Training-induced modifications in cardiorespiratory and ventilatory measurements in thoroughbred horses.

The study investigates the effects of training and detraining on the respiratory functions of Thoroughbred horses during standardized exercise tests, revealing that variations in oxygen uptake were likely due to cardiovascular and haematological alterations, not ventilatory changes.

Methodology

• Ten healthy Thoroughbred horses were subjected to five standardized treadmill exercise tests (SETs): before training, after acclimatization, after aerobic training, after anaerobic training, and after detraining.
• The tests were conducted in an air-conditioned laboratory and were held on a treadmill inclined at 6 degrees.
• Respiratory features like airflow, tidal volume (VT), respiratory frequency (RF), and expired minute volume (VE), along with heart rate, were consistently monitored.

Data Collection

• A face mask and two ultrasonic pneumotachographs were used to gather respiratory data.
• A mass spectrometer processed data breath-by-breath to calculate peak oxygen uptake (VO2 peak).
• Heart rate was continuously measured using a polar horse tester.
• The oxygen pulse (VO2/HR) was derived from the accumulated data.
• Venous blood was collected prior and post each SET for lactate, pH, and hemoglobin determinations.

Key Findings

• It was observed that trained horses showed significant alterations in all values, with the exception of VT, RF, and VE.
• The escalation in VO2 induced by training appears to be predominantly attributed to cardiovascular and hematological changes rather than ventilatory alterations.
• This implies that while systems like cardiovascular and haematological involved in exercise physiology can be effectively trained, the respiratory capacity shows limited adaptability to training.

The study concludes that rather than the alteration in the ventilatory system, the increased oxygen uptake observed in these horses can primarily be attributed to changes in the cardiovascular and hematological system. The research also highlights the limited adaptability of the ventilatory capacity to training in Thoroughbred horses, emphasizing more on other physiological systems to effectively improve performance.