What must be kept in mind when looking at all
of the studies Tom posted is WHEN the carbohydrate was fed. If we
look at the abstracts one by one - well, first of all we'll be here
all day - and I really do have work to do. But lets look at the
1] Kreider et al - this is a study which looks at effects
of nutritional manipulation during RESISTANCE TRAINING. We do not
weight train our endurance horses, Tom.
2] Tsintzas et al - this study looks at carbohydrate ingestion
during prolonged running. Carbs during exercise absolutely,
undeniably improve performance. DURING.
3] Hollozsy et al - "Regulation of carbohydrate metabolism
DURING/AFTER Running.." That says it all. It is not a discussion of
the merits of high carb diets in general but of their metabolism
during and just post exercise.
4] Lapachet et al - now Tom, it gets
interesting because this study finds that rats running for a very
long time [I read this last year, and I forget exactly how long they
ran, but it was hours and hours, like our horses] did best when
chronically fed a high fat diet. They did best if they were given a
high fat diet typically but were carbo loaded for a few days before
being run to exhaustion. To note though, the fat fed rats were much
fatter than the carb fed rats even though they ate less calories.
This study represents an extreme of manipulation since the rats got a
70% fat diet. A rodent can survive this; obviously a horse cannot.
But the point it makes runs somewhat counter to the constant high
carb diet, at least for omnivorous rats.
Other studies that show positive results in humans with a high fat
diet do exist. Muoio in 1994 demonstrated that cross country runners
ran for a mean of 91 minutes on at 73% fat diet compared to 69
minutes on their normal diets. A high carb diet also improved their
run to exhaustion but not as greatly as the high fat diet, 76
Now, I'll go on record here in saying that I do not advocate high fat
diets for human athletes. However, I am watching research as it comes
out to see if any other labs confirm positive performance effects
from high fat diets. We do know that in humans chronic ingestion of
high fat diets in sedentary people is associated with a variety of
diseases, including obesity, and cardiovascular disease so caution is
warranted. Furthermore, rats and humans are not herbivores and are
well adapted to tolerate large quantities of fat. I am not sure how
horses can be expected to fare in the long term, but perhaps they can
also increase their fat intake somewhat with good performance
As for the high protein diets, ie the Zone diet Barry Sears and so
forth. Although Dr Sears quotes himself repeatedly in his book he
really needs to show that anything he has done has been printed in a
peer reviewed journal. Saying "this is so because I say its science,
and I'm a Dr" just does not cut it. Anyone in the nutrition field
recognizes his diet as a rehash of former diets, like the Scarsdale
diet. These were high protein, moderate fat, low carb diets, and if
you want to lose weight they work. They work because following his
outline men will be eating around 1200 Kcal per day. Is is healthy
in the long run? I think probably not even if you increased the
Sorry for taking up so much space...
Beth Glace, MS