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Andrew Renfree, Louise Martin, Ashley Richards and Alan St Clair Gibson

Purpose:

This study examined individual contributions to overall pacing strategy during 2- and 5-km rowing trials in a coxless-4 boat.

Methods:

A crew of 4 male rowers performed maximal-effort on-water trials over 2 and 5 km, and power output during every individual stroke was measured for each crew member. Mean overall boat and individual rower stroke power were calculated for each 25% epoch (25% of total strokes taken), and power for each individual epoch was calculated as a percentage of mean power maintained over the entire distance. The coefficient of variation was used to determine stroke-to-stroke and epoch-to-epoch variability for individual rowers and the overall boat.

Results:

In both trials, the overall pacing strategy consisted of a high power output in the initial 25% that decreased in the middle 50% and increased again in the final 25%. However, individual rower data indicate wide variation in individual power profiles that did not always mimic the overall boat profile.

Conclusions:

This study demonstrates that overall boat power profiles during 2- and 5-km rowing trials are similar to velocity profiles previously reported for individual ergometry and on-water racing events. However, this overall profile is achieved despite considerable variation in individual rower profiles. Further research is warranted to determine the mechanisms through which individual contributions to overall pacing strategy are regulated and the effectiveness or otherwise of seemingly disparate individual strategies on overall performance.

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Nancy Getchell, Ling-Yin Liang, Daphne Golden and Samuel W. Logan

The primary purpose of this study was to examine the effect of auditory pacing on period stability and temporal consistency of a dual motor task in children with and without dyslexia and with varying amounts of motor deficiency. Fifty-four children were divided into groups based on dyslexia diagnosis and score on the Movement Assessment Battery for Children-Second Edition (Movement ABC-2). Participants performed a dual motor task (clapping while walking) at a self-determined pace in a pretest block, practiced 4 blocks of 4 trials with a metronome pacing signal, and finished with a posttest block without auditory pacing. Measures of period stability (interclap/interheel strike intervals across trial blocks) and temporal consistency (coefficient of variation of period with trials) were taken. The results suggest that auditory pacing may improve period stability across groups, but does not appear to impact temporal consistency. Weak support existed for a general impairment of motor function in children diagnosed with dyslexia.

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Robert N. Singer, Charmaine DeFrancesco and Lynda E. Randal

(Singer, 1986) on achievement in laboratory and simulated self-paced sport tasks were investigated. Forty undergraduates were randomly stratified according to gender into four treatment groups: (a) a strategy group that initially practiced the strategy while learning the laboratory task (SL), (b) a laboratory control group that began the experiment by learning the task without the strategy (CL), (c) a strategy group that initially applied the strategy to the learning of an applied sport task (SA), and (d) a control group that initially learned the sport task without the strategy (CA). Following the completion of 48 trials with the primary task, all groups performed 50 trials on a transfer task. ANOVAs indicated that both strategy groups performed significantly better than their respective control groups in the primary tasks. Results of the transfer task indicated that the SA group performed at the same level as the SL group but outperformed both control groups. It was concluded that the strategy facilitates achievement in laboratory as well as applied self-paced tasks.

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Koen Levels, Lennart P.J. Teunissen, Arnold de Haan, Jos J. de Koning, Bernadet van Os and Hein A.M. Daanen

Purpose:

The best way to apply precooling for endurance exercise in the heat is still unclear. The authors analyzed the effect of different preparation regimens on pacing during a 15-km cycling time trial in the heat.

Methods:

Ten male subjects completed four 15-km time trials (30°C), preceded by different preparation regimes: 10 min cycling (WARM-UP), 30 min scalp cooling of which 10 min was cycling (SC+WARM-UP), ice-slurry ingestion (ICE), and ice slurry ingestion + 30 min scalp cooling (SC+ICE).

Results:

No differences were observed in finish time and mean power output, although power output was lower for WARM-UP than for SC+ICE during km 13–14 (17 ± 16 and 19 ± 14 W, respectively) and for ICE during km 13 (16 ± 16 W). Rectal temperature at the start of the time trial was lower for both ICE conditions (~36.7°C) than both WARMUP conditions (~37.1°C) and remained lower during the first part of the trial. Skin temperature and thermal sensation were lower at the start for SC+ICE.

Conclusions:

The preparation regimen providing the lowest body-heat content and sensation of coolness at the start (SC+ICE) was most beneficial for pacing during the latter stages of the time trial, although overall performance did not differ.

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Christopher R. D. Wagstaff

This study used a single-blind, within-participant, counterbalanced, repeated-measures design to examine the relationship between emotional self-regulation and sport performance. Twenty competitive athletes completed four laboratory-based conditions; familiarization, control, emotion suppression, and nonsuppression. In each condition participants completed a 10-km cycling time trial requiring self-regulation. In the experimental conditions participants watched an upsetting video before performing the cycle task. When participants suppressed their emotional reactions to the video (suppression condition) they completed the cycling task slower, generated lower mean power outputs, and reached a lower maximum heart rate and perceived greater physical exertion than when they were given no self-regulation instructions during the video (nonsuppression condition) and received no video treatment (control condition). The findings suggest that emotional self-regulation resource impairment affects perceived exertion, pacing and sport performance and extends previous research examining the regulation of persistence on physical tasks. The results are discussed in line with relevant psychophysiological theories of self-regulation and fatigue and pertinent potential implications for practice regarding performance and well-being are suggested.

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Peter M. Christensen and Jens Bangsbo

Purpose:

To evaluate the influence of warm-up exercise intensity and subsequent recovery on intense endurance performance, selected blood variables, and the oxygen-uptake (VO2) response.

