carbs as fuel

["Beth Glace" <lb@nismat.org>]

Hello all,
I would agree that carbs used during a ride are ergogenic aids.  
That is, they aid performance by providiing energy.  However, as 
Steph points out, it would seem silly to limit sources of carbs 
during a ride in order to slow your horse down.  By that same 
reasoning we would not feed during the checks in order to continue on 
in an increasingly energy depleted state.  The amounts of 
carbohydrates that are being provided are relatively small, 
considering that 1 oz of sugars or carbs provides 100 calories and it 
costs the average horse about 750 calories to go 1 mile [see AERC web 
page] during these events.  It is hoped that adding sugars or 
starches during exercise will provide a small but significant outside 
source of carbohydrate to maintain blood sugar, thus sparing the 
muscles very limited reserves.  Continuing exercise despite glycogen 
depletion is, I think, far more metabolically stressful over the 
course of a long ride.  It will limit work to those muscle fibers 
that are very highly adept at using fats; the work will not be spread 
out over those fibers that are also adept at using carbs.  The real 
question is whether the small amounts of  carbs used while out on the 
trail actually are sufficient to attenuate the loss of glycogen, and 
most importantly, are they enough to improve exercise tolerance. The 
amounts being used, 1-2 oz/hour that some riders have reported, 
are identical to those proven to improve endurance performance in 
human runners who weigh typically 100-150 lbs, and who expend 70-100 
calories each mile.  At doses less than this there is no improvement 
in time to fatigue in humans, and it seems to me that providing such 
small amounts in a horse may be insufficient to make a significant 
improvement in performance.   We need people like Susan and Tom  and 
Sarah  to answer those questions in well controlled equine studies,  
for riders to experiment and share their experiences, and for vets 
like Heidi to critically observe metabolic paramters  to determine 
if these products are useful.

Beth Glace, MS
Sports Nutritionist, Nicholas Institute of Sports Medicine and 
Athletic Trauma
Lenox Hill Hospital
NY, NY



Steph wrote:
Somehow it seems as though you view this energy source as a 'false
high' - similar to a drug - that may mask fatigue, and enable a horse
to go faster than he should. But energy is energy. Blood sugar is
blood sugar.