It’s Time To Stop Blaming Lactic Acid

For many people, lactic acid is seen as a villain – a troublesome substance that actively works against their fitness goals. You’ve likely been told for most of your life in the health and fitness world that the acid is the thing slowing you down, making you weak, and leaving you sore.

According to modern science, however, that’s not really the case. The truth, it turns out, is that lactic acid is actually an incredibly useful substance. But, the role of lactic acid isn’t the only myth and misunderstanding at work here. So, what’s the truth about lactic acid?

Similar But Different

The first thing to understand is that you probably aren’t actually talking about lactic acid when you…talk about lactic acid. Although the terms lactate and lactic acid are generally used interchangeably – even by trainers, coaches and athletes – there’s a very important difference between the two substances.

And that difference is one little proton. Specifically, lactic acid contains a proton that’s missing from lactate. Lactic acid becomes lactate, however, when it donates that defining proton to other molecule.

So, although both lactic acid and lactate can typically be found in your body, lactate is the proper name for the chemical that receives the blame for so many fitness woes.

What People Thought

Next, we need to cover some of the previously held beliefs regarding lactate and athletic performance. As you’ve likely heard – and as mentioned above – the most common myth regarding lactate is that it is responsible for the fatigue and burn that you experience during exercise.

For the most part, this comes from a particularly strange experiment by Nobel laureate Otto Meyerhoff. In early 1900s, Dr. Meyerhoff cut a frog in half and stuck its back legs in a jar. Just to make things a little more odd, Otto then hit the frogs legs with electric shocks. Although the muscles had no blood, oxygen or fuel source, the muscles twitched. After a few contractions, though, the muscles stopped moving.

When Meyerhoff examined the frog’s legs, the muscles were full of lactic acid. Based on this bit of half-baked research, the conclusion was made that lactic acid – and its related lactate – causes muscular failure.

Beyond the short-term fatigue that occurs during strenuous work, though, lactate has also been blamed for delayed on-set muscle soreness (DOMS). This concept was based simply on conjecture and never had any actual science behind it.

What We Know Now

As you likely assumed, though, science has since uncovered that all of those assumptions are wrong. First, let’s start with the easy one: DOMS.

Just like its descriptive name suggests, delayed on-set muscle soreness sets in 24 to 48 hours after exercise. Remember, however, that lactate builds up during your workout and is usually cleared out within an hour. So the time frame simply does not line up.

This myth falls apart even more, though, when you look into the primary misconception regarding muscular fatigue. In the 1970s, studies found that working muscles actually burn lactate at incredibly high rates as fuel – specifically within the cellular powerhouse known as the mitochondria.

Further research has found that proper training can increase the amount of mitochondria in a cell, which then enhances that cell’s ability to use lactate as fuel. The longstanding idea that lactic causes fatigue, then, simply doesn’t hold up.

So while lactate does build up during intense exercise, it’s actually acting as a fuel and not a harmful, troublesome waste product.