Academic literature on the topic 'Performance swimming'

Master athletes have been widely used to examine the age-induced decline of human performance. However, so far very limited reviews are available consolidating the age-related differences in master swimming performance. The aim of the present review was to summarize existing knowledge about the age-related changes in three modalities of swimming performance (i.e., pool-swimming, open-water swimming and swim split in triathlons of different distances). In addition, the paradigm of freestyle swimming records from 50 to 1500 m was used to examine age-related differences and sex difference in performance for age groups 25–29 to 100–104 years. For this example of master freestyle swimmers, the sex difference was smaller in the longer events and increased significantly after the age of ∼70 years. In summary, master athletes competing in swimming as single discipline (i.e., pool-swimming and open-water) and in triathlon (i.e., swim split as first discipline) improved their performances across calendar years. The age-related performance decline in swimming seems to be specific to the discipline, the sex and the length of the swimming event.

Purpose:To investigate if swimming performance is better in a relay race than in the corresponding individual race.Methods:The authors analyzed 166 elite male swimmers from 15 nations in the same competition (downloaded from www.swimrankings.net). Of 778 observed races, 144 were Olympic Games performances (2000, 2004, 2012), with the remaining 634 performed in national or international competitions. The races were 100-m (n = 436) and 200-m (n = 342) freestyle events. Relay performance times for the 2nd–4th swimmers were adjusted (+ 0.73 s) to allow for the “flying start.”Results:Without any adjustment, mean individual relay performances were significantly faster for the first 50 m and overall time in the 100-m events. Furthermore, the first 100 m of the 200-m relay was significantly faster (P > .001). During relays, swimmers competing in 1st position did not show any difference compared with their corresponding individual performance (P > .16). However, swimmers competing in 2nd–4th relay-team positions demonstrated significantly faster times in the 100-m (P < .001) and first half of the 200-m relays than in their individual events (P < .001, ES: 0.28–1.77). However, when finishing times for 2nd–4th relay team positions were adjusted for the flying start no differences were detected between relay and individual race performance for any event or split time (P > .17).Conclusion:Highly trained swimmers do not swim (or turn) faster in relay events than in their individual races. Relay exchange times account for the difference observed in individual vs relay performance.

AbstractPeak performances in sport require the full deployment of all the powers an athlete possesses. How factors such as mechanical power output, technique and drag, each individually, but also in concert, determine swimming performance is the subject of this enquiry. This overview of swimming biomechanics focuses on three performance factors: (i) generation of propulsion in water; (ii) drag encountered by the body during swimming; and (iii) propulsive efficiency. Theoretical considerations will be put to use by predicting individual power requirements for swimming a world record in the 50 m freestyle based on experimental data.

Purpose: To study the relationship between tethered swimming in a flume at different speeds and swimming performance. Methods: Sixteen regional-level swimmers performed 25-, 50-, and 100-m front-crawl trials and four 30-s tethered-swimming tests at 0, 0.926, 1.124, and 1.389 m·s−1 water-flow velocities. Average and maximum force, average and maximum impulse, and intracyclic force variation (dF) were estimated for each tethered-swimming trial. Swimming velocity and intracyclic velocity variation (dv) were obtained for each free-swimming trial. Stroke rate and rating of perceived exertion (RPE) were registered for all trials. Results: Tethered-swimming variables, both at 1.124 m·s−1 and at 1.389 m·s−1 water-flow velocities, were positively associated with 25-m swimming velocity (P < .05). Average force and maximum impulse in stationary swimming were significantly associated with 25-m swimming velocity (P < .05). A positive relationship between water-flow velocities with dF was observed. Swimming performance was not related to dF or dv. Neither stroke rate nor RPE differed between the 4 tethered conditions and mean 50-m free-swimming velocity (P > .05). Conclusions: Measuring force in a swimming flume at higher water-flow velocities is a better indicator of performance than stationary tethered swimming. It enables assessment of the ability to effectively apply force in the water.

