Trivia

Hard

Muscle Soreness During Exercise Is Caused By The Buildup Of?

Lactic Acid
Citric Acid
Creatine
Glycogen
The Adrian C. "Ace" Israel Fitness room at Yale University in the Payne Whitney Gym.
Henry M. Trotter/Wikimedia

Answer: Lactic Acid

There’s a long standing fitness myth that after a hard workout, your muscles are sore because of the buildup of lactic acid, or lactate, but by the time your muscles are aching a day or two after a heavy workout, the lactic acid has long since been cleaned up and purged from your muscles. At that point, you’re experiencing inflammation as your muscles repair themselves, and what physiologists refer to as DOMS (Delayed-Onset Muscle Soreness), a post-workout ache that is still not fully understood.

When you’re actually in the process of exercising strenuously (and shortly thereafter), you can thank a temporary buildup of lactic acid in the muscle tissue for that biological reminder to slow down. While our body prefers to generate energy using aerobic mechanisms (which require an adequate supply of oxygen), during periods of intense exercise, we burn up the energy reserves in our muscle tissue faster than our oxygen intake can handle. As a result, our muscles briefly switch to an anaerobic energy process called glycolysis, wherein glucose is broken down into a compound called pyruvate. That pyruvate is then, in turn, temporarily converted into lactate for continued energy production by our energy-starved muscles.

The quick buildup of lactate increases the acidity of the muscle tissue and disrupts other metabolic processes. When you’re lifting heavy weights or running at peak capacity, the unpleasant sensation of your muscles burning due to overexertion is a result of high levels of lactic acid. Typically, the onset of that feeling gets us to slow down enough for the body to regain adequate levels of oxygen and begin clearing away the lactic acid, thus reducing the chance that we injure ourselves—a built-in safety mechanism, if you will, against pressing ourselves to the point of injury.

More Trivia Questions

Trivia

Hard

The Underside Of Nuclear Bombers Are Traditionally Painted What Color?

Trivia

Hard

Mining Companies Are Analyzing What Unusual Source To Find Gold?

Trivia

Hard

Which Iconic Sci-Fi Character Is Immortalized As A Grotesque On The Washington National Cathedral?

Trivia

Easy

Which Sci-Fi Actor Raised $25,000 For Charity By Selling His Kidney Stone?

Trivia

Hard

Which Of These Automotive Innovations Was Invented By Accident?

Trivia

Hard

Corn Farmers Purchase Micronutrients For Their Crops Made From What Unusual Source?

Trivia

Hard

What Are The Plastic Lumps Found On The Ends Of Computer Cables Called?

Trivia

Hard

What Office Ritual Is The Result Of Careful Marketing?

Trivia

Hard

Which Tech Company’s Name Means “Three Oceans”?

Trivia

Hard

Which Videogame’s In-Game Universe Corresponds Directly To The Real World?