Combined uphill and downhill sprint running training is more efficacious than horizontal

Purpose: This study examined the effects of sprint running training on sloping surfaces (3°) on selected kinematic and physiological variables. Methods: Fifty-four sport and physical education students were randomly allocated to one of two training groups (combined uphill–downhill [U+D] and horizontal (H)) and a control group (C). Pre- and post-training tests were performed to examine the effects of 8 wk of training on the maximum running speed (MRS), step rate, step length, step time, contact time, eccentric and concentric phase of contact time (EP, CP), flight time, selected posture characteristics of the step cycle, and 6-s maximal cycle sprint test. Results: MRS, step rate, contact time, and step time were improved significantly in a 35-m sprint test for the U+D group (P < .01) after training by 4.3%, 4.3%, −5.1%, and −3.9% respectively, whereas the H group showed smaller improvements, (1.7% (P < .05), 1.2% (P < .01), 1.7% (P < .01), and 1.2% (P < .01) respectively). There were no significant changes in the C group. The posture characteristics and the peak anaerobic power (AWT) performance did not change with training in any of the groups. Conclusion: The U+D training method was significantly more effective in improving MRS and the kinematic characteristics of sprint running than a traditional horizontal training method

Sprint mechanical differences at maximal running speed: Effects of performance level

The aim of this study was to analyze footstrike patterns in elite marathon runners at the 2017 IAAF World Championships. Seventy-one men and 78 women were analyzed in their respective races. Athletes’ footstrike patterns were recorded (120 Hz) at approximately 8.5, 19, 29.5 and 40 km (“Laps 1 – 4”) and categorized as either rearfoot (RFS), midfoot or forefoot striking; the latter two were classified together as non-rearfoot striking (NRFS). The most common footstrike pattern was RFS, with proportions never less than 54% of men or 67% of women at any distance. There were no sex-based differences for proportion of footstrike patterns, and there were no differences between footstrike proportions when comparing the top and bottom 50% of men finishers, or between women during Laps 1 and 2. A greater proportion of the top 50% of women maintained NRFS than amongst the bottom 50%. The proportion of RFS increased with distance run in the men’s race, although more than 75% of athletes across both marathons had consistent footstrike patterns between laps (79 RFS and 36 NRFS). As most athletes were RFS (including the top four finishing men), there appears to be no clear advantage to NRFS in marathon running. Coaches should note that it is normal for elite marathon runners to be either RFS or NRFS; however, forefoot striking was rare. The high proportion of athletes who maintained their footstrike pattern reflected individualized preferences for a given footstrike pattern

Force production during maximal front crawl tethered swimming: exploring bilateral asymmetries and differences between breathing and non-breathing conditions

The present study focused on propulsive forces applied during tethered swimming. The main aims were to identify asymmetries between dominant and non-dominant arms, quantify the effect of breathing on force application and, explore any association between each variable and swimming performance. Fifteen regional level swimmers completed a maximal front crawl tethered swimming test, with maximal kicking, under four conditions: 1) Dominant arm strokes only, no breathing; 2) non-dominant arm strokes only, no breathing; 3) full stroke, no breathing; 4) full stroke, breathing on the preferred side. The outcome variables were: absolute and normalised (force divided by body mass) minimum, mean and maximum force; stroke cycle time and; impulse. The symmetry index was also calculated, and all variables were correlated with the swimmers&apos; season best times in 50 m front crawl. Some bilateral force asymmetries were found, but they did not always favour the dominant side and were not directly linked with swimming performance. There was no strong evidence that force production is higher on the dominant side or that symmetry in force production affects performance. Despite the longer stroke cycle times when breathing, the breathing actions did not affect force production. Faster swimmers often produced higher maximum force values and, sometimes, higher mean force values

World-Class Male Sprinters and High Hurdlers Have Similar Start and Initial Acceleration Techniques

The effect of the inclusion of a high hurdle 13.72 m after the start line on elite sprint start and initial acceleration technique has yet to be investigated or understood. This highly novel study addresses that lack of information in an exceptional manner, through detailed biomechanical analysis of the world&apos;s best sprint and hurdle athletes, with data collected in situ at the 2018 IAAF World Indoor Championships, held in Birmingham, UK. High speed videos (150 Hz) were compared for eight sprinters and seven hurdlers for the start and initial acceleration phase of the finals of the men&apos;s 60 m and 60 m hurdles. Temporal and kinematic data were supplemented by vector coding analysis to investigate mechanisms by which these world-class athletes translate their centres of mass (CM) up to the fourth touchdown post-block exit. The sprinters and hurdlers coordinated their lower limb and trunk movement in a similar manner throughout the start and initial acceleration phases, which contributes new conceptual understanding of the mechanisms that underpin start and initial acceleration performance. Differences between groups were initiated from block set-up, with the hurdlers utilising a larger block spacing, but with the front block nearer to the start line than sprinters. Even after accounting for stature, the biggest differences in the raising of the CM occurred during the block phase, with hurdlers greater than sprinters (difference in vertical CM displacement scaled to stature = -0.037, very large effect size). Subsequent flight phases showed the biggest differences in the translation of the CM, in part due to longer flight times in the hurdlers, whilst the techniques of the two groups generally converged during the ground contact phases of initial acceleration. In highlighting that similar techniques are used by world-class sprinters and hurdlers, despite differing task constraints, this study has provided invaluable insights for scientists, coaches, and athletes, that will inform further developments in understanding and practice across both sprints and hurdles