Purpose: To observe changes in performance, physiological, and general kinematic variables induced by the use of wetsuits vs swimsuits in both swimming-pool and swimming-flume conditions. Methods: In a randomized and counterbalanced order, 33 swimmers (26.46 [11.72] y old) performed 2 × 400-m maximal front crawl in a 25-m swimming pool (with wetsuit and swimsuit), and their mean velocities were used later in 2 swimming-flume trials with both suits. Velocity, blood lactate concentration, heart rate (HR), Borg scale (rating of perceived exertion), stroke rate, stroke length (SL), stroke index, and propelling efficiency were evaluated. Results: The 400-m performance in the swimming pool was 0.07 m·s−1 faster when using the wetsuit than when using the swimsuit, evidencing a reduction of ∼6% in time elapsed (P < .001). Maximal HR, maximal blood lactate concentration, rating of perceived exertion, stroke rate, and propelling efficiency were similar when using both swimsuits, but SL and stroke index presented higher values with the wetsuit in both the swimming pool and the swimming flume. Comparing swimming conditions, maximal HR and maximal blood lactate concentration were lower, and SL, stroke index, and propelling efficiency were higher when swimming in the flume than when swimming in the pool with both suits. Conclusions: The 6% velocity improvement was the result of an increase of 4% in SL. Swimmers reduced stroke rate and increased SL to benefit from the hydrodynamic reduction of the wetsuit and increase their swimming efficiency. Wetsuits might be utilized during training seasons to improve adaptations while swimming.

This thesis examines the linear swimming motion of Carangiform fish, and investigates how to improve the swimming performance of robotic fish within the fields of kinematic modeling and mechanical engineering, in a successful attempt to replicate the high performance of real fish. Intensive research was conducted in order to study the Carangiform swimming motion, where observational studies of the common carp were undertaken. Firstly, a full-body length Carangiform swimming motion is proposed to coordinate the anterior, mid-body and posterior displacements in an attempt to reduce the large kinematic errors in the existing free swimming robotic fish. It optimizes the forces around the centre of mass and initiates the starting moment of added mass upstream therefore increasing performance, in terms of swimming speed. The introduced pattern is experimentally tested against the traditional approach (of posterior confined body motion). A first generation robotic fish is devised with a novel mechanical drive system operating in the two swimming patterns. It is shown conclusively that by coordinating the full-body length of the Carangiform swimming motion a significant increase in linear swimming speed is gained over the traditional posterior confined wave form and reduces the large kinematic errors seen in existing free swimming robotic fish (Achieving the cruising speeds of real fish). Based on the experimental results of the first generation, a further three robotic fish are developed: (A) iSplash-OPTIMIZE: it becomes clear that further tuning of the kinematic parameters may provide a greater performance increase in the distance travelled per tail beat. (B) iSplash-II: it shows that combining the critical aspects of the mechanical drive system of iSplash-I with higher frequencies and higher productive forces can significantly increase maximum velocity. This prototype is able to outperform real Carangiform fish in terms of average maximum velocity (measured in body lengths/ second) and endurance, the duration that top speed is maintained. (C) iSplash-MICRO: it verifies that the mechanical drive system could be reduced in scale to improve navigational exploration, whilst retaining high-speed swimming performance. A small robotic fish is detailed with an equivalent maximum velocity (BL/s) to real fish.

