Table of Contents
Physical Activity, Health-Related Fitness, and Classroom Behavior in Children: A Discriminant Function Analysis
– Timothy A. Brusseau and Ryan D. Burns
The purpose of this study was to examine the predictive relationship among physical activity, health-related fitness, and on-task classroom behavior in children using a discriminant function analysis.
Participants were a convenience sample of children (N = 533; Mage = 8.8 ± 1.9 years) recruited from 77 1st- through 5th-grade classrooms at 3 low-income schools in a capital city in the Southwest United States. Percent of the school day spent in sedentary behavior (%SED), moderate-to-vigorous physical activity (%MVPA), and health-related fitness scores (body mass index (BMI) and Progressive Aerobic Cardiovascular Endurance Run (PACER) laps) were assessed during school hours. Classrooms were observed for on-task behavior during the academic year with the use of 5-s momentary time sampling methodology. A discriminant function analysis was performed using a binary on-task behavior outcome, stratified by an 80% on-task behavior cut point.
The results yielded 1 function (r2 = .26, F = 13.1) explaining approximately one quarter of the total variance. The standardized function coefficients were −.29, .29, −.48, and .48 for %SED, %MVPA, BMI, and PACER laps, respectively. The sensitivity and specificity of the derived function for classifying a child into an on-task or off-task classroom were .79 and .73, respectively. Children who belonged to classrooms that achieved 80% on-task behavior displayed shorter times in sedentary behaviors (d = 1.01), lower BMI (d = 0.13), and higher PACER scores (d = 0.22) compared with children who belonged to off-task classrooms.
School-day physical activity behaviors and health-related fitness scores can moderately discriminate children who belong to classrooms from low-income schools that are categorized as being sufficiently on task.
Secular Changes in Physical Education Attendance Among U.S. High School Students, 1991–2015
– Morgan N. Clennin, Zewditu Demissie, Shannon L. Michael, Carly Wright, Stephen Silverman, Jamie Chriqui, and Russell R. Pate
The purpose of this study was to examine changes in school-based physical education (PE) attendance over time among nationally representative samples of U.S. high school students and how changes in PE attendance have varied across demographic subgroups.
Student demographic information and PE attendance data were obtained from 13 biennial cycles (1991–2015) of the national Youth Risk Behavior Survey (YRBS). Physical education variables derived from YRBS data included PE attendance, daily PE, average PE days/week, and PE frequency. Logistic regression models examined trends in PE attendance, daily PE, and PE frequency for the overall sample and demographic subgroups. Linear regression models examined trends in average PE days/week in the overall sample only.
Overall, there was no significant change in the percentage of students reporting PE attendance during 1991 to 2015. However, daily PE and average PE days/week declined significantly from 1991 to 1995 (41.6% to 25.4% and 4.64 days to 3.64 days, respectively) and then remained stable through 2015 (29.8% and 4.11 days, respectively). The percentage of students reporting a PE frequency of 3 days per week increased significantly from 1991 to 1995 (1.5% to 19.0%) before stabilizing through 2015 (9.1%). Trends across demographic subgroups revealed notable differences in PE attendance.
Study findings showed that U.S. schools have not substantially reduced PE amounts in recent years. Still, the prevalence of PE attendance among U.S. high school students is well below recommendations. For PE to contribute to increased adolescent compliance with national physical activity guidelines, significant policy actions are needed to improve PE access for all students.
The Influence of External Focus Instruction Characteristics on Children’s Motor Performance
– David C. Marchant, Gillian Griffiths, Julie A. Partridge, Leah Belsley, and Jared M. Porter
Research has demonstrated that verbal instructions directing attention externally (i.e., toward the effect of the movement) significantly enhance motor skill performance, and this effect is enhanced when the distance of the external focus relative to the body is increased. However, few studies have investigated this distance-of-focus effect in children. The present study aimed to examine the effect of increasing the distance of an external focus on children’s motor performance in 2 experiments.
In Experiment 1, children performed standing long jumps under 3 instructional conditions (control, internal attentional focus, and external attentional focus). In Experiment 2, children performed standing long jumps under 4 instructional conditions (control, internal, proximal external attentional focus, and distal external attentional focus).
In Experiment 1, results revealed a statistically significant jump distance advantage for the external focus condition. In Experiment 2, a statistically significant jump distance advantage for the distal external focus condition was found. However, instructional and task characteristics beyond distance of focus may have been influential.
