(ENG) Conconi test on a treadmill

Italian doctor and scientist Francesco Conconi developed his test for aerobic capacity in 1980s. The test is usually done on a stadium. I tried to do it on a treadmill.


Theory

The primary question answered by Conconi test is "where is (in terms of heart-rate or HR) the limit of my aerobic capacity". That is, we try to find a threshold (in terms of HR), which should not be exceeded if we want to stay in the aerobic zone. This threshold is called "anaerobic threshold" = AT. AT is also referred to as "lactate threshold", because above this threshold your muscles start to build up lactate (which is not what you want on a long-distance run). Please take note that anaerobic threshold is not the same as aerobic threshold. When you are below your aerobic threshold, your muscles fully utilize (almost) all the lactate produced within your body - this implies your lactate level stays below 2 mmol/L. As you go beyond your aerobic threshold, your lactate level starts to go up, but it is still manageable, as long as your stay below the anaerobic threshold (AT). You might, for instance, run with a (nearly) constant lactate level of 2.5 mmol/L or 3.0 mmol/L without being heavily exhausted. But when your exceed your AT (with is beleived to correspond to lactate level of 4.0 mmol/L), lactate production rate gets higher than your body's ability to utilize lactate, and you get the lactate level soaring and your muscles fill with it (which causes fatigue or sometimes even cramps). For a professional runner it is essential to know his or her HR rates which correspond to given levels of lactate (2.0 mmol/L, 2.5 mmol/L etc) - this demands a lactate test in a lab. However, an amateur can find his or her AT (at least approximately) through Conconi test.

The idea is to run 200m stretches at increasing pace (each stretch at constant speed, higher than that on the previous stretch), measuring HR. At the end, you have speed and HR data for each stretch. If you put those on a graph, you can usually find a sort of breaking point on the graph - this point shows your AT. The breaking point is explained by the fact that you don't have to increase oxygen supply to the muscles when you are in the anaerobic zone - that's why your HR doesn't go up so fast, as it does in the aerobic zone.

You can also use the Conconi test to follow your aerobic capacity progress. For example, if you compare test results before and after a training cycle, you can get an idea of you progress by looking at the graph (if your aerobic capacity improved, the graph will move rightwards). However, the test demands some aerobic capacity to start with, and is not recommended for complete beginners.

Implementation

I ran 250m stretches, increasing the speed by 0.5 kmh on each stretch. HR was measured by chest HR-monitor. I got average and peak HR for each stretch. I ran the test in minimalist shoes trying to keep my running technique as close to the "natural" as possible. Would test results differ, if I perfrmed the test on a stadium or a road? Probably yes, in terms of speed. But anaerobic HR would be the same, and HR is exactly what we are looking at in this test.

Results

Here are my average and peak HRs plotted vs speed:

I used average HR to find the beaking point:

It seems my AT is about 175-177 bpm, which makes approximately 90% of my max HR. This goes in line with theory found in literature.

Knowledge of my AT allows to determine training zones (I use zones described in Peter Janssen's book). Let's assume AT=177, HRmax=197, then

R - recreation zone, 70% - 80% of AT = 124 bpm - 142 bpm or  60% - 70% of HRmax = 118 bpm - 138 bpm

А1 - aerobic zone 1.  80% - 90% of AT = 142 bpm - 159 bpm or  70% - 80% of HRmax = 138 bpm - 158 bpm

А2 - aerobic zone 2.  90% - 95% of AT = 159 bpm - 168 bpm or  80% - 85% of HRmax = 158 bpm - 167 bpm

Е1 - development (transition) zone 1.  95% - 100% of AT = 168 bpm - 177 bpm or 85% - 90% of HRmax = 167 bpm - 177 bpm

Е2 - development zone 2.  100% - 110% of AT = 177 bpm - 195 bpm or 90% - 95% of HRmax = 177 bpm - 187 bpm

Literature

1. Peter Janssen. Training lactate pulse-rate. Polar Electro, 1987.

2. Dr. Philip Maffetone. The big book of endurance training and racing. Skyhorse Publishing, 2010.

3. Enrico Arcelli, Renato Canova. Marathon training: a scientific approach. International Athletic Federation, 1999.