Cardiorespiratory fitness and muscular fitness correlates in youth: A hierarchy of behavioral, contextual, and health-related outcomes

OBJECTIVES

Despite the health importance of identifying correlates of physical fitness in youth, no investigation to date has explored the influence of behavioral, health-related, and contextual correlates simultaneously. We investigated the hierarchical relationship of multiple modifiable correlates favoring or diminishing cardiorespiratory and muscular fitness in youth.

DESIGN

Cross-sectional investigation.

METHODS

In a sample of 5174 children and adolescents, 31 correlates were hierarchized according to their impact on cardiorespiratory and muscular fitness assessed using the FITESCOLA® fitness battery. A Chi-squared Automatic Interaction Detection approach was employed and measures of correlation and association were used to investigate the relationship between physical fitness and correlates.

RESULTS

In children, body mass index was the most relevant factor to discriminate between high and low cardiorespiratory and muscular fitness of the upper, middle, and lower body. While body mass index was more important than any other correlate to differentiate levels of upper and lower body muscular fitness during adolescence, specific characteristics of sports participation emerged as key factors to discriminate between high and low cardiorespiratory fitness and middle body muscular fitness. Other correlates, including the self-report of active recess time, active commuting to school, favorable neighborhood conditions, and limited time on screens and cellphones, were demonstrative of favorable physical fitness levels.

CONCLUSIONS

Both body composition and sports-related characteristics emerged as the two most relevant factors of physical fitness in youth. Additional health benefits may be obtained from building supportive environments for sports and healthy exercise habits within the household and at different school education levels.

Training efficacy of robotic duct-to-mucosa pancreaticojejunostomy simulation using silicone models for surgical fellows

Purpose

In the era of minimally invasive surgery (MIS), robotic pancreatoduodenectomy (PD) is actively performed, and clinical fellows need to thoroughly prepare for MIS-PD during the training process. Although pancreaticojejunostomy (PJ) is a difficult anastomosis that requires repeated practice, there are obstacles preventing its practice that concerns patient safety and limited time in the actual operating room. This study evaluated the efficacy of simulation-based training of robotic duct-to-mucosa PJ using pancreatic and intestinal silicone models using a scoring system.

Methods

Three pancreatobiliary clinical fellows who had never performed a real robotic PJ participated in this study. Each trainee, who was well acquainted with master's video created by a senor surgeon, performed the robotic PJ procedures 9 times, and 3 independent pancreatobiliary surgeons assessed the videos and analyzed the scores using a blind method.

Results

The mean robotic PJ times for the 3 trainees were 42.8 and 29.1 minutes for the first and 9th videos, respectively. The mean score was 13.8 (range, 6-17) for the first video and 17.7 (range, 15-19) for the 9th video. When comparing earlier and later attempts, the PJ time decreased significantly (2,201.67 seconds vs. 2,045.50 seconds, P = 0.007), whereas test scores increased significantly (total score 14.22 vs. 16.89, P = 0.011).

Conclusion

This robotic education system will help pancreatobiliary trainees overcome the learning curves efficiently and quickly without raising ethical concerns associated with animal models or direct practice with human subjects. This will be of practical assistance to trainees preparing for MIS-PD.

[Update of the recommendations of the Federal Falls Prevention Initiative-Identification and prevention of the risk of falling in older people living at home]

BACKGROUND

To reduce falls and their consequences, evidence-based and consensus-based recommendations are needed for risk stratification, screening, assessment, and fall prevention as well as treatment. In 2020, the Federal Falls Prevention Initiative (BIS) published recommendations for physical training for falls prevention as a group or individual intervention for older people living at home. In 2022, the world guidelines for falls prevention and management for older adults (WFG) were published.

OBJECTIVE

To update the recommendations of the BIS.

MATERIAL AND METHODS

The recommendations of the BIS were compared with those of the WFG and, if necessary, extended by methodological and subject-specific aspects. The following areas were considered: 1) screening and risk stratification, 2) interventions, 3) multifactorial assessment and interventions, and 4) specific target groups.

