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The science of running: what is lactate threshold?


What is lactate threshold? Lactate threshold is the exercise intensity at which lactate or lactic acid starts building up in the blood stream. This happens during high-intensity, all-out exercise. During moderate exercise lactate is absorbed by the body quickly. During high-intensity activity, lactate is produced faster than the body can absorb it.

Knowing your lactate threshold can help you determine what paces to train at to improve your performance in endurance sports.

What is my lactate threshold? Lactate threshold is different from VO2 max because VO2 max depends greatly on genetics while lactate threshold is controlled by training. Lactate threshold can be increased significantly with the proper training program.

Like VO2 max, you can learn your exact lactate threshold in an exercise physiology lab. You’ll have to do a prescribed workout on a treadmill or stationary bike and have a finger prick taken at different time intervals throughout the test to see when your lactate threshold is reached.

Unfortunately, this test is expensive and invasive. Home lactate analyzers are available for purchase, but you’ll need to be able to prick your finger and run at the same time – a skill few runners possess! There are several lactate threshold calculators and formulas online that don’t require a finger price, but they’re not always accurate.

Experts from East Carolina University say the 30-minute exam is one of the best ways to estimate your lactate threshold. For this test, you’ll need to use the WalkJogRun app, a GPS watch, or another device that accurately measures distance. Warm up and then run fast for exactly 30 minutes. At the end of the 30 minutes, divide the distance you ran (in meters) by 1800 seconds.

Example: Say in 30 minutes you ran 7000m (about 4.3 miles). Your calculation would be 7000m/ 1800 seconds = 3.89 meters per second. This translates to a tempo of 400/ 3.89 = 102 seconds. 102 seconds x 4 = 408 seconds, or 6.8 minutes. Therefore your lactate threshold is roughly a 6:47 minute/ mile.

How can I increase my lactate threshold? Once you know your lactate threshold, you can do workouts using that pace as a guide. Regularly running near your lactate threshold pace will improve your lactate threshold, overall fitness, and race times.

Try these workouts. Do a different one each week to get the maximum benefits:

  • 2-4 x 2000m repeats at eight seconds per mile faster than your lactate threshold pace.
  • 3–5 x 1200m- 1600m repeats at 16 seconds per mile faster.
  • 6–8 x 800m repeats at 32 seconds per mile faster.
  • 10–12 x 400m repeats at 48 seconds per mile faster.

For each workout, recover by running slowly between each work interval for the same amount of time it took you to complete the previous interval.

Keep in mind that lactate threshold changes a lot over the course of training, so repeat the 30-minute exam every season to learn your current lactate threshold.

Written by Jen Matz.

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