Jumping Abilities and Swimming Grab-Start Performances in Elite and Recreational Swimmers

This study examined the relationships between the performances of a swimming grab start and each of countermovement jump for distance, countermovement jump for height, squat jump for distance and squat jump for height. Nine elite and 7 recreational female swimmers performed 6 trials in each of the 4 jumping techniques, and six 25-m freestyle sprints following a grab start. Elite subjects performed significantly better in the start performances, and this was attributed to the greater horizontal impulse. Correlations in the elite group revealed that grab-start performance was not related to performances of any jumps. This suggests that the grab start is independent of the jumping techniques for this group, and performance of one skill may not translate to performance in the other. Significant correlations were found between performances of the grab start and the f4 jumps in the recreational group, possibly because of adoption of an “incorrect” motor pattern that may be similar to those of the jumps. This study highlighted the importance of practicing the start as a whole skill during training

FORCE DEVELOPMENT PROFILE OF THE LOWER LIMBS IN THE GRAB AND TRACK START IN SWIMMING

Left and right ground reaction forces of 9 male and 7 female national and international level swimmers were measured during grab and track starts. Analysis of temporal, kinetic and velocity measures indicated that while swimmers left the block faster in the track start, grab starts enabled swimmers to generate greater vertical impulses and take-off velocities. No significant differences were found in the horizontal impulses and the time to 6m between the two starts. Left and right force profiles were examined qualitatively to identify key points related to force development strategies and lateral asymmetr

MORPHOLOGY AND HYDRODYNAMIC RESISTANCE IN YOUNG SWIMMERS

Morphology and hydrodynamic drag were measured of 6 males and 6 females, from each of the 9, 11 and 13 yr age groups. Net forces were examined when towing swimmers while prone streamlined gliding and flutter kicking at 1.3 to 2.5 ms-1. The passive drag force at 1.9, 2.2 and 2.5 ms-1 increased with age and anthropometry, but no changes were found at 1.3 and 1.6 ms-1. Stepwise regression revealed passive drag best predicted net active drag at velocities of 1.3, 1.9, 2.2 and 2.5 ms-1. Results supported the Froude number theory that increased height will reduce wave-making drag

Kinetic and kinematic analysis of underwater gliding and kicking during towed swimming

Swim turns are a component of competitive swimming where considerable advantage can be gained or lost. Further, the importance of selecting an appropriate underwater kicking technique and minimising the deceleration caused by drag following wall push-off from a turn has been stated frequently. This investigation examined underwater kicking styles at speeds representing turn wall exits to enable greater understanding of technique and anthropometrical characteristics that are predictive of efficient underwater kicking

Technical note : the use of subject derived scale factors for one-camera 2D analysis in underwater swimming

This technical note describes a comparison of relative errors in one-camera 2D underwater motion annalysis when using two different control structure methods for calibrating video images. Eleven male and six female participants performed underwater kicking swim trials. A reference structure of known length and each swimmer's actual (land measured) thigh length were each used to calibrate the movement space from which digitised thigh lengths were calculated for each trial. For each trial, mean thigh lengths calculated using the two methods were then compared to actual thigh length for each swimmer and the differences recorded. Mean differences between actual and computed thigh lengths were shown to be similar. However, the spread of mean differences was much less when the actual thigh length was used for calibration. This result strongly supports the use of thigh length as a more accurate method of calibration for one-camera 2D underwater motion analysis

Perceptions of a family-based lifestyle intervention for children with overweight and obesity: a qualitative study on sustainability, self-regulation, and program optimization

Background Family-based lifestyle interventions (FBLIs) are an important method for treating childhood weight problems. Despite being recognized as an effective intervention method, the optimal structure of these interventions for children’s overweight and obesity has yet to be determined. Our aim was to better understand participants’ (a) implementation of behaviour strategies and long-term outcomes, (b) perceptions regarding the optimal structure of FBLIs, and (c) insights into psychological concepts that may explain the success of these programs. Methods Purposive sampling was used to recruit participants. We conducted focus groups as well as one-to-one interviews with parents (n = 53) and children (n = 50; aged 7–13, M = 9.4 yr, SD = 3.1) three months following their involvement in a 10-week, multi-component, FBLI involving education and activities relating to healthy nutrition, physical activity, and behavior modification. Using an interpretivist approach, a qualitative study design was employed to examine participant experiences. Results We identified three higher-order categories: (a) participants’ program experiences and perceptions (b) lifestyle changes post-program, and (c) recommendations for optimizing family-based programs. Themes identified within these categories included (a) support and structure & content, (b) diet and physical activity, and (c) in-program recommendations and post-program recommendations. Conclusions We identified several challenges that can impair lasting behavior change (e.g., physical activity participation) following involvement in a FBLI. On optimizing these programs, participants emphasized fun, interactive content, interpersonal support, appropriate educational content, and behavior change techniques. Concepts rooted in motivational theory could help address calls for greater theoretical and mechanistic insight in FBLIs. Findings may support research advancement and assist health professionals to more consistently realize the potential of these interventions.Education, Faculty ofNon UBCKinesiology, School ofReviewedFacultyResearche