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Arthur H. Bossi, Guilherme G. Matta, Guillaume Y. Millet, Pedro Lima, Leonardo C. Pertence, Jorge P. de Lima and James G. Hopker

Purpose:

To describe pacing strategy in a 24-h running race and its interaction with sex, age group, athletes’ performance group, and race edition.

Methods:

Data from 398 male and 103 female participants of 5 editions were obtained based on a minimum 19.2-h effective-running cutoff. Mean running speed from each hour was normalized to the 24-h mean speed for analyses.

Results:

Mean overall performance was 135.6 ± 33.0 km with a mean effective-running time of 22.4 ± 1.3 h. Overall data showed a reverse J-shaped pacing strategy, with a significant reduction in speed from the second-to-last to the last hour. Two-way mixed ANOVAs showed significant interactions between racing time and both athlete performance group (F = 7.01, P < .001, ηp 2 = .04) and race edition (F = 3.01, P < .001, ηp 2 = .02) but not between racing time and either sex (F = 1.57, P = .058, ηp 2 < .01) or age group (F = 1.25, P = .053, ηp 2 = .01). Pearson product–moment correlations showed an inverse moderate association between performance and normalized mean running speed in the first 2 h (r = –.58, P < .001) but not in the last 2 h (r = .03, P = .480).

Conclusions:

While the general behavior represents a rough reverse J-shaped pattern, the fastest runners start at lower relative intensities and display a more even pacing strategy than slower runners. The “herd behavior” seems to interfere with pacing strategy across editions, but not sex or age group of runners.

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Jonathan Esteve-Lanao, Eneko Larumbe-Zabala, Anouar Dabab, Alberto Alcocer-Gamboa and Facundo Ahumada

The aim of this study was to describe the pacing distribution during 6 editions of the world cross-country championships.

Methods:

Data from the 768 male runners participating from 2007 to 2013 were considered for this study. Blocks of 10 participants according to final position (eg, 1st to 10th, 11 to 20th, etc) were considered.

Results:

Taking data from all editions together, the effect of years was found to be significant (F 5,266 = 3078.69, P < .001, ω2 = 0.31), as well as the effect of blocks of runners by final position (F 4,266 = 957.62, P < .001, ω2 = 0.08). A significant general decrease in speed by lap was also found (F 5,1330 = 2344.02, P < .001, ω2 = 0.29). Post hoc analyses were conducted for every edition where several pacing patterns were found. All correlations between the lap times and the total time were significant. However, each lap might show different predicting capacity over the individual outcome.

Discussion:

Top athletes seem to display different strategies, which allow them to sustain an optimal speed and/or kick as needed during the critical moments and succeed. After the first group (block) of runners, subsequent blocks always displayed a positive pacing pattern (fast to slow speed). Consequently, a much more stable pacing pattern should be considered to maximize final position.

Conclusions:

Top-10 finishers in the world cross-country championships tend to display a more even pace than the rest of the finishers, whose general behavior shows a positive (fast-to-slow) pattern.

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Jason C. Tee, Mike I. Lambert and Yoga Coopoo

Purpose:

In team sports, fatigue is manifested by a self-regulated decrease in movement distance and intensity. There is currently limited information on the effect of fatigue on movement patterns in rugby union match play, particularly for players in different position groups (backs vs forwards). This study investigated the effect of different match periods on movement patterns of professional rugby union players.

Methods:

Global positioning system (GPS) data were collected from 46 professional match participations to determine temporal effects on movement patterns.

Results:

Total relative distance (m/min) was decreased in the 2nd half for both forwards (–13%, ±8%, ES = very likely large) and backs (–9%, ±7%, ES = very likely large). A larger reduction in high-intensity-running distance in the 2nd half was observed for forwards (–27%, ±16%, ES = very likely medium) than for backs (–10%, ±15%; ES = unclear). Similar patterns were observed for sprint (>6 m/s) frequency (forwards –29%, ±29%, ES = likely small vs backs –13% ±18%, ES = possibly small) and acceleration (>2.75 m/s2) frequency (forwards –27%, ±24%, ES = likely medium vs backs –5%, ±46%, ES = unclear). Analysis of 1st- and 2nd-half quartiles revealed differing pacing strategies for forwards and backs. Forwards display a “slow-positive” pacing strategy, while the pacing strategy of backs is “flat.”

Conclusions:

Forwards suffered progressively greater performance decrements over the course of the match, while backs were able to maintain performance intensity. These findings reflect differing physical demands, notably contact and running loads, of players in different positions.

