Cross-sectional and longitudinal research approaches: running pace and step characteristics of elite athletes in the 400-m hurdles

The aim of this study was to clarify the running pace and step characteristics among various competitive-level 400-m hurdlers through cross-sectional and longitudinal research approaches. We analysed spatiotemporal data for 13 male world-class and 14 male national-level 400-m hurdlers. We analysed 16.8 {+/-} 4.2 races for each world-class hurdler and 20.0 {+/-} 6.0 races for each national-level hurdler (the total number of analysed runs was 499) using publicly available television and internet broadcasts. Cross-sectional approach showed that positive relationships of finish time were highly obtained between both first- (r = 0.901) and latter-half split times (r = 0.914). In contrast, the first- and latter-half split times were not significantly correlated to SL and SF. A multiple single-subject approach showed that 14/27 hurdlers were identified as being latter-half speed reliant. In contrast, no hurdlers demonstrated first-half reliance. In the latter half of the race, 12/27 hurdlers were identified as being SF reliant; no hurdlers demonstrated SL reliance. In conclusions, important findings regarding high performance in a cross-sectional research approach do not always corresponded with those in a longitudinal research approach. Athletes and coaches should carefully improve performance in the first half of the race based on an individualization principle for training.