RESULTS

The BIS recommendations are largely consistent with those of the WFG. The main reason for differences is the previous focus of the BIS recommendations on physical training. The multifactorial approach, which is described in detail by the WFG, has so far been mentioned in the recommendation paper on physical training in individual settings but not elaborated in detail. The BIS recommendations are supplemented or clarified in this respect.

CONCLUSION

By updating the BIS recommendations, the establishment and promotion of fall prevention services for older people in Germany can be further advanced. The implementation can thus be carried out as consistently and scientifically proven as possible.

Weekly cumulative extracurricular core training time predicts cadet physical performance: A descriptive epidemiological study

Background

Core training can enhance athletic performance by enhancing core strength and stability. To achieve this outcome, however, a tailored training program is required; the normal military training curriculum is inadequate. The connection between cumulative weekly extracurricular training time, cumulative weekly extracurricular core training time and cadet performance is unknown.

Methods

The association between cumulative weekly extracurricular training time, cumulative weekly extracurricular core training time and performance has been discovered using a descriptive epidemiological study methodology. Questionnaires were used to collect information on personal characteristics and weekly cumulative extracurricular (core) training time, as well as the results of the Chinese Army Physical Fitness Test (C-APFT), which included 100-m dash, 5000-m run, 3000-m armed training run, 400-m steeplechase, 800 m breaststroke, horizontal bar pull-ups, 2-min sit-ups, 2-min push-ups, and hand grenade throwing. This study recruited two hundred and twenty male cadets (aged 18 to 23 years, 19.68 ± 0.91) from a military medical university.

Results

(a) The correlation between cumulative weekly extracurricular training time and C-APFT score is significant. The 100-m dash, 5000-m run, 3000-m armed training run, 400-m steeplechase, and 2-min push-ups performed the best when participants exercised for 5 to 10 h per week. (b) The number of cadets scoring good or excellent on the C-APFT improves with cumulative weekly extracurricular core training time. The recommended amount of core training for cadets per week is 120 min. (c) The average cumulative weekly extracurricular core training time was a effective predictor of performance on the 400-m steeplechase (R2 = 0.470, F = 10.641, P＜0.01), horizontal bar pull-ups (R2 = 0.238, F = 68.191, P＜0.01), 2-min sit-ups (R2 = 0.280, F = 84.710, P＜0.01), 100-m run (R2 = 0.031, F = 6.920, P＜0.01), 3000-m armed training run (R2 = 0.025, F = 5.603, P＜0.05), 2-min push-ups (R2 = 0.019, F = 4.295, P＜0.05), and hand grenade tossing (R2 = 0.025, F = 5.603, P＜0.05).

Conclusions

Active participation in extracurricular core training can improve cadets' C-APFT scores. An average cumulative weekly extracurricular training duration of 5-10 h showed the most progress, and more than 120 min per week was ideal for extracurricular core training. The amount of extracurricular time spent on core training exercises each week can be used as a predictor of the C-APFT.

Warm-up optimization in amateur male soccer players: A comparison of small-sided games and traditional warm-up routines on physical fitness qualities

The aim of this study was to compare the effects of small-sided soccer games (SSSGs) and traditional warm-up (TWU) routines on physical fitness qualities in soccer players. Following a between-subject, randomized design, amateur-level soccer players were assigned to a SSSG warm-up (n = 10; age: 19.3 ± 2.8 years) or TWU group (n = 10; age: 19.3 ± 2.4 years). Players completed multiple trials of 10-m and 30-m linear sprints, change-of-direction speed (CODS) tests, and countermovement jumps (CMJ) prior to and following the warm-up routine. Separate mixed ANOVAs were performed to assess group effects (SSSG vs. TWU), time effects within each group (pre- vs. post-warm-up), and their interaction for each physical fitness quality. No significant interaction effects were observed for any dependent variable. Significant improvements were evident between baseline and follow-up measurements for 10-m sprint time (p = 0.002, Hedges' g effect size [g] = 0.59) and CMJ variables (height: p = 0.016, g = 0.20; power: p = 0.003, g = 0.19; force: p = 0.002, g = 0.14) in the TWU group and for CODS performance time (p = 0.012, g = 0.51) and CMJ variables (height: p < 0.001, g = 0.46; power: p = 0.002, g = 0.35; force: p = 0.001, g = 0.27) in the SSSG warm-up group. Both SSSG and TWU protocols improved selected physical fitness qualities with SSSG more effective at improving CODS and CMJ performance, and TWU more effective at improving linear speed. Soccer coaches may choose between SSSG or traditional warm-up activities according to player needs and preferences; however, the superior effects of SSSG suggest it might offer greater benefits than TWU in preparing players for optimal physical output.

