Lactate Threshold
To understand lactate threshold, we first need to define the term lactate.
"Lactate is a product of glycosis (the conversion of carbohydrates into glycogen stored in the body)," Cournane says. "It's a natural by-product of the body produced by muscle contraction. As athletes exercise at a higher intensity, lactate production increases. Lactate is absorbed by the muscles during exercise."
This means lactate threshold is the maximum steady-state effort a runner can maintain without lactate continually increasing.
"When you're running at a pace within your lactate threshold, you can maintain a high-end aerobic effort that feels comfortably-hard," Karp says. "If you exceed your lactate threshold, your workout becomes more anaerobic and running becomes more difficult."
More: What Does Lactate Threshold Mean?
Why you should care: If you have a higher lactate threshold, you can run longer at a faster pace.
Simply stated: Lactate threshold is the speed at which lactate accumulates in the muscles and blood. If the amount of lactate produced exceeds the amount your body can absorb, that's when you start to experience muscle fatigue, and you'll slow down. If you have a higher lactate threshold, you'll be able to run faster and farther.
More: What are Threshold and Tempo Runs
Aerobic Capacity
Aerobic capacity describes the ability of the aerobic systems in your body to produce energy to be used by the muscles during exercise.
"The best synonym for aerobic capacity is endurance," Karp says. "It's a measure of the body's ability to produce energy for muscle contractions for a longer time."
Why you should care: As you build your aerobic capacity, you're able to run faster, harder and longer.
Simply stated: Aerobic capacity is your body's ability to produce energy to be used during exercise or running.
More: 4 Speed Workouts for Beginners
Ready to run? Search for a race.- 2
- of
- 2
About the Author
Get ACTIVE on the Go
Couch to 5K®
The best way to get new runners off the couch and across the finish line of their first 5K.
Available for iOS | Android
Discuss This Article