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Seihati A. Shiroma, Ursula F. Julio and Emerson Franchini

Purpose: To evaluate criterion validity, reliability, and usefulness of a test to measure maximal aerobic power using judo-specific movements (uchi-komi test [UKtest]). Methods: A total of 12 judokas performed 5 graded exercise tests (GETs) in 4 sessions. In sessions 1 and 2, upper-body (UBtest), lower-body (LBtest), and familiarization UKtest were performed. GETs were randomly performed and separated by at least 48 h. In sessions 3 and 4, test and retest UKtest were performed (7 d apart). For all GETs, peak oxygen consumption (V˙O2peak), maximal heart rate (HRmax), peak blood lactate concentration [Lapeak], maximal aerobic intensity, and rating of perceived exertion (RPE) were determined. Another group of 12 judokas performed the UKtest and 1 confirmation test (20 min after the UKtest) at 105% of maximal aerobic speed until exhaustion to confirm whether maximal responses were achieved. Results: V˙O2peak did not differ (P > .05) between UKtest (46.04 [5.34] mL·kg−1·min−1) and LBtest (44.78 [5.98] mL·kg−1·min−1), but it was higher (P < .05) than UBtest (37.03 [7.16] mL·kg−1·min−1). Total duration (551 [60] s) and [Lapeak] (7.10 [1.76] mmol·L−1) in the UKtest were different (P < .05) from UBtest (416 [47] s, 9.93 [2.15] mmol·L−1, respectively) and LBtest (433 [54] s, 10.29 [2.23] mmol·L−1, respectively). Very large relationships between V˙O2peak in UKtest with UBtest (r = .78; P = .003) and LBtest (r = .87; P < .001) were found. Maximal values were achieved for the UKtest V˙O2peak, HRmax, [Lapeak], RPE, and maximal aerobic speed, with no difference between test and retest (P > .05). In addition, very large intraclass correlation coefficients (ICC) for V˙O2peak (ICC = .86), HRmax (ICC = .90), and maximal aerobic speed (ICC = .81) were found. Conclusion: The UKtest can be considered a valid, reliable, and useful test to measure maximal aerobic power using judo-specific movements.

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David Giles, Joel B. Chidley, Nicola Taylor, Ollie Torr, Josh Hadley, Tom Randall and Simon Fryer

Purpose: To determine if the mathematical model used for the estimation of critical force (CF) and the energy store component W′ are applicable to intermittent isometric muscle actions of the finger flexors of rock climbers, using a multisession test. As a secondary aim, the agreement of estimates of CF and W′ from a single-session test was also determined. The CF was defined as the slope coefficient, and W′ was the intercept of the linear relationship between total “isometric work” (W lim) and time to exhaustion (T lim). Methods: Subjects performed 3 (separated by either 20 min or >24 h) tests to failure using intermittent isometric finger-flexor contractions at 45%, 60%, and 80% of their maximum voluntary contraction. Results: Force plotted against T lim displayed a hyperbolic relationship; correlation coefficients of the parameter estimates from the work–time CF model were consistently very high (R 2 > .94). Climbers’ mean CF was 425.7 (82.8) N (41.0% [6.2%] maximum voluntary contraction) and W′ was 30,882 (11,820) N·s. Good agreement was found between the single-session and multisession protocol for CF (intraclass correlation coefficient [ICC3,1] = .900; 95% confidence interval, .616–.979), but not for W′ (ICC3,1 = .768; 95% confidence interval, .190–.949). Conclusions: The results demonstrated the sensitivity of a simple test for the determination of CF and W′, using equipment readily available in most climbing gyms. Although further work is still necessary, the test of CF described is of value for understanding exercise tolerance and to determine optimal training prescription to monitor improvements in the performance of the finger flexors.

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Kasper Salin, Mikko Huhtiniemi, Anthony Watt, Harto Hakonen and Timo Jaakkola

Background: This study examined the distribution of objectively measured physical activity (PA) and sedentary time of fifth-grade students during school, leisure time, and physical education (PE) classes. Demographic, anthropometric, and PA data were collected from 17 representative Finnish schools. Methods: To estimate the PA and sedentary time, participants (N = 592) wore wGT3X-BT ActiGraphs for 7 consecutive days. Comparisons were made between genders and different BMI groups. Results: From the study sample, 43.7% met the moderate to vigorous PA (MVPA) guidelines. Participants spent 62.2% of the day sedentary and 8.2% in moderate and vigorous activities. Boys performed more MVPA than girls, and girls were more sedentary during school days. Boys had more MVPA than girls in leisure time, but there were no differences in sedentary time. However, an examination of PA assessed during PE classes revealed no differences between boys and girls. Normal-weight boys engaged in more MVPA than overweight and obese boys. No differences were found for girls. Conclusions: The PA levels differ between different BMI groups in leisure time and during school but not during PE lessons. PA for overweight children should be targeted and compulsory PE time should be increased to achieve the PA guidelines.

