Getting Scientific


Read on…

I highly doubt that anyone is seriously intersted in this, but I am taking a really brave step and sharing my first Lactate Threshold test (since my rowing days) with you.  But I thought that it was about time I had a check to see how unfit I am and how I can turn that into “fitter”

So I made an appointment with some sports physiologists in Zurich, and they stuck me on a treadmill for a step test. The test evaluates the amount of lactate acid you produce while you are running at different intensities. At the beginning of the test you start off with relatively little lactic acid in your blood, then that will increase accordingly with your heart rate as you run faster and faster until you reach your maximum heartrate.

A Perfect Test

A perfect test would show an athlete maintaining a low level of lactic acid during the first few steps, indicating that they are well trained and they can withstand the increased effort without producing inhibilitating lactic acid. The athlete will however, reach a stage where the lactic acid begins to `spike` and this indicates the athlete is nearing their lactate threshold. In this range the athlete is still aerobic, although working hard this intensity can be maintained for a relatively long duration, think a marathon. But once you go above that threshold you are in trouble. Your body begins to produce too much lactic acid in the muscles and oxygen is not transported as efficiently around the muscles and cardio vascular system – you enter an anaerobic phase and this cannot be maintained for long.

Why do this?

So. My idea is to be able to identify what speed I can maintain at lactate threshold and what heart rate is associated with that also. So when I am training I can more specifically identify what my zones are and get a bit more specific to pushing that threshold out so I can operate at a high energy output for even longer. Just like the dashboard of a car, you can see the revs, how much petrol you need, how fast you are going etc.

I learned that at my anaerobic or lactate threshold I am capable of running a marathon in under 2.43.55 minutes. This is actually what I had been thinking I could acheive. I can motor along at 14.36km per hour at a heartrate of 171 without getting into too much trouble in a marathon (according to Mr Machine)

So. Is this a good or a bad thing? We will just have to wait and see.


How much fade is there between a one off 2.43 marathon and a marathon at the end of a 3.8km swim and a 180km bike ride? That remains to be seen.

Feedback anyone?


Lactate Curve (sorry about it being a little askew, its how I felt afterwards) 



3 thoughts on “Getting Scientific

  1. Have you ever checked out the forums on They have a lot of discussion about such subjects, including this, from people ranging from first timers to some very serious athletes.

    My unlearned opinion, based on limited empirical data, is that, subject to constraints, you could expect a 10% addition to your time. Constraints are:
    -You don’t bonk (sounds unlikely).
    -You don’t exceed your lactate threshold for an unsustainable period of time (based on the above, controllable).
    -No muscular exhaustion (again, unlikely in your case).
    -Sufficient fuelling and hydration (figure you’ve got that down pat from the adventure racing – for me it’s a constraint still).
    -Mentally, you can maintain a sustained level of focus for the period required (9-12 hours? Again, seems unlikely to be a constraint bearing in mind where you are coming from)
    -No injuries (wild card really).

    Are you going to try a competetive marathon before IM, to set a benchmark? Zurich Marathon is sufficiently far away to allow ample recovery, even including minor injuries.

    For what it’s worth, my PB marathon time is 3:21 and my IM marathon was 4:45, so that’s about a 41% increase 🙂 My problem was legs muscles – just couldn’t get them to give anymore.

  2. Hi Ben!

    Well. I do have a coach now and I have been training specific and I have a race calendar set out and some training camps to plan for. I will do a marathon (euch) and some short tri races.

    I guess its really down to the individual. Then my friend also doing the IM Zurich said that I should expect a 45min increase…

    Here is some feedback from another friend

    “I read about your lactate test.Usually athletes can do an Ironman marathon approx one minute per mile slower.The real good guys can go a bit quicker.I did a 2.50 marathon and an ironman marathon in 3.26. You obviously have good results which isnt suprising and a 2.45 marathon does seem right for you-im not surprised.I do find though the reality on the ground can be different especially in an Ironman race where the muscular training on the bike and run is so important.My point been-your aerobic ability and lactic acid will not in any way be your limiter.
    So many people in the Ironman who have great stats dont do great times and fall down in the run”

    Sorry D ; )

  3. O-K, perhaps I’m being a tad optimistic 🙂 I reckon Coach will give you the best guide once he’s got to know you a bit. I’d definitely expect you to be on the fast side of the curve though – you’re coming down from longer distances, unlike most of us who come up from shorter ones. Whereas we’ll be getting to the end of our reserves, I reckon you might be working to make sure you’re giving it all you can and not subconsciously husbanding energy.

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