External focus instructions benefit children’s jump performance, but specifically when they are supported by a concrete movement goal reflecting relevant performance criteria. These findings highlight the importance of examining the content of instructions and relevant task characteristics provided to children beyond attentional focus to consider their motivational characteristics.
Effects of Generalization of Engagement in Parkour from Physical Education to Recess on Physical Activity
– Rosalie Coolkens, Phillip Ward, Jan Seghers, and Peter Iserbyt
Purpose: To investigate the effect of generalization of engagement in parkour from physical education (PE) to organized and supervised recess on voluntary participation and moderate-to-vigorous physical activity (MVPA).
Method: Children received a 6-day parkour unit in PE and every two lessons they could voluntarily participate in 20-min parkour recess. Fourteen elementary school classes constituting 281 children (8–10 years old) and 16 PE teachers were randomized to either three supervised or three organized parkour recess sessions. During supervised recess, PE teachers supervised to ensure safety, and children could play freely on the parkour landscape. During organized recess, PE teachers provided instructional tasks as well as supervision for safety on the parkour landscape. The parkour landscape in the gymnasium was identical in both recess conditions and similar to previous parkour landscape in PE. Participation and MVPA were measured using systematic observation.
Results: Significantly more children from organized compared to supervised recess participated in all three sessions (60% vs. 43%, p = .008, V = .16). Children showed significantly less sedentary behavior (24% vs. 30%, p = .013, η2 = .063) and more MVPA (76% vs. 70%, p = .012, η2 = .066) during organized compared to supervised recess. The proportion of total MVPA spent doing parkour was significantly higher in organized compared to supervised recess for low- (36% vs. 24%, p = .005, η2 = .082) and high-skilled children (33% vs. 26%, p = .034, η2 = .048).
Conclusion: Generalization of engagement in parkour was higher in organized compared to supervised recess.
Spousal Concordance for Objectively Measured Sedentary Behavior and Physical Activity Among Middle-Aged and Older Couples
– JulKazuhiro Harada, Kouhei Masumoto, and Narihiko Kondo
Purpose: Although it has been proposed that 1 spouse’s health behaviors might correlate with the other spouse’s health behavior among married couples, few studies have focused on sedentary behavior. This study examined whether objectively measured sedentary behavior and physical activity are correlated with each other and whether attachment to one’s spouse moderates such correlations among middle-aged and older married couples.
Excess Postexercise Oxygen Consumption and Fat Utilization Following Submaximal Continuous and Supramaximal Interval Running
Method: Seventy-two couples participated in the survey. This study measured time engaged in sedentary behavior and moderate-to-vigorous physical activity (MVPA), step counts by an accelerometer for 7 days, and attachment to one’s spouse, age, education, and frailty by questionnaires.
Results: Multiple regression analyses showed that the sedentary behaviors of 1 spouse statistically significantly regressed on those of the other spouse (β = .30–.47). The regressions of husbands’ MVPA and step counts on those of their wives were statistically marginally significant (β = .22–.25), while the regressions of wives’ MVPA and step counts on those of their husbands were not statistically significant (β = .15–.18). The interaction terms of the attachment with one’s spousal accelerometer variables on those of the other spouse were not statistically significant (β = –.02 to .16).
Conclusion: This study revealed that sedentary behaviors were correlated with each other among couples and attachment to one’s spouse did not moderate these correlations. Sedentary behaviors of 1 spouse might influence the other, regardless of attachment to one’s spouse. The concordance for physical activity was weaker than that for sedentary behavior.
– ClHashim Islam, Logan K. Townsend, and Tom J. Hazell
Purpose: Few studies have directly compared excess postexercise oxygen consumption (EPOC) and fat utilization following different exercise intensities, and the effect of continuous exercise exceeding 75% of maximal oxygen uptake (VO2max) on these parameters remains unexplored. The current study examined EPOC and fat utilization following acute moderate- and vigorous-intensity continuous training (MICT and VICT) and sprint interval training (SIT).
Effects of Resistance Training on Vascular and Hemodynamic Responses in Patients With Coronary Artery Disease
Method: Eight active young men performed 4 experimental sessions: (a) MICT (30 min of running at 65% VO2max); (b) VICT (30 min of running at 85% VO2max); (c) SIT (4 30-s “all-out” sprints with 4 min of rest); and (d) no exercise (REST). Excess postexercise oxygen consumption and fat oxidation were estimated from gas measurements (VO2 and carbon dioxide production (VCO2)) obtained during a 2-hr postexercise period.
