laboratory equipment. Visits 2 to 4 consisted of three supervised exercise sessions, each consisting of three separate self-paced exercise bouts; three RPE-anchored exercise intensities (RPE = 9, 13, and 17) lasting either 1, 4, or 8 minutes completed in a randomized order during each visit (see “Exercise
Ciaran O’Grady, Louis Passfield, and James G. Hopker
David M. Williams
The article reviews research relevant to a proposed conceptual model of exercise adherence that integrates the dual mode model and hedonic theory. Exercise intensity is posited to influence affective response to exercise via interoceptive (e.g., ventila-tory drive) and cognitive (e.g., perceived autonomy) pathways; affective response to exercise is posited to influence exercise adherence via anticipated affective response to future exercise. The potential for self-paced exercise to enhance exercise adherence is examined in the context of the proposed model and suggestions are given for future research. Further evidence in support of self-paced exercise could have implications for exercise prescription, especially among overweight, sedentary adults, who are most in need of interventions that enhance adherence to exercise programs.
David M. Williams, Shira Dunsiger, Jessica A. Emerson, Chad J. Gwaltney, Peter M. Monti, and Robert Miranda Jr.
Affective response to exercise may mediate the effects of self-paced exercise on exercise adherence. Fiftynine low-active (exercise <60 min/week), overweight (body mass index: 25.0–39.9) adults (ages 18–65) were randomly assigned to self-paced (but not to exceed 76% maximum heart rate) or prescribed moderate intensity exercise (64–76% maximum heart rate) in the context of otherwise identical 6-month print-based exercise promotion programs. Frequency and duration of exercise sessions and affective responses (good/bad) to exercise were assessed via ecological momentary assessment throughout the 6-month program. A regression-based mediation model was used to estimate (a) effects of experimental condition on affective response to exercise (path a = 0.20, SE = 0.28, f 2 = 0.02); (b) effects of affective response on duration/latency of the next exercise session (path b = 0.47, SE = 0.25, f 2 = 0.04); and (c) indirect effects of experimental condition on exercise outcomes via affective response (path ab = 0.11, SE = 0.06, f 2 = 0.10). Results provide modest preliminary support for a mediational pathway linking self-paced exercise, affective response, and exercise adherence.
Louise Martin, Anneliese Lambeth-Mansell, Liane Beretta-Azevedo, Lucy A. Holmes, Rachel Wright, and Alan St Clair Gibson
Given the paucity of research on pacing strategies during competitive events, this study examined changes in dynamic high-resolution performance parameters to analyze pacing profiles during a multiple-lap mountain-bike race over variable terrain.
A global-positioning-system (GPS) unit (Garmin, Edge 305, USA) recorded velocity (m/s), distance (m), elevation (m), and heart rate at 1 Hz from 6 mountain-bike riders (mean ± SD age = 27.2 ± 5.0 y, stature = 176.8 ± 8.1 cm, mass = 76.3 ± 11.7 kg, VO2max = 55.1 ± 6.0 mL · kg−1 . min−1) competing in a multilap race. Lap-by-lap (interlap) pacing was analyzed using a 1-way ANOVA for mean time and mean velocity. Velocity data were averaged every 100 m and plotted against race distance and elevation to observe the presence of intralap variation.
There was no significant difference in lap times (P = .99) or lap velocity (P = .65) across the 5 laps. Within each lap, a high degree of oscillation in velocity was observed, which broadly reflected changes in terrain, but high-resolution data demonstrated additional nonmonotonic variation not related to terrain.
Participants adopted an even pace strategy across the 5 laps despite rapid adjustments in velocity during each lap. While topographical and technical variations of the course accounted for some of the variability in velocity, the additional rapid adjustments in velocity may be associated with dynamic regulation of self-paced exercise.
