Hyperbolic relationship between time-to-fatigue and workload.

This research aimed to understand the relationship between power exerted during high-intensity exercise and time-to-fatigue in horses, which can assist in determining their anaerobic work capacity. The study concluded that this relationship is hyperbolic and potentially helpful in assessing the anaerobic capacity of horses.

Objectives of the Study

• The main aim of the study was to analyze how the power exerted during high-intensity exercise relates to the time until fatigue sets in for horses, a relationship that can assist in determining their anaerobic work capacity.
• These findings were intended to improve our understanding of equine physiology, and potentially provide valuable information for training and healthcare practices for horses.

Methodology

• The study involved eight standardbred horses, each of which performed five or six run-to-fatigue trials on a treadmill.
• The exercise intensities were chosen to trigger fatigue within 30 to 240 seconds.
• The order in which the horses performed the trials was randomised for each horse but balanced overall for the first four trials.
• The data for power exerted (the independent variable) and time-to-fatigue (the dependent variable) were rigorously analysed using nonlinear regression to check for goodness of fit to hyperbolic, linear, and exponential equations.

Results of the Study

• The best fit to the data was found using the hyperbolic relationship. A corresponding formula was deduced: t = W'(P- φPA), where ‘t’ represents the time to fatigue, ‘W” represents the anaerobic work capacity, ‘P’ represents the power, and ‘φPA’ depicts the critical power value.
• The calculated mean values for the anaerobic work capacity (W’) and the critical power value (φPA) were 47,000 ± 500 J (joules) and 2490 ± 150 watts, respectively.

Conclusion of the Study

• According to the findings, the relationship between power exerted during high-intensity activities and time-to-fatigue in horses is hyperbolic.
• This hyperbolic relationship can be potentially beneficial in assessing the anaerobic work capacity of horses, which can directly influence their training and care.