Results: Total EPOC was similar (p = .097; effect size (ES) = 0.3) after VICT (8.6 ± 4.7 L) and SIT (10.0 ± 4.2 L) and greater after both (VICT, p = .025, ES = 0.3, and SIT, p < .001, ES = 0.6) versus MICT (6.0 ± 4.3 L). Fat utilization increased after MICT (0.047 ± 0.018 g· min−1, p = .018, ES = 1.3), VICT (0.066 ± 0.020 g•min−1, p = .034, ES = 2.2), and SIT (0.115 ± 0.026 g•min−1, p < .001, ES = 4.0) versus REST (0.025 ± 0.018 g•min−1) and was greatest after SIT (p < .001, ES = 3.0 vs. MICT; p = .031, ES = 2.1 vs. VICT).
Conclusion: Acute exercise increases EPOC and fat utilization in an intensity-dependent manner.
– Kerstin Grafe, Phillip Bendick, Margaret Burr, Judy Boura, and Barry A. Franklin
The purpose of this study was to determine the impact of adjunctive resistance training (RT) in aerobically trained patients with coronary artery disease on systolic blood pressure (SBP), heart rate (HR), rating of perceived exertion (RPE; using the traditional 6-to-20 scale), and rate-pressure product (RPP) responses to lifting fixed submaximal workloads. Additionally, pretest and posttest RT measures of brachial artery reactivity were obtained.
Fifteen patients with coronary artery disease (Mage = 66.1 ± 5.1 years) who were already performing regular aerobic exercise completed an adjunctive 12-week progressive RT program. Prior to and immediately after the training period, hemodynamic responses and RPE were obtained while participants performed one set of exercises including the bicep curl (BC), shoulder press (SP), and leg press (LP) at individually determined fixed submaximal loads, using ~ 60% to 80% of estimated maximal voluntary contraction. Vascular function was assessed by flow-mediated vasodilation (FMD) testing before and after training.
Attenuated hemodynamic and RPE responses for all variables were observed. Meaningful changes were attained for RPP ((HR × SBP) / 100) during BC (106 ± 27 mmHg × beats/min × 10−2 to 91 ± 22 mmHg × beats/min × 10−2, d = 0.6, p < .05) and SP (102 ± 24 mmHg × beats/min × 10−2 to 86 ± 17 mmHg × beats/min × 10−2, d = 0.8, p < .05). Rating of perceived exertion decreased significantly during all exercises (d ranging from 1.8 to 3.1, p < .05): BC (14.3 ± 2.6 to 9.7 ± 1.6), SP (13.9 ± 1.6 to 9.2 ± 1.5), and LP (14.3 ± 1.4 to 10.3 ± 1.6). Peak group FMD responses were 12.8% and 10.3% dilation at pretraining and posttraining, respectively (p > .05). Five of the 15 participants showed modest improvements in their posttraining time to achieve maximum dilation from a mean of 117 s to 81 s, although this change was not statistically significant (p > .05).
Among aerobically trained cardiac patients, a supplemental RT program resulted in decreased hemodynamic and RPE responses to lifting fixed submaximal workloads.
Does Aerobic Exercise Impair Neuromuscular Function During Water-Based Resistance Exercises?
– Stephanie Santana Pinto, Cristine Lima Alberton, Eduardo Lusa Cadore, Ana Carolina Kanitz, Rodrigo Sudatti Delevatti, Patrícia Dias Pantoja, Leonardo Alexandre Peyré-Tartaruga, Thaís Reichert, Luciana Peruchena Bregagnol, Salime Donida Chedid Lisboa, and Luiz Fernando Martins Kruel
The purpose of this study was to investigate the acute effects of water-based aerobic exercises on the performance of water-based resistance exercises by assessing kinematic parameters during protocols and neuromuscular responses after them.
Ten women performed 2 water-based protocols (i.e., resistance and concurrent water-based exercises) on separate days. We evaluated isometric force and electromyographic signal (sEMG) before and after protocols and analyzed kinematic parameters during a water-based resistance exercise.
There was no significant difference between knee extension force production and sEMG from the vastus lateralis during the maximal voluntary contraction performed before and after the protocols. However, sEMG from the rectus femoris presented a significant difference between pretest and posttest measurements in both water-based protocols with greater values in the measurement after the end of the protocol (p = .046). The peak angular velocity of knee extension and mean angular velocity of knee extension and flexion showed similar values among the sets, with no difference between protocols. The peak angular velocity of knee flexion presented greater values in the water-based resistance exercises compared with the water-based concurrent protocol in the last set (p < .001).