Feasibility and validity of the push-up test for synchronous and asynchronous strength tele-assessment in spinal cord injury individuals with paraplegia

OBJECTIVES

This study aimed to determine whether the synchronous and asynchronous push-up tele-assessment in individuals with spinal cord injury (SCI) is feasible and valid and to identify the relationship between the participants' self-reported asynchronous strength tele-assessment and asynchronous push-up tele-assessment.

STUDY DESIGN

Cross-sectional study.

METHODS

Thirty-three men and women with SCI were included in this study. The participants were assessed using the one-maximum repetition test (1RM), the maximum repetitions with 60% of 1RM (MRT) of the bench press exercise, and synchronous and asynchronous push-up tele-assessment. The videos and the total repetitions performed were recorded. The primary outcomes were 1RM, MRT, synchronous push-up tele-assessment and asynchronous volume loads, and the participants' self-reported asynchronous strength tele-assessment volume load.

RESULTS

The synchronous push-up tele-assessment and asynchronous volume loads presented significant correlations with 1RM (0.73 and 0.45, p < 0.001, respectively) and MRT volume loads (0.87 and 0.66, p < 0.001, respectively). The asynchronous push-up tele-assessment presented significant correlations with the synchronous version (intraclass correlation coefficient, ICC = 0.86; 95% CI: 0.72-0.93, p < 0.001) and participants' self-reported asynchronous strength tele-assessment volume loads (ICC = 0.88; 95% CI: 0.75-0.94, p < 0.001). The difference between the synchronous push-up tele-assessment and asynchronous volume load means was 254.9 kg, and the interval around the differences was 1856.1 kg. The difference between asynchronous push-up tele-assessment and participants' self-reported asynchronous strength tele-assessment means was -239.4 kg, and the interval around these was 1884.1 kg.

CONCLUSION

The synchronous push-up tele-assessment is a feasible and valid way to assess the maximum resistance strength of individuals with SCI. Although the asynchronous push-up tele-assessment demonstrated excellent and significant correlations with the synchronous push-up tele-assessment and participants' self-reported asynchronous strength tele-assessment, the test repetitions and the volume loads were underestimated by 15.5% (synchronous push-up tele-assessment vs. asynchronous) and overestimated by 17.3% (asynchronous push-up tele-assessment vs. participants' self-reported asynchronous strength tele-assessment), and the effect sizes ranged from 0.19-0.38. The authors suggest emphasizing the criteria of repetition validity to reduce test error.

Attendance in physical education classes, sedentary behavior, and different forms of physical activity among schoolchildren: a cross-sectional study

Background

Attendance in physical education classes (PE) helps young people to achieve the physical activity recommendations and to reduce their exposure to sedentary behavior. However, the association between PE attendance and the daily frequency of specific forms of physical activity is less known. The current study analyzed the association between weekly attendance in PE and daily frequencies of different forms of physical activity (active play, non-active play, structured physical activity), and overall daily frequencies of physical activity (PA) and sedentary behaviors (SB) among schoolchildren.

Methods

Cross-sectional study with schoolchildren from second to fifth grade of 11 public schools (n = 2,477; 9.1 ± 1.38-y-old; 53.2% girls; 17.5 ± 3.5 kg/m²) in Feira de Santana (Northeast Brazil). PA, SB, and attendance in PE were self-reported using a previously validated on-line questionnaire based on the previous day's recall (Web-CAAFE). Multiple Binomial Negative regression modeling was carried out to analyze the association (Prevalence Rate: PR) between weekly attendance in PE (0/week, 1/week, ≥ 2/week) and frequencies of active play, non-active play, and structured physical activity, with adjustments by age, school shift, and BMI z-scores. Regression models analyzing overall PA also included adjustments by household chores.

