Effects of two field continuous incremental tests on cardiorespiratory responses in Standardbred trotters.

This research aimed to study how two different exercise tests impacted the cardiovascular responses in Standardbred trotter horses. Results indicated that one of the tests might provide better information about the cardiorespiratory adaptations to exercise and estimation of aerobic energy expenditure in these horses.

Objective and Methodology

• The purpose of this research was to study cardiovascular responses in Standardbred trotters by subjecting them to two different continuous incremental field tests. This was designed to address a gap in equine exercise physiology, where there’s a huge dearth in oxygen consumption measurements in field conditions.
• The two exercise tests were carried out at a trotting speed and ended when the horses started to gallop. They were named T1 and T2 respectively.
• T1 started at a speed of 4.2 m/s with speed increments of 1.4 m/s every 3 minutes. On the other hand, T2 began at 6.4 m/s increasing by 0.8 m/s every 2 minutes.

Measurements and Findings

• Throughout the tests variables like speed (v), heart rate (HR), gas exchange rates were continuously recorded, while blood lactate concentration was measured before and after the tests.
• Results showed that horses reached higher peak oxygen consumption (VO2peak) and peak heart rate (HRpeak) during T1 compared with T2. Also, T1 lasted longer than T2.
• The number of steps the horses ran tended to, but not significantly, vary between the two tests.

Analysis and Conclusion

• The design of Test T1 was considered easier to implement and allowed better cardiorespiratory responses in the horses as compared to Test T2.
• The relation between heart rate and oxygen consumption obtained through T1 offered a better correlation than those obtained from T2, suggesting that T1 could generate better data when analyzing the horses’ cardiorespiratory adaptations to exercise.
• Overall, the study indicates that Test T1 might be more effective for evaluating cardiorespiratory adaptations and estimating aerobic energy expenditure in exercising trotters.