1. Heart size increases
The heart is made of muscle tissue and this is developed through the fitness program. The average heart size of a horse is 9 pounds, but in fit horses it can be up to 14 pounds. A larger heart allows blood to be pumped around the body faster and more efficiently.
2. Red Blood Cell count increases
Red Blood Cells carry oxygen around the horse’s body. Working on a progressive fitness program stimulates the horse’s body to produce more red blood cells. More cells mean a larger quantity of oxygen can be moved around and get to the muscles.
3. Lung capacity increases
Horses have huge lungs, but most of the time a lot of their capacity is unused. As the horse gets fitter more of the lung space is used which allows the lungs to be used more efficiently to get more oxygen into the blood stream. The more oxygen that can be absorbed, the longer the muscles can work without fatiguing.
4. Tendons become stronger
Working horses speeds up the shedding and replacing of the collagen fibres which make up the tendons. This process improves tendon strength. It’s important to make sure that horses have enough recovery time after strenuous work because it takes 48 to 72 hours for tendons to recover from strenuous work and adapt. If you have a gallop session planned, make sure you plan a couple of easier days afterwards.
5. Bones strengthen
Of all the materials in the body, bone has one of the greatest capacities to adapt. Like tendons, the breakdown of old bone and building of new bone is sped up by exercise. This causes the bone density to increase and become stronger.
6. Temperature regulation improves
Horses cool down using three methods, breathing, direct heat loss through their skin and evaporation of sweat. When they exercise they become more efficient at cooling down and monitoring their temperature, especially through sweating. This is why it’s important to get horses used to working in hotter or more humid weather if that is the climate they will be competing in.
7. Coordination improves
As horses work through a fitness program their muscles will become stronger and their hoof-brain coordination will improve. Their muscles will also adapt to the type of work they are being asked to do, eg short faster bursts or longer endurance type work. This coordination is important as it reduces any movements which could cause strains and makes it easier for the horse to do the work asked of them.
As always these improvements only occur from a fitness program where the workload is increased gradually over a period of weeks and months. Any sudden increase in workload is likely to lead to increased strain for the horse and a higher chance of injury.