CHALLENGE: Muscle damage and fatigue (Sport Horse, Dressage, Eventer)

Two types of fatigue have been recognised. The first, muscle fatigue occurs when muscles run out of energy sources and can no longer create the ATP that is required for them to contract. The second is central fatigue whereby an increase in serotonin levels in the brain contribute to fatigue. Muscles rely on glycogen as a source of energy, and glycogen reserves can be spared by increasing the fat content of muscle so that the fat metabolism spares the glycogen reserves thus enabling muscles to work for longer before fatiguing.

High-intensity bursts or long-duration exercise results in significant damage to muscle cells. Energy production from metabolism results in free radicles which damage muscle cells. Prolonged exercise results in the depletion of enzymes and vitamins that scavenge and remove these damaging free radicals and oxidation of the fats in the cell walls occurs leading to cell rupture and death. Several cells can be affected including red blood cells and muscle cells. To further compound the matter, when horses deplete their energy reserves of glycogen and fat in the muscles they start to break down the muscle tissue to use as an energy source. Muscles are composed of amino acids and one-third of equine muscle in composed of the branch chain amino acids (BCAA), leucine, isoleucine and valine. Leucine, isoleucine and valine are essential amino acids and cannot be synthesised by the horse and must, therefore, be supplied in the diet.

RECOMMENDATION: AMINOBOOST AND BCAA

BCAA PASTE contains the three essential BCAAs, leucine, isoleucine and valine to support muscle recovery following exercise. Supplementation with BCAA has been demonstrated to increase the levels of these amino acids in muscle following strenuous exercise. The administration of leucine has been shown to reduce the concentration of amino acids in the blood following exercise, indicating a beneficial reduction in protein breakdown. Additionally, BCAA also contains rosemary a powerful antioxidant to protect muscle cells against oxidative damage and seaweed which acts as a pre-biotic to support intestinal health. Leucine also has a powerful insulin-like effect and promotes the uptake of glucose into cells. Several studies have demonstrated that during endurance events horses metabolise a large amount of BCAA to produce energy. BCAA and another amino acid called tryptophan use the same transport system for entering the brain and it has been suggested that as blood and muscle levels of BCAA fall, more tryptophan can enter the brain. Tryptophan is converted to serotonin and increasing levels of brain serotonin may contribute to central fatigue.

AMINOBOOST contains all the essential amino acids required by horses. It may be especially important to supplement amino acids in horses who are poor eaters or who have variable appetites, as many horses do when they are travelling and away from their familiar environment. The functions of amino acids are diverse and insufficient levels of one, may impact levels of another. Supplementation with amino acids in the immediate recovery period has been shown to reduce muscle breakdown and promote recovery following strenuous exercise. Recent studies show that in addition to muscle breakdown, a significant number of amino acids are lost in equine sweat. AMINOBOOST contains creatine, carnitine and ϒ-oryzanol. Creatine is an amino acid that is naturally present in the diet and muscle. Creatine is an important source of energy for aerobic metabolism and has been demonstrated to improve the aerobic capacity of horses following long term supplementation. Creatinine is turned into creatinine phosphate which provides energy for muscle contraction. Carnitine is a component of enzymes that is involved in the utilisation of fatty acids as an energy source. Supplementation with carnitine increases utilisation of fatty acids as an energy source and this spares glycogen and could improve aerobic capacity. ϒ- oryzanol is derived from brown rice bran and has been shown to have a powerful anti-oxidant effect which may protect muscle cells against free radicle damage.