Performance when gliding in the streamlined position depends on a swimmer’s morphological characteristics, body orientation and water characteristics. The purpose of this thesis was twofold. First to identify and assess the effect of controllable factors that contribute to glide performance and second to form the foundations of an improved approach of simulating the fluid flow around the swimmers’ body. To address the purposes of the thesis four investigations were conducted. Study 1. The effect of the head position on glide performance was investigated. When the high, medium and low head positions were compared, it was found that swimmers experience significantly greater resistance and decelerate faster when they adopt a high head position. It was also found that there is no significant difference between the medium and low head position indicating for the first time that swimmers can choose any of the positions according to their natural tendency. Study 2. The second study examined the effect of gliding depth on gliding performance. A range of depths was investigated ranging from 0.8 m to 0.2 m from the water surface. The results demonstrated significantly higher glide factor values for glides at a greater depth when compared to glides closer to the water surface highlighting the retarding effect of wave drag when gliding close to the surface. The optimum gliding performance was reported for glides at 0.8 m from the surface. Study 3. The third study investigated the effect of full body swimsuits on glide performance. According to the findings, it is demonstrated for the first time that the improved gliding performance when wearing full body swimsuits is linked to changes in swimmers’ morphology due to compression. Study 4. In the fourth study the magnitude of resistive forces applied on a swimmer’s body when gliding underwater was assessed with the use of computational fluid dynamics (CFD) and the LES approach. The results showed a close match between the glide factor values of the experimental and the computational findings demonstrating the effectiveness of the CFD method when the LES approach is employed.

This thesis examines the swimming performance of mackerel (Scomber scombrus L.), herring (Clupea harengus L.), and saithe (Pollachius virens (L.)), and relates it with the mechanical and the electrical properties and the volume of the red and the white swimming muscle. Analysis of kinematics of swimming from cine films and video recordings allows development of a mathematical model of swimming movements and examination of thrust and power output during swimming. This output can be scaled for the time of the tail beat cycle and the size of the fish. Swimming of mackerel at low speeds is related to the lift required in this negatively buoyant species in order to maintain a constant swimming depth. Longitudinal tilting of the mackerel body at low speeds is observed and related to the echo sounder target strength in fisheries surveys. Swimming performance of mackerel, herring and saithe at intermediate speeds is measured in terms of speed and endurance. The maximum sustained swimming speed for each species is related to the maximum cross-section area of the red muscle. Maximum burst swimming speed up to 18 body lengths per second is measured in a 30.5 cm long mackerel. This maximum speed is found to be limited by the minimum contraction time of the white muscle which is measured in 60 samples of 20 individual mackerel. Recordings of the electromyograms of swimming mackerel and measurements of muscle contraction time and muscle cross-section area lead to a new fish swimming model demonstrating how the thickest part of the red muscle is used when the maximum thrust is output from the caudal fin during one tail beat cycle. The swimming performance of marine fish near fishing gears, especially otter trawls is summarised by analysing video tapes recorded at sea and compared with the measured swimming performance in laboratory conditions. Some models of fish swimming behaviour near fishing gears are developed.