The main impairment induced by the water-based concurrent exercises was the lower peak angular velocity in the knee flexors compared with water-based resistance exercises alone.
Differences in Physiological Responses During Wheelchair Basketball Matches According to Playing Time and Competition
– Aitor Iturricastillo, Cristina Granados, Jesús Cámara, Raúl Reina, Daniel Castillo, Itziar Barrenetxea, Lander Lozano, and Javier Yanci
The main purpose of the present study was to determine physiological responses in wheelchair basketball (WB) matches in relation to heart rate (HR), match load (ML), differentiated perceived exertion (dRPE), lactate concentrations (LA), and tympanic temperature (TEMP), while specifying the individual player’s playing time during different types of matches.
Nine Spanish First Division WB players participated in the study. Three groups were determined for each observation (i.e., HR, ML, dRPE, LA, and TEMP) according to the minutes played by the WB players: players who had played 30 min to 40 min (WB30–40), those who played 20 min to 30 min, and those who played 0 min to 20 min.
The WB30–40 group attained statistically significantly higher results in mean HR than the other groups in league and playoff matches (p < .05; Δ% > –25.73%; ES > –1.31, large). With regard to the difference in each variable between league and playoff matches, the differences were highlighted in the WB30–40 group according to ML (Edwards, p < .05, Δ% = –11.14%, ES = –0.87, large; Stagno’s modified TRIMP, p < .05, Δ% = –16.95%, ES = –0.77, large). Tympanic temperature also reached higher values in playoff matches compared with league matches in WB30–40 (p < .05; Δ% = 1.1%; ES = 0.67, moderate) but not in LA values.
Coaches should take into account that playoff matches were more demanding than league matches, thus forcing coaches to try to peak WB players’ physical performance for the former.
Impact of a Simulated Stress Training Program on the Tactical Shooting Performance of SWAT Trainees
– Yuxin Liu, Lida Mao, Yunan Zhao, and Yufang Huang
To create a high-stress shooting among the crowd (SAC) program and to examine its effectiveness in reducing SWAT trainees’ stress level and their shooting performance in a simulated hostage-rescue situation.
After the SAC program was created, it was evaluated using a pretest and posttest experimental design: 98 young male SWAT trainees were randomly divided into experiment and control groups, with the former group trained in hostage rescue, shooting with real persons (high stress), and the latter group trained with “dummy” men (low stress); training for both lasted three days. Their shooting performance was assessed by a tactical shooting test in both high- and low-stress tests in a counterbalanced order, before and after the training, and monitored during the training, as were their stress levels by a set of physical (heart rate (HR) and heart rate recovery time (HRRt)), psychological (salivary cortisol and α-amylase), and self-reported anxiety measures.
The SAC program created needed high-stress for hostage rescue situations as reflected in increased physical, psychological, and anxiety scores and reduced shooting performance. Even with short SAC training, SWAT trainees’ capacity in handling high stress and tactical shooting performance were significantly improved. HR, HRRt, and anxiety tests have been found to be effective in monitoring stress and should be a part of future SWAT training.
A SAC program involving real people was created, and its effectiveness was confirmed using a pretest and posttest experimental design.
Predicting Physical Activity Among Children: Investigating Interaction Effects in the Theory of Planned Behavior
– Mathieu Gourlan, Julie Boiché, Monica Takito, Bruno Fregeac, and Florence Cousson-Gélie
Purpose: The theory of planned behavior (TPB) has been criticized for not including interactions between the variables assumed to predict behavior. This study sought to test how TPB variables interact to predict physical activity (PA) in children.
Swimmers’ Compliance to Training as a Function of Observation: A Pilot Study
Method: Four hundred thirty-eight children (Mage = 8.6 years, SD = 1.6 years) completed a TPB questionnaire and a PA questionnaire at Time 1. The PA measure was repeated 2 months later. Path analyses were performed to test the hypothesized model including interaction terms between TPB variables. Simple slopes analyses were also carried out to examine the statistically significant interaction terms.
Results: Path analyses confirmed the classical hypotheses of TPB (R2 for intentions = .39, R2 for PA = .12) and also demonstrated only statistically significant Attitudes × Perceived Behavioral Control and Subjective Norms × Attitudes interactions (R2 change for intentions = .01, p = .009). Simple slopes analyses revealed that the strength of the association between perceived behavioral control and intentions was only statistically significantly higher (t = 2.18, p = .05, d = 0.34, 95% CI (0.03, 0.65)) when attitudes were high compared with when attitudes were low. The link between attitudes and intentions was only statistically significant at a low level of subjective norms but not at a high level.
