Hematological and physiological responses in polo ponies with different field-play positions during low-goal polo matches.
Authors: Sanigavatee Kanokpan, Poochipakorn Chanoknun, Huangsaksri Onjira, Wonghanchao Thita, Yalong Mona, Poungpuk Kanoknoot, Thanaudom Kemika, Chanda Metha
Journal: PloS one
Summary
# Editorial Summary Polo represents one of the most physiologically demanding equestrian disciplines, yet little is known about how position-specific demands affect individual ponies' stress responses. Kanokpan and colleagues measured haematological markers, heart rate variability (HRV), and stress hormones in 32 polo ponies across different field positions during low-goal matches, sampling before play, immediately post-exercise, and at 30-minute intervals for three hours afterwards. Number two (midfielder) ponies sustained significantly higher effort intensities, spending more time in zone 4 (90–95% maximum heart rate) compared to number four (defender) ponies, though cortisol elevation—a key stress marker—resolved within 60–90 minutes post-play for all positions. More concerning was the sustained elevation of haematocrit, haemoglobin, red and white blood cells, neutrophils, and creatine kinase for at least 180 minutes after exercise, alongside persistently suppressed HRV (indicating reduced parasympathetic tone) extending to 90 minutes, with defenders showing the most prolonged stress index elevation. These findings suggest that defenders experience cumulative physiological strain despite lower peak heart rates, implying that training and recovery protocols should be position-specific; practitioners should particularly monitor defensive ponies for extended recovery demands and consider staggered work schedules to mitigate prolonged immune and musculoskeletal stress in regular competition schedules.
Read the full abstract on PubMed
Practical Takeaways
- •Defenders (number 4 position) experience greater physiological stress and require longer recovery periods (90+ minutes) compared to forwards and midfielders—adjust training and match scheduling accordingly
- •Monitor cortisol recovery (expect 60-90 minute baseline return) and elevated muscle enzymes for 3+ hours post-play to assess true recovery status before subsequent exertion
- •Heart rate variability remains suppressed well beyond perceived recovery; allow 90+ minutes of passive recovery before returning ponies to training or competition
Key Findings
- •Number 2 (midfielder) ponies spent significantly more time in high-intensity zones (zone 4, >90% HRmax) compared to number 4 (defender) ponies
- •Cortisol levels peaked immediately and 30 minutes post-exertion, returning to baseline within 60-90 minutes
- •Heart rate variability decreased during play and remained suppressed for approximately 90 minutes post-exercise, indicating prolonged parasympathetic nervous system depression
- •Hematological markers (Hct, Hb, RBC, WBC, neutrophils, CK) remained elevated for at least 180 minutes post-exertion, with defenders showing more prolonged stress responses than other positions