Synchronized swimming (SS) is a sports discipline combining swimming, dancing and gymnastics. Synchronized Swimmers perform a choreography called routine consisting of elaborate moves in the water accompanied by music. Previous research investigating SS from a physiological perspective has mainly used figures or fractionated and/or simulated routine protocols during training, although the nature of sports leads to continuous very demanding exercises (~2-4 minutes) performed at increasingly higher levels of intensity with almost 50% of this time underwater. In addition, different from training, competition is a challenging situation which usually stimulates higher psycho-physiological responses in the participant. Current knowledge is thus limited as regards physiological responses in competitive elite SS. Therefore, the overall aim of this thesis is to study the physiological responses related to performance during the execution of competitive routines both during training and competitive sessions in elite synchronized swimmers. The thesis is based on three studies (Studies I – III); all of them use the same protocol with continuous cardiovascular monitoring during competitive routines, perceived exertion assessment after the executions, and blood lactate measurements (Studies I and III). Study I characterized the physiological responses in relation to performance during an official competition. In Study II the execution of the duets in both conditions –training and competitive session– was used to compare the athletes’ internal load in order to ascertain whether swimmers may achieve the competitive intensity during training sessions, and Study III was performed to investigate how immersion periods, with the concomitant bradycardic events, affect perceived exertion with both physiological (HR) and subjective perceptual markers (RPE). The current thesis demonstrates that cardiovascular responses during competition are characterized by intense anticipatory pre-activation and rapidly developing tachycardia up to maximal levels with interspersed periods of marked bradycardia during the exercise bouts performed in apnea (Studies I­III). Moderate blood lactate accumulation suggested the activation of the glycolytic metabolism in the exercising muscles and an adaptive metabolic response due to the specific training adaptations in this kind of athletes (Studies I and III). Furthermore, competitive routines were perceived as very to extremely intense by all swimmers, likely reflecting not only the absolute exercise demands but also their previous experience and expectations (Studies I – III). In Study II, the internal load (HR and RPE) imposed by SS duets performed during training was virtually identical to that elicited in a real competitive situation due to the effects of automaticity –embodied through the replication of the same movement sequence in practice–, and by the swimmers’ long-term adaptations to specific routine exercise and apnea. There was a strong positive relationship between RPE and the duration and / or frequency of bradycardic events during routines (Studies II – III). In fact, the frequency and duration of immersions, the magnitude of subsequent bradycardic events, the blood lactate concentration, and the HR recovery during competitive SS routines explained 62% RPE variance changes in perceived exertion, with cardiorespiratory factors providing a relatively greater neural input as compared to metabolic factors (Study III). Attending the relationships between physiological parameters and performance, the magnitude of anticipatory heart rate activation and bradycardic response explained 26% of variability in performance (Study I) supporting the concept that an augmented diving response was associated to higher performance in SS. However, in Study III the percentage of variance rose to 53% by adding the blood lactate concentration, the number of immersions and longest immersion time, and the lower mean time immersed during the routine. This could explain that best swimmers show a greater adaptation to breath holding and this would likely translate into a more efficient O2 conservation effect (Study III).

