As a follow up to my lactic acid discussion last week about Watermelon as the best pre-workout snack, I wanted to go deeper into what creates muscle soreness. For over thirty years we have heard from coaches, trainers, and other medical professionals that lactic acid is the cause of muscle soreness. Although untrue, we believed this statement mostly because it has been proven that lactic acid is responsible for the burning sensation after exercise. But, as I stated in the "Watermelon" blog post, that burning sensation is just a warning sign for muscle breakdown. Lactic acid isn't the cause of muscle soreness!
A Little More On Lactic Acid Just to give you a little background, lactic acid is the product of producing energy without oxygen. You can feel its effects when pushing your limits during an extreme exercise. Lactic acid will build in your muscles and you will begin to feel the associated burning sensation. This sensation is an evolutionary warning sign that is telling you that you are nearing injury if you continue. It is very important to note that as soon as you stop the exercise, the lactic acid in your muscles will begin to be converted back into a source of energy and the burning sensation will gradually leave. |
Intuitively, lactic acid can't cause muscle soreness. The timeline between the two events isn't consistent. As mentioned above, lactic acid begins being converted back into a source of energy for your muscles immediately when the exercise is stopped. It only takes about 20 second to and hour for all of the lactic acid to be depleted, depending on the extent of exertion. Muscle soreness usually doesn't occur till about 8 hours after muscle breakdown. This is why we call it Delayed Onset of Muscle Soreness (DOMS).
What is Muscle Soreness or DOMS
So what causes it? It turns out DOMS is simply a result of trauma to the muscles. Just like having trauma to the ankle when you roll it, your muscles elicit a similar response when broken down through exercise.
And YES, when you are working out, you ARE breaking down muscle fibers and causing trauma to the muscle. Therefore, DOMS is a inflammation response. Just like an ankle sprain, after an exercise, your muscles will swell and ache. The damage of the muscle fibers makes them highly sensitive and unable to function at maximum workloads until after repair. |