Measurements of fitness in thoroughbred racehorses using field studies of heart rate and velocity with a global positioning system.

The research tested the use of heart rate and global positioning system (GPS) in assessing the fitness levels of Thoroughbreds during training. It concluded that this method provides reliable measurements of the horses’ fitness levels and it also records their response to training.

Methodology

• Two groups of healthy Thoroughbreds were used in this study. One group consisted of twelve horses between 3 and 5 years old to test the reliability of the measurements, and the other group consisted of twelve 2-year-old horses to investigate the effect of training.
• A typical fast exercise training session was then conducted and five-second averages of the horses’ velocities and heart rates were recorded using a GPS and a Polar heart rate monitor. The researchers did not use a standardized exercise test protocol.
• Regression analyses from collected data were utilized to estimate velocities at a heart rate of 200 beats per minute (V200), as well as at the maximum heart rate (VHRmax).
• Data were collected on consecutive ‘fast’ training sessions to compare measurements and assess their reliability. The impact of training was also investigated with fitness tests in weeks 2 and 6 of ‘fast’ training.
• General statistical methods were used to analyze the collected data. Absolute and relative differences were calculated to evaluate reliability and paired t-tests were used to detect an effect of training.

Results

• The measures VHRmax, V200, and HRmax were found to be reliable fitness measures with average differences of 2% or less. The reliability of VHRmax was found not to depend on VHRmax.
• Training had significant positive effects on VHRmax and V200 values (P<0.01), but did not impact HRmax.
• The regression analyses did not exhibit significant changes in the slope or intercept after training.

Conclusion

• Heart rate and velocity measurements during field gallop exercises were shown to provide trustworthy measures for fitness. These measures were also capable of tracking the training response in the Thoroughbreds.
• This non-invasive and field-based method could be used broadly to monitor Thoroughbred horses’ adaptations to training, providing a simple yet effective approach to equine fitness evaluation.