mindbodygreen podcast that muscle burn does not directly indicate muscle growth or strength gains.
According to Ritchey, the burning feeling is a buildup of hydrogen ions in the muscle, a byproduct of metabolic stress when the muscle is working under fatigue. She described it as a chemical signal, not a growth signal. While metabolic stress can play a role in muscle hypertrophy, the burn itself is not what builds muscle.
Muscle growth is driven by mechanical tension and how close a person gets to muscular failure, which is the point where they physically cannot complete another rep with good form. Ritchey noted that many people stop a set because it becomes uncomfortable, not because the muscle is truly fatigued. Burning sensations often appear early, especially with lighter weights and higher reps, but that does not mean the muscle has been adequately stimulated to grow.
Ritchey pointed out that the fitness industry has often equated discomfort with results, leading to workouts designed to maximize burn, sweat, and exhaustion. This mindset can lead to inefficient training and burnout. High-rep, burn-heavy workouts often use lighter loads that do not provide enough mechanical tension for meaningful muscle growth. They can also cause excessive fatigue without a clear strength benefit, especially when repeated daily.
Instead of asking whether a movement burns, Ritchey encourages people to ask if they are training close to failure. Muscle can be built with six reps or 30 reps, as long as the set brings the person close to the point where another rep is not possible with good form. The key is the effort required at the end of the set, not the burn.
Strength training often looks less intense from the outside than it feels internally. The last few reps may not be fast or dramatic, but they demand focus, control, and strength. When training is structured this way, it becomes more efficient. The approach requires intentional loading, adequate recovery, and enough effort to signal change, rather than endless volume or constant soreness.
For people who have been using muscle burn as their main indicator of a good workout, Ritchey suggested a shift in approach. She recommended choosing weights or resistance that make the final reps genuinely challenging, even if the movement does not burn right away. She also advised focusing on form and control instead of rushing through reps to feel discomfort. People should pay attention to whether they are stopping due to fatigue or just because it feels uncomfortable. Allowing rest and recovery is also important so muscles can adapt and grow.
Ritchey stated that the burn has been oversold as a measure of effectiveness. While it can be part of the workout experience, it is not the gold standard. Muscle growth comes from intentional effort, smart loading, and recovery, not from chasing discomfort. When people stop equating pain with progress, workouts become less about punishment and more about purpose, which can change what the body is capable of over the long term.
