Related Experiment Video
Updated: Jun 20, 2025
09:24
A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers
Published on: January 28, 2020
8.8K
Workload and spirometry associated with untethered swimming in horses
R Leguillette1, P McCrae2, S Massie2
1Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, AB, T2N4N1, Canada. rleguill@ucalgary.ca.
BMC Veterinary Research
|July 19, 2024
Summary
Untethered swimming in horses is a submaximal, aerobic exercise. Horses exhibit unique breathing patterns, including a longer initial apneic period and shorter inspiratory time during swimming.
Area of Science:
- Equine physiology
- Sports science
- Animal exercise physiology
Background:
- Swimming is empirically used for horse rehabilitation and conditioning.
- The physiological intensity of free swimming in horses remains largely unquantified due to measurement challenges in water.
Purpose of the Study:
- To quantify the physiological workload and cardiorespiratory responses of untethered swimming in horses.
- To characterize the unique breathing patterns horses exhibit during free swimming.
Main Methods:
- Five fit Arabian horses underwent assessment in a 100m indoor pool.
- Physiological parameters including oxygen consumption (V̇O2), ventilatory variables, and heart rate (HR) were measured using a facemask and underwater ECG.
- Post-exercise blood lactate and ammonia levels were analyzed.
Main Results:
- Horses displayed bradypnea (12 breaths/min) initially, with V̇O2 at 43.2 ml/(kg.min) and HR at 178.0 bpm.
- Distinct ventilatory patterns were observed, including a shorter inspiratory duration (tI=0.5s) compared to expiratory duration (tE=1.2s).
- Submaximal exercise indicators like lactate (1.5 mmol/L) and ammonia (41.0 µmol/L) were recorded post-exercise.
Conclusions:
- Untethered swimming in horses constitutes a primarily aerobic, submaximal exercise intensity.
- The respiratory pattern during swimming is characterized by an initial apneic phase and a significantly shorter inspiratory time relative to expiratory time.
