Conditioning equine athletes on water treadmills significantly improves peak oxygen consumption

Abstract

Equine water treadmills (WT) were initially designed for rehabilitation of musculoskeletal injuries, but are also commonly used for conditioning sport horses, however the effects are not well documented. The purpose of this study was to test the effect of an 18-day WT conditioning programme on peak oxygen consumption (V̇O₂peak). Nine unfit Thoroughbreds were used in a randomised controlled trial. Six horses worked daily for 18 days in stifle-height water (WT group), while 3 control horses worked without water (dry treadmill group (DT)). Preconditioning and postconditioning maximal exercise racetrack tests (800 m) were performed using a portable ergospirometry system. Measured outcomes were V̇O₂, tidal volume, minute ventilation, breathing frequency, heart rate, blood lactate and instantaneous and average speed. The workload as assessed by V̇O₂ was 21.7 per cent of preconditioning V̇O₂peak values for WT horses. V̇O₂peak on the racetrack increased by 16.1 per cent from preconditioning to postconditioning in the WT horses (P=0.03), but did not change in the DT horses. Therefore, exercising horses in high water heights may improve conditioning.

Keywords: Conditioning; Heart rate; Horses; Sports physiology; Ventilation; V̇O2peak; Water treadmill.

Figure 1

Peak oxygen consumption (V̇O₂peak in ml/(kg.min)) in two groups of horses preconditioning and postconditioning. figure 1A shows a significant increase of V̇O₂peak (n=6) after 18 total days of water treadmill (WT) training (9 days under maximal conditions: water at the height of the stifle, 1.45 m/s). figure 1B shows a non-significant decrease of V̇O₂peak (n=3) after 18 days of training on a dry treadmill (DT) at the same speed. Asterisk (*) denotes significant differences.

Figure 2

Average speeds over an entire maximal intensity test (a, b) and over the final 30 seconds of the test (c, d) in two groups of horses preconditioning and postconditioning (a and c following 18 days of water treadmill (WT) training; b and d following 18 days of dry treadmill (DT) training). Asterisks (*) denote significant differences.