Effect on VLa4 of Reduced Exercise Periods During Conditioning of Horses

Introduction One week of reduced workload between 3 periods of 2 weeks of conditioning ( CP ) 5 times/fortnight at VLa10 for two bouts of 5 minutes allowed for a continuous increase of VL a4, but the extent was smaller than in another study with the same conditioning program but for the recovery week ( VL a4, VLa10: horse's speed, which produced a blood lactate concentration of 4 and 10 mmol/l). Methods Six Purebred Arabians were submitted to the same conditioning protocol of the studies mentioned above except for increasing the duration of treadmill exercise in each CP by 2.5 minutes (2 x 10 minutes in the third CP ). A standardized exercise test ( SET ) was performed at the beginning of CP to determine VL a4 and VLa10, and repeated after the week with reduced workload after each CP . Exercise speed was individually adapted to the new VLa10 for every CP . The effects of conditioning on VL a4 were examined using repeated measures analysis of variance. Significant results were analyzed further with Fisher's test. Results Mean VL a4 increased after the first CP (P<0.001), fell between first and second CP (P<0.001) and remained at this level after the third CP (P>0.05). Conclusions This conditioning program did not allow for VL a4 increases of the magnitude observed in other studies with the same exercise protocols but without the week with reduced workload and increases in exercise duration. It is possible that the decline of VL a4 of the horses after the first CP was due to overtraining (simultaneous increase of speed and duration of exercise). The effect of recovery from training needs further studies. Ethical Animal Research All procedures were approved by the Bioethical Committee of the University of L a P lata, A rgentina. Sources of funding: Verein zur Förderung der Forschung im Pferdesport, G ermany. Competing interests: none.