WHAT ACUALLY IS FATIGUE IN HORSES?
Much of our knowledge of fatigue in animals comes from horses because they can be readily trained to exercise on high-speed treadmills, allowing for controlled investigation of respiratory, cardiovascular, and metabolic responses. When fatigue sets in, changes occur in the horse’s gait, joint movements, muscular support, and willingness to perform over prolonged periods of time. When a horse is fatigued, he typically has the inability to continue exercise at a given level of intensity. Generally, the more intense the exercise, the earlier the onset of fatigue.
According to Dr. David Marlin, the use of the word “fatigue” in relation to exercise has very specific meanings and covers a wide range of manifestations including:
• The horse that will not move another step
• The endurance horse at the end of a 100-mile race that is reluctant to trot
• The racehorse that has slowed in the last eighth of a mile of a race, but when passing the post is still travelling in excess of 35 miles per hour
• The event horse on cross country that slows down from a fast gallop pace, but when given a few strides at a slightly slower pace, is able to return to the original faster pace
CAUSES OF FATIGUE IN HORSES
Fatigue in performance horses can result from the failure of one enzyme system, one cell, one organ or one body system, but is more often due to multiple factors contributing simultaneously. This can place an excessive burden on other body systems as they try to compensate. In many ways, fatigue is still poorly understood. However, it’s generally accepted that no single mechanism explains all the different aspects of fatigue that are recognized. For example, a dramatic reduction of muscle glycogen can play a significant role in fatigue at the end of an endurance ride. But, fatigue also occurs when muscle glycogen concentrations are still high, for example in a show jumper after completing its round.
Factors unrelated to the intensity, duration or pattern of exercise influence the onset of fatigue, including: metabolic myopathies (tying up and polysaccharide storage myopathy), over-training, fitness, age, body condition and environmental conditions (temperature, humidity, pollution or altitude).
Numerous areas have been studied to try and understand the mechanisms of fatigue during exercise including:
• Depletion of the energy-generating systems inside and outside muscle cells
• Accumulation of metabolic by-products (i.e. lactic acid, ammonia, H+ ions, and ATP metabolites) and failure of the muscular contractile mechanism
• Disturbances to acid-base, electrolyte, hydration, and thermoregulatory homeostasis
• Central and peripheral nervous system fatigue
REDUCING FATIGUE WITH FLAIR® STRIPS
Early research on horses exercising on treadmills showed that horses using FLAIR Equine Nasal Strips used 5-6% less oxygen and produced less carbon dioxide than when doing the same amount of work without a Strip. Using less oxygen means the horse consumed less energy. It’s believed that by reducing resistance to airflow (allowing horses to breathe easier), the work required of the respiratory muscles like the diaphragm during exercise is reduced, which reduces the energy required for breathing. It was theorized that by reducing energy consumption, fatigue would be delayed since this energy would now be available to the exercising muscles. This delays the onset of time to fatigue, helps horses fatigue less and conserve energy so there’s more available for tomorrow. Conserved energy helps sustain performance longer and potentially reduces the chance of fatigue-related injuries. Fatigue contributes to structural injuries of the musculoskeletal system, such as pulled suspensory and other ligaments, bowed tendons and fractured bones.
The Strips are also beneficial during shorter duration, sprint exercises (such as 1/4 mile races), where 60% of energy is generated by anaerobic metabolism and 40% of the energy is generated via aerobic pathways that require oxygen. However, at races over 5 furlongs (1000 meters), over 70% of energy is generated via aerobic pathways and at one mile (1600 meters), 80% of energy is generated via aerobic pathways. During longer distances even more energy is generated using aerobic pathways, making efficient oxygen intake even more important.
Oxygen is also very important in the recovery phase following intensive exercise to rebuild energy stores consumed during exercise. The benefits that FLAIR Strips provide for efficient oxygen intake during intensive exercise continues through the recovery phase to continue providing efficient oxygen intake to rebuild energy stores. This is one more reason why it’s important to not remove the Strip until the horse is fully cooled out and breathing has returned to normal.
Breathe easy with FLAIR Strips – improve airflow, reduce fatigue, conserve energy, quickes recovery and reduce lung bleeding. Visit https://flairstrips.com/conserve-energy-reduce-fatigue/ to read more from this article.
FLAIR® Equine Nasal Strips are brought to you by Achieve Equine