Results

Attendance in PE ≥ 2/week was associated with higher frequencies of active play (girls: PR = 1.40, 95%CI = 1.11–1.78; boys: PR = 1.49, 95%CI = 1.15–1.94) and structured physical activity (girls: PR = 2.11, 95%CI = 1.31–3.40; boys: PR = 4.33, 95%CI = 1.63–11.52). Higher attendance in PE (≥ 2/week) was associated with high overall PA (girls: PR = 1.31, 95%CI = 1.06–1.62; boys: PR = 1.42, 95%CI = 1.14–1.77) and low SB (girls: PR = 0.80, 95%CI = 0.71–0.90; boys: PR = 0.81, 95%CI = 0.68–0.97). Attendance in PE 1/week was also associated with a lower frequency of daily SB among girls (PR = 0.73, 95%IC = 0.64–0.84)

Conclusion

Higher weekly attendance in PE was associated with higher frequencies of active play, structured physical activity, higher overall PA, and lower SB among both girls and boys.

Isokinetic force-power profile of the shoulder joint in males participating in CrossFit training and competing at different levels

Background

As participants who engage in CrossFit training and competition perform a large volume of high intensity overhead activities, injuries to the shoulder are one of the most common in this sport. Previous research in other sports has indicated that the isokinetic force power profile of the shoulder joint (IPSJ) rotator muscles may assist in the prediction of shoulder injury.

Aim

Therefore, the objective of this study was to determine the IPSJ in males engaged in CrossFit training at different competitive levels.

Methods

In a cross-sectional study design, participants (age, 24.1 ± 2.7 years) classified as ‘beginner’ (n = 6), ‘intermediate’ (n = 7) or ‘advanced’ (n = 9) provided informed consent to participate in this study. The IPSJ assessment involved rotational and diagonal movements, including internal and external shoulder rotator muscles, at both 180°.s⁻¹ and 300°.s⁻¹. The variables analysed were peak torque/body mass (%), mean power (W) and the external/internal peak torque/body mass ratio (%). A Kruskal–Wallis test was used to compare the IPSJ of the three groups, with Dunn’s test used for post-hoc analysis. The alpha level was set at p < 0.05.

Results

The IPSJ showed greater torque and power values in those who competed at the advanced level as compared to those at a lower competitive level (i.e. intermediate, beginner). This was observed mainly for the internal rotation and internal diagonal movements at both 180°.s⁻¹ and 300°.s⁻¹. However, such differences between competitive levels were, in general, absent for the external rotation and external diagonal movements. Moreover, the participants from the advanced competitive level exhibited an imbalance of peak torque between the muscles responsible for the external–internal rotational and external-internal diagonal movements of the shoulder (i.e. peak torque external/internal ratio <66%), particularly in the dominant shoulder.

Conclusion

These findings suggest greater development of the shoulder internal rotators and a higher probability of shoulder injury in CrossFit athletes at the advanced competitive level. Based on these results, participants engaged in CrossFit training and competition may wish to increase the volume of training for the shoulder external rotator muscles to complement the large increases in shoulder internal rotator strength that occur as a part of their regular training regimes.

Using distance learning as a strategy for maintaining income of Physical Education professionals during the COVID-19 pandemic

The period of social distancing caused by the COVID-19 pandemic is characterized as an effective proposal to control the spread of the coronavirus (SARS-CoV-2), however, it changes the social dynamics of individuals in society. Based on this question, the present study aimed to understand how was the performance of Brazilian physical education professionals during this period. The sample consisted of 400 Physical Education professionals from Brazil, 224 women (56.0%) and 176 men (44.0%), selected at random, by filling out a questionnaire. Sports activities were predominant among professionals, followed by bodybuilding activities or functional training. Most professionals performed their activities at home (71%) and used different digital platforms as work tools, noting that distance learning was a strategy used and well regarded by professionals. However, even with the use of specific intervention strategies, professional income showed fluctuations during the pandemic, with academic degrees being one of the factors responsible for changing the workload.

Plyometric jump training effects on the physical fitness of individual-sport athletes: a systematic review with meta-analysis

Background

The aim of this study is to conduct a systematic review with meta-analysis to explore the effects of plyometric jump training (PJT) on the physical fitness of individual sport athletes (ISA).

