Achieving marginal gains: perfecting the pacing strategies of Australian swimmers

  • Katie Mcgibbon

Student thesis: Doctoral Thesis

Abstract

Effective pacing, or energy distribution during exercise, is considered critical to maximise swimming performance given the low mechanical efficiency and highly resistive properties of water. Although pacing profiles in competition have been well characterised in swimming, it is unclear whether these are optimal for performance, and how coaches approach the entrainment of pacing skills. This thesis comprises six chapters: a systematic review, pacing analysis of individual and relay events, a questionnaire on pacing knowledge for coaches, swimmers and support staff, a coach interview on pacing practices and beliefs, an evaluation of the use of pacing aids, and finally the effects of a short-term pacing entrainment intervention.
A systematic review of the literature on pacing in swimming provided useful benchmark data for coaches and highlighted gaps in the research literature. Given the lack of pacing research in relay events, a retrospective analysis of competition data comparing pacing profiles in the 4x200-m freestyle relay to the corresponding individual 200-m freestyle event was conducted. The importance of being conservative in the first lap was clearly demonstrated in both individual and relay events. A fast start lap strategy led to a positive pacing profile in 71% of swimmers and the combination of both these characteristics was associated with slower overall performance times by 0.4-0.7%. Whereas, even or negative pacing were more commonly displayed following an average or slow start lap strategy. A higher percentage of swimmers (males +7%, females +13%) displayed a positive pacing profile in relays than in individual events, which may relate to the pressure to perform well for the team.
For the next study the knowledge and perceptions of pacing among coaches, swimmers and support staff were examined using a questionnaire. Although pacing was considered important, there appeared to be a lack of understanding on the most successful pacing profiles for each event. Discrepancies between coaches, swimmers and staff indicate that further education on pacing is required. A semi-structured interview was also conducted to gain further insight into the current practices of high-performance swimming coaches in relation to pacing entrainment and competition preparation. Coaches spoke of the challenges associated with providing individual feedback when working with large groups of swimmers. As a result, the monitoring of key pacing variables such as stroke rate (SR), stroke count (SC) and split times is often neglected by coaches. Many coaches reported using pacing aids for the purpose of entraining pacing strategies, however, the ability of swimmers to effectively use these devices remains unclear.
The reliability and accuracy of pacing was examined using two commercially available pacing aids: underwater pacing lights and a wearable metronome, compared to self-pacing during sub-maximal and high-speed swimming. Pacing reliability was typically higher with both pacing aids compared to self-pacing, although it was high in all conditions (ICC ≥0.84, CV ≤2.7%). Swimmers were unable to pace evenly across multiple laps with a metronome or self-pacing and typically swam faster than the target time in the first lap. However, the continuous feedback provided by the underwater lights aided even pacing across all swimming speeds. In the final study, the effectiveness of a short-term pacing entrainment intervention in improving pacing accuracy was assessed. Swimmers completed one pacing session per week for 5 weeks where they received detailed feedback derived from a wearable automated sensor. The pacing session comprised a series of aerobic freestyle repetitions using three different pacing strategies: even, negative and positive. There were no improvements across the 5 weeks, pacing accuracy was inconsistent and varied from week-to-week. The percentage difference between the target and actual total time for the swimming intervals varied from 0.1-1.4% across the 5 weeks. It appears that swimmers require multiple sessions per week as part of a targeted pacing entrainment block to yield meaningful changes in pacing ability. The outcomes of these studies provide coaches with evidence-based support for both practical tools (pacing lights, wearable metronome, wearable automated sensor) and guidelines (effective pacing profiles in individual and relay events, general knowledge on pacing for swimmers and coaches) to improve pacing skills in swimmers.
Date of Award2020
Original languageEnglish
SupervisorKevin Thompson (Supervisor), David Pyne (Supervisor) & Megan E Shephard (Supervisor)

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