This thesis examined the benefits of physiological and performance testing of elite swimmers. The study considered the following research questions: the degree to which physiological and performance measures in training contribute to swimming performance; sources and magnitude of variability in testing, training and competition performance; the magnitudes of changes in test measures during routine training; and the reliability, validity and utility of miniaturised and automated smart sensor technology to monitor the stroke and performance times of swimmers in training. The experimental approach involved the retrospective analysis of five years of physiological and performance testing of elite level swimmers, the development of a new accelerometry-based smart sensor device to monitor swimmers in the pool, a cross-sectional study comparing the physiological and performance responses of swimmers of different levels, and the effects of an intensive 14-day training program on submaximal physiological and performance measures. Collectively, the outcomes of these studies provide a strong justification for the physiological and performance testing of elite swimmers, a quantitative framework for interpreting the magnitude of changes and differences in test scores and sources of variation, and highlight the potential utility of new smart sensor technology to automate the monitoring of a swimmer�s training performance. The first study (Chapter 2) characterises the changes and variability in test performance, physiological and anthropometric measures, and stroke mechanics of swimmers within and between seasons over their elite competitive career. Forty elite swimmers (24 male, 16 female) performed a 7 x 200-m incremental swimming step test several times each 6-month season (10 � 5 tests, spanning 0.5 to 6.0 y). Mixed linear modeling provided estimates of change in the mean and individual responses for measures based on submaximal performance (fixed 4-mM lactate), maximal performance (the seventh step), and lean mass (from skinfolds and body mass). Submaximal and maximal swim speed increased within each season from the pre to taper phase by ~2.2% for females and ~1.5% for males (95% confidence limits �1.0%), with variable contributions from stroke rate and stroke length. Most of the gains in speed were lost in the off-season, leaving a net average annual improvement of ~1.0% for females and ~0.6% for males (�1.0%). For submaximal and maximal speed, individual variation between phases was �2.2% and the typical measurement error was �0.8%. In conclusion, step test and anthropometric measures can be used to confidently monitor progressions in swimmers in an elite training program within and between seasons. The second study (Chapter 3) quantified the relationship between changes in test measures and changes in competition performance for individual elite swimmers. The primary question addressed was whether test measures could predict a swimmers performance at the major end-of-season competition. The same sample group as in Study 1 was examined. A 7 x 200-m incremental swimming step-test and anthropometry were conducted in up to four training phases each season. Correlations of changes in step-test and anthropometric measures between training phases between and within seasons, with changes in competition performance between seasons, were derived by repeated-measures mixed modeling and linear regression. Changes in competition performance were best tracked by changes in test measures between taper phases. The best single predictor of competition performance was skinfolds for females (r = -0.53). The best predictor from the step-test was stroke rate at 4-mM lactate (females, r = 0.46; males, r = 0.41); inclusion of the second-best step-test predictor in a multiple linear regression improved the correlations marginally (females, r =0.52 with speed in the seventh step included; males, r = 0.58 with peak lactate concentration included). Changes in test measures involving phases other than the taper provided weak and inconclusive correlations with changes in performance, possibly because the coaches and swimmers took corrective action when tests produced poor results. In conclusion, a combination of fitness and techniques factors are important for competitive performance. The step test is apparently a useful adjunct in a swimmer�s training preparation for tracking large changes in performance. These initial studies identified stroke mechanics as a major determinant of a swimmer�s performance. Chapter 4 details the development of a small tri-axial accelerometry-based smart sensor device (the Traqua) that enables continual monitoring of various performance/stroke characteristics in swimming. The initial focus was to develop a device that automated the detection of a swimmer�s movements, specifically lap times, stroke rate and stroke count. The Traqua consists of a tri-axial accelerometer packaged with a microprocessor, which attaches to the swimmer at the pelvis to monitor their whole body movements while swimming. This study established the failure/error rate in the first generation algorithms developed to detect the swimming-specific movements of stroke identification, laps (start, turn and finish), and strokes (stroke count and stroke rate) in a cohort of 21 elite and sub-elite swimmers. Movements were analysed across a range of swimming speeds for both freestyle and breaststroke. These initial algorithms were reasonably successful in correctly identifying the markers representing specific segments of a swimming lap in a range of swimmers across a spectrum of swimming speeds. The first iteration of the freestyle algorithm produced error-rates of 13% in detection of lap times, 5% for stroke rate, and 11% for stroke count. Subsequent improvements of the software reduced the error rate in lap and stroke detection. This improved software was used in the following two studies. The next study (Chapter 5) evaluated the reliability and validity of the Traqua against contemporary methods used for timing, stroke rate and stroke count determination. The subjects were 14 elite and 10 sub-elite club-level swimmers. Each swimmer was required to swim seven evenly paced 200-m efforts on a 5-min cycle, graded from easy to maximal. Swimmers completed the test using their main competitive stroke (21 freestyle, 3 breaststroke). Timing was compared for each 50-m lap and total 200-m time by electronic touch pads, video coding, a hand-held manual stopwatch, and the Traqua. Stroke count was compared for video coding, self-reported counting, and the Traqua, while the stroke rate was compared