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched through PubMed, Web of Science, and SCOPUS electronic databases. We included controlled studies that incorporated a PJT intervention among ISA (with no restriction for age or sex), that included a pre-to-post intervention assessment of physical fitness (e.g., sprint; jump). From the included studies, relevant data (e.g., PJT and participants characteristics) was extracted. We assessed the methodological quality of the included studies using the PEDro scale. Using a random-effects model, meta-analyses for a given outcome was conducted. Means and standard deviations for a measure of pre-post-intervention physical fitness from the PJT and control groups were converted to Hedges' g effect size (ES). Heterogeneity was assessed using the I ² statistic. The risk of bias was explored using the extended Egger's test. The statistical significance threshold was set at p < 0.05. Moderator analyses were conducted according to the sex, age and sport background of the athletes.

Results

Twenty-six studies of moderate-high methodological quality were included (total participants, n = 667). Compared to controls, PJT improved vertical jump (ES = 0.49; p < 0.001; I = 0.0%), linear sprint (ES = 0.23; p = 0.032; I ² = 10.9%), maximal strength (ES = 0.50; p < 0.001; I² = 0.0%) and endurance performance (ES = 0.30; p = 0.028; I² = 11.1%). No significant effect was noted for sprint with change of direction (ES = 0.34; p = 0.205; I² = 70.9%). Athlete's sex, age and sport background had no modulator role on the effect of PJT on vertical jump, linear sprint, maximal strength and endurance performance. Among the included studies, none reported adverse effects related to the PJT intervention.

Conclusions

PJT induces small improvements on ISA physical fitness, including jumping, sprinting speed, strength and endurance.

Pulmonary Rehabilitation

Pulmonary rehabilitation (PR) is an essential intervention in the management of patients with chronic obstructive pulmonary disease. To guide health care professionals in the implementation and evaluation of a PR program, this article discusses the current key concepts regarding exercise testing, prescription, and training, as well as self-management intervention as essential parts of PR and post-rehabilitation maintenance. Moreover, new approaches (alternative forms of organization and delivery, tele-rehabilitation, exercise adjuncts) and unique and challenging situations (patients experiencing acute exacerbations, advanced disease) are thoroughly reviewed. Finally, validated point-of-care resources and online tools are provided.

Effect of aerobic exercise in the treatment of myofascial pain: a systematic review

Myofascial pain is prevalent chronic pain disorder that is comorbid with many conditions. Strengthening and stretching exercises are capable of inducing hypoalgesic effects in people with myofascial pain syndrome. The goal of this systematic review was to summarize the effects of aerobic exercise on the management of myofascial pain. A comprehensive database search was conducted. A total of 1,331 articles were identified for review. One article was eligible for inclusion after full screening. Risk of bias was assessed using the Downs and Black quality assessment questionnaire (1998). Mean difference scores were calculated for continuous variables. The identified study had a low risk of bias. It was a randomized controlled trial assessing the influence of an 8-week water aerobic exercise program on myofascial pain in breast cancer patients. Visual analogue scale pain intensity ratings and the number of myofascial trigger points present in the neck and shoulder/axillary area of participants significantly decreased in the exercise group compared to those in the control group. Pain pressure thresholds significantly increased in muscle areas of the cervical spine in the water exercise group. Aerobic exercise presents a potential treatment modality for managing myofascial pain. Additional research is necessary.

Impact of a Georgia elementary school-based intervention on physical activity opportunities: A quasi-experimental study

OBJECTIVES

To assess the impact of Power Up for 30, a flexible, Comprehensive School Physical Activity Program-based state-wide elementary school initiative, on school physical activity opportunities (physical education, recess, in-class physical activity, before-school physical activity, and after-school physical activity) one year after Power Up for 30 training.

DESIGN

Quasi-experimental.

METHODS

In 2013, all 1333 public Georgia elementary schools were invited to complete the School Physical Activity Survey which assessed school physical activity opportunities. Upon survey completion, schools were invited to attend training. Of the 719 (54%) schools meeting survey response criteria, 300 schools attended training by 9/2014 and 419 schools did not. Between 3/2015-5/2015, 79 trained and 80 untrained schools were randomly selected to receive a follow-up survey assessing the frequency and duration of physical activity opportunities. Analyses, adjusted for baseline physical activity opportunities and school characteristics, compared weekly minutes of physical activity opportunities at follow-up between trained and untrained schools.

