When you’re doing an intense weightlifting workout, sometimes you have to stop an exercise because your muscles burn too much. Most people who exercise know the feeling. Perhaps you’ve even felt the burn in your legs from walking up a long flight of stairs.
What causes this burning sensation, and what can be done about it? For a long time, lactic acid was thought to be the culprit. This isn’t surprising, since acidic chemicals are often associated with burning sensations. Just think about getting lime or lemon juice in a cut. Ouch!
Upon further investigation, scientists realized that acidity is likely the cause, but lactic acid doesn’t cause acidity. That sounds counterintuitive, but makes sense after further explanation.
Your muscles contract hard and very quickly when you lift a weight. These short, intense efforts demand a lot of energy. Your muscles rush to keep up, and use a lot of resources to make energy. They break down sugars to get fuel, which creates chemical byproducts that accumulate in the muscle.
This process is similar to eating a bunch of bananas for energy. The more energy you need, the more bananas you’ll have to eat. However, every banana you eat has to be peeled, and the peel is cast aside. Eventually, you’re left with a bunch of banana peels.
All the accumulated byproducts tip the pH balance of your muscle to be more acidic. This causes burning, and makes it harder for your muscles to contract. Lactic acid, which you may have heard of, actually takes some of these leftover byproducts (banana peels) and shuttles them out of your muscles. So, in a way, lactic acid actually helps fight against muscle burn!
While this might seem complicated, the solution for feeling less muscle burn is quite simple. You need to make your body better at creating energy and throwing away byproducts from muscle contraction. You do this by training more often, and performing higher reps with lower weight. Then, when you do less reps with heavier weight, you won’t feel as much of a burn because your body will be better keeping pH balanced.