LK

Lactate Inflection Point (HL)

Lactate Inflection point: the point when lactic acid starts building up in your blood faster than your body can remove it during intense exercise.

--> lactate threshold

Threshold or inflection point: point at which something begins to change or happen

VO2 max: the maximum rate at which an individual takes in and uses oxygen

Once exercise exceeds VO2 max 'oxygen debt' occurs

--> metabolism switches from aerobic to anaerobic

--> leads to abrupt increase in blood lactate levels

Increase in blood lactate leads to the impairment of muscle contractility and fatigue

More recent research in the critical power threshold - a measure of the max power output a person can sustain for long periods of time without fatigue

Impact on training:

  1. Set training zones - helps athletes identify their optimal intensity for endurance training, improves aerobic capacity and lactate clearance, and bush the body to tolerance and buffer lactate better

  2. Enhance performance - allows athletes to sustain higher intensities for longer

  3. Tailor training plans - can focus on different energy systems by targeting specific zones

Below LIP: improves aerobic efficiency and recovery

At or slightly above LIP: boosts lactate threshold, delaying fatigue

  1. Monitor progress: regular testing enables adjustments in training to meet new goals

Negative relationship between power output and the time it is sustained for

Power sustained for

  • 20 min (CP20)

  • 45 min (CP 45)

  • 60 min (CP60)

As the duration of exercise increases, the body's ability to produce and sustain high power decreases. This is because of:

  1. Fatigue - significantly depletes energy stores

  2. Lactic acid buildup - higher intensities for shorter periods rely on anaerobic energy, which can't be sustained over time

  3. Aerobic reliance - as time increases, the body shifts towards slower, aerobic energy systems which produce less power