Interesting week, more and more people preparing for the cross season and some late season Ironmans. Helping out a few different riders and triathletes at the moment and really starting to understand how years of study actually relate to some thing.
Got some nice data to play with off Russell Cox , full timer in the IM game, and had a play with it looking at his rates of carbohydrate usage and fat oxidation. About two years ago Rich Brady came to me with the magic number. 2.5g of CHO/min. At the time i didn't know where he'd gotten it from but turns out years of training and racing as a pro had given him the idea. Figure i better credit the guy/coach/my ex coach.
Of late in the labs, and through some pretty hefty reading, ive looked into where this number may come from and how it will relate to performance not on the bike leg of the IM split, but more so on its effects on the running leg.
Starting to think more about not only the rate of CHO oxidation but perhaps the ratio of CHO:Fat oxidation as a better predictor. Obviously having more fat being oxidised at a given intensity as well as carbohydrate is ideal, but hitting the max fat burning intensity for racing is not exactly the ideal situation as it may result in super maximal/sub maximal burning of CHO at that point. Which in turn may not be optimal for the run.
More of a stream oc conciousness idea here, but what if we were to look at improving the ratio fo CHO:Fat not as a more CHO to Fat or more Fat to CHO but as an optimisation of the fat oxidation with minimal CHO utilisation at intensity that may not traditionally be fuelled this way. Possibly a dynamic pacing approach to the bike that initially up regulates fat oxidation and CHO consumption but allows for a throttling off of CHO usage and higher ability to oxidise fat could be used.
I could also be wrong.
It happened once.