6 Things Runners Need to Know About Lactic Acid

I took a mandatory biochemistry course in Nutrition school and I have to admit, I was a little afraid of it when I entered the program. Math is not my thing, plus I never took chemistry in high school. I expected the course to be highly technical, fairly dry, and I didn’t think I could apply it to my running. But the opposite was true.

Every once in a while, my workouts really hurt. I am sore for days afterwards. It hurts to sit, to lie down, and especially to walk. Many runners associate this type of soreness with a lactic acid buildup in the muscles. In biochemistry, we took a microscope to that offending acid and learned exactly how and why it occurs, as well as how to relieve it.


Speaking from a strictly chemical perspective, lactic acid falls under the carboxyl functional group. This is a group of acidic molecules that occur during the breakdown of sugars. Lactic acid is a byproduct of our body breaking down the sugar we need for energy.

When we are involved in intense exercise, we are not getting enough oxygen to completely metabolize sugar. So our body starts making energy from glucose without oxygen. The byproduct of this is lactic acid, which quickly accumulates in our muscles. The pH acidity of our muscles starts to rise, and we feel sore.

After we have worked out, our body will eventually send the excess lactic acid back to our liver to be made into sugar again, but it takes a couple of days for this process to complete itself. This is why it takes us two or three days to recover from a strenuous workout.


1. Hyperventilating increases lactic acid buildup.

It does this by changing the acid level in our blood by altering the balance of carbon dioxide. So proper breathing while running or working out are crucial to your recovery later. When you see people huffing and puffing and wheezing through their exercise – those are the ones who may be suffering in two days. Deep breathing, on the other hand, is a great defense.

I have learned that breathing well doesn’t come naturally. At least not at first. You have to consciously make an effort to inhale and exhale slowly and deeply. At first I worried that I wouldn’t be able to get enough oxygen this way. But I actually ended up getting more. Here is a post on proper breathing technique for runners.

2. Dips in blood sugar can increase lactic acid buildup.

Many runners have experienced low blood sugar. It’s that energy crash, sluggishness, irritability, moodiness, headache, etc. You can combat this by eating little and often. Nutrition is key both to running long, as well as a quick recovery. Experimentation is everything here. Try different forms of nutrition until you find something that works for you.

3. A vitamin B1 deficiency may be a factor.

The B’s are my favourite vitamin because they’re so complex in their functions, and extremely important for so many things. But this particular B vitamin helps in the body’s breakdown of glucose. A B1 deficiency could hinder your glucose breakdown, promoting a lactic acid buildup. Aside from eating plenty of fresh fruits and vegetables, you may want to consider a multivitamin and/or a B complex vitamin (contains all the B vitamins) if you think this may be an issue for you.


1. Keep moving.

Sitting around in pain will only backfire. Go for a walk, or get on a treadmill and set it uphill on a very slow setting. Take long, slow strides for about 10 minutes. This will probably hurt, but it will help in the long run (pun intended).

2. Stretching helps.

I’m guilty of not always doing this, but I find that the post-workout stretch helps improve my recovery time. I don’t always feel like I need to stretch in the moment, but I will tighten up afterwards. Yoga is a great compliment to running. I feel much stronger when I supplement running with some form of yoga.

3. Protein repairs your muscles.

I have found that supplementing with BCAAs (branch chain amino acids) right after a particularly strenuous workout (especially involving weights) makes an enormous difference. I take this in powder form. BCAAs are easy for my body to process and they don’t give me any stomach issues.

I’ve been in pain before and I’m sure I’ll be in pain again. Exercise is basically a process of damaging the body a little bit, and then allowing it to repair itself. In the end, it all comes down to a chemical balance. And a biochemistry equation that used to mean nothing, but now makes sense.


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