Effects of Amount of Intensive Training on VLa4 in 3‐Year Old Standardbred Horses

Abstract

IntroductionThe effects of different amounts of training on performance of young horses have not yet been studied in a long term perspective. The aim of this study was therefore to assess the effect on VLa4 of two training programs performed from the age of 2 to 3 in Standardbred horses.MethodsFourteen horses were in March as 2‐year olds divided into two groups; one was randomized to a training program including intensive exercise (control) and the other to a training program with reduced amount of intensive exercise (distance −30% compared to control). Group division was partly based on breeding index (means: control 110, reduced 109) and gluteus medius fiber type ratio (IIA/IIB, both groups mean 1.34). Horses were trained ∼2 times/week. After 14 months, a VLa4‐test was performed on a track (4 x 1000 m). Speed was measured by GPS and increased by ∼3 s/1000 m for every interval. Blood samples were collected after each interval and lactate concentration was determined using Lactate Pro. Exponential regression analysis of speed and lactate concentration were used to estimate individual VLa4. ANOVA and Tukey's test were used to analyse differences between groups.ResultsThere was no difference in VLa4 between the control and reduced exercise group (10.6 ± 0.1 and 10.8 ± 0.1 m/s).ConclusionsThe study indicates that it might be possible to reduce the amount of intensive training by ≤30% without impairing performance of 3 year old Standardbred horses.Ethical Animal ResearchThe study was approved by the local ethics committee in Umeå. Sources of funding: Swedish University of Agricultural Sciences, Swedish National Trotting School at Wången, Swedish Trotting Association, Swedish Horse Council Foundation, Swedish Horse Racing Totalisator Board (ATG), Trioplast AB, Dow Chemicals, Polar Sverige AB, and Scandivet AB. Competing interests: none.