Equine Fitness and Physiology

Horse physiology as it relates to physical conditioning and well-being.
Horse physiology as it relates to physical conditioning and well-being.

Physiology: A branch of biology that deals with the functions and activities of life or living matter (as organs, tissues, or cells) and of the physical and chemical phenomena involved.... --Merriam-Webster Dictionary

Whether your horse is competing as a top-level athlete or is simply used for an occasional trail ride, it must have a level of fitness to perform well and to endure the activity without injury. To make an improvement in overall fitness, activities should be gradually increased in a systematic way. A gradual approach protects the horse from injury as the horse's body adapts to the increased workload.

How the physiology of the horse adapts with training

An adequate period of physical conditioning based on your horse's current condition and level of activity will affect five important major systems:

  1. Cardiovascular system -- improved capacity to deliver oxygen to working muscles
  2. Muscular system -- improved capacity to utilize oxygen and more efficient fuel utilization
  3. Supporting structures (bone, tendon,ligaments,muscle) -- an increase in the size and/or strength )
  4. Temperature regulating system -- greater ability to lose body heat during exercise, thereby avoiding excessive increases in body temperature
  5. Central nervous system -- improved neuromuscular coordination enabling the horse to complete skills involved in a particular discipline more effectively and efficiently

Although the amount of time it takes for a horse to gain a higher level of fitness will vary, the average time for structural and physiological adaptations to an effective exercise training program are:

Physiologic response Adaptation time
Increase in oxygen delivery to muscles 1-2 weeks
Increase in plasma volume 1-2 weeks
Improved sweating response 1-2 weeks
Increase in red blood cells/hemoglobin 2-4 months weeks
Increase in muscle capillaries 3-6 months
Increase in mitochondria 4-6 months
Increase in muscle aerobic enzymes 4-6 months
Increase in bone density 4-6 months
Increase tendon/ligament strength* 4-6 months
*Available research is limited

Interruptions to a horse's fitness training are inevitable because of weather, injury, sickness or the end of a competitive season. Horses that have minimal or no training for up to a month, usually experience a minimal loss of fitness, especially if they have been in training for several months.

Interruptions that extend to months or longer will suffer a greater loss of cardiovascular condition and will lose musculoskeletal strength that will have to be regained before progressing further.

Most research shows that for each additional month of little or no training beyond the first month's layoff, you will need an month's reconditioning to reach the level achieved prior to the period of inactivity.

Maintain - easier than regain

Maintaining a baseline of fitness during down-times or the off-season is important especially in older horses. Horses that maintain a baseline of fitness, especially as it relates to cardiovascular workouts at least twice a week, will return to the higher level of fitness much more quickly than horses that are allowed periods of inactivity.

Knowing the physiology of your horse and how it is affected by training and conditioning will help you maintain an adequate program that will keep cardiovascular and muscular systems, as well as the horse's other important systems in condition to withstand the rigors of riding and competing whatever the workload of the horse might be.

Dig deeperTM

EquiMed's equine fitness and conditioning health center contains more information on how you can keep your horse in-shape and good health.

About the Author

EquiMed Staff

EquiMed staff writers team up to provide articles that require periodic updates based on evolving methods of equine healthcare. Compendia articles, core healthcare topics and more are written and updated as a group effort. Our review process includes an important veterinarian review, helping to assure the content is consistent with the latest understanding from a medical professional.