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Jeremiah J. Peiffer and Chris R. Abbiss

The purpose of this study was to examine the effect of environmental temperature on variability in power output, self-selected pacing strategies, and performance during a prolonged cycling time trial. Nine trained male cyclists randomly completed four 40 km cycling time trials in an environmental chamber at 17°C, 22°C, 27°C, and 32°C (40% RH). During the time trials, heart rate, core body temperature, and power output were recorded. The variability in power output was assessed with the use of exposure variation analysis. Mean 40 km power output was significantly lower during 32°C (309 ± 35 W) compared with 17°C (329 ± 31 W), 22°C (324 ± 34 W), and 27°C (322 ± 32 W). In addition, greater variability in power production was observed at 32°C compared with 17°C, as evidenced by a lower (P = .03) standard deviation of the exposure variation matrix (2.9 ± 0.5 vs 3.5 ± 0.4 units, respectively). Core temperature was greater (P < .05) at 32°C compared with 17°C and 22°C from 30 to 40 km, and the rate of rise in core temperature throughout the 40 km time trial was greater (P < .05) at 32°C (0.06 ± 0.04°C·km–1) compared with 17°C (0.05 ± 0.05°C·km–1). This study showed that time-trial performance is reduced under hot environmental conditions, and is associated with a shift in the composition of power output. These finding provide insight into the control of pacing strategies during exercise in the heat.

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Angela Heidenfelder, Thomas Rosemann, Christoph A. Rüst and Beat Knechtle

Purpose:

To examine pacing strategies of ultracyclists competing in the Race Across AMerica (RAAM), the world’s longest ultracycling race, covering ~4860 km from the West to the East coast of America.

Methods:

Age, cycling speed at and across time stations, race distance, relative difference in altitude between time stations, wind velocity, wind gradient, and temperature at each time station were recorded for women and men competing from 2010 to 2014. Changes in cycling speed and power output of elite and age-group finishers were analyzed using mixed-effects regression analyses.

Results:

Cycling speed decreased across time stations for women and men where men were faster than women. Power output decreased across time stations in women and men and was lower for women for all finishers, the annual 3 fastest, and age group 60–69 y but not for age groups 18–49 and 50–59 y. The change in temperature and altitude had an influence on cycling speed and power output in all finishers, the annual top 3, nonfinishers, and in all different age groups for both women and men but in the age group 50–59 y altitude had no influence on cycling speed.

Conclusions:

Positive pacing (ie, decrease in speed throughout the race) seemed to be the adequate strategy in the RAAM. The top 3 finishers started faster and had a higher power output at the start than less successful competitors, achieved the highest peak cycling speeds and power output, and maintained peak cycling speed and power output longer before slowing down.

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David N. Ellis, Pamela J. Cress and Charles R. Spellman

This report describes an effort to train adolescents and young adults with mental retardation to modify their rates of pedaling exercycles during 10-min self-paced exercise sessions in a public school setting using commercially available heart rate (HR) monitors. A signal sounded when participants’ heart rates fell outside their predetermined cardiorespiratory conditioning ranges. During Study 1 most participants consistently avoided the alarm by pedaling at rates that maintained their HRs above their criterion levels. Study 2 included a more intensive warm-up period on the treadmill. All subjects but one consistently responded to the signal, maintaining HRs within the criterion range. Two of the participants in Study 2 were exposed to a positive reinforcement condition, with music contingent on maintaining HRs above a preset lower limit. Two subjects participated in maintenance phases and continued to exhibit relatively high HRs during exercise in the absence of signals from the HR monitor.

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Martin D. Hoffman

Purpose:

To examine pacing among the most successful runners in the 161-km Western States Endurance Run (WSER) to determine if variations in segmental speed relate to performance, ambient temperature, and calendar year.

Methods:

Segmental speed and coefficient of variation (CV) in speed were analyzed for 10 race segments of 24 races from 1985 through 2013.

Results:

Segmental speeds did not differ between the eventual winners and lead runners and only differed between the 1st and 2nd finishers in the 2nd half of the race. Mean CV in speed was lower (P < .01) for the winners (12%) than for the other top-5 finishers (14–15%). CV in speed was related (r = .80, P = .006) to finish time for the fastest 10 finish times at the WSER. Multiple linearregression analysis revealed mean CV in speed for the top-5 runners to be related to maximum ambient temperature (coefficient =.14, P < .05) and calendar year (coefficient = –.086, P = .034).

Conclusions:

Mountain trail running is characterized by wide variations in speed, but the fastest times are achieved when speed fluctuations are limited. This is generally accomplished by the winners remaining relatively close behind the lead runners before taking the lead in the middle half of the race, and then avoiding slowing as much as the other top runners in the latter race stages. Variations in speed increase with high ambient temperatures, and the small decrease in segmental speed variability among top runners across the nearly 30 y of this study suggests that the best runners have improved at pacing this race.

