Wednesday, March 24, 2010
What does it take to Qualify?: A physiologist's perspective
OK, so back to my normal milieu this week …..
Questions and emails on my ‘what does it take to finish an Ironman’ post seemed to indicate that you all liked the format but, for you, finishing isn’t going to cut it. You want to qualify! :-)
Today’s pic is of one of the top Age Groupers I coach, Shawn Burke, busting out a 9:23 qualifying time in Ironman Florida. Being able to work with Shawn and a number of other top age group athletes ‘up close and personal’ over multiple seasons, I’ve been able to witness first hand ‘what it takes’.
I’ve written a previous post on what it takes from a general work/commitment perspective to reach the very top of your age group. Despite the heat received, I stand by the message:
- Multiple years of physical training, amounting to several thousand hours of work.
Perhaps the message would be a little more moderate for a Kona slot, but the way things are going at the pointy end of the field, Kona qualifier and top AG are rapidly becoming one and the same. In fact, based on last year, most flat course qualifying males under 50 were in the 9:30’s!
But is work enough?
Gordo wrote a great blog this week on personal excellence. His conclusion that “protocol does not matter UNLESS it is supported by a habit of personal excellence” is worth a re-read. Or, put another way, you need to set up your life (& your program) to enable you to ‘do’ before worrying about ‘what you do’.
Based on the Kona qualifiers that I have worked with, some 20hr training weeks are almost a pre-requisite. Also based on the athletes that I have worked with (excepting those with freakish recovery abilities), 20hr weeks are going to be VERY hard to string together on much more than a ‘standard’ 40hr work week. Add in the constraints of a young family and you can see that for many, VO2max or FTP is NOT the #1 limiter.
That said, while a 20hr week load (and the life conditions to absorb said load) may be bordering on a pre-requisite for a Kona slot, it is not sufficient in and of itself. Put another way, just because you set up your life so that you’re able to string together the requisite load doesn’t guarantee that this load will give you all of the fitness abilities necessary to race at the very front of your age-group and secure a Kona slot. I can guarantee this from personal experience!
There is somewhat of a ‘bottle neck’ effect that kicks in around the 10hr Ironman mark. A lot of very serious folks getting their consistent 2-a-days in and all shooting for a limited number of slots. Under these conditions, only the smart survive. In these conditions, work is not enough, it is focused work that counts.
‘Focused work’, to me, means work targeted towards a specific objective. This necessitates that we define what physiological objectives are ‘mission critical’ to fast Ironman racing. By defining them we can assess whether you have that base covered as an athlete, and if not, the best way to rectify that shortcoming.
In my last blog piece I outlined the key endurance adaptation of glycogen supercompensation, in which with repeated bouts of glycogen depleting exercise, the body’s energy stores can double. Maybe somewhat surprisingly, this adaptation seems to have a ceiling that can be reached pretty quickly by novice or prospective Kona qualifier alike, i.e. both have ~3000-3500 cals to work with.
The major difference between the novice and the Konee when it comes to long duration fueling comes from the energy contribution from fat. Based on our lab testing, athletes who qualify for Hawaii are typically generating >33% of their energy needs from fat (~300kcal/hr). This is an important adaptation and one that can be limiting for a lot of athletes with V8 power but lousy fuel economy. By generating 5kcal/min from fat, a 10hr Ironman gets an additional 2800 calories of work done over the course of a 9.5hr Ironman. Add in ~2400 cals of worth of energy from exogenous carbs (gels, sports drink etc) and we’re up to ~8500 cals worth of energy to play with. So how much fitness do we need to get 8500 cals of work done over 9.5hrs?
8500 cals of energy output over 9.5hrs is equivalent to ~230W of power on the bike. Now, as outlined above, we want this 230W to occur within the zone of max fat oxidation (~60-65% VO2max) This infers that the athlete has a VO2max of ~5L/min at an economy of 75W/L.
These numbers also pre-suppose that a 230W output will ‘get the job done’ and get the athlete from A-B in ~9.5hrs. Based on my calcs, probably true for a 75kg athlete with decent position over a well paced flat course. Much bigger or any less aero, and the athlete will need more power.