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Peter Ibbott, Nick Ball, Marijke Welvaert and Kevin G. Thompson

Purpose: To assess pacing strategies using prescribed and self-selected interset rest periods and their influence on performance in strength-trained athletes. Methods: A total of 16 strength-trained male athletes completed 3 randomized heavy strength-training sessions (5 sets and 5 repetitions) with different interset rest periods. The interset rest periods were 3 min (3MIN), 5 min (5MIN), and self-selected (SS). Mechanical (power, velocity, work, and displacement), surface electromyography (sEMG), and subjective (rating of perceived exertion) and readiness-to-lift data were recorded for each set. Results: SS-condition interset rest periods increased from sets 1 to 4 (from 207.52 to 277.71 s; P = .01). No differences in mechanical performance were shown between the different interset rest-period conditions. Power output (210 W; 8.03%) and velocity (0.03 m·s−1; 6.73%) decreased as sets progressed for all conditions (P  < .001) from set 1 to set 5. No differences in sEMG activity between conditions were shown; however, vastus medialis sEMG decreased as the sets progressed for each condition (1.75%; P = .005). All conditions showed increases in rating of perceived exertion as sets progressed (set 1 = 6.1, set 5 = 7.9; P < .001). Participants reported greater readiness to lift in the 5MIN condition (7.81) than in the 3MIN (7.09) and SS (7.20) conditions (P < .001). Conclusions: Self-selecting interset rest periods does not significantly change performance compared with 3MIN and 5MIN conditions. Given the opportunity, athletes will vary their interset rest periods to complete multiple sets of heavy strength training. Self-selection of interset rest periods may be a feasible alternative to prescribed interset rest periods.

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Maria K. Talarico, Robert C. Lynall, Timothy C. Mauntel, Erin B. Wasserman, Darin A. Padua and Jason P. Mihalik

Although single-leg squats are a common dynamic balance clinical assessment, little is known about the relationship between parameters that influence squat movement and postural control performance. The objective of this study was to determine the relationships between squat parameters (speed and depth) and postural control under single task and dual task. A total of 30 healthy college students performed single-leg squats under single task and dual task with Stroop. Random-intercepts generalized linear mixed models determined the effect of squat parameters on center of pressure (CoP) parameters. For each 1-cm·s−1 increase in squat speed, sway range (mediolateral: β = −0.03; anteroposterior: β = −0.05) and area (β = −0.25) decreased, whereas sway speed (mediolateral: β = 0.05; anteroposterior: β = 0.29; total: β = 0.29) increased. For each 1-cm increase in squat depth, sway range (mediolateral: β = 0.05; anteroposterior: β = 0.20) and area (β = 0.72) increased, whereas sway speed (anteroposterior: β = −0.14; total: β = −0.14) decreased. Compared with single task, the association between total and anteroposterior sway speed and squat speed was stronger under dual task. Clinicians and researchers should consider monitoring squat speed and depth when assessing dynamic balance during single-leg squats, as these parameters influence postural control, especially under dual task.

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Jason C. Laffer, Aaron J. Coutts and Job Fransen

Dynamic motor skills such as volleyball blocking rely on efficient perception–action coupling and are influenced by individual, environmental, and task constraints. However, limited research studies have assessed the effect of an individual constraint such as blocking skill on visual attention during an in-situ volleyball blocking task. Therefore, this study used a cross-sectional, observational design to investigate the gaze behavior of 18 male volleyball players (25.6 ± 4.9 years), of two different levels of blocking skill determined a priori according to success during an on-court blocking task. When compared to relatively unsuccessful players (RUS), the gaze of relatively successful players (RS) was observed to fixate more often (RUS: 0.7 ± 0.7 n, RS: 1.3 ± 0.3 n) and dwell for longer (Total; RUS: 12.2 ± 18.4%, RS: 48.0 ± 37.2%, Phase 4; RUS: 6.6 ± 8.8%, RS: 16.9 ± 12.4%) on the opposition spiker, demonstrating that important perceptual information about an opposing team’s attack lies within the behavior of the opposition spiker. More successful blockers were also observed to be taller (RUS: 181.8 ± 6.6 cm, RS: 192.6 ± 3.9 cm), longer in arm-span (RUS: 185.7 ± 5.6 cm, RS: 195.2 ± 5.6 cm), and heavier (RUS: 78.6 ± 11.4 kg, RS: 90.5 ± 8.5 kg). These results can consequently be used to develop a profile of the visual attention and physical attributes of successful blockers for use in developing talented players.

