By in Sports Physiotherapy

Lactic Acid – Facts and Myths

Lactic acid can come in many forms and avenues, but what we are interested in is the human body and physical exertion. Does lactic acid cause the achiness the days after training? How do we limit that soreness? Is there anything we can do to avoid lactic acid build up? These are questions answered in this article.

What is Lactic Acid for?

Lactic acid, or Lactate, is a compound in the body we generate during exercise to provide energy to muscles primarily in the first 1-3 minutes of training. This time zone is known as the anaerobic phase, is more applicable when sprinting or having a high intensity of training, and explains why the first few minutes of a run, cycle etc can be quite unpleasant. When the body is rich with oxygen, it can feed the muscles and keep everything running smoothly along with another substance called puruvate, but if the body is low on oxygen it needs a reserve tank which comes in the form of glucose stores. Pyruvate in this situation is broken into lactate, which then converts glucose into energy for our muscles.

It’s all very scientific, but in Layman’s terms lactic acid is the substance in your body that makes energy for muscles during high intensity training. The reason your muscles ache in the gym after a number of reps, or after a few track sprints, is because the acidity in your muscles trying to covert so much energy builds up and forces you to stop so that your muscles can clear out all that acid build up once the muscles have relaxed. This is actually a natural response and has its own reasons – if you continually load a muscle without feeling that pain, eventually the energy stores will deplete and oxygenation is needed and without that you could damage your muscles. The “burn” you feel from lactic acid in training is your body telling you to allow your muscle to recover before it snaps ultimately.

Lactic Acid Build-up

From studies deeply looked into on the delayed onset of muscle soreness (DOMS) after training, there’s no evidence to suggest lactic acid is the reason for that pain. In actual fact there is no 100% fact on what causes that pain, but the popular theory is the way hypertrophy works. In order for muscles to grow, they need to break which is what causes your pain after exercise. Now when we say break, we mean a very small percentage. As these fibres within the muscle break they repair with more branches, leading to muscle growth and more strength, and that process is why we have pain after training. Lactic acid plays no role in that, and never actually builds up in the muscle itself during this period, but it does build during intense training as mentioned earlier when you “feel the burn.”

To sum up, lactic acid in relation to exercise isn’t really anything to concern about. The pain during exercise you feel is caused by it, but that’s the signal that you may be going too far. In principle that makes lactic acid a good thing!

Kieran
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