Yesterday, we learned about Type 1 muscle fibers: slow-twitch. These fibers support endurance, are fatigue resistant and provide extended small movements and postural control. Slow-twitch are referred to as red fibers due to their rich blood supply.
Think Arabians, Andalusians, endurance races and dressage.
The second type of muscle fiber is Type 2: fast-twitch fibers. Fast-twitch fibers provide big, powerful and explosive movement. Due to their lessened blood supply they fatigue quickly and are referred to as white fibers.
Quarter Horses and Thoroughbreds muscle masses consist of up 80-90% of fast-twitch muscle fibers.
Fast-twitch fibers are broken into two groups - Type 2A and 2B.
2A - High-Oxidative Muscle Fibers: these fibers take in more oxygen due to their myoglobin content, so fatigue is slower than 2B. 2A are important for long lasting, powerful performance and are typically found in event horses.
2B - Low-Oxidative Muscle Fibers: these fibers have less capacity to take in oxygen and fatigue quicker. 2B fibers produce the most force and execute explosive movement, but they can’t maintain this power for long. 2B are typically found in jumpers, reiners, and barrel horses.
Slow-twitch type 1 = cardio & endurance athletes = Arabians, Andalusians = endurance riders, dressage, polo
Fast-twitch type 2 = weight-lifting & HIIT = Quarter Horses, Thoroughbreds = racing, barrel racing, eventing, jumping
While genetics and selective breeding play a huge role in muscle fiber percentages there are other factors that can influence their ratios as well.
AGE - age causes a decline in fast-twitch fibers, but an increase in slow-twitch. It makes sense, as as our horses age they tend to slow down from explosive movement yet have good stamina!
TRAINING - Type 1 fibers can be developed through endurance training (low resistance, high rep exercises or low duration, low intensity). If your horse needs more stamina, simply taking them on longer trail rides is a great place to start.
Type 2 fibers can be developed through strength training (high resistance, low rep). You can take your horse for an explosive gallop, or add in some challenging pole work.
Since type 1, 2A and 2B fibers all exist in muscle at different ratios, you can’t target one fiber group without influencing the others. Any work you do will benefit them all, but you can change techniques to greater influence the fiber you’d like to improve on.
{{Training is a process - give your horse 3 months of consistent work to see big changes in their muscle mass, stamina and strength.}}
Understanding what our horse’s muscles are made of helps us better understand our horse’s capabilities. The saying ‘horses for courses’, meaning matching appropriate breed to appropriate work, has merit down to the very muscle mass of the horse.
Comments