Methods:

Twelve highly trained male cyclists (VO2max 72.4 ± 8.0 mL · min−1 · kg−1, incremental-test peak power output (iPPO) 432 ± 31 W; mean ± SD) performed 3 warm-up strategies lasting 20 min before a 4-min maximal-performance test (PT). Strategies consisted of moderate-intensity exercise (50%iPPO) followed by 6 min of recovery (MOD6) or progressive high-intensity exercise (10–100%iPPO and 2 × 20-s sprints) followed by recovery for 6 min (HI6) or 20 min (HI20).

Results:

Before PT venous pH was lower (P < .001) in HI6 (7.27 ± 0.05) than in HI20 (7.34 ± 0.04) and MOD6 (7.35 ± 0.03). At the same time, differences (P < .001) existed for venous lactate in HI6 (8.2 ± 2.0 mmol/L), HI20 (5.1 ± 1.7 mmol/L), and MOD6 (1.4 ± 0.4 mmol/L), as well as for venous bicarbonate in HI6 (19.3 ± 2.6 mmol/L), HI20 (22.6 ± 2.3 mmol/L), and MOD6 (26.0 ± 1.4 mmol/L). Mean power in PT in HI6 (402 ± 38 W) tended to be lower (P = .11) than in HI20 (409 ± 34 W) and was lower (P = .007) than in MOD6 (416 ± 32 W). Total VO2 (15–120 s in PT) was higher in HI6 (8.18 ± 0.86 L) than in HI20 (7.85 ± 0.82 L, P = .008) and MOD6 (7.90 ± 0.74 L, P = .012).

Conclusions:

Warm-up exercise including race-pace and sprint intervals combined with short recovery can reduce subsequent performance in a 4-min maximal test in highly trained cyclists. Thus, a reduced time at high exercise intensity, a reduced intensity in the warm-up, or an extension of the recovery period after an intense warm-up is advocated.

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Michael J. Davies, Bradley Clark, Laura A. Garvican-Lewis, Marijke Welvaert, Christopher J. Gore and Kevin G. Thompson

Pacing strategies are often defined as predetermined “templates” which are built through prior experience and recalled for future performances. 1 Once exercise commences, incoming sensory information is evaluated to determine if the current work rate should be maintained or adjusted, ensuring an

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Deborah Hebling Spinoso, Nise Ribeiro Marques, Dain Patrick LaRoche, Camilla Zamfollini Hallal, Aline Harumi Karuka, Fernanda Cristina Milanezi and Mauro Gonçalves

normalized to body mass, and a spreadsheet program (Excel 2013, Office 15; Microsoft, Redmond, WA) was used to identify the peak joint torques and joint angle at which they occurred for both habitual and fast-pace walking. FD for each muscle group was calculated as the ratio of the peak joint torque and the

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Maxwell Ruby, Chris P. Repka and Paul J. Arciero

Background:

Yoga/Stretching (YS) and functional resistance (FR) training are popular exercise routines. A protein-pacing (PP) diet is a common dietary regimen. Thus, we assessed the effectiveness of a PP diet alone and in combination with either YS or FR to improve body composition and cardiometabolic health.

Methods:

Twenty-seven overweight women (age = 43.2 ± 4.6 years) were randomized into 3 groups: yoga (YS, n = 8) or resistance (FR, n = 10) training (3 days/week) in conjunction with PP diet (50% carbohydrate, 25% protein, and 25% fat) or PP diet-only (PP, n = 9) throughout 12-week study. PP maintained preexisting levels of physical activity. Body weight (BW), total (BF) and abdominal (ABF) body fat, waist circumference (WC), plasma biomarkers, and aerobic fitness (VO2) were measured at baseline and 12 weeks.

Results:

WC and total cholesterol improved in all groups, whereas glycemia tended to improve (P = .06) in S. BF, ABF, and VO2 increased significantly in YS and FR (P < .05). Feelings of vigor increased in YS and tension decreased in FR (P < .05).

Conclusions:

YS training tended to decrease blood glucose compared with FR and PP and is equally effective at enhancing body composition, and aerobic fitness in overweight women providing a strong rationale for further research on YS training.

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Hugh Trenchard, Andrew Renfree and Derek M. Peters

Purpose:

Drafting in cycling influences collective behavior of pelotons. Although evidence for collective behavior in competitive running events exists, it is not clear if this results from energetic savings conferred by drafting. This study modeled the effects of drafting on behavior in elite 10,000-m runners.

Methods:

Using performance data from a men’s elite 10,000-m track running event, computer simulations were constructed using Netlogo 5.1 to test the effects of 3 different drafting quantities on collective behavior: no drafting, drafting to 3 m behind with up to ~8% energy savings (a realistic running draft), and drafting up to 3 m behind with up to 38% energy savings (a realistic cycling draft). Three measures of collective behavior were analyzed in each condition: mean speed, mean group stretch (distance between first- and last-placed runner), and runner-convergence ratio (RCR), which represents the degree of drafting benefit obtained by the follower in a pair of coupled runners.

Results:

Mean speeds were 6.32 ± 0.28, 5.57 ± 0.18, and 5.51 ± 0.13 m/s in the cycling-draft, runner-draft, and no-draft conditions, respectively (all P < .001). RCR was lower in the cycling-draft condition but did not differ between the other 2. Mean stretch did not differ between conditions.

Conclusions:

Collective behaviors observed in running events cannot be fully explained through energetic savings conferred by realistic drafting benefits. They may therefore result from other, possibly psychological, processes. The benefits or otherwise of engaging in such behavior are as yet unclear.