“Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes” by Wu SS et al. International Journal of Sports Physiology and Performance © 2016 Human Kinetics, Inc.

Note. This article will be published in a forthcoming issue of the International Journal of Sports Physiology and Performance. The article appears here in its accepted, peer-reviewed form, as it was provided by the submitting author. It has not been copyedited, proofread, or formatted by the publisher.

Section: Original Investigation Article Title: Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes Authors: Sam S. X. Wu1,2, Jeremiah J. Peiffer3, Peter Peeling4, Jeanick Brisswalter5, Wing Y. Lau2, Kazunori Nosaka2, and Chris R. Abbiss2 Affiliations: 1Sport Performance Optimisation Research Team, School of Health Sciences, University of Tasmania, Tasmania, Australia. 2Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia. 3School of Psychology and Exercise Science, Murdoch University, Murdoch, Western Australia. 4School of Sport Science, Exercise and Health, University of Western Australia, Crawley, Western Australia. 5Laboratory of Human Motricity, Education Sport and Health University of Nice Sophia Antipolis, France. Journal: International Journal of Sports Physiology and Performance Acceptance Date: February 3, 2016 ©2016 Human Kinetics, Inc.

DOI: http://dx.doi.org/10.1123/ijspp.2015-0580

“Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes” by Wu SS et al. International Journal of Sports Physiology and Performance © 2016 Human Kinetics, Inc.

Positive swim pacing improves sprint triathlon performance in trained athletes

Sam S. X. Wu 1,2, Jeremiah J. Peiffer 3, Peter Peeling 4, Jeanick Brisswalter 5, Wing Y. Lau 2, Kazunori Nosaka 2, Chris R. Abbiss 2 1

Sport Performance Optimisation Research Team, School of Health Sciences, University of Tasmania, Tasmania, Australia Downloaded by University of Exeter on 09/25/16, Volume 0, Article Number 0

2

Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia 3

School of Psychology and Exercise Science, Murdoch University, Murdoch, Western Australia 4

School of Sport Science, Exercise and Health, University of Western Australia, Crawley, Western Australia 5

Laboratory of Human Motricity, Education Sport and Health University of Nice Sophia Antipolis, France

Corresponding author: Sam Shi Xuan Wu School of Health Sciences University of Tasmania Locked Bag 1322, Newnham Campus, Launceston, Tasmania 7250 Ph: +61 3 6324 5468, Fax: +61 3 6324 3995, E-mail: [email protected] Preferred Running Head: Swim pacing and triathlon performance Abstract Word count: 238 Text-Only Word Count: 2926 Number of Figures: 2 Number of Tables: 1

“Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes” by Wu SS et al. International Journal of Sports Physiology and Performance © 2016 Human Kinetics, Inc.

Abstract Purpose: The purpose of this study was to investigate the effect of three swim pacing profiles on subsequent performance during a sprint distance triathlon (SDT). Methods: Nine competitive/trained male triathletes completed five experimental sessions, including a graded running exhaustion test, a 750 m swim time-trial (STT), and three SDTs. The swim time of the three SDTs were matched, but pacing was manipulated to induce positive (i.e. speed gradually decreasing from 92 to 73% STT), negative (i.e. speed gradually increasing from 73 to 92%

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STT) or even pacing (constant 82.5% STT). The remaining disciplines were completed at a self-selected maximal pace. Speed over the entire triathlon, power output during the cycle discipline, rating of perceived exertion (RPE) for each discipline and heart rate during the cycle and run were determined. Results: Faster cycle and overall triathlon times were achieved with positive swim pacing (30.5 ± 1.8 and 65.9 ± 4.0 min respectively), as compared with the even (31.4 ± 1.0, P=0.018 and 67.7 ± 3.9 min, P=0.034, ES=0.46 respectively) and negative (31.8 ± 1.6, P=0.011 and 67.3 ± 3.7 min, P=0.041, ES=0.36 respectively) pacing. Positive swim pacing elicited a lower RPE (9 ± 2) than negative swim pacing (11 ± 2, P=0.014). No differences were observed in the other measured variables. Conclusions: Results of this study indicate that a positive swim pacing may improve overall SDT performance, and should be considered by both elite and age-group athletes during racing. Keywords: Cycle; run; pacing strategy; even pacing; negative pacing

“Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes” by Wu SS et al. International Journal of Sports Physiology and Performance © 2016 Human Kinetics, Inc.

