Effect of show jumping training on the development of locomotory muscle in young horses.

The research article focuses on the effect of early training on muscle development in young show jumping horses. The study shows that early show jumping training increases the Na(+),K(+)-ATPase content in certain muscle groups but doesn’t significantly affect other muscular variables.

Study Design and Methodology

In this research, the team worked with 19 Dutch Warmblood horses. They divided these horses into two groups: trained and untrained (control). After weaning, training commenced on the trained group and continued until the horses were 3 years old. The exercises included free jumping twice a week and 20-minute stints in a mechanical rotating walker three days a week.

Muscle specimens from the gluteus medius (a key muscle used in locomotion and jumping) were obtained when the horses were 0.5, 1, 2 and 3 years old. These specimens were analyzed for characteristics such as:

• Fiber type composition (using myosin heavy chain [MyHC] content)
• Fiber area
• Diffusion index (area covered by a single capillary)
• Citrate synthase activity
• Na(+),K(+)-ATPase content

Findings of the Research

As the horses developed, several changes in muscle characteristics were noted. These included an increase in MyHC fiber type IIa and a decrease in type IIad, an enlargement of fiber area, a high diffusion index and increased citrate synthase activity. However, there was a decrease in Na(+),K(+)-ATPase content. The proportion of MyHC fiber type I was high, whereas type IId was found in lower proportions.

The training was found to increase the Na(+),K(+)-ATPase content, but it had no discernible impact on the other variables. This implied that early training predominantly influenced the Na(+),K(+)-ATPase content, which plays a vital role in muscle contraction and nerve impulses.

Conclusion of the Study

The study concluded that early show jumping training helps increase Na(+),K(+)-ATPase content in the deep portions of the gluteus medius muscle. However, it doesn’t significantly alter other muscle characteristics. This can be explained partially by the presence of an appropriate (aerobic) fiber type composition already established when training began. The study’s findings also imply that inherent developmental changes in equine muscles are efficient to meet the demands of this specialized training.