2.3.1. Horse Exercise Protocol

Each horse was ridden in gallop by one experienced jockey (the same for all horses; male 73.5 kg body mass) on a 500 m section of a half-mile racetrack (Calgary Stampede, Calgary, AB, Canada) to a target speed of 16 ms⁻¹ guided by a GPS watch on the jockey’s wrist (fenix 6, Garmin, Cochrane, AB, Canada). Horses repeated three runs per day, one for each lane in randomized order. After the first session (session 1) with the first four horses, the track was prepared for the second session in an identical fashion to prior to data collection. In the second session (session 2), the remining eight horses conducted their three runs. On the second day, six of the twelve horses performed an additional three runs with the track prepared with increased compression of the track underlay (session 3).