TY - JOUR T1 - RELIABILITY OF RETROSPECTIVE PERFORMANCE DATA IN ELITE 400-M SWIMMING AND 1500-M RUNNING JF - British Journal of Sports Medicine JO - Br J Sports Med SP - e4 LP - e4 DO - 10.1136/bjsports-2013-093073.6 VL - 47 IS - 17 AU - GJ Mytton AU - DT Archer AU - KG Thompson AU - A St Clair Gibson Y1 - 2013/11/01 UR - http://bjsm.bmj.com/content/47/17/e4.50.abstract N2 - It is beneficial for coaches and athletes to know the most effective pacing profiles that have occurred during elite races and to establish how reproducible these profiles are in order to assist tactical preparation for competition (Tucker et al. IJSPP 2006;1:233–245). This study aimed to establish the repeatability of lap data of international standard competitors in 400-m freestyle swimming and 1500-m track athletics, events of similar duration. Data were collected from five Olympic, World and European international competitions between 2005 and 2011 in 400-m swimming and 1500-m running events. Swimming lap times were freely available in the public domain from the Omega Timing results service (www.omegatiming.com). Running lap times were measured using a validated frame by frame playback method (Mytton et al. IJSPP 2013, e-pub). Eleven swimmers and twelve runners with repeat final appearances were analysed with a mean time between finals of 20.5±13.3 months. Trial one to trial two data were compared using Hopkins’ reliability spreadsheet (Hopkins, Sport Sci 2011) and the typical error (TE) and coefficient of variation (CV) reported. The TE and CV values tended to increase in swimming but significantly decreased in running as laps progressed. CV values were greater in running than swimming in laps 1 (p=0.001), 2 (p=0.01) and 4 (p=0.01) but not different in lap 3 or for total time (p>0.05). The findings of this study suggest that in elite competitors, within-subjects reliability for 400-m swimming is greater than for 1500-m running times. The differences in reliability between exercise modalities might be due to a number of factors such as a greater degree of tactical racing in the early laps in track athletics when athletes compete for position, the manner of the start being different to swimming (i.e. dive start in swimming), and differences in mechanical efficiency, kinetic energy production and loss between the two sports (de Koning et al. PIoS One 6:e15863). ER -