I'm pasting this article from The Horse.com below. So just what does this
mean to you guys who talk the talk? I thought we wanted to supplement
potassium chloride. :-P
>snip<
Endurance riding can lead to significant losses of water and electrolytes,
which can cause clinical illnesses related to increased neuromuscular
excitability, including cardiac arrhythmia, muscle cramping and twitching, and
gut motility changes. When plasma potassium (K+) increases--as it does with
increasing exercise intensity--there is a concomitant increase in neuromuscular
excitability. Yet, many endurance riders believe that oral potassium
supplementation before and during competition is critical to the good health of
their horses.
Researchers from the Virginia-Maryland Regional College of Veterinary
Medicine, Virginia Polytechnic Institute and State University, Rutgers
University, Virginia Intermont College, Rectortown Equine Clinic, and the
Waltham Center for Pet Nutrition in the United Kingdom evaluated whether
potassium-free oral electrolytes given during endurance work could moderate the
expected increase in plasma potassium, decreasing related neuromuscular side
effects. They compared the effects of a potassium-free high-sodium electrolyte
mixture (EM-K) to a potassium-rich mixture (EM+K) on plasma ions and acid-base
status in horses during an endurance ride.
Forty-six horses entered in an 50-mile (80-km) endurance race were used for
the study--24 receiving EM-K and 22 EM+K. Rest stops and veterinary inspections
were conducted at 21, 37, 56, and 72 km. Electrolyte mixtures were given orally
by syringe after each loop.
Seventeen horses in each group finished; the others were withdrawn for
various reasons. For all horses, plasma potassium significantly increased from
the ride's start to the 56-km rest stop, then significantly decreased to the end
of the ride. Plasma sodium significantly increased from before the ride to 37
and 56 km, and significantly decreased from there to the end of the ride.
However, hydrogen ion (H+, a measure of acid-base status ) was found to be
significantly lower in EM-K horses compared to EM+K horses. Another significant
finding was that plasma potassium was significantly lower at 80 km and during
recovery in EM-K horses compared to EM+K horses.
The authors concluded that the decrease in potassium and hydrogen ion in the
last stage of the ride in EM-K horses might have been attributable to the
absence of potassium and the increase in sodium in the EM-K formula. However,
despite the differences, EM+K horses had increases in plasma hydrogen and
potassium that were moderate and not likely to cause clinical neuromuscular
signs. The authors conceded that the moderate nature of the ride and mild
weather were likely the reason for this, as well as the reason that the
significant differences between groups were not evident until the end of the
ride. The EM-K mixture would therefore likely be most beneficial in faster
horses working harder during more strenuous rides.
Hess, T.M.; Kronfeld, D.S.; Williams, C.A.; et al. American Journal of
Veterinary Research, 66(3): 466-473, 2005.