via video coding, hand-held stopwatch, and the Traqua. Retest trials were conducted under the same conditions 7 d following the first test. All data from the Traqua presented in this and the subsequent studies were visually inspected for errors in the automated algorithms, where the algorithms had either failed to correctly identify the start, turn, finish or individual strokes and corrected prior to analysis. The standard error of the estimate for each of the timing methods for total 200 m was compared with the criterion electronic timing. These standard errors were as follows: Traqua (0.64 s; 90% confidence limits 0.60 � 0.69 s), Video (0.52 s; 0.49 � 0.55 s); Manual (0.63 s; 0.59 � 0.67 s). Broken down by 50-m laps, the standard error of the estimate for the Traqua compared with the electronic timing for freestyle only was: 1st 50-m 0.35 s; 2nd and 3rd 50-m 0.13 s; 4th 50-m 0.65 s. When compared with the criterion video-coding determination, the error for the stroke count was substantially lower for the Traqua (0.6 strokes.50 m-1; 0.5 � 0.6 strokes.50 m-1) compared to the self-reported measure (2.3 strokes.50 m-1; 2.5 � 2.9 strokes.50 m-1). However, the error for stroke rate was similar between the Traqua (1.5 strokes.min-1; 1.4 � 1.6 strokes.min-1) and the manual stopwatch (1.8 strokes.min-1; 1.7 � 1.9 strokes.min-1). The typical error of measurement of the Traqua was 1.99 s for 200-m time, 1.1 strokes.min-1 for stroke rate, and 1.1 strokes.50 m-1 for stroke count. In conclusion, the Traqua is comparable in accuracy to current methods for determining time and stroke rate, and better than current methods for stroke count. A substantial source of error in the Traqua timing was additional noise in the detection of the start and finish. The Traqua is probably useful for monitoring of routine training but electronic timing and video are preferred for racing and time trials. Having established the reliability and validity of the Traqua, Chapter 6 addressed the ability to discriminate the pattern of pacing between different levels of swimmers in the 7 x 200-m incremental step test. This study also sought to quantify the differences in pacing between senior and junior swimmers. Eleven senior elite swimmers (5 female, 6 male) and 10 competitive junior swimmers (3 female, 7 male) participated in this study. Each swimmer was required to swim seven evenly paced 200-m freestyle efforts on a 5-min cycle, graded from easy to maximal. The Traqua was used to measure time, stroke rate and stroke count. The senior swimmers were better able to descend in each of the 200-m efforts. Overall the senior swimmers were ~2-3 s per 50 m faster than the junior swimmers. Both groups were fastest in the first 50-m lap with the push start. The senior swimmers then descended the 50- m time for each of the subsequent laps, getting ~0.5 s faster per lap, with the final lap the fastest. In contrast, the junior swimmers swam a similar time for each of the subsequent laps. The junior swimmers were marginally more variable in their times (coefficient of variation: ~2%) compared with the senior swimmers (~1.8%). In comparison to junior swimmers, the senior swimmers in this study were faster, adopted a more uniform negative split strategy to pacing within a 200-m effort, and were more consistent in reproducing submaximal and maximal swimming speeds. The final study (Chapter 7) analysed the effect of 14-d of intensive training on the reproducibility of submaximal swimming performance in elite swimmers. Submaximal physiological and performance testing is widely used in swimming and other individual sports but the variability in test measures, and the effects of fatigue, during intensive training have surprisingly not been quantified systematically. Seven elite swimmers (3 male and 4 female) participated in an intensive 14-d training camp one month prior to the National championships. The aim of the study was to characterise the intra-session, daily and training block variability of submaximal swimming time, physiological and stroke characteristics in elite swimmers. The swimmers performed a specified submaximal 200-m effort in most sessions, after the warm-up and at the end of the session for both morning and afternoon sessions. During the efforts, swimming time and stroke mechanics were measured and physiological measures were recorded immediately on completion. The Traqua was worn by all swimmers in every training session. Mixed linear modeling was used to provide estimates of changes in the mean and individual responses (within-athlete variation as a coefficient of variation) for all measures. The swimmers were moderately slower (1.4%; �1.4%) over the 14-d training camp. The mean submaximal 200-m effort was very likely to be faster (0.7%; confidence limits �0.7%) in the afternoon compared with the morning session. The females were more variable in their submaximal performance times (CV=2.6%) than the male swimmers (1.7%). Blood lactate concentration was almost certainly lower (-23%; �10%) following higher volume in the previous session; however a higher intensity workout the previous session almost certainly leads to higher lactate (21%; �15%) in the current session. Considered together, these results indicate that the 200-m submaximal test is useful in monitoring submaximal physiological and performance measures and the negative effects of cumulative fatigue. In conclusion, changes in the physiological and performance measures derived from the poolbased progressive incremental step test are moderately correlated with changes in end-ofviii. season competition performance. The magnitudes of changes and differences in test measures between phases within a season, from season to season, and between males and females, established in this study can be applied to similar elite level swimmers preparing for major competition. The quantification of typical error of the same measures demonstrates that coaches and scientists can distinguish real and worthwhile improvements using the 7 x 200-m step test. Continual pool-based monitoring with the automated smart sensor Traqua device may provide more accurate and detailed information about a swimmer�s training adaptation than current fitness tests and monitoring methods. Finally, submaximal testing in trained swimmers is useful in monitoring progress in physiological and performance measures, and the impact of cumulative fatigue during an intensive period of training. Collectively, the outcomes of these studies indicate that routine physiological and performance testing can provide measurable benefits for elite swimmers and their coaches.

