The lactate threshold refers to a physiological barrier the human body encounters during exercise. During exercise the body uses oxygen as energy to power the muscles. The body uses three energy systems which provide energy for exercise, two of which are anaerobic (without oxygen) and one is aerobic (with oxygen). These anaerobic energy systems produce energy without the use of oxygen. As this is done the production of lactic acid occurs as there is no supply of oxygen to break it down in to pyruvate and Co2, and disperse it from the body.
If this exercise is to continue and the production of lactate continues at a rate faster than that of which the body can remove it this is then called the Lactate Threshold, or Anaerobic Barrier. The lactate that is built up then has nowhere to go so is in and around the muscles and blood stream causing blockages. This is what causes the legs to feel heavy after periods of sustained exercise. Once oxygen is available the oxygen is used in a chemical reaction to convert the lactate back into pyruvate and co2 which can then be dispersed thus freeing up the muscles.
During this test the heart rate of the athlete is also monitored and recorded, therefore when the lactate threshold is reached the heart rate at which it was reached is determined. This information can then be taken to the coach and used in training, as the coach will know at what intensity to peak and plateau the athlete at. Therefore the rationale for this lab report is to obtain a lactate threshold level for a participant in order for them to maximise their training.
The participant turned up to the test dressed in the appropriate clothing for the event. Once there a consent form and Par Q were signed to ensure good health of the participant, the measures and statures of the participant were then recorded. Once completed the participant undertook a 2 min running warm-up on the Woodway treadmill, then a lower limb stretch was done. The treadmill computer was then programmed to conduct the appropriate test, the levels were dictated due to the participant predicting their fitness level against table 1.
The participant ran for as many four minute stages with a one minute rest in between as possible, with the level increasing at each stage. During the one minute rest period a blood sample was taken and a lactate level recorded. The Oxygen level was monitored throughout the duration of the test. At the end of the test a 2 minute cool down was performed to reduce the participant’s heart rate.