Monday, December 2, 2013

Triathlon Improvement: The Seven-Year Hypothesis--some empirical evidence

Early in my triathlon career I remember reading that upon taking up triathlon in a serious way that one could reasonably expect to see improvements for around seven years or so.  This improvement expectation seemed to not be dependent on age either--in other words, the benefits of improved fitness and technique that come with years of training and growing expertise through accumulated experience would counteract the natural human tendency to slow down as we age.

Now mind you, I never saw any actual studies on this and this Seven-Year Hypothesis seemed to be more of conventional wisdom that an empirically established result of a sophisticated study.   Upon simple reflection, one might assume that it would vary from person to person based on (at least) how fit one was when one started racing triathlons, how skilled one's techniques were in each of the three disciplines, how serious one was about training from year-to-year, how consistent that training was, whether or not one had to deal with serious injuries or major life distractions, etc.

Now in my case, I've completed 13 years of a pretty consistently serious focus on getting better at triathlon racing.  Over these 13 years I've logged over 10,000 hours of training and have raced in 137 triathlons.  If someone was likely to see the improvements hypothesized in the Seven-Year Rule it might very well be me.

A couple of more personal things are probably also relevant.  When I started I was the least advanced at swimming (of the three disciplines)--in fact, my first race I did the breaststroke!  Based on this low starting point and the great importance of technique in swimming it might be reasonable to hypothesize that I might continue to see improvements for longer than 7 years.  On the bike, while I was only a casual cyclist, I was soon to find that I had a natural affinity for cycling fast and so with a high starting point and relatively low cycling technique importance, perhaps my improvement curve would be shallower and shorter.  One counter to this is the importance of technology and one might get faster just by spending money over time.  My running background was the deepest and it's common knowledge that old guys like me (I'm 56) see the most dramatic decreases in the run vs. the swim or bike.  So perhaps the improvement curve would be shortest for the run for me.  And the decline the greatest....

Another issue is how best to measure performance over time.  After a bunch of experimenting I decided that there were two primary ways.  First I'd track my average percentile (or a slighly different measure--the % of racers I beat in a race) against the field as a whole from year to year.  To be valid, this method requires that the competitive quality is fairly uniform from year to year.  With 10+ races/year this seems a valid assumption as long as the mix of races is constant.  Unfortunately, this is  NOT true for me.  For example, any year I race Kona my percentile average is going down due to the strong competitors there.  I dealt with this in two ways--by limiting the comparative set to just local races or just to short course races--these two methods end up with a lot of overlap.  The second way i measure it is by taking my average swim, bike and run pace and comparing from year-to-year.  Now these numbers vary widely due to the course difficulty and climatic conditions (among other factors). I dealt with this by taking the average of my best 3 performances in each discipline each year--my thinking here is that this approach gives me what i call my "demonstrated fitness potential" each year.  Demonstrated, because I did it on average over at least three of the races in any given year.  As it turns out, I do enough shorter and similar difficulty races each year to make this a fairly valid approach.

OK, with that lengthy backdrop, let's look at my historical race data says.

The Swim 
Here are three charts on my swim performance over the last 13 years.  The first looks at my mile swim pace (min/mile).  The second tracks my Swim percentile for Short Course races.  The third graphs the percentage of competitors I beat for local races:

The blue lines are the actual data and the black lines are best fit polynomial regressions.  Potential conclusions might be:

- I had two swim improvement phases.  The first from 2001-2004 and the second from 2007 to the present.  I think this reflects a fitness improvement for the first phase and then a technique improvement for the second phase (although obviously both occur in both time frames).  I did begin to really focus on technique in 2007 after I found myself plateauing and this suggests the value of focusing on technique in the swim.
-All three charts show what looks like the end of the improvement road somewhere around years 10-12.  In my case the improvement curve was definitely longer than 7 years and seems consistent with the hypotheses discussed above.
-Perhaps I can find another improvement phase by returning to working with a coach and refining my swim technique and if not getting faster, perhaps heading off the inevitable age-driven decline in performance.

The Bike

Same three charts:

 Possible conclusions:

- The speed chart seems to indicate that I peaked in year five and I've lost about 0.1 mph/year since.  Lots of other race data seems to confirm this.  Notice how much shallower the curve is--the range from worst to best is about 4 times less on the bike than the swim.

-The competitive comparison charts seem to confirm a 5-6 year peak as well.

-All three seem to indicate that I may have slowed the erosion of fitness potential over the last couple of years--this may be a reflection of my returning to my roots and relatively re-emphasizing my biking the last couple of years.  It will be interesting to see if i can draw a line in the sand around 24 mph for a few more years.  I'd certainly like to!

The Run

Possible conclusions:

- All three charts seem to indicate (after some ups and downs in the early years) that I peaked around year 6

-Since 2006 things have clearly been heading down hill--and pretty quickly at that--for me in the run. It would seem in a five year period that I've lost about 1 min/mile--which is a pretty steep fall-off.  Much, much more than the bike and the swim.

-I'd like to think there is an indication of a slowing of my fall-off over the last couple of years but my gut tells me this is probably wishful thinking on my part.

Overall Race Performance

Both of these charts seem to indicate that I did enjoy about 7-8 years of improvement but now am experiencing that dreaded fall-off.  Basically my swim has helped deflect the decline in my run but this effect now seems to be running out.  My bike continues to be my saving grace and helping me fight the ravages of old age....

I decided to do one more analysis.  I wanted to look at my AG performance because I would have expected to see a bump up over the last two years as I moved up to the 55-59 YO AG....

Age Group

The upshot of the above 4 charts is I did indeed enjoy an improvement in relative performance in 2012 and 2013--with the exception of the swim.  Clearly, I've slacked off on the swim over the last two years (by choice).  I now have a decision to make about whether or not to reinvest in my swim....I'm going to think on it when I'm climbing at Aconcagua--my guess is that I'll decide to pay the price and see if i can't change the slope of these curves....

we'll see....

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