LACTATE INFLECTION POINT & RECOVERY

Week 11

OBLA

Onset of Blood Lactate AccumulationAt rest, everyone has lactic acid in their

musclesWhen exercise begins the muscular levels

of lactic acid begin to riseThe level of hydrogen ions (H+) also riseThis is known as OBLA

Lactate Threshold

Now better known as Lactate Inflection Point (LIP)

Lactic acid production is greater than lactic acid removal

At exercise intensities beyond the LIP blood lactic acid concentration increases

Beyond the lactate threshold/LIP the athlete has to stop or reduce muscle effort

Trained athletes can and aim to increase their tolerance to lactic acid accumulation

Determining the LT/LIP

Scientific testing in labs (eg: AIS) is the best method

Some rough estimates are in table 2.3, p.76 Untrained athlete ~60% max HR Trained athlete ~90% max HR

Determining the LT/LIP

VO2 max

• Untrained athlete: LIP = ~50% VO2 max

• Trained athlete: LIP = ~75-80% VO2max

LIP & Fatigue

Exercise intensities beyond the LIP are associated with fatigue

The greater the exercise intensity above the inflection point, the more rapid the fatigue

This fatigue is generally considered to be a consequence of a greater reliance on the anaerobic systems to supply the adenosine triphosphate (ATP) and the resultant accumulation of the by-products of anaerobic metabolism Lactic acid and hydrogen ions

Lactic Acid Removal/Recovery

When lactic acid builds up an active recovery is best

Keep moving and keep HR slightly elevated This keeps blood flow higher to help break down

lactic acid Lactic acid pyruvic acid ATP (Kreb’s cycle) Lactic acid is now thought to have some

positive effect on performance When oxygen is available it can help to produce

ATP See fig. 2.17, p.78

Learning Activities

Activity 8, p.77Newspaper article, p.79