Defining the Heart Rate Zone Corresponding to the Lactate Threshold in Colombian Paso Horses

Area of Science:

• Equine physiology
• Exercise science
• Animal sports science

Background:

• Colombian Paso horses (CPs) require high cardiorespiratory fitness for competitions.
• Current training methods for CPs often lack scientific validation.
• Optimal training zones based on physiological parameters are poorly understood in CPs.

Purpose of the Study:

• To estimate the aerobic lactate threshold (LTaer) in Colombian Paso horses using mathematical methods.
• To correlate LTaer with heart rate (HR) zones and blood lactate concentrations.
• To provide a scientific basis for training zone determination in CPs.

Main Methods:

• Eighteen CPs were divided into trained (GT) and untrained (GD) groups.
• Field-based incremental exercise test (IET) with continuous HR monitoring and serial blood lactate sampling.
• LTaer estimation using visual inspection, 2 mmol/L, and 4 mmol/L lactate thresholds.

Main Results:

• Different methods yielded varying LTaer estimations across HR zones (Zone 2 to Zone 4).
• Intragroup lactate accumulation increased exponentially above 75% of maximum HR (HRmax).
• No significant differences in lactate or HR were observed between trained and untrained groups during the test.

Conclusions:

• Field-based LTaer prediction in CPs is feasible using wearable HR technology and blood lactate.
• Correlating HR zones with lactate thresholds enables effective workload analysis for training.
• Further research on maximal lactate steady state (MLSS) in CPs is recommended.