The effects of training on ventilation and blood gases in exercising thoroughbreds.
The effects of training on ventilation and blood gases during exercise were investigated in 6 clinically normal, detrained Thoroughbred horses. They underwent a 16 week training programme similar to the type frequently used for Thoroughbred racehorses in Great Britain. Standardized treadmill exercise tests (2 min canter at 8 and 10 m/s C8 and C10[ and 2 min gallop at 12 m/s [G12], on a level surface) were performed prior to and after 16 weeks of training. Respiratory flow rates were measured using ultrasound flow transducers. Blood samples were drawn from a transverse facial artery and the right atrium. Minute ventilation, respiratory frequency and tidal volume were not significantly altered by training. Peak inspiratory flow rate was lower following training at 8 and 10 m/s, but not at 12 m/s. Arterial oxygen tension was decreased during trot and canter following training. Blood lactate concentration post G12 decreased following training (10.5 +/- 2.2 mmol/l vs. 7.7 +/- 2.2 mmol/l; P < 0.05). The increase in the degree of exercise-induced arterial hypoxaemia following training may reflect a lack of pulmonary adaptation to training in the face of improved cardiovascular and muscular function.
Roberts
C A
CA
Centre for Equine Studies, Animal Health Trust, Newmarket, Suffolk, UK.
Marlin
D J
DJ
Lekeux
P
P
D000818:Animals; D001784:Blood Gas Analysis / Q000662:veterinary; D005260:Female; D006736:Horses / Q000502:physiology*; D008297:Male; D010366:Peak Expiratory Flow Rate; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012119:Respiration