Daniel S. Rooks, Bernard J. Ransil, and Wilson C. Hayes
The aim of this study was to determine the efficacy and safety of 16 weeks of self-paced resistance training or walking protocols on neuromotor and functional parameters in active, community-dwelling older adults. Twenty-two sequentially recruited older adults were randomly assigned to one of two exercise groups: self-paced resistance training and self-paced walking. Static and dynamic balance, upper and lower extremity reaction times, muscle strength, and stairclimbing speed were measured before and immediately after 16 weeks of exercise. Preliminary data showed that 16 weeks of self-paced. progressive, lower body resistance training improved balance (one-legged stance with eyes open, 68%). reaction time (10%), muscle strength (160%), and stair climbing speed (28%), while a self-paced walking program improved balance (one-legged stance with eyes open, 51%), stair climbing speed (16%), and in certain circumstances muscle strength (25%), in active, community-dwelling older adults.
Ross Tucker, Michael I. Lambert, and Timothy D. Noakes
To analyze pacing strategies employed during men's world-record performances for 800-m, 5000-m, and 10,000-m races.
In the 800-m event, lap times were analyzed for 26 world-record performances from 1912 to 1997. In the 5000-m and 10,000-m events, times for each kilometer were analyzed for 32 (1922 to 2004) and 34 (1921 to 2004) world records.
The second lap in the 800-m event was significantly slower than the first lap (52.0 ± 1.7 vs 54.4 ± 4.9 seconds, P < .00005). In only 2 world records was the second lap faster than the first lap. In the 5000-m and 10,000-m events, the first and final kilometers were significantly faster than the middle kilometer intervals, resulting in an overall even pace with an end spurt at the end.
The optimal pacing strategy during world-record performances differs for the 800-m event compared with the 5000-m and 10,000-m events. In the 800-m event, greater running speeds are achieved in the first lap, and the ability to increase running speed on the second lap is limited. In the 5000-m and 10,000-m events, an end spurt occurs because of the maintenance of a reserve during the middle part of the race. In all events, pacing strategy is regulated in a complex system that balances the demand for optimal performance with the requirement to defend homeostasis during exercise.
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.
Ashley A. Herda, Brianna D. McKay, Trent J. Herda, Pablo B. Costa, Jeffrey R. Stout, and Joel T. Cramer
The purpose of this trial was to examine the effects of self-selected exercise intensities plus either whey protein or placebo supplementation on vital signs, body composition, bone mineral density, muscle strength, and mobility in older adults. A total of 101 participants aged 55 years and older (males [n = 34] and females [n = 67]) were evaluated before and after 12 weeks of self-selected, free-weight resistance exercise plus 30 min of self-paced walking three times per week. The participants were randomized into two groups: whey protein (n = 46) or placebo (n = 55). Three-way mixed factorial analyses of variance were used to test for mean differences for each variable. The 12 weeks of self-selected, self-paced exercise intensities improved resting heart rate, fat-free mass, percent body fat, handgrip strength, bench press strength, leg press strength, and all mobility measurements (p < .05) in males and females despite supplementation status. This suggests that additional protein in well-fed healthy older adults does not enhance the benefit of exercise.
Margina Ruiter, Charly Eielts, Sofie Loyens, and Fred Paas
Background: Although active workstations, such as desk bikes, have proven to be beneficial for health, there is limited information regarding their effects on children’s acute cognitive performance during self-paced exercise. Methods: This study used a within-subjects, fully counterbalanced design with a sample of 38 preadolescent children (mean age = 12.50 y, SD = 0.62; 43% male), who performed cognitive tests while being seated or while cycling for 45 minutes with a 7-day interval. Effects of using a desk bike were evaluated on cognitive control: verbal and visuospatial working memory capacities were tested, and inhibition was assessed using a modified flanker task. In addition, subjective task experience was explored using self-report measures. Results: Cognitive control performance was not degraded but also not improved with the short-term use of desk bikes. Because of the null effects, there is no direction and magnitude of the outcomes to discuss. Conclusions: These findings suggest that schools can successfully implement desk bikes to increase physical activity and reduce sedentary time among children without compromising cognitive control processes necessary for academic achievement.
Kleverton Krinski, Daniel G. S. Machado, Luciana S. Lirani, Sergio G. DaSilva, Eduardo C. Costa, Sarah J. Hardcastle, and Hassan M. Elsangedy
of our knowledge, our study is the first to compare the psychological and physiological responses to self-paced exercise in different environments (outdoor vs. indoor) among sedentary obese individuals and contributes to an important gap in the literature concerning the effectiveness of self-paced