Muscles – Why Do They Burn After Exercise?

 In Aubs In The Blog

Nothing feels better than leaving the gym after a great workout, with your sweat pouring, heart pumping, and muscles burning. Wait, whaaaaaat? Muscles burning? Is that normal? Should they feel that way? Wait, why do they feel that way? Don’t worry, put the fire extinguisher down. That muscle burn is completely normal and—prepare yourself—will peak 24–72 hours after the end of your workout. Building lean muscle mass requires strenuous exercise, and soreness generally follows as that awesome muscular burn.

The Science Is Inside Us

Despite its unmistakable stingy-y burning sensation, lactic acid isn’t the culprit for post-workout muscle soreness. Allow me to get my nerd on for a moment and explain what is actually going on.

When the body is working at its greatest capacity, our muscles aren’t able to get enough oxygen to convert food to energy. This is what causes lactic acid production and build up in the muscle, giving us that intra-workout burn. Lactic acid results from the conversion of glycogen, and studies dating as far back as 1924 reveal the truth. “Upon the cessation of exercise the accumulation of lactic acid in the muscles immediately ceases, and its concentration begins to decrease by diffusion into the bloodstream and on to other tissues by oxidative recovery” (Muscular Exercise, Lactic Acid, and The Supply and Utilisation of Oxygen – Parts I-III).

So who’s to blame for that nagging, achy, soreness? Believe it or not, the sensations you are experiencing post-workout are a direct result of small micro-tears in the muscle! This sounds kind of horrific, but it’s a completely natural process that the body undergoes in order to build lean muscle. Have you ever noticed when you cause damage to your palms from daily use, they eventually build calluses? It is the body’s natural response to get tougher in areas that are being damaged and muscles are no different!

Teeny, Tiny, Little Tears

When we exercise, the stress that is placed on our muscles cause micro-tears (the damage factor) and the body’s response factor is growth. These micro tears happen in every fiber of the muscle that was recruited during the exercise and are the stimuli telling the body to come pay attention to these muscles (aka send nutrients for repair + recovery).

This is why eating the proper amount of carbs, fats, and proteins post-workout is so important. I have found, as both a personal trainer and a nutrition coach, that clients don’t understand how crucial pre and post-workout meals are. These are key to fueling our bodies throughout our workout, increasing our endurance and strength, and thereafter improving our rate of repair and recovery.

My number one piece of advice to anyone spending time in the gym—whether it is to drop body fat, build lean muscle mass, increase endurance, or improve their overall health—is to always prioritize fueling their bodies properly. Our bodies and muscles don’t build or recover by magic. It is our responsibility to give it what it needs, when it needs it.

For more information on the nutrition programs provided by Jada Blitz Fitness, please visit or contact us today at (716) 568-9057.

Recent Posts