Conclusion: The integration of interaction effects between TPB variables did not increase for the variance of PA explained by the model. More research appears to be necessary to explore how the TPB could be augmented to better predict PA in children.
– Brian V. Wright and Joel M. Stager
Purpose: The purpose of this study was to determine swimmers’ compliance to prescribed training intensity during 3 observational conditions using activity monitors.
Is Postexercise Blood Flow Restriction a Viable Alternative to Other Resistance Exercise Protocols?
Method: Individualized prediction equations were created via linear regression analyses for intensity using arm-stroke and leg-kick activity counts during a series of seven 91.4-m swim bouts in a group of 17 collegiate swimmers. Equations were used to calculate intensity performed during a standardized training session during which only the observational condition varied (e.g., a coach present on deck, no coach present on deck, and an appointed observer in addition to the coach present on deck). Compliance was calculated from the difference between prescribed training intensity and performed swim intensity. Comparisons were made between observed coaching conditions for compliance using a repeated-measures analysis of variance.
Results: Swimmers’ compliance to prescribed training intensity during the no-coach condition was less compared with the other conditions, including (a) when a coach was present and (b) when a coach and an additional observer were present (η2 = .58).
Conclusion: The presence of a coach or lack thereof appeared to be critical in terms of swimmers’ compliance to prescribed training intensity. Additional observation by nonsupervisory individuals appeared to have no significant effect on swimmers’ compliance.
– Matthew J. Barnes, Jeremy Fraser, Karl Coley, and Blake G. Perry
The purpose of this study was to identify whether post-resistance exercise (REx) blood flow restriction (BFR) can elicit a similar acute training stimulus to that offered by either heavy REx or traditional low-load BFR REx.
Ten men completed trials with 30% one-repetition maximum (1RM) for 5 sets of 15 repetitions without BFR (30%), with BFR during exercise (30% RD), and with postexercise BFR (30% RP) and at 75% 1RM for 3 sets of 10 repetitions. Lactate and cortisol were measured before and up to 60 min after exercise. Thigh circumference, ratings of perceived exertion (RPE), and pain were measured before and after exercise. Surface electromyography was measured during exercise.
All conditions had a large effect (effect size (ES) > 0.8) on lactate, with the largest effects observed with the 75% condition; no differences were observed between the 30% conditions. All conditions had a moderate effect (ES > 0.25 ≤ 0.4) on increasing thigh circumference. This effect was maintained (ES = 0.35) with the application of BFR after REx (30% RP). Change in RPE, from the first to last set, was significantly greater with 30% RD compared with other conditions (all p < .05). Electromyography amplitude was higher and percentage change was greater for the 75% condition compared with the other conditions (both p < .05).
The application of BFR immediately post-REx altered several of the responses associated with REx that is aimed at inducing muscular hypertrophy. Additionally, these changes occurred with less pain and perceived exertion suggesting that this form of REx may offer an alternative, tolerable method of REx.
Cardiorespiratory Responses to Downhill Versus Uphill Running in Endurance Athletes
– Marcel Lemire, Evelyne Lonsdorfer-Wolf, Marie-Eve Isner-Horobeti, Blah Y. L. Kouassi, Bernard Geny, Fabrice Favret, and Stéphane P. Dufour
Purpose: Mountain running races are becoming increasingly popular, although our understanding of the particular physiology associated with downhill running (DR) in trained athletes remains scarce. This study explored the cardiorespiratory responses to high-slope constant velocity uphill running (UR) and DR.
Method: Eight endurance athletes performed a maximal incremental test and 2 15-min running bouts (UR, +15%, or DR, −15%) at the same running velocity (8.5 ± 0.4 km·h−1). Oxygen uptake (O2), heart rate (HR), and ventilation rates (E) were continuously recorded, and blood lactate (bLa) was measured before and after each trial.
Results: Downhill running induced a more superficial E pattern featuring reduced tidal volume (p < .05, ES = 6.05) but similar respiratory frequency (p > .05, ES = 0.68) despite lower E (p < .05, ES = 5.46), O2 (p < .05, ES = 12.68), HR (p < .05, ES = 6.42), and bLa (p < .05, ES = 1.70). A negative slow component was observed during DR for O2 (p < .05, ES = 1.72) and HR (p < .05, ES = 0.80).
Conclusion: These results emphasize the cardiorespiratory responses to DR and highlight the need for cautious interpretation of O2, HR, and E patterns as markers of exercise intensity for training load prescription and management.