What Is Lactic Acid?

So what is lactic acid? Most people just know it as whatever is burning in our muscles, apparently there’s something called lactic acid in there. But why do our muscles burn. and what is making this ‘lactic acid’ happen anyway?

Lactic acid is an organic acid produced by our bodies when sugar is broken down to be used as energy, hence why this happens while we are exercising or doing strenuous activity. In a previous email, we have talked about the different muscle fibres and energy systems, one being with oxygen and one being without (aerobic/anaerobic). When our bodies break down sugar or “glucose” for energy, this processed is called glycolysis. The product from glycolysis is then referred to as “pyruvate”. When our anaerobic energy system first kicks in during high intensity activities, our body is in an urgent need for energy. Your fast-twitch muscle fibres will kick in first and start to produce energy anaerobically (without oxygen.) The working muscles will still be relying on glycolysis to produce this energy, but pyruvate but can only be compiled in the presence of oxygen. This turns the excess pyruvate into a waste product called lactic acid!

The muscles when being worked are also being slightly torn and micro damaged, which can be the reasoning for the feeling of soreness as well. This is the reason for what we call “DOMS” or Delayed Onset Muscle soreness, when your muscles feel sore after s workout the next day or the day after.

You can’t avoid lactic acid when working out, but you can make your body more tolerant to it. The more we exercise and expose our muscles to these high intensities, the more adapted they will become.