So, in relative terms we’re talking about a VO2max in the neighborhood of 65ml/kg, equivalent to 5K speed of ~17:30 and a CP5 of ~400W. It goes without saying, that this represents a very high level of aerobic fitness: 1 in 200 fitness for a young male, 1 in 10,000 fitness for a 40-49 yo guy based on the Cooper Institute’s data!
It is also worthwhile remembering that this level of fitness is not sufficient if not paired with appropriate race specific endurance. If it is paired with a high level of fat oxidation and an AeT of >60% of VO2max, the athlete will be in a good spot for their Kona assault.
If the athlete has a particularly strong fitness base, i.e. an AeT at a higher % of max and a fat oxidation profile that continues over a broader range, they may ‘get by’ with marginally less VO2 ‘top end’. However, there are limits to the % of VO2 that any athlete can hold for a given duration and in the interests of long term development, shooting for this balanced mix of ingredients is the athletes best bet towards achieving their potential in the sport.
Setting these fitness pre-requisites in place before putting the final race specific endurance block in place represents a strategy of ‘reverse periodization’. I’ll talk a little more about this in a future blog. Until then…..
Posted by Alan Couzens at 7:59 AM
Labels: athlete data, exercise physiology, fat oxidation
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Another great post. What's the definition of AeT? How is it tested?
Great post as usual! I have one question: Where you discuss 5K speed and CP5 results, you mention that this is "1 in 200 fitness for a young male, 1 in 10,000 fitness for a 40-49 yo guy."
Is that for Ironman competitors or the general public? For some reason, those numbers seem pretty low based on Ironman qualifying times of late, but WAY high if they are based on the public at large.
Glad you asked the question. There is lots of bunk in the forums about the invalidity of AeT largely because its not widely used in scientific studies.
That said, if a lactate test starts low enough the first points will all fall along a pretty flat baseline (or even dip) followed by a point where a slow grade begins. This first break from the flat baseline is what we call the Aerobic Threshold or 'AeT'.
Despite scientific 'invalidity', this point happens in 100% of well executed tests
If you don't have access to a lab, would it be fair to say that your Aet is generally located toward the bottom of zone 2 (Friels zones)?
The data represented a pretty broad sample of the general pop.
I think it makes 'real world sense' when taken in the context that while these numbers represent a good 'starting point' for a Kona bound athlete, it also takes specific fitness for the event.
I'd say in a big high school class there would be at least one guy out of the 200 capable of running 17:30's.
Also for the older group. There are ~16,000,000 guys in the 40-50AG in the US. 1/100000 would be 1600 folks capable of running 17:30. Just so happens that ~400 of these 1600 guys seem to be on the big island at the same time each October :-)
Great one Alan....
Let's keep going....what's it take to win one?
Correction: Added an extra zero in the above comment. Should read 1/10000.
That makes sense. I was thinking more in terms of my own age rather than a high schooler. Guess it was just wishful thinking that 30-34 is still a "young male." ;-)
I think the bottom of Z2 is actually a bit higher (5pm) or so than AeT for most athletes.
For very fit (elite) or very aerobic athletes, it's probably appropriate.
Brings to light the importance of individual lactate testing for athletes, esp when considering that the benefits of training below AeT is questionable.
Thanks for the idea, Mike.
Coming right up...
A fit 30-34yo guy IS still young. But unfortunately for most of the general pop, things are already starting to head south!
I coach a guy who went 10:24 at IMGermany 08. I had his Aet right at the bottom of zone 2.
This year with more training I moved his Aet up 5bpm to mid zone 2(on the bike only) and at IMNZ he went 9:45.
I don't have a lab to do lactate testing and we assessed our capabilities on long rides, 5.5-6hr in order to make honest judgements as to how well we felt he could run. Did the same on long runs with long intervals at HIMeffort.
If he could hold his HIMeffort for 1-1.5hrs within a long run then that indicated his IMeffort (Aet) was on the mark.
At NZ PB is run by 20min with a 3:30.
This is how we get around having access to a lab.
thank you for you to make me learn more,thank you∩０∩ ........................................
Thanks for the kind words, Chris.
All the best in training.
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