RESULTS

In adjusted analyses at follow-up, trained schools provided 36 more minutes of weekly physical activity opportunities than untrained schools (99% confidence interval: 16-56), particularly during recess (mean difference: 8min per week; 99% confidence interval: 0-17), during in-class breaks (mean difference: 11min per week, 99% confidence interval: 3-20), and before school (mean difference: 8min per week, 99% confidence interval: 4-12).

CONCLUSIONS

Flexible, multi-component interventions like Power Up for 30 increase physical activity opportunities. If future studies identify that school physical activity opportunities positively impact student physical activity, this model may be a feasible strategy for broad-scale implementation.

Physical fitness predicts technical-tactical and time-motion profile in simulated Judo and Brazilian Jiu-Jitsu matches

Background

Among combat sports, Judo and Brazilian Jiu-Jitsu (BJJ) present elevated physical fitness demands from the high-intensity intermittent efforts. However, information regarding how metabolic and neuromuscular physical fitness is associated with technical-tactical performance in Judo and BJJ fights is not available. This study aimed to relate indicators of physical fitness with combat performance variables in Judo and BJJ.

Methods

The sample consisted of Judo (n = 16) and BJJ (n = 24) male athletes. At the first meeting, the physical tests were applied and, in the second, simulated fights were performed for later notational analysis.

Results

The main findings indicate: (i) high reproducibility of the proposed instrument and protocol used for notational analysis in a mobile device; (ii) differences in the technical-tactical and time-motion patterns between modalities; (iii) performance-related variables are different in Judo and BJJ; and (iv) regression models based on metabolic fitness variables may account for up to 53% of the variances in technical-tactical and/or time-motion variables in Judo and up to 31% in BJJ, whereas neuromuscular fitness models can reach values up to 44 and 73% of prediction in Judo and BJJ, respectively. When all components are combined, they can explain up to 90% of high intensity actions in Judo.

Discussion

In conclusion, performance prediction models in simulated combat indicate that anaerobic, aerobic and neuromuscular fitness variables contribute to explain time-motion variables associated with high intensity and technical-tactical variables in Judo and BJJ fights.

Health promotion initiatives at school related to overweight, insulin resistance, hypertension and dyslipidemia in adolescents: a cross-sectional study in Recife, Brazil

Background

The emergence of diseases such as dyslipidemia, systemic arterial hypertension, insulin resistance and metabolic syndrome in children and adolescents has brought about a change in the epidemiologic profile of the pediatric population. As action to promote health in the school environment is a useful tool for changing the pattern of health/disease in the young population, the present study aimed to identify schools that promote healthy eating and physical activity and to study the relationship between these practices and the prevalence of overweight, hypertension, insulin resistance and hypercholesterolemia in adolescents.

Methods

A cross-sectional population-based study was conducted with 2400 adolescents aged from 12 to 17 years old and participating in the “Study of Cardiovascular Risk in Adolescents” (ERICA – Estudo de Riscos Cardiovasculares em Adolescente). The association between dependent (overweight, insulin resistance, hypertension and dyslipidemia) and independent variables (implementation of health promoting initiative in schools) was investigated using the chi-square test and prevalence ratio (PR) with a confidence index (CI) of 95%.

Results

The unsatisfactory implementation of a “health promoting environment” (PR = 1.02; CI 95%: 1.0; 1.04) and “partnerships with the health sector” (PR = 1.03; CI 95%: 1.01; 1.05) were linked to a high prevalence of overweight in adolescents. Hypercholesterolemia was found to be higher in the schools with unsatisfactory implementation of “healthy eating and health on the scholar curriculum” (PR = 1.71; CI 95%: 1.22; 2.44) and those lacking a “healthy-eating promoting environment” (PR = 1.29; CI 95%: 1.10; 1.54). Schools with unsatisfactory implementation of a “health-eating promoting environment” (PR = 1.36; CI 95%: 1.04; 1.79) and those lacking “partnership with the health sector” (PR = 2.12; CI 95%: 1.38; 3.24) had more adolescents with insulin resistance. There was no association between hypertension and any other component studied.

