LACTATE THRESHOLD

 

The point during all-out exercise when lactic acid builds up in the blood faster than the body can remove it. Lactic acid is a by-product of anaerobic energy, which provides energy to muscles by breaking down glucose without oxygen, for short, high-intensity bursts of activity. When lactic acid builds-up and reaches a threshold where it can no longer be absorbed and accumulates it is known as the lactate threshold. It is usually reached between 50 to 80% of an athlete's VO2 max.

Measuring Lactate Threshold

In our lab, lactate threshold tests are performed in a similar manner to VO2 Max testing and use either a treadmill or stationary bike. The exercise intensity is increased in periods of about 4-5 minutes and blood samples are taken with a finger stick at the end of each period. Along with blood lactate concentration, heart rate, power output and VO2 are often measured. This process continues until the blood lactate concentration increases significantly as evidenced by an obvious spike. Because lactate threshold occurs sooner than VO2 max is reached, it is often measured as a percentage of VO2 max.

Lactate Threshold Values

• The average person reaches their LT at 60 percent of their VO2 max
• Recreational athletes reach their LT at 65-80 percent their VO2 max
• Elite endurance athletes reach their LT at 85-95 percent their VO2 max

Increasing Lactate Threshold

 

Debate continues regarding the science of the lactate threshold, whether there is such a point, and the value of trying to measure it at all. The good news for athletes is that although these numbers may or may not be proven, it has been shown that with training athletes are able to tolerate higher intensity exercise for longer periods of time.

• Proper Training to help increase your LT include:
  
  • Interval LT Training: Twice a week perform three to five 10 minute high effort intervals at 95-105 percent of your LT heart rate with 3 min rest between intervals.
  • Continuous LT Training: Twice a week perform one 20-30 minute high intensity effort at 95-105 percent of your LT heart rate.