The role of the biomechanics analyst in swimming training and competition analysis.

Swimming analysts aid coaches and athletes in the decision-making by providing evidence-based recommendations. The aim of this narrative review was to report the best practices of swimming analysts that have been supporting high-performance athletes. It also aims to share how swimming analysts can translate applied research into practice. The role of the swimming analyst, as part of a holistic team supporting high-performance athletes, has been expanding and is needed to be distinguished from the job scope of a swimming researcher. As testing can be time-consuming, analysts must decide what to test and when to conduct the evaluation sessions. Swimming analysts engage in the modelling and forecast of the performance, that in short- and mid-term can help set races target-times, and in the long-term provide insights on talent and career development. Races can be analysed by manual, semi-automatic or fully automatic video analysis with single or multi-cameras set-ups. The qualitative and quantitative analyses of the swim strokes, start, turns, and finish are also part of the analyst job scope and associated with race performance goals. Land-based training is another task that can be assigned to analysts and aims to enhance the performance, prevent musculoskeletal injuries and monitor its risk factors.

The characteristics of the breaststroke pullout in elite swimming.

Since the rule change permitting the inclusion of one dolphin kick during the underwater breaststroke pullout phase following a swim start or turn, there has been an emergence of several different pullout techniques adopted by elite swimmers. The aim of this study was to characterize the underwater breaststroke pullout technique trends and to assess the effectiveness of each technique as utilized by elite male and female swimmers. The sample included 60 swimmers (n = 26 male, n = 34 female) competing across the 50, 100, and 200 m long-course breaststroke final races from the World Championships 2015, 2017, 2019 and Olympic Games 2016. An above-water camera was used to identify and measure the different phases of the underwater pullout techniques, which was found to be a highly accurate methodological approach (ICC = 0.97). From the 150 trials analyzed, three different pullout techniques were identified: the Fly-Kick First technique, the Combined technique and the Pull-Down First technique. Although the most common underwater pullout technique utilized by elite competitive breaststroke swimmers was the Combined technique (n = 71), followed by the Fly-Kick First technique (n = 65) and the Pull-Down First technique (n = 14), it was observed that technical selection deviates according to gender. This indicates that male and female swimmers should not be coached adhering to the same technical model. This study found no significant difference in terms of performance outcome with respect to each of these techniques, indicating that technique selection should be guided by one's individual preference. It was concluded that the results of this study will serve as an up-to-date resource for coaches and swimmers working with elite breaststroke swimmers and as a useful insight to current underwater pullout trends.

Augmented feedback can change body shape to improve glide efficiency in swimming.

Curvatures of the body can disrupt fluid flow and affect hydrodynamic resistance. The purpose of this study was to evaluate the effect of a feedback intervention on glide performance and torso morphology. Eleven male and female national swimmers performed glides before and after augmented feedback. Feedback consisted of self-modelling visual feedback and verbal cuing, to manipulate body curvatures that affect hydrodynamic resistance. Two-dimensional landmark position data (knee, hip and shoulder) were used to enable computation of glide factor and glide coefficient as indicators of glide efficiency; posture (trunk incline and hip angle); and performance (horizontal velocity). Underwater images of the swimmers were manually traced to derive transverse and sagittal diameters, cross-sectional areas, and continuous form outlines (anterior and posterior) of the torso. Maximum rate of change in cross-sectional area and form gradient progressing caudally, were calculated for torso segments: shoulder-chest, chest-waist, waist-hip. Mean velocity, glide factor and glide coefficient values significantly (p< 0.001) improved due to the intervention, with large effect size (d) changes 0.880 (p= 0.015), 2.297 and 1.605, respectively. Significant changes to form gradients were related to reductions in lumbar lordosis and chest convexity. The study provides practical cuing phrases for coaches and swimmers to improve glide efficiency and performance.