The initial bike tests were interesting, and below are the results from my run test. I was extremely surprised with my run test results which showed that my metabolic efficiency point (i.e. the crossover from burning more fat than carbs, to burning more carbs than fat) was when I was running at approximately 7min/mile (~8.5 mile/hr). I was expecting the crossover point to be much further to the left.
My target Ironman marathon finish time this year was going to be about 3hr10 using a mostly run strategy with pre-planned 1 minute walk breaks each time I pick up nutrition. This translates to a ~ 4:20 min/km pace with a break every 30 minutes or so. The testing shows that this, from a metabolic perspective, is a fairly conservative target. In fact if my muscular endurance could support it, I could potentially run faster. Given my PR in the IM marathon is a comparatively slow 3:27 I’m not particularly keen to make the target much fast than 3h10. I tell myself that in the race if I’m still feeling good in the last hour I’ll kick and make up the time there – time will tell 😉
The orange paces show the zones where I will be encouraging my body to burn fats. The overall goal is to use the philosophies of eating metabolically efficient foods to help shift the MEP to the right. The further to the right I can move the orange line, the more I’ll be burning fat during the Ironman run which theoretically means I can run faster, or run with less risk of bonking towards the end of the race. I haven’t picked my target pace yet. I’ll pick that about 6 weeks out from the race and rehearse it (plus a couple variations) in the final 3-4 big training weekends to see what feels good.
The two ideal paces to encourage fat burning are: 8:06 pace and 6:40 pace. I don’t know the science behind but I figure I’ll pick up the recommendations and work with them and see what happens. 6:40 pace isn’t comfortably easy at all, but is probably a pace that I can use for medium-long runs and tempo sessions. However, at the track sessions I’ll still be going 100%, although the goals for those sessions are very different.
Tired Legs Empty Mind 