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Robert J. Aughey

Previous research has suggested elite Australian footballers undertake pacing strategies to preserve high intensity activity later in matches. However, this research used GPS with slow sample rates, did not express performance relative to minutes played during games and used lowly ranked players.

Methods:

Therefore in this study movement was recorded by GPS at 5 Hz. Running performance was expressed per period of the match (rotation) divided into low-intensity activity (LIA, 0.10 to 4.17 m⋅s–1); high-intensity running (HIR, 4.17 to 10.00 m⋅s–1) and maximal accelerations (2.78 to 10.00 m⋅s–2). All data were expressed relative to the first period of play in the match and the magnitude of effects was analyzed with the effect size (ES) statistic and expressed with confidence intervals.

Results:

The total and LIA distance covered by players did not change by a practically important magnitude during games (ES< 0.20). High intensity running was reduced in both rotations of the second quarter, Q3R2 and both rotations of the fourth quarter (ES -0.30 ± 0.14; -0.42 ± 0.14; -0.30 ± 0.14; -0.42 ± 0.14; and -0.48 ± 0.15 respectively). Maximal acceleration performance was reduced in Q1R2, and each rotation of the second half of matches.

Conclusion:

When expressed per minute of game time played, total distance and low intensity activity distance are not reduced by a practically important magnitude in AF players during a match. These data are therefore inconsistent with the concept of team sport players pacing their effort during matches. However, both high intensity running and maximal accelerations are reduced later in games, indicative of significant fatigue in players.

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Sarah E. Scott, Jeff D. Breckon, Robert J. Copeland and Andrew Hutchison

Background:

Physical activity is promoted to help adults manage chronic health conditions, but evidence suggests that individuals relapse after intervention cessation. The objective of this study was to explore the determinants and strategies for successful and unsuccessful physical activity maintenance.

Methods:

A qualitative study using semistructured interviews was conducted with 32 participants. Purposive sampling was used to recruit 20 successful and 12 unsuccessful maintainers. Adults with chronic health conditions were recruited having completed a physical activity referral scheme 6 months before study commencement. The IPAQ and SPAQ were used to categorize participants according to physical activity status. Data were analyzed using framework analysis.

Results:

Eleven main themes emerged: 1) outcome expectations, 2) experiences, 3) core values, 4) trial and error, 5) social and practical support, 6) attitudes toward physical activity, 7) environmental barriers, 8) psychological barriers, 9) physical barriers, 10) cognitive-behavioral strategies for physical activity self-management (eg, self-monitoring), and 11) condition management (eg, pacing).

Conclusions:

The findings identified determinants and strategies for successful maintenance and highlighted the processes involved in physical activity disengagement. Such findings can guide the development of physical activity maintenance interventions and increase activity engagement over the long-term in adults with chronic health conditions.

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Katherine T. Oberlin-Brown, Rodney Siegel, Andrew E. Kilding and Paul B. Laursen

The oral presence of carbohydrate (CHO) and caffeine (CAF) may independently enhance exercise performance, but their influence on performance during prolonged exercise is less known.

Aim:

To determine the independent and combined effects of CHO and CAF administered in chewing gum during a cycling time trial (TT) after prolonged exercise.

Method:

Eleven male cyclists (32.2 ± 7.5 y, 74.3 ± 6.8 kg, 60.2 ± 4.0 mL · kg–1 · min1 V˙O2peak) performed 4 experimental trials consisting of 90-min constant-load cycling at 80% of their second ventilatory threshold (207 ± 30 W), followed immediately by a 20-km TT. Under double-blinded conditions, cyclists received placebo (PLA), CHO, CAF, or a combined CHO+CAF chewing gum at 0-, 5-, 10-, and 15-km points of the TT.

Results:

Overall TT performance was similar across experimental and PLA trials (%mean difference ± 90%CL 0.2% ± 2.0%, 0.4% ± 2.2%, 0.1% ± 1.8% for CHO, CAF, and CHO+CAF). Compared with PLA, mean power output tended to be higher in the first 2 quarters of the TT with CHO (1.6% ± 3.1% and 0.8% ± 2.0%) and was substantially improved in the last 2 quarters during CAF and CHO+CAF trials (4.2% ± 3.0% and 2.0% ± 1.8%). There were no differences in average heart rate (ES <0.2) and only small changes in blood glucose (ES 0.2), which were unrelated to performance. Blood lactate was substantially higher post-TT for CAF and CHO+CAF (ES >0.6).

Conclusion:

After prolonged constant-load cycling, the oral presence of CHO and CAF in chewing gum, independently or in combination, did not improve overall performance but did influence pacing.