CARDIORESPIRATORY AND METABOLIC EFFECTS OF WALKING, STANDING, AND STANDING WITH A SPLINT DURING THE RECUPERATIVE PERIOD FROM MAXIMAL EXERCISE IN HORSES

Objective-To determine the effects of walking, standing, or standing w ith a splint on 1 forelimb on rate of recuperation of horses after a b rief, intense bout of exercise. Animals-6 adult Thoroughbreds (435 to 542 kg). Procedure-Horses were preconditioned by exercise on a treadmi ll to establish a uniform level of fitness. Once fit, the treadmill sp eed causing each horse to exercise at 120% of its maximal oxygen consu mption was determined and was used in simulated races at 14-day interv als. Horses were instrumented for collection of arterial and mixed Ven ous blood samples for measurement of acid-base status, concentrations of metabolites, and cardiopulmonary indices. The horses were exercised at a speed inducing 120% of their maximal oxygen consumption until fa tigued or for a maximum of 2 minutes. Three recuperative interventions were evaluated: walking al 1.8 m/s for 30 minutes, then standing for the remainder of the 90-minute trial; standing stationary for 90 minut es, and standing stationary for 90 minutes with a splint on the right forelimb. Results-Walking significantly increased cardiac output durin g the recuperative phase and hastened recovery of normal acid-base sta tus and return of blood lactate concentration to baseline values. Conc lusion-Limiting movement of horses during the recuperative period dela ys recovery from maximal exercise. Most measured indices returned to b aseline by 60 minutes after exercise. All measured cardiopulmonary ind ices returned to baseline values by 90 minutes after exercise. Clinica l Relevance-Horses that are not allowed to walk during recuperation fr om exercise may have a prolonged recovery period.