Busting Myths and Misconceptions About Lactic Acid
We all love a good know-it-all.
After all, who doesn’t love to be corrected when they’re wrong? And isn’t it even better when it’s just a bit condescending so it really sinks in?
So to help you win over your workout friends, I’ll equip you with some wisdom about common gym misconceptions—so everyone will know you’re the smartest person in the gym.
If you ever hear someone screw these up, be sure to stop them immediately and correct their error.
The Truth About Lactic Acid
For decades, we’ve thrown around lactic acid as the culprit behind the misery during an intense workout. However, we now know that this “lactic acid” thing isn’t actually the bad guy.
More specifically, it’s not the reason for the muscle burn during exercise or the fatigue felt following a hard workout. Now, let’s uncover some truth.
During intense exercise, our bodies rely on carbohydrates to provide energy. If our muscles need that energy quickly, they don’t have the luxury of waiting for oxygen and instead rely on anaerobic metabolism (without oxygen) to meet the demand.
We used to think lactic acid was like the exhaust of this process, and we convinced athletes they needed to “flush it out” after training.
However, we now understand that the muscle burn and fatigue experienced during exercise are not caused by lactic acid. Instead, they’re associated with the accumulation of hydrogen ions (H+) in our muscles.
As we exercise, the breakdown of carbohydrates produces H+ ions, which lowers pH levels in the muscle. This drop in pH contributes to the burning sensation and fatigue—not lactic acid.
Lactate For Lactate
The true end product of this rapid metabolism is lactate, not lactic acid—and it plays a crucial role in performance.
Lactate actually helps shuttle and buffer hydrogen ions, supporting pH balance and delaying fatigue. It can also be recycled into glucose for energy and acts as a powerful signaling molecule for training adaptations.
In other words, lactate isn’t the problem—it’s part of the solution.
So the end result is that “lactic acid” actually helps us sustain intensity and isn’t something we need to fear.
So What Should You Say at the Gym?
The next time your coach blames “lactic acid” for the burn, feel free to fire back:
“Don’t blame lactic acid.”
(Then maybe explain it nicely… or don’t. Your call.)
For those interested in digging deeper, here is an article from George Brooks, who helped reshape how we understand this entire process. Or, here is a more laymen explanation in Sports Illustrated.
Originally published as Movement #188
For more myth busting, check out:
Busting Myths and Misconceptions About Pain
Busting Myths and Misconceptions About High Altitude Training
