Who Builds More Lactic Acid: a Sprinter or a Jogger?

Lactic acid is a byproduct your body creates when it uses up your oxygen reserves and doesn't fully break down the glucose it uses for energy due to a temporary lack of oxygen in your muscles. Although both aerobic exercises, like jogging, and anaerobic exercises, such as sprinting, can cause lactic acid to build up in your muscles, lactic-acid buildup is more common during sprinting.

The sudden bursts of energy needed for sprinting burn up the oxygen in your muscles much faster than a leisurely jog does. In fact, sprinting burns up oxygen faster than your body can deliver it to your muscles, causing you to exercise in a state of oxygen debt. You can exercise for one to three minutes in this state, but it causes large amounts of lactic acid to build up in your muscles. Most people jog at a pace that still allows the body to deliver sufficient oxygen to your muscles to fully break down the glucose used for energy without creating lactic acid.

Some people believe that the muscle soreness that occurs after exercising is due to lactic acid in their muscles. This is not the case, according to a "Scientific American" article published in January 2006. Although lactic acid can cause a burning sensation during exercise, the lactic acid is quickly cleared from the body after exercise. Any delayed-onset pain is likely due to small tears in your muscles caused by your exercise.

Lactic acid may actually be beneficial. It serves as a source of fuel, affects your metabolism and may even help with weight loss, notes a June 2006 article in "The New York Times." The brain, diaphragm and heart all perform well using lactic acid as a fuel, so exercises that produce lactic acid don't need to be avoided. The soreness it causes during exercise usually causes athletes to stop before major damage is done to the muscles.

Both sprinting and jogging provide health benefits. Aerobic exercises like jogging strengthen your heart, help with weight loss, increase your stamina, keep your arteries clear, improve your mood and help you live longer. Sprinting intervals can provide many of these same benefits in a shorter time for those healthy enough for intense exercise who want to shorten their workouts, notes a July 2008 study published in "American Journal of Physiology — Regulatory, Integrative and Comparative Physiology."

Article reviewed by John Hagemann Last updated on: Feb 1, 2012

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