Equine water treadmills were initially designed for rehabilitation of musculoskeletal injuries but are now also widely used for conditioning sport horses. High-intensity exercise is important in improving fitness in horses however, strenuous ground exercise can cause excessive strain and overload of lower limb structures, resulting in injuries. In humans and dogs, buoyancy during water treadmill training reduces ground reaction forces (the forces between the feet and the ground and hence transmitted up the limbs), likely reducing the pressure on joints. Workload on a water treadmill is a function of water height and, to a lesser extent, treadmill speed. Increasing water height increases resistance to forward motion which causes an increased limb flight arc, decreased stride frequency and increased stride length. But does working horses on a water treadmill result in the same cardiovascular conditioning as traditional ground exercise programmes?
A recent study by North American researchers investigated the effect of an 18-day water treadmill conditioning programme on peak oxygen consumption (V̇O2peak). Peak (sometimes referred to as maximal) oxygen uptake is considered to be the single best measure of skeletal muscle aerobic capacity and cardiovascular fitness. Nine unfit Thoroughbreds were used in a randomised controlled trial. Six horses were worked 5 days per week, for 18 days, in stifle-height water (WT group), while 3 control horses worked on the same treadmill without water (dry treadmill group (DT)). All horses underwent an incremental exercise test on a racetrack before and after completion of the treadmill training period. The first step consisted of 300 m at ~4 m/s, followed by two 300 m steps at ~6 and 8 m/s, respectively, and finally an 800 m gallop at the fastest speed that the horse was capable of performing.
All horses were of a similar fitness level before conditioning. Post-conditioning, V̇O2peak was significantly greater in the WT horses than the DT horses (P=0.02). V̇O2peak significantly increased by an average of 16.1% in the WT horses (P=0.03). In comparison, V̇O2peak did not significantly change, and even showed a tendency to decrease, in the DT horses. To assess endurance, average speeds during ridden exercise tests were also analysed. Average speed over the entire maximal intensity field test (800 m) increased by 17.4% in the WT horses from 8.7 m/s pre-conditioning to 10.5 m/s post-conditioning (P=0.03). Time taken to complete the 800 m test decreased from an average of 92 seconds pre-conditioning, to an average of 76 seconds post-conditioning in the WT horses, but did not change in the DT horses. The average speed over the final bout of exercise (final 30 seconds before crossing the finish line) also increased by 12.1% per cent in the WT horses from 8.0 m/s to 9.1 m/s (P=0.03). Average speed and final 30 seconds speed did not change in the DT horses.
The authors concluded that “despite the relatively low-intensity nature of water treadmill exercises, a protocol employing a high-water height was able to significantly increase V̇O2peak and endurance in Thoroughbreds. Therefore, the inclusion of WT protocols in the training programmes of athletic horses may have a beneficial conditioning effect.”
Greco-Otto, P., Bond, S., Sides, R., Bayly, W., Leguillette, R. (2020) Conditioning equine athletes on water treadmills significantly improves peak oxygen consumption Veterinary Record 186, 250.
TOP TEN TIPS FOR FITNESS TRAINING
1) Limit the amount of trotting on roads to 5-10 minutes a day
2) Walk as much as you want on roads
3) Use a variety of surfaces - road, arena, tracks, all-weather
4) 3-4 sessions per week is sufficient for increasing fitness
5) Space sessions as equally as possible (working only on Sat and Sun does little to increase fitness)
6) Increase work gradually; one of the biggest risks for lameness is a sudden increase in work e.g. from 30 minutes walk and trot to cantering uphill on a soft surface!
7) Increase the workload approximately every 2 weeks - with regular exercise 3-4 times a week - this is how long it takes the body to adapt
8) Use a combination of ridden and lunging exercise (even treadmill and or swimming if you have it), especially in the first few months of training when your horse’s back is not as used to carrying weight!
9) Try to avoid uneven or very deep surfaces
10) Boots and bandages protect - they don't support. Don't overtighten as this will do more harm than good!