Hiya Tom,
I agree that competing with low blood glucose is a mistake (which is why
the recommendations to avoid insulin spikes which would result in lower
glucose levels). I would also 100% agree that strategically timing a
high glucose level so that it peaks during competition would be
advantageous. However, while it's feasible to stategically aim for a
glucose peak when your elapsed competition time is only two or three
minutes, as is the case in TB racing, it's virtually impossible to do so
when the elapsed competition time is between three to twelve or more
hours (depanding on the length, course and how fast you're going).
It seems to me that the tailing-off glucose and insulin effects (and
inhibition of beta-oxidation, the primary fuel source for submaximal
exercise) after feeding highly soluble carbos are unavoidable and
therefore best avoided as a primary fuel source---better replaced by a
food source that provides a lesser, but sustained, supply of glucose
throughout the day to support, rather than inhibit the burning of fats.
So that's why my recommendations of grain the night before, no grain
immediately prior to a ride, and beet pulp during the ride. I wouldn't
apply those same recommendations to horses on the track, of course,
where the energetics and energy expenditure is entirely different.
Susan Garlinghouse