Introduction The distribution of pace during triathlon is crucial to performance, with previous work suggesting that any time lost during various segments of a race (specifically swim and transitions) could have significant impact on the competitive outcome.1 However, determining the best possible pacing is a challenging task due to the complexity of optimising energy expenditure throughout each discipline and the numerous factors influencing pacing2 and performance3 in a triathlon. Although the effect of cycling on subsequent running performance

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is well documented, the majority of previous studies lack an initial swim, which may inaccurately reflect the metabolic demands and pacing adopted during a triathlon.2,3 Certainly, Kreider et al.4 have shown that cycling power output during 75 min of cycling was reduced by 17% after an 800 m swim as compared with a control cycle bout without the initial swim. Current literature indicates that swim performance is extremely important to overall triathlon success, particularly during short distance triathlons.5-7 For instance, Peeling et al.7 indicated that swimming at a constant 80-85% of the mean speed attained during a control 750 m swim time-trial (STT) resulted in a faster overall triathlon time during a subsequent selfpaced sprint distance triathlon (SDT) when compared with swimming at 98-102% of STT. However, pacing during the swim discipline within their study was held at a constant velocity, which is uncommon during competition. Indeed, pacing during the swim leg of triathlon is likely to be heavily influenced by race dynamics.2 In mass-start triathlons, both elite and agegroup athletes are allowed to draft during the swim discipline. As a result athletes typically adopt a fast start pacing strategy in an attempt to avoid congestion,2 and to stay near faster swimmers in both elite8-10 and age-group racing.11 However, the influence of such pacing during swimming on overall triathlon performance is unclear. Swimming performance is extremely crucial in short distance triathlons, as evidence indicates that poor swimming performance may require a tactic demanding greater initial

“Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes” by Wu SS et al. International Journal of Sports Physiology and Performance © 2016 Human Kinetics, Inc.

cycling effort, which negatively affects running and overall performance.10 It is plausible that successful manipulations in pacing during the swim discipline could produce beneficial outcomes for overall race performance. Indeed, research has shown that a fast-start at commencement of 2 min kayaking12 and both 3-min13 and 5-min cycling events improves ˙ O2 kinetics. However, no such overall performance,14 and has been attributed to faster V performance improvements were observed with a fast-start during longer 6 min cycle performance,15 400 m freestyle STT16 or a 20 km cycle time trial.17 As such, the optimal pacing

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required for peak performance may differ based on the distance or duration of the event18,19 and exercise mode.11,20 There is evidence to suggest that an even pacing may be optimal during prolonged exercise lasting more than two minutes.21 The complexity of triathlon provides an interesting model for the manipulation of pacing, due to the importance of optimal energy distribution within each individual discipline and also the entire event. It should also be noted that the different capabilities of an athlete across the three disciplines may also affect the way that an athlete paces each individual discipline. Therefore, the purpose of this study was to investigate the effect of positive (relatively fast-start), negative (relatively slow-start) and even pacing during the swim discipline on subsequent SDT performance. It was hypothesised that an even swim pacing would result in superior overall sprint triathlon performance, compared with positive and negative swim pacing. Methods Subjects Nine competitive/trained male triathletes (x̅ ± SD: running V̇O2max = 63.7 ± 3.6 ml·kg1

