I created a line graph with the data for a 1000 lb horse going
50 miles at the various speeds and an 850 lb horse going 25 miles at the various
speeds. The graphs were fairly identical to each other, the numbers being
changed only, but the graph looked the same. With the exception of the dip from
2.1 mph to 3.4 mph, the graph is fairly linear going steadily up the faster the
horse goes.
Another interesting statistic from the spreadsheet is that it
takes 17% more calories to go from 7.13 mph to 8.92 mph; 20% more calories from
8.92 to 10.7 mph; and 22% more calories from 10.7 to 12.5 mph. (I used those
because those speeds are evenly spaced.)
From a purely caloric standpoint, it's better to go 50 miles
at 3.4 mph for 14 hours 45 minutes than to go at any other speed. However,
obviously, expended calories is not the only factor involved in a horse's
optimum speed. Conformation, training, oxygen usage, weather and trail
conditions, and any number of other factors figure into that. Not to
mention that you can't have a ride time of 14:45 for a 50 mile endurance ride
and still get a completion. :-)
I plugged the numbers into a spreadsheet using the KER data. The only
time the DE went down when the speed increased was going from a slow walk
(2.1 mph) to a fast walk (3.4 mph). For all other increases in speed, the
DE requirement went up.
April--
This is really interesting in that it suggests there IS in fact
an "optimum" speed re: the discussion about "too slow"...so following this
out, does the spreadsheet suggest a curve? That is, the same horse
that does the optimum 50 would require more energy to go either much slower
or much faster? That is, either the 4:45 50 or the 11 hour fifty
requires more than the optimum--whatever that point is, in terms of DE
requirements?
