By Jec A. Ballou

While dressage and other arena-based sports place relatively low aerobic demands on horses, emerging studies indicate that improved muscle function may come from occasional exercise in higher heart rate zones. It is worth exploring the use of heart rates during arena training, and how riders can use it to improve physiological responses.

The purpose of conditioning across different aerobic zones is to acquire fitness adaptations that are missed when remaining at one intensity every day. These include energy metabolism, fatigue resistance, and improved blood circulatory capacity to skeletal muscles. It is this final adaptation we should pay particular attention to, mainly for the fact that it happens when exercising at a heart rate of 150 to 160 beats per minute (bpm). As a comparison, the average dressage horse rarely works in this zone during his or her routine training. This is considered a moderate aerobic zone with the heart rate at 70 to 80 percent of its maximum. For most horses, a brisk canter or riding cross-country is needed to enter this zone.

Increasing blood circulatory capacity means working muscles receive more blood and oxygen. This makes them capable of working stronger and harder. They can generate more power and, just as importantly, adapt to clear away metabolic waste generated from that exertion. This allows them to keep firing in a fresh state while avoiding the effects of sustained effort: loss of force, delayed firing patterns, discomfort.

Related: Multi-Discipline Horse Conditioning Evaluation

A heart monitor provides data to track the progress of fitness, allowing the rider to train the horse at the appropriate intensity. The horse pictured is wearing a heart monitor by Enduro Equine. Photo: Enduro Equine

Heart rate data collected from upper-level dressage horses in competition hovered between 110 and 140 bpm. It can be assumed that the bulk of daily schooling falls in a similar range. Exercise in this range is categorized as light intensity. While it contributes to overall health and well-being, it does not create the same conditioning effects for muscles as the higher zones previously referenced. Most notably, these effects include lactate shuttling, improved blood supply to muscles, and stronger neuromuscular signals. It can be argued that when strength development matters, occasional exercise at higher zones becomes crucial.

If heart rate parameters are new to you, the basic aerobic zones for horses are as follows:

• Resting/inactive — 25 to 35bpm
• Very light exercise (walking, trotting, slow canter on flat ground) — up to 140bpm
• Moderate exercise (brisk trot/canter, riding hills) — 150 to 160bpm
• Hard/Intense exercise (gallop, sprints, hills) — up to 180bpm
• Maximal heart rate — approximately 200bpm or higher, only used for horses in sprinting sports.

To be clear, horses in arena disciplines do not need to spend a majority of time working outside their normal aerobic zone. For most, the bulk of training will remain at intensities below 140 bpm. One or two strategic sessions per week at a higher zone provides adequate stimulus to improve skeletal muscle function. At this point there is not an exact prescription beyond the general goal of accumulating several minutes in this higher zone per week.

Related: Designing an Effective Equine Fitness & Conditioning Plan

For some riders, a weekly trail outing on hilly terrain will push the heart rate into this zone for several minutes. For others, one-minute intervals of galloping will do the trick, with the number of intervals and rest in between dictated by a horse’s age and development. A favourite routine of mine, due to its simplicity and the ability to perform it nearly anywhere, is to canter briskly for one minute followed by one minute of easy jogging. This sequence is repeated without walking or stopping for a total of at least eight times. More seasoned horses will do 10 or 12 reps.

Any conversation about heart rate needs to include accurate data collection. Assessing aerobic zones does require riding with a heart monitor, but the good news is that nowadays these are both easy to find and affordable. They do not need to be used every ride. It is only necessary to gather heart rate readings every few weeks at various paces to maintain an accurate interpretation of your horse’s actual aerobic demands at different efforts. 

Without a heart monitor, it is common to incorrectly guess a horse’s heart rate based on other factors — sluggishness, heavy breathing, and so on. These tend to mislead riders. There is also the possibility for riders to falsely assume that just because something feels challenging for them it is also a hard effort for the horse, which is often not the case. Consider a big Warmblood with an enormous ground-covering trot that has a lot of suspension. As the rider secures her balance and absorbs all the motion of this springy gait, it gives her quite a workout. It can be tempting to think the horse, too, is working hard. In reality, this energetic and bounding trot might occur at 95bpm. 

The other helpful — and sometimes surprising — feedback offered by monitors is the demands of each gait for individual horses. Monitors tell you which gait is more efficient for the horse, which sometimes differs from what we feel in the saddle. While some horses’ heart rates might spike during a brisk canter, for instance, others might have a lower heart rate when cantering as opposed to trotting. 

Collecting occasional heart rate data also informs riders when their horses have adapted to the conditioning effects of exercises and routines. As they gain fitness, they can perform once challenging exercise with greater ease and therefore lower heart rates. To continue making fitness gains it is important at this point to modify or change exercises. 

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Main Photo: Shutterstock/Alex Bros