At Best Day Fitness, we often hear the phrase, "my muscles hurt", and the question, "why am I so sore?" While we tend to take (triumphant) pride when we hear these exclamations, what are the physiological processes that underlie post-workout soreness?
Archaic science taught that lactic acid accumulation, resulting from the muscle’s inability to produce enough energy through aerobic (oxygen-requiring) pathways thereby requiring anaerobic (less-efficient non-oxygen dependent) metabolism, was the cause for delayed onset muscle soreness (DOMS).
“Lactic acid is an acid after all and my muscles feel like they are burning!”
New research has discovered that the majority of lactic acid is reabsorbed within an hour post-exercise to assist the cells with energy production and repair.
So what then is the cause for DOMS?
The following article explores some of the prevailing theories leading to post-exercise soreness:
In summary, with each repetition of a movement, micro-tears occur to the cellular contractile elements of muscle. This infinitesimal trauma causes inflammation, which brings a flood of compounds that initiate the healing and repair process. Under most daily activities, our body maintains a balanced, homeostatic inflammatory response. However, our body becomes complacent with this level of activity. When we begin to amplify our exertion, through increasing our daily activity’s intensity, duration, or frequency, such as when we begin an exercise regiment, our body is not able to keep up with the amount of cellular trauma. This leads to an accumulation of inflammation, placing pressure on the sensory nerves attached to our individual muscle fibers, which is then recognized as pain by our brain.
Soreness is a wonderful defense mechanism, letting us know that an area of our body has not fully healed. Counterintuitively, the best way to manage this soreness is to increase blood flow to the area through light-intensity, full range of motion exercise. Research is beginning to show that ice and NSAIDs only mask the pain without decreasing recuperation time.
So what is the take-away? Well, just because you are sore does not mean you should stop moving! Get-up, go, and help the body keep the pain at bay.