Effect of Randall foils on the rowing propulsive cycle.

Rowing performance depends on the design and building materials used for competition. Recently, attempting to improve rowing performance, the Randall foil has been attached to the top edge of a rowing Big blade, making it spoon shaped. The current study aimed to analyse the differences between Big blades with and without Randall foils in force-related variables. Nineteen rowers performed two bouts of 90 s at maximal effort tethered rowing and differences were found in cycle average peak force (4.33 ± 1.46 vs. 5.26 ± 1.57 N/kg), propulsive cycle average time (1.79 ± 0.38 vs. 1.52 ± 0.24 N/kg.s) and rate of force development (8.79 ± 4.75 vs. 12.07 ± 4.60 N/kg/s) for Big blades with and without foils (respectively). Differences were also observed between the middle (4.79 ± 1.21 vs. 4.08 ± 1.48 N/kg) and final phases (4.86 ± 1.45 vs. 4.04 ± 1.47 N/kg) of the rowing effort for the cycle average peak force of Big blades with and without Randall foils. Data suggest a positive effect of these foils on the force-time curve profile. Future studies should focus on testing its influence on free on-water rowing.

Behavioural variability and motor performance: Effect of practice specialization in front crawl swimming.

The aim was to examine behavioural variability within and between individuals, especially in a swimming task, to explore how swimmers with various specialty (competitive short distance swimming vs. triathlon) adapt to repetitive events of sub-maximal intensity, controlled in speed but of various distances. Five swimmers and five triathletes randomly performed three variants (with steps of 200, 300 and 400m distances) of a front crawl incremental step test until exhaustion. Multi-camera system was used to collect and analyse eight kinematical and swimming efficiency parameters. Analysis of variance showed significant differences between swimmers and triathletes, with significant individual effect. Cluster analysis put these parameters together to investigate whether each individual used the same pattern(s) and one or several patterns to achieve the task goal. Results exhibited ten patterns for the whole population, with only two behavioural patterns shared between swimmers and triathletes. Swimmers tended to use higher hand velocity and index of coordination than triathletes. Mono-stability occurred in swimmers whatever the task constraint showing high stability, while triathletes revealed bi-stability because they switched to another pattern at mid-distance of the task. Finally, our analysis helped to explain and understand effect of specialty and more broadly individual adaptation to task constraint.

Anthropometric and somatotype characteristics of world class male roller skaters by discipline.

AIM: The aim of this study was twofold: 1) to describe the anthropometric profile and somatotype of the elite male roller skaters; and: 2) to assess if there are any differences in these items by roller skating discipline (figures, freestyle, pair and dance). METHODS: Eighty-eight male skater participants in the 51st Figure Roller Skating World Championship were selected for the study. The International Society for the Advancement of Kinanthropometry (ISAK) protocol was used to determine the anthropometric profile of the figure skaters. Additionally, Body Mass Index (BMI), sum of four and six skinfolds and somatotype were also analysed. RESULTS: No significant differences were found for the sum of four and six skinfolds among disciplines. Significant differences were found for flexed arm (P≤0.05), forearm (P≤0.05) and wrist girths (P≤0.001) between artistic roller figure and pair skaters. Significant differences were found in waist girth (P≤0.05), flexed arm, forearm and wrist girths (P≤0.001) between artistic roller freestyle and pairs skaters. No differences were found in lower limbs girths among disciplines. Significant differences were found in humerus (P<0.05) and bistyloid (P<0.05) breadth among disciplines. The general somatotype is endo-mesomorphic for roller freestyle and figure skaters. In pair skaters the somatotype is ecto-mesomorphic, and for dance skaters it is balanced mesomorphic.

Psychometric properties of the "sport satisfaction instrument (SSI)" in female athletes: predictive model of sport commitment.

The objective of this research was to assess the psychometric properties of the Sport Satisfaction Instrument (SSI) in a Spanish sample of female athletes in team sports federations, to decide whether it constitutes a valid and reliable instrument to be used in the context of female competitive sport in future research. The SSI was administered to a total of 615 athletes from 12 to 38 yr. of age. Confirmatory procedures and psychometric analysis supported the hypothesized theoretical model of two factors (Satisfaction/fun and Boredom). For female athletes, the 7-item model showed better goodness-of-fit indexes upon eliminating Item 2 from the Boredom subscale. Concurrent validity was explored through the correlations with the Perception of Success Questionnaire and Sport Commitment, obtaining positive correlations between Satisfaction/fun and Task Orientation and Sport Commitment, whereas Boredom correlated positively but less closely with Ego Orientation. The importance of Satisfaction/fun in the prediction of Sport Commitment, starting from task orientation, is emphasized.

Relationship among maximal grip, throwing velocity and anthropometric parameters in elite water polo players.

AIM: As independent aspects, body size, body composition, and physiological performance of elite athletes have aroused the interest of sports scientists but, unfortunately, studies that combine these aspects are scarcely avalaible in water polo. The aim of the present study was to: 1) to develop an anthropometric profile of highly skilled male Water Polo players, and 2) to identify significant relationships between these features and overhead throwing velocity in highly skilled male water polo players. METHODS: Thirteen male water polo players, with a mean age of 26.10±4.82, were recruited from the Spanish Water Polo team and an anthropometric assessment on all of them was carried out. Throwing velocity was evaluated in three different situations from the 5 m-penalty line on the center of the water polo goal: A) throwing without a defender nor a goalkeeper; B) throwing with a goalkeeper only, and C) 3) armfuls running shot with goalkeeper. Maximal handgrip was also tested. RESULTS: Biacromial breadth shows a significative correlation with hand grip in water polo players (r=0.792; P=0.001) and also correlates with Throwing velocity (r=0.716; P<0.001). Biepicondylar femur breadth correlates significatively with hand grip (r=0.727; P<0.05) and also with throwing velocity in "throwing with goalkeeper" situation (r=0.664; P<0.05). Hand grip shows a significant correlation with throwing velocity in "throwing with goalkeeper" situation (r=0.603; P<0.05). CONCLUSION: In conclusion, body mass aspects are not related with throwing velocity in highly skilled Water Polo players. Maximal hand grip is related with throwing velocity in "throwing with goalkeeper" situation. More investigations about water polo are necessary.