Relationship between Resting and Recovery Heart Rate in Horses.
Authors: Lindner Arno, Esser Martina, López Ramón, Boffi Federico
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Resting and Recovery Heart Rate in Horses Endurance competition relies on standardised recovery heart rate (HR) thresholds at veterinary gates to determine fitness to continue, yet the relationship between an individual horse's baseline resting HR and its post-exercise recovery has never been formally investigated. Lindner and colleagues exercised seven horses on a treadmill for both 10 and 60-minute periods at varying speeds, recording resting HR before exercise and repeatedly during the 30-minute recovery window, whilst also establishing each horse's aerobic threshold (v4, the speed at which blood lactate reaches 4 mmol/L). Whilst resting and recovery HR showed significant correlation in 16 of 35 comparisons, there was no consistent relationship between aerobic fitness (v4) and either resting or recovery HR values across most exercise protocols, suggesting that horses with identical aerobic capacity may have substantially different HR profiles. These findings challenge the validity of applying fixed recovery HR criteria in endurance competition, as horses with naturally higher resting rates—which may be entirely normal and unrelated to fitness—would be disadvantaged at standardised veterinary gates; the authors argue that individualised threshold values, or assessment methods accounting for baseline HR variation, may be necessary to ensure fair evaluation across the sport.
Read the full abstract on PubMed
Practical Takeaways
- •Fixed recovery heart rate gates in endurance competitions do not account for individual horses' baseline resting rates, potentially disadvantaging horses with naturally higher resting heart rates
- •Resting heart rate alone cannot reliably predict a horse's fitness level (v4) or post-exercise recovery capability
- •Consider individualizing veterinary gate criteria based on each horse's resting heart rate rather than applying arbitrary universal thresholds
Key Findings
- •Resting heart rate and recovery heart rate were significantly related in 16 out of 35 comparisons across seven horses
- •No significant relationship found between v4 (lactate threshold speed) and resting heart rate or recovery heart rate after 10 minutes of exercise
- •Relationship between v4 and recovery heart rate after 60 minutes of exercise was significant only at the fifth minute post-exercise at 3.5 m/s
- •Pre-determined arbitrary recovery heart rate cutoff values may create unfair competition in endurance racing due to individual variation in resting-recovery relationships