Friday, December 14, 2012

Timberman 70.3 Ironman Goal Setting using Data

A little more than a month ago I signed up for the Timerberman Ironman 70.3, aka Half Ironman, in August of next year (8 months away). I've done a few sprint triathlons over the last couple years and really wanted to step it up in 2013. Ideally I would have liked to do an Olympic distance triathlon as a stepping stone, but life got in the way of that this year so I decided to take the jump.

Obviously one of the first thoughts that enters your mind after registering (apart from the, "oh no, what did I get myself into!') is, "how do I properly train for this event"? There are tens if not hundreds of books written specifically about training for various distance triathlons. So I won't pretend I know anything about the actual training part, though I hope to learn more, maybe even pick up a book or two on it. Instead I'll focus on the often overlooked step before that, setting a goal for yourself. This can range from just finishing, to a specific time, to a place in your age group (male, 25-29). I chose to set a time-based goal, and as all good engineers do, I need a basis for the time that I choose, I can't just pick it out of thin air. That would be just silly.

Past Performance

Most (sane) people considering an event like this have some experience with triathlons or at least some of the individual sports. I've got a bit of both so I'll summarize my "race" history here:
  • Swimming: 
    • 800 meter freestyle race (highschool, a long time ago I know, but still a data point): 10:30
    • 1.2 miles lap swim (self-timed): 31:26
  • Running:
    • 5k GE Run: 25:29
    • 13.1 Skunk Cabbage Half Marathon: 2:04:00
  • Biking
    • HMCC Century: 6:10:00
  • Triathlon
    • Hudson Crossing Sprint Tri
      • 500 yd swim - 0:08:11
      • 12m bike - 0:36:51 
      • 5k run - 0:25:40
If I use my Hudson Crossing pace of 1.6 min/hundred for the swim, 19.5 mph for the bike and 8.25 min/mile for the run, that would equate to 0:33:36 for the 1.2 mile swim, 2:52:18 for the 56 mile bike, 1:48:04 for the 13.1 mile run, at Half Ironman distances. Adding in 5 minutes for transitions puts me across the finish line at around 5:19:00. As you would expect, when you compare the scaled times to the individual events that I've done for the run and bike, they are significantly faster. However I keep a pretty consistent pace for the swim regardless of distance (which means I must have been dogging it on the sprint tri!) Scaling those sprint tri paces to the Half Ironman distances may seem impractical, but I have a lot of room to improve, plus, it's a starting place.

Now lets take what we know and compare it to the results of my age groups for this specific race and course even. Fortunately there was data, broken down by event, from the website for '09-'12 for me to play with! I just looked at the data for my age group, male 25-29. I took the individual event times and plotted them versus the overall finish time. This allowed me to do two things. First, I was able to see trends for each of the individual diciplines and how they varied with overall finish time. Secondly, this allows me set a goal of a particular finish time and determine what each time would need to be based on the trendlines from the data. Here's the plot for your viewing pleasure:

(click to enlarge)

One of the interesting things that is very apparent is as the total time increases the variation in the run and bike times becomes huge. My guess is that this is most likely from those participants being really strong in one sport and not in the other. That or killing themselves on the bike and bonking on the run (foreshadowing?).

Finally, I chose 6 hours as my goal finish time. Partly because it was a nice round number and partly because it allows plenty of cushion from my scaled sprint triathlon time. If I use the trendlines (basically the average person) that gives me the following breakdown:

0:38:00 Swim, 3:05:00 Bike, 2:16:00 Run

I think that I can do the swim in around 33 minutes, which plus the 2 minute transition time, gives a few minutes of extra time to distribute between the bike and run. Heck, add it all to the run! So the final goal breakdown is:

0:35:00 Swim (Includes T1), 3:05:00 Bike (Includes T2), 2:19:00 Run

Hope you find this method helpful or at least interesting. Good luck!