Lactate Threshold and Critical Power Testing

 

Test 1

Over the course of three sessions I’ve been one of many guinea pigs taking part in a study that will essentially assess the effects of recovery on the ability to work at anaerobic levels, and produce a repeatable test to measure it. I think the findings will be published sometime in the future and will undoubtedly contribute to the body of knowledge in Sports Science.  It’s a technical subject but interesting nonetheless and I look forward to seeing the finished article in the future.

From a personal perspective it has given me some up-to-date data carried out in laboratory conditions which I’ll describe here.

BodPod

At the first session I was measured and weighed and my body composition was analysed. There were a couple of anomalies with this that are worth mentioning. The first is that I appear to have slightly shrunk since the last time I was “formally” measured. Apparently I am now 174.2cm in height, as opposed to the 175cm that I was in 2005 when I last had a proper medical. A bit of research suggests that we can lose up to 1cm every 10 years over the age of 40 so that kind of explains it, but it was a bit of an unwelcome surprise. The second anomaly was the results of the BodPod body composition analyser. It came out with a 24% bodyfat, even after a second go and a calibration. Which suggested I am overweight and that I’m carrying the equivalent of about 16 bags-of-sugar worth of fat!  To put that into some sort of context – if it is correct and I somehow managed to lose that amount of fat to get down to “lean” levels I could have a power-to-weight ratio not dissimilar to a Tour de France rider – not going to happen!  A series of 9 measurements were also taken using calipers and this apparently resulted in a measure closer to 12%. As all previous subjects had shown a close correlation between the BodPod and the calipers something was clearly a bit weird about me, but it’s probably safe to say the answer is somewhere in between (my Tanita bio-impedance scales at home report between 12% and 16% depending on hydration levels – but these are notoriously inaccurate).  I’m a couple of kilos heavier than I was this time last year – I’m currently in the process of shedding some of that!

Then it was time to have my finger pricked and some blood spots taken to analyse normal lactate levels.

The ergonometer is behind the VDUs – we didn’t use the Wattbike

Onto the bike test, or more correctly, the ergonometer test. The ergonometer is a very accurate static “bike” that strictly controls the resistance of the ramp.  I was given a face mask and hooked up to a gas exchange analyser and off we went. After a warmup the power started at 100W and then slowly ramped up until I could do no more. I topped out at a tad over 410W and 175bpm. Another blood test and then I had to immediatly go as hard as I could for 2 minutes. The ramp was to clear out my anerobic energy systems and then the 2 minute effort would be all about my aerobic capabilities, from which my Critical Power (CP) could be assessed.  At the end of that it was back to a ramp, this time starting at 360W, I didn’t last long beyond that before I couldn’t turn the pedals. After a cooldown that was it.  The power and HR graph at the start of this post is the trace from the test.

My CP (equivalent to 20 minute power) came out at around a very surprising 333W – which means I’m not trying hard enough in 10’s!

The second and third tests followed a similar approach but without the CP test.

Test 2

The tests themselves seem innocuous enough until you are doing them.  In total they last about 33 minutes (for me anyway – if you hold the ramp for longer they will last longer!) and run out at around 40-ish TSS.

Test 3

The ramp itself is reasonably comfortable until you get to the pointy end.  Then I found that I became very aware of the mask and I often had a real desire to scratch my face!  At the point of failure I was gasping for air and my legs were burning, and the guys are shouting to keep going.  The ergononmeter doesn’t let up so my cadence just got slower and slower until I couldn’t really turn the pedals.  It’s a horrible feeling, and then you do it again!  That said, I found the experience very interesting and the data has given me a lot of food for thought.

Edit – results can be found in this post here