Boat Classes Research Articles

Variability and Predictability of Finals Times of Elite Rowers

Little is known about the competitive performance characteristics of elite rowers. We report here analyses of performance times for finalists in world-class regattas from 1999 to 2009. The data were official race times for the 10 men's and 7 women's single and crewed boat classes, each with ∼ 200-300 different boats competing in 1-33 of the 46 regattas at 18 venues. A linear mixed model of race times for each boat class provided estimates of variability as coefficients of variation after adjustment for means of calendar year, level of competition (Olympics, world championship, World Cup), venue, and level of final (A, B, C, …). Mean performance was substantially slower between consecutive levels of competition (1.5%, 2.7%) and consecutive levels of finals (∼ 1%-2%). Differences in the effects of venue and of environmental conditions, estimated as variability in mean race time between venues and finals, were extremely large (∼ 3.0%). Within-boat race-to-race variability for A finalists was 1.1% for single sculls and 0.9% for crewed boats, with little difference between men and women and only a small increase in lower-level finalists. Predictability of performance, expressed as intraclass correlation coefficients, showed considerable differences between boat classes, but the mean was high (∼ 0.63), with little difference between crewed and single boats, between men and women, and between within and between years. The race-to-race variability of boat times of ∼ 1.0% is similar to that in comparable endurance sports performed against water or air resistance. Estimates of the smallest important performance enhancement (∼ 0.3%) and the effects of level of competition, level of final, venue, environment, and boat class will help inform investigations of factors affecting elite competitive rowing performance.

Pacing Patterns in Competitive Rowing Adopted in Different Race Categories

Data from 7 World Rowing Championships between 2001 and 2009 were analyzed to determine the time distribution during 2,000-m heavyweight races (from 500-m quarter times) and to assess whether pacing patterns differ between boat classes (single vs. team boats) and qualifying rounds (heats vs. finals). Analyses of variance with repeated measures on quarter times revealed that pacing patterns in heat races were better described (i.e., higher amount of variance explained) by a linear trend line with a positive slope (women: η² = 0.76, men: η² = 0.68) but followed a quadratic trend line (parabolic-shaped pattern) during finals (women: η² = 0.81, men: η² = 0.60). Not using a spurt at the end of the heat races may indicate an attempt to conserve energy for subsequent rounds or reflect reduced effort made by losing crews or both aspects. In single boats, the pacing pattern was better represented by a linear trend line with a positive slope (women: η² = 0.76, men: η² = 0.68), but the amount of variance explained was virtually the same for both the linear and the quadratic trend component in team boats. The absence of a final spurt in single boat races suggests that the physiological status of the athlete plays an important role to control the timing and rate of decline in rowing speed.

Variability and predictability of elite competitive slalom canoe-kayak performance

Little is known about the race performance characteristics of elite-level slalom canoeists or the magnitude of improvement necessary to enhance medal-winning prospects. Final placing in this sport is determined by the aggregate of semi-final and final run times inclusive of penalty times. We therefore used mixed linear modelling to analyse these times for finalists ranked in the top and bottom half in the men's canoe, men's kayak, and women's kayak boat classes at World Cups, World Championships, and Olympic Games from 2000 to 2007. The run-to-run variability for top-ranked athletes at different courses ranged from 0.8% to 3.2% (90% confidence limits ×/÷1.11–1.31), reflecting differences in how challenging these courses were. The race-to-race variability of aggregate run time was 1.2–2.1% (×/÷~1.09); 0.3 of this variability yields the smallest worthwhile enhancement of 0.4–0.6%. The variabilities of bottom-ranked finalists were approximately double those of top-ranked finalists. The home advantage was small (0.3–0.8%), and incurring a penalty had a marginal effect on reducing actual run time (0.2–0.7%). Correlation coefficients for performance predictability within competitions (0.06–0.35), within years (0.12–0.47), and between years (0.12–0.43) were poor. In conclusion, the variability of performance and smallest worthwhile enhancements in slalom canoe-kayaking are larger than those of comparable sports, and race outcomes are largely unpredictable.

The social and linguistic conditioning of back vowel fronting across ethnic groups in Memphis, Tennessee

While a number of recent studies have documented the back vowel changes affecting White varieties nationally, few studies have examined back vowel fronting in non-Anglo dialects or compared the social and linguistic commonalties and contrasts in the progress of the shift and the vowel classes affected. The present study explores how ethnic and regional alignment affects the dispersion of fronting in three key back vowel classes, the BOOT, BOOK, and BOAT classes. Using instrumental acoustic measurement of relevant vowel classes, this article will examine both the social and linguistic conditioning governing the fronting of these classes in White and Black speakers in Memphis, TN, looking at these results in light of those found by Anderson, Milroy & Nguyen (2002), Ash (1996), and Labov (1994) elsewhere in the US.

Changes in Recovery-Stress State and Performance in Elite Rowers during Preparation for Major Competitions

This study investigated changes in the perceived recovery-stress state and performance in 6 highly trained Estonian rowers preparing for major competitions and representing Estonia in double sculls (age: M = 23.0, SD = 1.4 yr.; height: M = 198.0, SD = 0.0 cm; body mass: M = 97.1, SD = 6.4 kg), and quadruple sculls (age: M = 21.5, SD = 2.5 yr.; height: M = 189.5, SD = 5.4 cm; body mass: M = 90.9, SD = 4.8 kg). The subjects were training regularly and had been doing so for the last 10.5 yr. (double scullers, SD = 2.1 yr.) and 7.5 yr. (quadruple scullers, SD = 3.1 yr.), respectively. The Recovery-Stress Questionnaire for Athletes of Kellmann and Kallus was given two days before World Cup competitions. Standardized Stress and Standardized Recovery scores and RESTQ-Index were computed. In addition, resting cortisol in blood was measured at the same time. The performance of both boat classes constantly decreased from World Cup 1 to World Cup 3 as indicated by percent losses for winning boats. Resting cortisol and RESTQ-Index increased and decreased, respectively, at the same time. For double scullers, a decrease in RESTQ-Index mainly reflected the large decrease in the Standardized Recovery score. A decrease in RESTQ-Index was mainly based on a large increase in the Standardized Stress score for rowers performing in a quadruple scull. Present results indicate that the recovery-stress state affects performance of rowers in international competitions. RESTQ-Index could be used as the athletes' resource measure, while the Standardized Stress and Standardized Recovery scores reflect the athletes' extent of stress and recovery separately.

Patrol Boats: A World Market Overview

This is a brief discussion of "patrol boats" from a marketing analysis viewpoint. The methodology of analyzing a foreign navy's current fleet and projected acquisitions is described. The factors affecting the purchase of ships or systems are given. There is a detailed discussion of "definition," including the parameters that are used in defining classes of ships. Examples of representative ships that fall into a given definition are shown. The importance of properly defining a ship, especially in the patrol boat class, is discussed. The world market in patrol boats is then presented. The data are broken down with numbers and value of existing ships plotted by vessel type and region. Finally, future projections for the patrol boat market are given