Last week, Charlie, Lauren, Steve and I (Eli Kirk) made our way down to the EIS (English Institute of Sport) physiology lab at Loughborough University for some testing on the treadmill. Physiological testing is something we do once or twice a year. It helps monitor our progress and gives Steve an idea of where we’re at in training and the paces/heart rates some of our sessions and runs should be done at to get maximum benefit.

Both Lauren and I have done the testing before, so we were well aware of what we had to look forward to/or not look forward to! However, this was Charlie’s first experience, so he was slightly unaware of what lay ahead! Despite sounding like a slightly unpleasant experience, the testing is actually not that bad, it is just like doing an interval session, except on a treadmill with a mask over your face!

Charlie in full flow on the treadmill

Why do we do it?

As athletes, we are all unique in terms of our physiological profile. For a given speed, we all have different heart rates and produce different amounts of lactate. The testing is done to identify two main things.

  1. Lactate Threshold (LT): This is the first increase in blood lactate above baseline levels. Speed at LT is a strong predictor of the speed that can be sustained in the marathon.

  2. Lactate Turnpoint (LTP) : LTP is the running speed at which there is a distinct “sudden and sustained” breakpoint in blood lactate. This typically occurs at 2.0-4.0mM of lactate depending on the individual athlete, and tends to be 1-2km/hr above LT.

This data is useful to know because training at and around LT and LTP pace can be a huge benefit for endurance runners, and it therefore helps Steve in setting us the appropriate paces and heart rates for some of our threshold sessions.

Our individual LT and LTP can be manipulated and changed, which is the main reason we do regular physiological testing to monitor it. Ideally we want our LT and LTP speeds to increase. This essentially means that we can run at a faster pace before we start to accumulate lactate and feel the burn!

Graph showing the relationship between Speed, Blood Lactate Levels, and Heart Rate in an athlete. The graph also demonstrates how this athletes speed at LTP has progressed from March 2014-Sept 2015

How is it done?

For those that are imagining that the test involves running to exhaustion on a treadmill, you’ll be pleased to know that is isn’t quite that dramatic/traumatic! Kitted out with a heart rate monitor and a not so comfy mask over our mouth and nose to monitor the content of our expired air, the test, which is facilitated by the physiologist, involves running for three minute intervals at different speeds on a treadmill. After each three minute interval, the speed is increased. The test ends when LTP is reached. Prior to starting, baseline lactate levels are measured by taking a tiny sample of blood from our ear lobes. Lactate levels along with our heart rates are recorded after each three minute stage.

The first few three minute stages are relatively easy, however I don’t think any of us would say the same about the last few stages! The burn really starts to kick in on the last stage, but we had plenty of encouragement from the physiologists to keep us going. Other than the final stage, it’s actually (in hindsight!) quite a fun experience, and the physiologists at Loughborough are really great and know what their doing. The most uncomfortable thing is probably running with a tight mask around your mouth and nose!

Lauren looking happy to have finished!

After the test, we all had a run to do around the Loughborough University Campus to try and flush out some of the lactate that we’d accumulated on the treadmill, and then it was time for refueling, coffee and the drive back up north to Manchester.

Thank you to the Physiologists Kate Spilsbury and Andy Shaw at British Athletics for looking after us so well. Hopefully next time we’re there we’ll be running even faster before lactate starts to set in! In the mean time, Steve eagerly awaits all of our results!

As well as physiological testing on the treadmill, I also had a Haemoglobin (Hb) Mass test which is the most accurate way of measuring total Hb mass in the body. It is also called the Carbon Monoxide (CO) Re-breathing Test, as it involves breathing in a small amount of Carbon Monoxide using the interesting looking device I am holding!