How fast can an athlete recover during exercise?

Most competitions are not won by maintaining a steady intensity. Football, basketball, road cycling, mountain biking, cross-country skiing, triathlon and even running races etc. are all decided in moments of accelerations, attacks or other high-intensity periods followed by opportunities to recover.

In these situations, recovery has two dimensions. The first is how quickly the athlete can reduce accumulated lactate. The second is the power output or speed the athlete can maintain while doing so. Fast clearance alone is of limited competitive value if recovery requires the athlete to slow down so much that they cannot keep up with competitors.

Lactate Clearance Rate therefore describes both sides of the performance problem: how fast can the athlete recover, and how much performance can the athlete maintain while recovering?

Imagine two athletes who both reach a blood lactate concentration of 8 mmol/L and want to reduce it to 4 mmol/L, a decrease of 4 mmol/L. At a clearance rate of 0.5 mmol/L per minute, it will take Athlete A approximately 8 minutes. For athlete B with a clearance rate of 0.8 mmol/L per minute, the same reduction would take only 5 minutes. This is 3 min earlier, a huge competitive advantage over the competition.

But time is only half of the story. Two athletes can have the same maximum clearance rate while reaching it at very different power outputs or running speeds. In competition, the athlete who can recover while maintaining the higher external workload has a major practical advantage.

The combination of clearance rate and the power or speed maintained during clearance provides a knowledge that a single threshold value does not capture. For example in professional cycling, the lactate clearance rate has been proven effective to create individual pacing strategies.

In triathlon using the intensity at maximum lactate clearance rate results in higher running speed and therefore race performance.

The on-phase of interval training is usually planned very precisely by intensity, duration and number of repetitions. However the recovery phase between intervals is often specified much less precisely, even though it changes the metabolic stimulus of the session substantially.

Repeatedly insufficient recovery with little lactate and pH clearance compounds during the set resulting in a progressive shift to a less anaerobic and more aerobic training stimulus.

If the recovery period allows greater clearance, each new repetition can begin from a more recovered metabolic state. This can preserve a larger glycolytic contribution during repeated high-intensity efforts.

The same work intervals will therefore create different training stimuli depending on what happens between them.

Lactate clearance capacity differs between athletes and changes with training status. A recovery duration and intensity that restores one athlete sufficiently may leave another athlete with substantial residual lactate and pH values before the next repetition.

This means two athletes can complete exactly the same work intervals, same power or speed, same duration and same number of repetitions, yet experience different training stimuli because their recovery kinetics are different.

If the objective is to control and apply the correct and most efficient training stimuli of an interval session, the recovery phase needs to be individualized as deliberately as the work phase.