Tuesday, May 10, 2011

Lactate test

Definitely one of the less unpleasant tests I have had to do. The first part of test involved cycling at ever increasing intensities (Watts) while my pulse and CO2 / O2 interchange were measured (as in previous VO2 Max tests) as well as my blood lactate concentration.

I'm smiling under the mask, honest!
Here's where the unpleasantness comes in: the only way to measure your blood lactate concentration is by measuring the lactate concentration in your blood - doh! In other words, every 3 minutes Diego would prick my ear and extract a drop of blood for analysis. Oh, and by the way, each analysis costs 3 euros (not Diego's fault, but just the cost of the patches).

Blood, sweat but thankfully no tears
After safely clearing my second threshold on the bike - the anaerobic threshold above which the energy metabolism is primarily from glycogen - it was time to go out on the track and repeat the same test running. I got quite a lot of funny looks from the people playing football on the pitch I was running round. On my back in the backpack was the little machine that measures my CO2 / O2 interchange and sends the signal by radio (what technology!) to where Diego was waiting with his needle to take yet more blood samples. I had to run around the track at a predetermined and ever increasing pace which is trickier than it sounds. To help, Diego had set a stopwatch to beep every certain number of seconds and my job was to make sure I was passing a marker at exactly this moment. We had a few technical difficulties with tubes falling out and stopwatches running out of batteries but it looks as though we managed to get some good data for analysis. The good thing is that the conditions were very similar to what I imagine Brazil will throw at me.

If you are curious as to what the point of this bizarre test is, have a look at a post I wrote some time ago in which I tried to explain the significance of the aerobic and anaerobic thresholds, as well as the MLSS (Maximum Lactate Steady State) threshold. Hopefully I'll get the results in the next few days and they will give me an indication as to what kind of pace / heart rate I can aim for both on the bike and for the Marathon leg of the Ironman.

Before starting the test, I bumped into Carlos - who is also doing Ironman Brazil. He had just done his test and was happy that the pain he'd been experiencing in his leg while running over the last few weeks had finally subsided. So - TOUCH WOOD - it looks as though both of us are ready to DO THIS THING!


  1. Very useful,you will have some data for the pace in the final leg, i imagine the bike will be close to aerobic threshold, won't it?

  2. Hi there

    Well actually it will be somewhere above my maximal aerobic threshold (which is where I've done most of my bike training, at around 123bpm). I expect it will be something like 140-145bpm but I'll be posting something on that once we get the results. This is where the art and science comes in... Going at 123bpm would be very safe but the question is, how far can you (safely) push the envelope before it rips?