Global Positioning System-Determined and Stopwatch-Determined Running Speeds of Horses Differ.

The research sought to determine if GPS-determined running speeds of horses were accurate by comparing them with stopwatch-determined speeds. The comparison revealed notable differences, with GPS-determined speeds being consistently lower, bringing the accuracy of GPS into question.

Methodology

• The research involved 19 horses running a standardized exercise test (SET) in two different sandy arenas, one indoor and another outdoor. The tracks consisted of either 130m or 250m laps.
• The running speeds were determined using two methods: an equine heart rate meter GPS (G-speed) and a stopwatch (W-speed). The stopwatch speed was determined manually through the division of the measured time over the distance run.
• Each SET comprised five intervals at escalating speeds, each interval ranging between 3 and 6 minutes. Horses ran a pre-determined number of laps for each interval to meet the set duration.

Data Analysis

• The collected data was examined using a paired Student’s t-test, a statistical procedure used to determine the significance of the differences between two sets of data.
• A significance level of P < .05 was set. When the P-value is less than .05, the differences observed are deemed statistically significant, and the null hypothesis (which proposed both methods would yield the same speeds) can be rejected.

Findings and Conclusion

• The results advocated substantial differences between the GPS (G-speed) and stopwatch-determined (W-speed) running speeds of horses. The G-speeds were consistently lower than the W-speeds for all intervals and in both riding arenas, the differences augmenting with increasing speed.
• Since the P-values for all intervals ranged from .01 to .001, all less than .05, these differences were statistically significant.
• Thus, the initial hypothesis that both measurement methods would yield similar speeds was rejected. This invites questions about the accuracy of the GPS method (Polar M400) in determining speed under such conditions.