In the last post we talked about why people may use a heart rate monitor. Click here if you missed that post.
Besides the most common value people check when they use a heart rate monitor, which is calories burned there are a number of other benefits to using one. But first we should do a quick review so we’re all on the same page as to what we’re talking about. So here’s a quick recap of some of the terms you may get thrown around on blogs and in training circles.
Anaerobic Threshold – This is the intensity of exercise where energy demands cannot solely be supplied by oxygen and must be supplemented by anaerobic metabolism.
Lactate Threshold – As the demands for energy produced anaerobically increase there is a lactate accumulation in the blood as well. Lactate accumulates because it is being produced faster than it can be cleared from the blood. The units for this measure may be expressed as mmol/L.
VO2max – This is the highest rate of oxygen consumption at maximal intensity exercise. In other words when we are below our VO2max we can still consume more oxygen with increasing intensity. However once our VO2max has been achieved further increases with intensity will not result in increased oxygen consumption. In terms of units it is usually expressed as ml/kg/min.
If I’ve worked with you before or you are familiar with our coaching style at Okanagan Peak Performance Inc you’ll know we use a lot of analogies. So here’s the analogy for lactate threshold and VO2max.
Lactate Threshold is like the floor in your home. VO2max is like the ceiling.
With my own training I would like to improve my lactate threshold. In other words I want to raise the floor up towards the ceiling.
Let’s throw in some numbers so we can see what this looks like.
Lactate threshold = 147 bpm (determined from lab testing)
VO2max = 51 (determined from lab testing)
Max heart rate = 178 (220-age)
Resting heart rate = 48 (taken in morning upon rising)
Heart rate reserve (HRR) = Max heart rate – resting heart rate = 178 – 48 = 130
Now if I hadn’t done any lab testing I could estimate my lactate threshold as 80-90% of my HRR. So this would look like 130 * 0.8 = 104 if I went with 80% or with 90% this would be 130 * 0.90 = 117.
But from the test in the lab with Dr. DuManoir we determined my lactate threshold to be 147. So you can see the immediate value of a lab lactate threshold test is the accuracy. Had I simply gone with the estimations of 80 or 90% of HRR I would be training at least 30 beats lower than what I could sustain aerobically.
As I progress with my training I may notice my fitness improves. And this could be expressed as either a lowering of my resting heart rate, an increase in my max heart rate or both. Either way I would hope there is an increase in my HRR. This would mean my floor (lactate threshold) should be climbing slightly and getting closer to my VO2max.
The great thing about having a lactate threshold closer to my VO2max means I can train or compete at a faster pace or higher intensity while still staying aerobic.
Why is this beneficial?
Well here’s another analogy for you. Imagine that once you exceed lactate threshold and keep pushing past, that you have lit the fuse of a bomb. For some this might be a very short fuse before they ‘blow up’. So it would be ideal to save lighting this fuse until the final leg of a race when you can empty the tank and push for the finish.
When there is a big difference between lactate threshold and VO2max this fuse can potentially be lit prematurely when we push to climb a hill in a race, pass an opponent or anything else where we need to increase our pace or intensity.
For your own training take some to figure out your heart rate reserve. In the mornings count your pulse for 30 seconds and double your number. Do this for three days in a row and take the average. This will give you a good idea of your resting heart rate.
Next subtract your age from 220 to figure out your max heart rate. Realize this number can be up or down 5 beats and is simply an estimate. With both a resting and max heart rate you can figure out your HRR.
In a future blog we can break down your heart rate zones and identify how much time to dedicate to each to improve your performance.