Twelve competitive male swimmers were studied for a comparison of lactate/velocity profiles to heart rate/velocity profiles during a season of swim training. Lactate concentration (mM) and post-exercise heart rate (sum of three) after a 200-yard submaximal swim (approximately 90% of maximal attainable velocity) and a maximal swim were determined three times during the season: at the beginning (T1), after two months of training (T2) and after four months of training (T3). Both profiles demonstrated a significant rightward shift at T2 and a smaller, further shift at T3. Both lactate and heart rate significantly decreased at an absolute and relative exercise intensity in response to training. It is concluded that either parameter can be useful in monitoring training progress and for determining optimal training intensities. Because of the expense and difficulty of blood lactate measurements, heart rate/ velocity profiles can provide a practical and non-invasive alternative to blood lactate testing.

Choking under pressure is a devastating experience for athletes who have invested their time and energy to master a sport. This study reviewed the mechanisms of choking under pressure to further understand the phenomenon and identify possible remedies. Twenty-eight competitive swimmers from the University of Arizona swim team were assessed on measures of dispositional mindfulness and trait anxiety, while three current staff members rated each athlete on measures of skill transfer and receptiveness to feedback. Athlete performances were recorded over the course of one season, and assigned a pressure rating of low, medium, and high. Results indicated significant effects of pressure on change in performance, and revealed non-significant trends between trait anxiety, mindfulness, and performance improvements as a function of pressure. Significant relationships were also found for trait anxiety with mindfulness and gender. Coach ratings were not found to be accurate predictors of improvements in swimming performance. These findings call into question theory suggesting trait anxiety is facilitative when low and detrimental when high, instead suggesting it may distribute as an inverse-u relative to performance. They also suggest dispositional mindfulness may be facilitative of performance under pressure, an endorsement for continued research into the efficacy of mindfulness training in athletics. Finally, they call into question the accuracy of coach ratings of athletes, and reveal a need for further investigation in that area. Implications for choking under pressure are discussed.

This study examines swimming in fish as a function of the performance of the locomotor musculature. Aspects of evolutionary adaptation and scaling relevant to swimming performance in fish are introduced. The concepts of resistance and capacity adaptations are illustrated in relation to the evolution of the suborder Notothenioidei to the antarctic environment. Alterations in hydrodynamics, swimming performance and efficiency with growth/scaling are discussed.

