Lactate profile

A lactate profile is a test used to examine how increased workloads affect lactate concentration in the blood, heart rate, and oxygen uptake.

It is a fundamental prerequisite for later interpretation of the results that lactate concentration after the first and second workloads is stable and that a minimum of four workloads is implemented. In various protocols, a workload time substantiating one stabilisation of HF (heart rate) and VO2, is given weight as well.

Warm-up

Warm-up should be moderate (BPM<150) for 10 min, preferably using the ergometer used for the test itself. Any feature with a higher workload should not be implemented before the lactate profile test. Following the warm-up, a five minute break is given for the purpose of any remaining preparations (hydration, toilet break, changing clothes or shoes).

Many of those who test their lactate profile, choose to test their oxygen uptake right after, but some choose to forego the VO2 max test. We highly recommend performing the VO2 max test, as it provides valuable additional information, and a better starting point for the interpretation of the lactate profile.

Specific testing equipment

We may use different ergometers for different sports. It is crucial that the equipment is checked frequently for any critical faults that may harm the athlete.

Test procedure and criteria for an approved test

All lactate profile protocols are implemented by increasing the workload at regular intervals, and with set workload levels.

If the athlete has been tested before, the workload layout is provided. If the athlete is “new,” a discretionary decision must be made in cooperation between the trainer and the athlete. 

Each workload level lasts for five minutes. Five minutes are the preferred rule, but some sports traditionally have shorter level length which are offered on sport-specific tests.

The workload is determined based on sport type and ergometer (see protocols below). The increments from one level to the next should correspond to an increase in VO2 in the range 4-6 ml/kg per min. At the end of each workload level, heart rate (last 30 seconds) and VO2 (last minute) are measured. Between each increase, a blood test is taken for determining lactate (excluding when testing on bicycle ergometer, see protocol below). All lactate analyses are carried out using Bios lactate meter.  

Below are specific conditions related to testing using different ergometers.

Common to all procedures:

  • Total workload levels are 4-6
  • 30 second break between each level (excluding bicycle).
  • Workload, lactate, VO2, ventilation (Ve), breathing frequency (BF), heart rate (HF), respiratory exchange ratio (RER), are recorded at every level.
  • HF is recorded during the last three minutes of every level.
  • Blood test is taken during the break (excluding bicycle), and is analysed for lactate.
  • The test ends when the selected limit of lactate is reached (4.0).

Running on treadmill

  • Duration of each level: 5 min
  • Tilt: 1,75 % or 10,5 % (exception 5,25%)
  • Speed increase between levels: 1,0 km/h or 1,5 km/h.
  • VO2 is measured from 2,5-4 min for each workload
  • Average VO2 for one minute from the third to the fourth is used
  • Limit value for lactate:  >1,5 mmol/l over the mean value of the first two increments.

Bicycle

  • Duration of each level: 5 min
  • Cadence; free
  • Watt increase men over 65 kg: 50w. Boys and girls under 65 kg: 40w.
  • No breaks between levels
  • VO2 measurements from 2 to 4 ½ minutes
  • Average VO2 for one minute from the 2,5 minute is used
  • Blood test is taken during the last 15 seconds of each level, and is analysed for lactate.      
  • Limit value for lactate:  >1,5 mmol/l over the mean value of the first two increments.