1. Lactic Threshold and Differences Between Trained and Untrained Individuals

2. Rest to Exercise Transition
During incremental exercise ventilation initially increases proportional to the increase in workload
Eventually a point is reached when ventilation increases much more rapidly (VENTILATORY THRESHOLD)
Normally this occurs at 65-85% of VO2 Max depending on the individual’s fitness level
This can also be called the Anaerobic Threshold

3. Increase in ventilation occurs b/c of an increase in lactic acid accumulation (by product of anaerobic metabolic processes in muscle) and the drop on pH
The Ventilatory Threshold is often used as a marker of increase reliance on anaerobic metabolic systems during exercise

4. The Talk Test can be used to indicate this Anaerobic Threshold (point at which lactate levels increase abruptly beyond resting values)
Think about it…when you exercise there is a point when it is hard to talk and exercise at the same time

5. Talk Test and RPE

6. Blood lactate can be measured during this time to determine a certain threshold
Initially it is low and as the exercise progresses it reaches a point where blood lactate concentrations rise exponentially

7. This is referred to as the Lactate Threshold
This is where lactic acid builds up in the blood stream faster than the body can remove it
High concentrations can be seen in these blood samples

8. Lactate Response to Intensity

9. Trained people have a higher tolerance for Lactic Acid compared to unconditioned people
The fitter you are, the harder you can exercise before surpassing the LT

10. The lactate threshold is closely associated with the Ventilatory threshold
When blood lactate levels begin to accumulate rapidly (shortly after the Lactate Threshold) this is referred to as the OBLA
OBLA is the onset of blood lactate accumulation

11. Ventilatory and Blood Lactate Response to Exercise

12. Training and OBLA (page 130 in text)
With proper aerobic training the OBLA curve can be shifted to the right such that OBLA occurs later and during higher levels of intense exercise