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Use a Lactate Pro to Find Training Zones

Thu, Sep  7, 2006 - By Mike Muha

The usual way of finding your training zones is to determine your max heart rate, then compute the various zones as percentages of your max heart rate. For example, 60-70% of your max heart rate would be consider Zone 1, the target range for long distance training.

This method, described in more detail in Getting in the Zone!, is only the poor man's way to estimate what you really want to know: your lactate zones. Lactate blood level is a more accurate measurement of workload. Lactate levels below 2 mmol is considered distance training; around 4 mmol, threshold training.

One participant at June's NordicSkiRacer Training Camp with Sten Fjeldheim and Jenny Ryan underwent a true lactate test to determine his lactate zones. Steve Kuhl, a member of Team NordicSkiRacer and part of the Fischer Ambassador Program, was randomly selected from numerous volunteers to take part in a demonstration of how lactate testing is done.

Steve getting warmed up on the treadmill

Test methodology

The first part of the test involved taking a blood sample and determining lactate levels at rest. Steve sat in a chair and had his middle finger pricked using a Lancet Device. The area was then cleaned with cotton gauze in alcohol, then a drop of blood was squeezed from his finger onto a test strip sticking out the the Lactate Pro device. Steve's lactate level at rest? 1.3 mmol.

Hmmm...He's resting but has lactate in his blood? What gives?

Lactate is constantly produced by your body and is in fact an energy source. As your muscles produce lactate, it is removed from the blood and reused by other tissues or muscles.

Cotton gauze pads (to clean sweat from Steve's finger), test strips (inserted into the top of the Lactate Pro), Lancet Device (pricks the finger to draw blood) and the Lactate Pro.

Close up of the Lancet Device and the Lactate Pro

Steve was outfitted with a Polar heart rate monitor chest strap, and the heart rate monitor was attached to the treadmill so both Steve and Jen could easily see it.

Steve warmed up on a treadmill for ten minutes. After warm up, this process was repeated:

  1. Run 3 minutes
  2. Step off the running belt to the treadmill side for 1 minute and mmediately record the heart rate.
  3. Collect a blood sample using the same protocol as before: prick, clean, get the sample.
  4. Increase the speed and/or incline on the treadmill. In this test, the treadmill was running at 6.2 mph and the incline was increased by 2% for each test. For the last test, the speed was also increased to 6.5 mph.
  5. At the end of the 1 minute, record the "resting" heart rate, then start running again.
  6. Repeat until lactate levels approach 4 mmol or until there is a sharp curve upward in the lactate vs. time graph.

Because sweat affects the results, the first step is to wipe the blood with a gauze and alcohol, then squeeze the finger to draw blood for the test.

Jen Ryan increasing the elevation of the treadmill during the 1 minute rest period between measures. Looks like Steve is starting to sweat a little...

The treadmill was running at 6.2 mph and the incline was increased by 2% for each blood sample. For the last sample, the speed was also increased to 6.5 mph.

A total of six samples were collected, until the Steve's lactate levels reached 3.7 mmol and the graph (below) showed a marked upward trend.

If you do this test yourself, you should record both the speed and incline so you can reproduce the exact test at a later time. (In the graph below, Sten marked the incline setting at each stage, i.e., 2%, 4%, 6% ...).

Table of lactate levels, heart rate at the time the sample was taken, and the heart rate at the end of the 1 minute rest period.

Test Results

I've reproduced the graph to make it a little easier to read:

As you can see, lactate levels gradually increase to 1.9 mmol at about 0.1 mmol every four minutes, then suddenly shoot up by 0.8 to 2.7 mmol at the fifth sample.

Notice the heart rate changes: between sample 3 and 4, heart rate increased by 9 beats (lactate by 0.1 mmol); between sample 4 and 5, by 6 beats (lactate by 0.8 mmol). It only took a small increase in heart rate for lactate levels to increase significantly!

The rapid increase in lactate levels indicates that the body is no longer able to keep up with clearing lactate from the blood.

This is critical information when training. According to Sten, too many skiers go to hard during long distance sessions, getting past the 2 mmol level. Once lactate levels are above 2 mmol, the session becomes significantly harder and recovery takes longer. This will lower the quality of threshold and V02 max sessions because the skier will not take enough time to recover from the too hard distance session.

Turning Lactate Levels into Training Zones

Sten defined four training levels for Steve: an "over-distance" or long distance training level, a shorter distance zone, plus threshold and max V02 training zones. Notice the gap in heart rate between L2 and L3: training in that area is not bad, simply not optimal.

Zone

Target Lactate Level

Heart Rate Range Suggested Training Sessions
L1 Up to 1.8mm 159-166 2.5 to 3.0 hour distance sessions
L2 1.8 to 2.0 mm 155-175 45 min to 1.5 hour distance sessions
L3 3.7 - 4.0 mm 187-189 Threshold intervals
L4 Over 4.0 mm 189-192 to max V02 Max intervals

So Steve knows that if he wants to go a threshold session with a lactate value around 4.0, he simply needs to set his heart rate monitor to beep at him if he goes below 187 or above 189 beats per minute.

Costs

Lactate testing is something a club or team could conceivably afford. A quick search on the web turned up these sample costs:

$370-$415   Lactate Pro
60-65   Box of 25 Test Strips
35-40   Softclix Pro Lancet for multiple users
44-48   Box of 200 Lancets for Softclix Pro

$509-$568

  Plus tax and shipping

The cost for Steve's testing was about $20 for test strips and lancets.


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