No abstract

The purpose of this study was to evaluate which measure of a drop jump (DJ) has the highest correlation with sprinting speed over 60 m. For use of comparison, maximal leg strengths in a front squat, countermovement jump, and squat jump were also assessed. The subjects in the study were all high-caliber female university rugby players. Subjects did DJs from 0.12, 0.24, 0.36, 0.48, 0.60, 0.72, and 0.84 m. Jump height and reactive strength index (RSI) were calculated at each drop height. Pearson correlations were used to analyze the relationship between the strength and jumping measures with sprinting speed. The DJ height from 0.84 m had the highest negative correlation with 0- to 10-m split (r = -0.66), the 10- to 30-m split (r = -0.86) and 30- to 60-m split (r = -0.86). The use of RSI is questioned as a measurement of DJ performance. It is suggested that maximal height achieved in a DJ is the most important DJ measure. If it is desired to measure ground contact time, then it may be more useful to use a second test where the jump height for the athlete is set by having the athlete jump onto a box or touch a target overhead set at a standard height and measure the ground contact time with a switch mat or force plate.

Sprint kayaking stroke phase descriptions for biomechanical analysis of technique vary among kayaking literature, with inconsistencies not conducive for the advancement of biomechanics applied service or research. We aimed to provide a consistent basis for the categorisation and analysis of sprint kayak technique by proposing a clear observational model. Electronic databases were searched using key words kayak, sprint, technique, and biomechanics, with 20 sources reviewed. Nine phase-defining positions were identified within the kayak literature and were divided into three distinct types based on how positions were defined: water-contact-defined positions, paddle-shaft-defined positions, and body-defined positions. Videos of elite paddlers from multiple camera views were reviewed to determine the visibility of positions used to define phases. The water-contact-defined positions of catch, immersion, extraction, and release were visible from multiple camera views, therefore were suitable for practical use by coaches and researchers. Using these positions, phases and sub-phases were created for a new observational model. We recommend that kayaking data should be reported using single strokes and described using two phases: water and aerial. For more detailed analysis without disrupting the basic two-phase model, a four-sub-phase model consisting of entry, pull, exit, and aerial sub-phases should be used.

This investigation compared supramaximal oxygen uptake interval training with continuous training in collegiate, national, and international class rowers. It was hypothesized that 6 supramaximal intensity sessions over 11 days would increase power on selected power measures. After 8 weeks of training for a new season, 10 heavyweight and 6 lightweight rowers were randomized into 2 groups. A ramp test to limit of tolerance to determine peak aerobic power (6 females: 25 W·min; 10 males: 30 W·min) and an all-out 3-minute test to determine peak power, 60-second power, critical power, and work above critical power (W') were performed before and after training. A supramaximal training session consisted of 10 cycles of 10-second work (140% peak aerobic power):5-second recovery followed by 8 minutes of active recovery, and repeated 6 times. The continuous group performed predominantly moderate intensity (below lactate threshold) training. All training was performed on rowing ergometers. Critical power increased pre-to-post supramaximal (Δ7%) and continuous training (Δ9%), respectively (336 ± 59W to 360 ± 59W; 290 ± 73W to 316 ± 74W; p ≤ 0.05), whereas the mean power output from all performance measures increased only after supramaximal training (Δ7%) (464 ± 158W to 496 ± 184W; p ≤ 0.05). Testing also revealed decreased W' (Δ21%) and 60-second power (Δ4%) pre-to-post continuous training only (p ≤ 0.05). No differences (p > 0.05) in peak aerobic power or peak power were observed pre-to-post training in either group. In conclusion, after an 8-week preconditioning period, supramaximal interval training preserved anaerobic capacity compared with predominantly continuous training and elicited similar increases in critical power in rowers.