·min-1, age = 26.7 ± 8.2 y, mass = 71.8 ± 10.3 kg, height = 1.78 ± 0.07 m) with more than 3

years triathlon racing experience and a sprint distance triathlon time of less than 70 min in the previous season were recruited for this study. Participants were informed of the possible risks

“Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes” by Wu SS et al. International Journal of Sports Physiology and Performance © 2016 Human Kinetics, Inc.

involved and provided written informed consent approved by the Edith Cowan University Human Research Ethics Committee in accordance with the Declaration of Helsinki. Design Each participant performed an incremental running test, a 750 m STT, and three randomised SDTs (750 m swim, 20 km cycle, 5 km run). Each exercise bout was performed at the same time of day, one week apart. Intensive exercise was avoided for a minimum of 24 h

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prior to each session. Methodology A fast-ramp incremental run test to exhaustion on a motorised treadmill (Trackmaster, JAS Fitness Systems, Kansas, USA) was performed to determine V̇O2max. Participants commenced this test with a 5 min warm-up at 10 km∙h-1, followed by 1 km∙h-1 increments every minute up to 16 km∙h-1, and subsequently 2% increments in gradient every minute thereafter until volitional exhaustion. Expired air was analysed using the Parvo-Medics metabolic measurement system (TrueOne 2400, ParvoMedics, Utah, USA) and averaged over 15 s. V̇O2max was determined according to previously published methods by Abbiss et al.22 Following the incremental running test, participants performed a 10 min familiarization timetrial on the TacX bicycle trainer (TacXFortius, Wassenaar, Netherlands). All swims were performed in a six lane, 25 m outdoor pool at a water temperature of 28 °C. Mean daily temperature and humidity were 24.2 ± 1.0 °C and 63 ± 4% respectively. Cycling was performed on the TacX bicycle trainer (TacX Fortius, Wassenaar, Netherlands) which has been shown to be valid (r=0.99 compared with the PowerTap for the measurement of power output) and reliable (r=0.99 for test-retest reliability23). The use of a bicycle trainer allows the participants to make adjustments in pacing according to the associated internal feedback, minimising the influence of external factors such as topography and wind. Participants’ own race bicycle and racing setup was used for all SDT. All runs (except the

“Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes” by Wu SS et al. International Journal of Sports Physiology and Performance © 2016 Human Kinetics, Inc.

incremental running test) were performed on a 2-loop out and back course on flat tarmac surface, totalling 5 km in distance. Participants performed a standardised 400 m warm up followed by 5 min rest prior to all STT and SDT trials. The maximal effort self-paced 750 m STT was performed prior to any SDT trial. During the STT, participants were instructed to self-select a pace they deemed appropriate to elicit the fastest 750 m swim time. No feedback was provided during the swim. Mean swim speed for the subsequent SDT swims were calculated based on the mean speed

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achieved during the STT.7 The swim disciplines of the three SDTs were performed with randomised even, negative and positive pacing profiles, while the mean speed achieved across the entire swim remained constant. The negative and positive pacing profiles were based on slow-start and faststart pacing profiles respectively, where magnitude was established according to the range of deviations in swim speed observed during an actual competitive SDT event.20 During the even pacing trial, participants swam at a constant 82.5% of the initial STT. Based on similar previous research by Peeling et al.,7 swimming at an intensity of 80-85% has been shown to result in superior subsequent cycling and SDT performance, as compared with swimming at 90-95 and 98-102% (similar to speeds commonly observed during races). Negative and positive pacing profiles were completed with up to 9.5% change in speed from the mean. Specifically, the negative-pacing swim began at 73% of the STT pace, and increased consistently (2.5% of STT change in speed per 100 m) to 92% by the finish. The positive-pace swim began at 92% of the STT speed, and finished at 73% by completion. Total work done in all swims were workmatched. Swim pacing was controlled by a walking pacer with a pre-determined split schedule who provided auditory and visual cues to ensure uniform pacing was achieved. Following the swim, participants immediately moved onto a bicycle ergometer with compatible simulation software, located ~10 m from the swim finish. The ergometer allowed quantification of

“Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes” by Wu SS et al. International Journal of Sports Physiology and Performance © 2016 Human Kinetics, Inc.

instantaneous power output and speed throughout the 20 km cycle section of the SDT. On completion of the cycle discipline, athletes commenced the 5 km run. Running speed was determined by a GPS watch (910XT, Garmin, US) worn on the wrist. Participants were provided only with distance feedback throughout the cycle and run disciplines, and were instructed to complete the cycle and run disciplines as quickly as possible at a self-selected pace. All trials were performed solo by participants. An overall RPE (scale of 6-20)24 for each discipline was obtained at the conclusion of

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each discipline. Heart rate (HR) was determined throughout exercise using a Polar S810i (Polar Electro Oy™, Kempele, Finland) for accuracy. Identical exercise clothing was worn for every session. A training and dietary log was maintained throughout the experimental period. Nutrition and hydration were ad libitum and were not different between trials. Power output during the cycle, in addition to HR and speed during the cycle and run disciplines were divided into 10 equal splits according to distance. Each split during the cycle discipline represented 2 km, while each split during the run represented 500 m. Statistical Analysis Completion times for swim, cycle, run and overall SDT performance, in addition to RPE were compared between pacing trials using one-way repeated measures analysis of variance (ANOVA). Effect sizes (ES) were calculated for differences observed between overall SDT performance times. Magnitude based differences were calculated to determine the smallest worthwhile change in overall SDT performance at the 90% confidence level. The smallest worthwhile change was set according to Cohen’s effect size of 0.2.25 Power output and HR was compared between conditions with a separate repeated measures two-way ANOVA. Where a significant interaction effect was observed, a Tukey’s post-hoc test was used to identify where differences occurred. All analysis was completed using Statistical

“Positive Swim Pacing Improves Sprint Triathlon Performance in Trained Athletes” by Wu SS et al. International Journal of Sports Physiology and Performance © 2016 Human Kinetics, Inc.

Package for the Social Sciences 21.0 (StatSoft, Tulsa, OK, USA) All data was expressed as mean ± SD unless otherwise specified. The alpha level was accepted at P≤0.05. Results A faster overall SDT performance time was achieved during the positive (65.9 ± 4.0 min) as compared with the even (67.7 ± 3.9 min, P=0.034, ES=0.46) and negative (67.3 ± 3.7 min, P=0.041, ES=0.36) swim pacing trials respectively (Figure 1). Analysis of magnitude based differences revealed that the chances of the positive swim pacing being practically Downloaded by University of Exeter on 09/25/16, Volume 0, Article Number 0

beneficial/trivial/harmful were 97.0/2.0/1.0% compared with even swim pacing, and 96.9/1.8/1.3% compared with negative swim pacing, respectively. Chances of negative swim pacing being practically beneficial/trivial/harmful compared with the even swim pacing were 27.3/14.7/58.1% respectively. By design, no differences in swim performance times were observed between the positive (14.52 ± 1.77 min), even (14.56 ± 1.74 min) and negative (14.48 ± 1.87 min) pacing trials (Figure 1).. A faster cycle time was achieved during the positive pacing trial (30.5 ± 1.8 min) as compared with the even (31.4 ± 1.0 min, P=0.018) and negative (31.8 ± 1.6 min, P=0.011) pacing trials. Cycling power output was consistently higher in the positive pacing trial from 4 to 10 km (233.8, 231.5, 229.1, and 231.9 W), as compared with the negative pacing trial (223.8, 221.7, 215.0 and 220.2 W, respectively, P

Improvement of Sprint Triathlon Performance in Trained Athletes With Positive Swim Pacing.

To investigate the effect of 3 swim-pacing profiles on subsequent performance during a sprint-distance triathlon (SDT)...
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