Climate May Dictate Altered Training Protocols for Young Horses

Thoroughbreds are born, raised, trained, and raced in a variety of environmental conditions and ambient temperatures. Does temperature matter during training? Data generated in Japan suggest that temperature affects body condition and therefore training effectiveness.^*

In the study, Thoroughbred yearlings were purchased in July and August from public sales and then transported to training facilities in Hidaka or Miyazaki. Hidaka is frigid in the winter, whereas Miyazaki experiences milder cold weather. An average temperature difference of 18° F (10° C) is observed between the two locations. The two groups of yearlings were managed similarly in terms of diet, turnout, pasture access, and exercise or training from the start of the study in October until the following April when the horses were two years old.

During the study, researchers weighed horses each month and measured rump fat thickness with ultrasound. They calculated percent fat and fat free mass (FFM, a measure representing muscle mass). The researchers found:

• Body weight and FFM increased in both groups of horses from October to April in growing yearlings, as expected; and
• A higher rate of increase in FFM was observed in warmer climates (Miyazaki) than in colder climates (Hidaka) in all horses. The significantly higher rate of FFM was more notable in the colts than the fillies.

“The researchers suggested that the increased FFM may represent more effective training. Training that occurs in mild winter conditions appears more effective than training in severely cold conditions,” explained Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research. “Theoretically, growing horses in mildly cold climates do not have to delegate as much of their energy resources to keeping warm as those in a severely cold climate, so there is more energy available for muscle building.”

According to the researchers, horses trained in mild winter environments may experience more days of high-intensity exercise and training than those in frigid environments. In turn, this “enhanced training” could translate to earlier racing of two-year-olds. However, the researchers warned readers that, in their opinion, training in severely cold environments should be done carefully to avoid overloading immature horses and to prevent musculoskeletal injuries.

These results also support the assertion that the training protocols for horses may need to be altered based on the ambient temperatures in which the horses are reared and trained. In other words, a Thoroughbred being trained in Florida may require a different approach compared to one trained in Pennsylvania or New York.

“This study reminds owners and trainers there is no ‘cookbook’ when it comes to training horses, and environmental factors should be considered alongside diet and exercise,” advised Crandell.

Any horse involved in active training or competition has some level of risk for musculoskeletal injuries or even overtraining injuries.

“Support the musculoskeletal system with targeted supplements like Triacton, which helps increase bone density in intensively exercised growing horses through an array of bone-building nutrients important for bone health,” advised Crandell.

^*Ishimaru, M., A. Matsui, K. Seki, and K. Korosue. 2022. Effects of different winter climates in Japan on body composition of young Thoroughbreds in training. Journal of Veterinary Medical Science (84)12:22-0378.