What is lactate threshold

The lactate threshold (LT) is a critical concept in exercise physiology and endurance training. It refers to the intensity of exercise at which lactate (a byproduct of anaerobic metabolism) starts to accumulate in the blood at a faster rate than it can be cleared. This point signifies a shift from predominantly aerobic energy production to a greater reliance on anaerobic energy production.

 

Key Points About Lactate Threshold:

Lactate Production and Clearance:

 

During low to moderate intensity exercise, lactate is produced at a low rate and is easily cleared by the body.

As exercise intensity increases, lactate production increases. When the production surpasses the clearance rate, lactate begins to accumulate.

Significance of Lactate Threshold:

 

Performance Indicator: The lactate threshold is a strong predictor of endurance performance. Athletes with a higher LT can sustain higher intensities without fatigue.

Training Tool: Understanding and training at or around the LT can improve endurance performance by increasing the body’s ability to clear lactate and delay fatigue.

Measurement:

 

LT is often measured during graded exercise tests in a lab, where blood lactate levels are monitored at various intensities.

It can also be estimated through field tests, such as time trials or specific interval sessions.

Training at Lactate Threshold:

 

Threshold Training: Workouts that involve sustained efforts at or just below the lactate threshold intensity. This typically feels like a "comfortably hard" effort.

Interval Training: Alternating periods of work at or above LT with recovery periods can also help improve lactate clearance and tolerance.

How to Determine and Use Lactate Threshold:

Determining LT:

 

Lab Testing: Conducted using a graded exercise test with blood lactate measurements. The point where lactate levels rise significantly marks the LT.

Field Testing: Use a heart rate monitor and perform a time trial (e.g., a 30-minute all-out effort). The average heart rate for the last 20 minutes can approximate the LT heart rate.

Using LT in Training:

 

Training Zones: Establish training zones based on LT. For instance, Zone 3 might be set around LT to improve lactate clearance.

Specific Workouts: Incorporate workouts like tempo runs, threshold intervals, or steady-state efforts at LT pace to improve aerobic and anaerobic efficiency.

Example of a Lactate Threshold Workout:

Warm-Up: 10-15 minutes of easy running.

Main Set:

Tempo Run: 20-40 minutes at a pace that corresponds to your LT (typically around 80-90% of maximum heart rate).

OR

Interval Session: 4 x 10 minutes at LT pace with 2-3 minutes of easy jogging recovery between intervals.

Cool Down: 10-15 minutes of easy running.

Benefits of Lactate Threshold Training:

Enhanced Endurance: Increases the duration you can sustain a higher intensity.

Improved Efficiency: Enhances the body’s ability to use lactate as a fuel and clear it from the muscles.

Delayed Fatigue: Helps you maintain performance for longer periods without experiencing significant fatigue.

Understanding and training around the lactate threshold can be a game-changer for endurance athletes, offering a pathway to improved performance and greater efficiency in long-distance events.