AbstractIn the lead up to major competitions,swimming coaches and sport scientists spend many hours ensuring their athlete’s training and recovery strategies are appropriate to elicit optimal performance. However,on competition day itself there are additional opportunities in which event performance might be improved by utilising various preconditioning strategies,the most common being the pre-competition warm-up. Both passive and active warm-ups can enhance swimming performance,though the competition warm-up practices of elite swimming coaches are presently unknown or have been poorly documented. In addition,competitive swimmers typically experience a delay between the pool warm-up and race start (transition phase). Transition phases of > 20 min are not uncommon which is problematic given that muscle temperature declines immediately following exercise,with appreciable reductions occurring after ~15-20 min. Additional warm-up strategies within the transition phase may therefore be required to optimise performance. Recent research has also demonstrated that completion of an exercise bout several hours prior to a competitive event may provide a priming effect to improve performance later that same day. The studies contained within this thesis aimed to investigate how altering the content of these two preconditioning strategies would affect subsequent sprint swimming performance. Study 1: An initial survey was conducted to determine the current pre-competition warm-up practices and contemporary issues faced by elite swimming coaches (n = 46) during competition. The combination of dryland-based activation exercises followed by pool-based warm-up routines appears to be the preferred approach taken by elite swimming coaches when preparing their athletes for racing. Elite swimming coaches believe the pool warm-up affords athletes the opportunity to gain a tactile “feel” for the water and surrounding pool environment. Coaches stated that transition phases were unnecessarily lengthened due to extended marshalling periods (> 15-20 min),delays in the competition schedule and the lengthy time required to don race swimsuits (~10 min). Therefore,a number of experimental studies were undertaken to address the issue of lengthy transition phases. Study 2: In the first of these investigations,16 national junior swimmers completed a standardised pool warm-up followed by a 30 min transition phase and a 100 m freestyle time-trial. Within the transition phase,swimmers wore a conventional tracksuit and remained seated (Control),wore a tracksuit jacket with integrated heating elements (Passive),performed a dryland-based exercise routine (Dryland) or a combination of Passive and Dryland (Combo). Faster overall junior time-trial performances were recorded in Combo (1.1% ± 0.3%; mean ± 90% confidence limits,p <0.01) and Dryland (0.7% ± 0.3%,p = 0.02),with start times (to 15 m) also faster for Combo (0.4% ± 0.1%,p <0.01) compared to Control. Core temperature declined less during the transition phase in Combo (-0.1 ± 0.3°C,p = 0.01,effect size,ES,-1.18) compared to Control (-0.6 ± 0.2°C),with a smaller reduction in core temperature related to better time-trial performance (R2 = 0.91,p = 0.04). Elite swimmers are more consistent performers (~0.8% typical variation in performance between competitions) than their less experienced counterparts (versus ~1.1%) and may not respond to the same degree to particular interventions. Therefore,the influence of the Combo additional warm-up strategy on elite swimming performance was investigated. Studies 3 and 4: Elite sprint freestyle (n = 25) and breaststroke (n = 10; heated tracksuit pants were used) performance was examined following completion of the Control and Combo warm-up strategies. Faster start (1.5% ± 1.0%; mean ± 90% confidence limits,p = 0.02) and 100 m freestyle time-trial (0.8% ± 0.4%,p <0.01) performances were yielded with Combo compared to Control. Core temperature again declined less during transition (-0.2°C ± 0.1°C versus -0.5°C ± 0.1°C,p = 0.02,ES,0.78) within Combo compared to Control in freestyle swimmers. Total local (trapezius) haemoglobin concentration immediately prior to the 100 m freestyle time-trial was greater within Combo compared to Control (81μM ± 25μM; mean ± standard deviation,versus 30μM ± 18μM,p <0.01,ES 1.45). Pre time-trial skin temperature was also higher in Combo (30.6 ± 1.0°C,p <0.01,ES,1.10) compared to Control (29.1 ± 1.2°C). Combo did not enhance elite sprint breaststroke performance (p = 0.55) despite significantly higher Tskin values recorded immediately prior to the 100 m time-trial in Combo (30.1 ± 0.9ºC; mean ± standard deviation,p = 0.01,ES,0.70) compared to Control (29.1 ± 1.3ºC). It was unclear if the decline in core temperature during the transition phase was less in Combo (-0.1 ± 0.2°C; mean ± 90% confidence limits,p = 0.36,ES,0.65) in comparison with Control (-0.3 ± 0.2°C) in elite breaststroke swimmers. Completion of additional warm-up strategies during the transition phase can enhance elite senior sprint freestyle,but not breaststroke performance. Study 5: Completion of a morning (07:30-08:30) exercise priming bout consisting of swimming exercise (SwimOnly),swimming and dryland-based resistance exercise (SwimDry) or no exercise (NoEx) was investigated to ascertain the effect upon afternoon swimming performance (n = 13). Following a six hour break,afternoon (14:30-16:00) time-trial performance was faster in SwimOnly (1.6 ± 0.6%; mean ± 90% confidence limits,p <0.01) and SwimDry (1.7 ± 0.7%,p <0.01). First 50 m stroke rate was higher in SwimOnly (0.70 ± 0.21 Hz; mean ± standard deviation,p = 0.03) and SwimDry (0.69 ± 0.18 Hz,p = 0.05) compared to NoEx (0.64 ± 0.16 Hz). Before the afternoon session,core (0.2°C ± 0.1°C; mean ± 90% confidence limits,p = 0.04,ES,1.03),body (0.2°C ± 0.1°C,p = 0.02,ES,1.74) and skin (0.3°C ± 0.3°C,p = 0.02,ES,0.78) temperatures were higher in SwimDry compared to NoEx. Completion of a morning swimming exercise bout alone or in combination with resistance exercises can enhance afternoon sprint swimming performance. Swimming coaches are concerned that lengthy marshalling periods may compromise the retention of beneficial effects induced by pre-competition warm-ups. Coaches can be advised that a combination of heated jackets and dryland-based activation exercises employed within lengthy transitions can yield benefits to sprint freestyle performance in the range of 0.8% (seniors) to 1.1% (juniors). Attenuation in the decline of core temperature and augmented total local haemoglobin concentration appear as likely mechanisms. Tracksuit pants integrated with heating elements covering a greater surface area may be required to enhance core temperature maintenance during lengthy transition phases and subsequently,elite sprint breaststroke performance. Preliminary evidence suggests that afternoon sprint swimming performance is enhanced following the completion of a morning exercise bout consisting of swimming exercise alone or in combination with resistance exercises. In summary,utilising additional warm-up strategies during the transition phase between pool warm-up end and race start and completion of a morning exercise bout prior to afternoon racing was shown to significantly enhance sprint swimming performance.
|Date of Award||1 Jan 2016|
Competition day preparation strategies to enhance performance in swimmers
McGowan, C. J. (Author). 1 Jan 2016
Student thesis: Doctoral Thesis