. As factors external to the network itself influence the behaviors and foundations upon which someone builds and sustains social relationships, 57 , 58 important behavioral and social patterns are revealed through egocentric network analysis (ie, a young person that smokes is likely connected to
Megan S. Patterson and Patricia Goodson
Graeme L. Close, Craig Sale, Keith Baar and Stephane Bermon
. Preparticipation predictors for Championships injury and illness have been identified ( Timpka et al., 2017 ). For instance, athletes who reported an illness symptom causing anxiety before the competition were five times more likely to sustain an injury during the championships. Moreover, intensive training camps
Mark Loftin, Patricia Strikmiller, Barbara Warren, Leann Myers, Leslie Schroth, James Pittman, David Harsha and Melinda Sothern
Peak cardiorespiratory responses, physical activity patterns, and the association of VO2peak and physical activity were examined in 16 elementary (ES) and 16 high school (HS) females. Peak responses were assessed during treadmill running, and physical activity patterns were examined over two 12-hour weekdays. Results indicated similar relative VO2peak responses between groups (ES: M = 46.8 ml · kg−1 · min−1;HS:M = 46.6 ml · kg−1 · min−1). No statistical differences (p ≤ .05) were noted when moderate to vigorous physical activity (MVPA) and vigorous physical activity (VPA) were compared. Also, a three-way (Group × HR level × Sustained minutes) ANOVA revealed no statistical differences. A median correlation (r = .27) was found from 8 independent correlations of habitual physical activity and VO2peak. ES and HS appeared similar in regard to VO2peak, accumulative and sustained MVPA and VPA. Low levels of sustained MVPA and VPA (≥ 10 min) were evident in both groups.
Linda E. Kelly
Physical activity levels of 40 American children, 9–10 years old, were assessed by 12-hrs of continuous heart rate monitoring over the 7 different days of the week. Most participants (92.5%) accumulated 30 min of moderate physical activity on most days of the week. A little more than half (52.5%) reached this level for 7 days of the week. Less than one third (27.5%) accrued the greater health benefits of physical activity by being active for 30 sustained minutes 3 times per week. A slightly larger percentage (35%) obtained 30 min in 10-min or greater sustained bouts 5 or more days of the week. Boys (95.2%) were 6.4% more active in accumulating 30 min or more on most days of the week than girls (88.9%). Boys (40.8%) also obtained 30 min of physical activity in sustained bouts of 10-min or greater at a higher percentage than girls (27.7%).
composition periodization coupled with performance and health outcomes. The overriding ethos was that it is not sustainable from a health and performance perspective to be at peak body composition year-round, so body composition needs to be strategically periodized. Although correlative in nature, this case
Anna E. Chalkley, Ash C. Routen, Jo P. Harris, Lorraine A. Cale, Trish Gorely and Lauren B. Sherar
strategic approach to the growth and development of MK within the United Kingdom with specific attention being given to how schools can effectively implement the program to ensure sustained participation. Methods As part of a broader study ( Chalkley et al., 2018 ) on the implementation of MK, the data for
Sandra C. Webber, Francine Hahn, Lisa M. Lix, Brenda J. Tittlemier, Nancy M. Salbach and Ruth Barclay
). Nevertheless, few studies have attempted to identify episodes of sustained walking in free-living data collected in older adults, and there is no consensus on appropriate methods for analyzing such data. Tudor-Locke, Camhi, et al. ( 2011 ) and Tudor-Locke and Rowe ( 2012 ) suggested that cadences between 40
Rebecca Jane Willcocks, Jon Fulford, Alan Robert Barker, Neil Armstrong and Craig Anthony Williams
The phosphocreatine (PCr) recovery time constant (τ) following exercise provides a measure of mitochondrial oxidative capacity. The purpose of this investigation was to use 2 different protocols to determine τ in adolescent females. 31P-MR spectra were collected during 2 exercise tests in 6 adolescent girls (13.8 ± 0.3 y) and 7 women (23.2 ± 3.4 y). The first test consisted of 23 repeated 4 seconds maximal isometric calf contractions separated by 12-second recovery; PCr recovery between the final 18 contractions was used to calculate τ. The second test was a sustained 20-second maximal contraction; recovery was fitted with an exponential function to measure τ. PCr τ did not significantly differ between groups: (gated exercise: 4 girls: 16 ± 5 s, 7 women: 17 ± 5 s, p; sustained exercise: 6 girls: 19 ± 6 s, 7 women: 19 ± 4 s). Bland-Altman analysis demonstrated a close agreement between sustained and gated exercise. Both gated and sustained exercise appear feasible in a pediatric population, and offer a noninvasive evaluation of mitochondrial oxidative capacity.
Neil Armstrong, John Balding, Peter Gentle, Joanne Williams and Brian Kirby
The present study examined the relationship between peak V̇O2 and habitual physical activity in 11- to 16-year-old students. The peak V̇O2 of 111 girls and 85 boys was determined using treadmill or cycle ergometry. Habitual physical activity was estimated from minute-by-minute heart rate monitoring over three 12-hr periods during normal school days. Over half of the girls and one third of the boys failed to sustain a single 10-min period with their heart rate at or above 140 bpm. Only one boy sustained a daily 20-minute period with a heart rate at or above 160 bpm. During Saturday monitoring over 90% of the girls and 75% of the boys failed to sustain a single 10-min period with their heart rate at or above 140 bpm, and only one girl and four boys sustained a 20-min period with their heart rate at or above 160 bpm. No significant relationship was detected between peak V̇O2 and heart rate indicators of habitual physical activity. This study suggests that few children have periods of physical activity of sufficient intensity and duration to stress the cardiopulmonary system.
Pål Haugnes, Per-Øyvind Torvik, Gertjan Ettema, Jan Kocbach and Øyvind Sandbakk
pacing strategy, with the main factor leading to reduction of speed being reduced cycle rate. Based on these findings, we would advise sprint XC skiers to concurrently develop both these capacities, and to employ technical strategies where a high cycle rate can be sustained when fatigue occurs. However