Swimming performance is primarily judged on the overall time taken for a swimmer to complete a specified distance performing a stroke that complies with current regulations defined by the Fédération Internationale de Natation (FINA), the International governing body of swimming. There are three contributing factors to this overall time; the start, free swimming and turns. The contribution of each of these factors is event dependent; for example, in a 50m event there are no turns, however, the start can be a significant contributor. To improve overall performance each of these components should be optimised in terms of skill and execution. This thesis details the research undertaken towards improving performance-related feedback in swimming. The research included collaboration with British Swimming, the national governing body for swimming in the U.K., to drive the requirements and direction of research. An evaluation of current methods of swimming analysis identified a capability gap in real-time, quantitative feedback. A number of components were developed to produce an integrated system for comprehensive swim performance analysis in all phases of the swim, i.e. starts, free swimming and turns. These components were developed to satisfy two types of stakeholder requirements. Firstly, the measurement requirements, i.e. what does the end user want to measure? Secondly, the process requirements, i.e. how would these measurements be achieved? The components developed in this research worked towards new technologies to facilitate a wider range of measurement parameters using automated methods as well as the application of technologies to facilitate the automation of current techniques. The development of the system is presented in detail and the application of these technologies is presented in case studies for starts, free swimming and turns. It was found that developed components were able to provide useful data indicating levels of performance in all aspects of swimming, i.e. starts, free swimming and turns. For the starts, an integrated solution of vision, force plate technology and a wireless iii node enabled greater insight into overall performance and quantitative measurements of performance to be captured. Force profiles could easily identify differences in swimmer ability or changes in technique. The analysis of free swimming was predominantly supported by the wireless sensor technology, whereby signal analysis was capable of automatically determining factors such as lap times variations within strokes. The turning phase was also characterised in acceleration space, allowing the phases of the turn to be individually assessed and their contribution to total turn time established. Each of the component technologies were not used in isolation but were supported by other synchronous data capture. In all cases a vision component was used to increase understanding of data outputs and provide a medium that coaches and athletes were comfortable with interpreting. The integrated, component based system has been developed and tested to prove its ability to produce useful, quantitative feedback information for swimmers. The individual components were found to be capable of providing greater insight into swimming performance, that has not been previously possible using the current state of the art techniques. Future work should look towards the fine-tuning of the prototype system into a useable solution for end users. This relies on the refinement of components and the development of an appropriate user interface to enable ease of data collection, analysis, presentation and interpretation.

A comparative analysis of the performances of three outdoor swimming pools for private use with different types of covers is presented in this paper. They are designed to take advantage of solar irradiation to maintain the swimming pool temperature within certain acceptable limits, so that the swimming pool can be used during most of the year under South-Europe climatic conditions. In this region, the annual global irradiation is of the order of 1800 kWh/m2 and air temperature is in the range from 0°C to 40°C during the whole year. No auxiliary boosting is used to heat the swimming pools.

This paper presents a novel robot fish propelled by an active and compliant propulsion mechanism. The key innovation of this robot fish is the combination of an active wire-driven mechanism with a soft compliant tail to construct the active compliant propulsion mechanism, which can accomplish multi-modal swimming motions. First, the design method was proposed, the wire-driven mechanism and the compliant tail could be well designed. Second, using this robot fish experimental platform, numerous experiments were conducted to investigate the effect of different controllable parameters on cruising speed, descending speed and turning performance. These parameters include flapping frequency and amplitude of the propulsion mechanism, attack angle of the pectoral fins. A more detailed parametric study was conducted with these significant parameters to study and understand the relationship between swimming performance and various parameters. This process can help to optimize controllable parameters for superior swimming performance. Based on the parametric study, we obtained the best experimental swimming performance under optimized parameters; the maximum speed reached 2.15 BL/s (body length per second), the maximum turning speed is 269°/s the descending speed is 42 cm/s (when attack angle is 60 degree). Compared with existing robot, the new robot fish has several advantages: it is simple in structure, easy to control, and capable of high speed swimming and maneuverable swimming.

The performance of 26 PVT-Systems was analysed and compared in IEA-SHC Task 60. The systems are located in countries with different climatic conditions. The applications range from direct domestic hot water production and heating of public swimming pools to heat pump systems with PVT as the main heat source of the heat pump. The Key Performance Indicators (KPIs) determined for the different PVT solutions give the possibility to compare the systems despite their diversity. The goal was to show the potential of PVT collectors in different fields of application. The results show that the integration of PVT collectors in different kinds of well-dimensioned systems leads to competitive solutions, both from an energy and a financial perspective. Additionally the answers to a survey about control strategies for PVT systems, showing some main problems and possible solutions, are summarised.