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Charity B. Breneman, Christopher E. Kline, Delia West, Xuemei Sui and Xuewen Wang

This study investigated the acute effect of exercise on sleep outcomes among healthy older women by comparing days with structured exercise versus days without structured exercise during 4 months of exercise training. Participants (n = 51) in this study had wrist-worn actigraphic sleep data available following at least 3 days with structured exercise and 3 days without structured exercise at mid-intervention and at the end of intervention. The exercise intervention was treadmill walking. Multilevel models were used to examine whether structured exercise impacted sleep outcomes during the corresponding night. Overall, 1,362 nights of data were included in the analyses. In unadjusted and adjusted models, bedtimes were significantly earlier on evenings following an acute bout of structured exercise than on evenings without structured exercise. No other sleep parameters differed between exercise and nonexercise days. Understanding the effects of exercise on sleep in this understudied population may help to improve their overall sleep quality.

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Lisa E. Bolger, Linda A. Bolger, Cian O’Neill, Edward Coughlan, Wesley O’Brien, Seán Lacey and Con Burns

This study examined the effectiveness of a physical activity (Year 1) and a multicomponent fundamental movement skill (FMS) (Year 2) intervention on primary school children’s FMS proficiency. Data were collected from 6- and 10-year-old cohorts from two intervention schools and age-matched groups from one control school, in south Ireland. In Year 1 (N = 187), intervention (n = 96) and control (n = 91) groups were children from senior infant (6-year-old cohort) and 4th class (10-year-old cohort). In Year 2 (N = 357), intervention (n = 195) and control (n = 162) groups were children from senior infant and 1st class (6-year-old cohort) and 4th and 5th classes (10-year-old cohort). FMS assessment was conducted across both academic years, using the Test of Gross Motor Development-2. Linear mixed models were used to investigate the effectiveness of each intervention, adjusting for age group. Following Year 1, the intervention group significantly improved locomotor proficiency (p < .05), with no changes in object-control or overall proficiency. No group-time interactions were found. Following Year 2, the intervention group significantly improved locomotor, object-control, and overall proficiency (p < .001). Group-time interaction effects were found for both subsets and overall FMS in favor of the intervention group (p < .001). FMS proficiency among primary school children was significantly greater following the multicomponent FMS intervention.

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Sarah E. Roth, Monique Gill, Alec M. Chan-Golston, Lindsay N. Rice, Catherine M. Crespi, Deborah Koniak-Griffin and Michael L. Prelip

Purpose: This study examines the effects of the middle school SPARK physical education (PE) curriculum on predisposing, enabling, and reinforcing factors for physical activity (PA) as well as self-reported PA in a predominantly low-income, Latinx student population in Los Angeles, CA. Methods: Data were collected from 3763 students of seventh and eighth grades at 2 time points at the 16 middle schools enrolled in the study. Hierarchical logistic regression models were used to assess intervention effects on PA attitudes, PE enjoyment, FitnessGram passing, daily PA, and muscle-strengthening PA, controlling for demographic variables. Results: Although there was no detectable intervention effect on increasing the number of students exercising 60 minutes per day, there was a negative intervention effect detected for muscle-strengthening exercises. A significant positive intervention effect was detected for both PE enjoyment and FitnessGram passing. Deeper analysis of these findings revealed that the positive effect on PE enjoyment occurred only among male students. Conclusion: The SPARK curriculum had mixed effects on students’ PA behavior as well as predisposing, enabling, and reinforcing factors for PA. Incorporating student perspectives into the evaluation of intervention efforts to promote PA can facilitate a better understanding of the ways in which these efforts influence PA behaviors and its determinants.

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Susan J. Leach, Joyce R. Maring and Ellen Costello

The aim of this study was to investigate whether a 6-week Divided-Attention Stepping Accuracy Task (DATSAT) intervention improved the primary outcome measure, maximal step length; other balance measures (Berg Balance scale and Timed Up and Go test); leg strength; endurance (6-min walk test); and functional tasks in 15 community-dwelling healthy older adults (x¯ age: 71.5 years, female: 46.7%) compared with 15 community-dwelling healthy older adults in a Bike and Strength (B&S) program (x¯ age: 73.8 years, female: 33.3%). Participants trained 3× per week, 30–60 min per session. Stepping-group differences were significant for all measures. B&S group improved in maximal step length (anterior and lateral), strength, and one functional task. Stepping group outperformed B&S group in Timed Up and Go and maximal step length posterior. B&S group outperformed stepping group in two strength measures. Exertion scores were lower for the stepping group. Overall, Divided-Attention Timed Stepping Accuracy Task training resulted in more within-group improvements and two between-group measures with less perceived effort and shorter intervention times.