Cardiac Changes after Lactate-Guided Conditioning in Young Purebred Arabian Horses

Area of Science:

• Equine physiology
• Sports medicine
• Cardiovascular adaptation

Background:

• Empirical training protocols are common in equine conditioning.
• Understanding cardiac adaptation to structured exercise is crucial for performance horses.

Purpose of the Study:

• To evaluate cardiac adaptation in horses following a six-week treadmill conditioning program.
• To assess the safety and efficiency of the conditioning protocol on aerobic capacity and cardiac remodeling.

Main Methods:

• Twelve untrained Arabian horses underwent a six-week treadmill conditioning program.
• Incremental exercise tests (IET) determined velocities at blood lactate concentrations of 2 mmol/L (V2) and 4 mmol/L (V4).
• Echocardiography (B-mode, M-mode, pulsed-wave and tissue Doppler) assessed cardiac structure and function before and after conditioning.

Main Results:

• Significant increases in V2 (5.2 to 6.7 m/s) and V4 (5.8 to 7.6 m/s) were observed (p < 0.0001).
• Left ventricle internal diameter at diastole, left ventricle mass, and stroke volume increased post-conditioning.
• No significant changes in left ventricle free wall thickness or relative wall thickness were noted.

Conclusions:

• The six-week conditioning protocol is safe and effective for improving aerobic capacity in horses.
• Physical training induced beneficial cardiac remodeling, primarily involving increases in ventricular dimensions and mass.
• The study provides objective data supporting structured training for enhancing equine athletic performance.