I think we have all heard that muscle soreness is produced by lactic acid. That somehow, when you train your body, it produces lactic acid and that is what causes the pain after an intense workout. But the truth of the matter is that this is not true. Scientists have proven that years ago but the myth still persist, even within the sports community. The myth started back in the 1920´s when researchers showed that the exposure of frog legs to high levels of lactic acid interfered with the ability of the muscles to contract in response to electrical stimulation. Later research determined that lactate was produced through the breakdown of glucose without the help of oxygen. So, they concluded that fatigue happened at high exercise intensities because the cardiovascular system could no longer supply the muscles with enough oxygen to keep up with muscular energy demands. This would eventually lead the body to rely on the breakdown of glucose without the help of oxygen, which would lead to the buildup of ¨lactic acid¨. But now we know that is not true, in fact, lactic acid is a chemical that your body produces to feed your muscles so that you can move (1). So it really does the opposite of what a lot of people think!!
So what produces muscle soreness? It is still not 100% certain but most scientist think that next-day soreness is more likely the result of damage to muscle and connective tissue, or inflammation. (That is normal, even good, so don´t get scared)
But the real question most people want to know is what they can do to get rid of the muscle soreness that sometimes occurs after training? And like I said in one of my previous post (click here), not that much! Massage, stretching, it feels good and it relaxes but it won´t prevent you from having that uncomfortable feeling the next day (2-4).
- Cairns SP. Lactic acid and exercise performance: culprit or friend? Sports Med 2006;36 (4) 279-91.
- Lund et al. The effect of passive stretching on delayed onset muscle soreness, and other detrimental effects following eccentric exercise.Scandinavian Journal of Medicine & Science in Sports 1998.
- Cheung et al. Delayed onset muscle soreness: treatment strategies and performance factors.Sports Medicine 2003 .
- Weber et al. The Effects of Three Modalities on Delayed Onset Muscle Soreness. Journal of Orthopaedic & Sports Physical Therapy 1994.