Conclusion

Schools which have implemented adequate health promotion in their curriculums showed a lower prevalence of overweight, insulin resistance and hypercholesterolemia in adolescents.

Elementary physical education: A focus on fitness activities and smaller class sizes are associated with higher levels of physical activity

Optimizing physical activity during physical education is necessary for children to achieve daily physical activity recommendations. The purpose of this study was to examine the relationship among various contextual factors with accelerometer measured physical activity during elementary physical education. Data were collected during 2015–2016 from 281 students (1st–5th grade, 137 males, 144 females) from a private school located in a metropolitan area of Utah in the U.S. Students wore accelerometers for 12 consecutive weeks at an accelerometer wear frequency of 3 days per week during physical education. A multi-level general linear mixed effects model was employed to examine the relationship among various physical education contextual factors and percent of wear time in moderate-to-vigorous physical activity (%MVPA), accounting for clustering of observations within students and the clustering of students within classrooms. Explored contextual factors included grade level, lesson context, sex, and class size. Main effects and interactions among the factors were explored in the multi-level models. A two-way interaction of lesson context and class size on %MVPA was shown to be statistically significant. The greatest differences were found to be between fitness lessons using small class sizes compared to motor skill lessons using larger class sizes (β = 14.8%, 95% C.I. 5.7%–23.9% p < 0.001). Lessons that included a focus on fitness activities with class sizes that were < 25 students associated with significantly higher %MVPA during elementary physical education.

•

Small class sizes relate to increased physical activity during physical education.

•

Fitness lessons yielded higher physical activity compared to motor skills/games.

•

Small classes and fitness lessons are additive for increasing physical activity.

A systematic review and meta-analysis of moderate-to-vigorous physical activity levels in elementary school physical education lessons

OBJECTIVE

To examine elementary school students' moderate-to-vigorous physical activity (MVPA) levels during physical education (PE) lessons.

METHODS

A systematic search of nine electronic databases was conducted (PROSPERO2014:CRD42014009649). Studies were eligible if they were in English; published between 2005-April 2014; assessed MVPA levels in PE lessons of elementary school children (aged four-12years); and used an objective MVPA measure. Two reviewers retrieved articles, assessed risk of bias, and performed data extraction. The findings were synthesised using a meta-analysis.

RESULTS

The search yielded 5132 articles. Thirteen studies from nine countries met the inclusion criteria. Eight studies measured MVPA through observational measures, five used accelerometry and one used heart rate monitoring. The percentage of PE lesson time spent in MVPA ranged between 11.4-88.5%. Meta-analysis of seven studies (4 direct observations; 4 accelerometers) found that children spent a mean (95% CI) 44.8 (28.2-61.4)% of PE lesson time in MVPA. When measured using direct observation and accelerometers, children spent 57.6 (47.3-68.2) and 32.6 (5.9-59.3)% of PE lesson time in MVPA, respectively. The review has limitations; the search strategy was restricted to studies in English; theses, dissertations and conference abstracts were excluded; and six studies that provided insufficient data were excluded from the meta-analysis.

CONCLUSION

MVPA levels during elementary school PE lessons do not meet the United States Centre for Disease Control and Prevention and the United Kingdom's Association of Physical Education recommendation (50% of lesson time), but is higher than estimated in the previous review (34.2%). Interventions to increase MVPA in PE lessons are needed.

Influence of nitric oxide in the improvement of muscle power

OBJECTIVE

To evaluate whether nitric oxide (NO) supplementa-tion is directly related to increased muscle power in response to strength exercise training.

METHODS

The study included 36 individuals who underwent training for eight weeks (three times per week) with weights, who were randomly divided into two groups, both receiving the same training protocol, but one group used 3g of arginine, as a precursor of NO, and the other received placebo.

RESULTS

There was no significant difference between groups, only a significant difference for both groups between moments: before and after the training protocol.

CONCLUSION

Oral administration of arginine asso-ciated with a training program did not increase the muscular power of individuals. Level of Evidence I, Study Type: Highquality randomized trial with statistically significant diffe-rence or no statistically significant difference but narrow confidence intervals.

[Effectiveness of a school-based program to prevent obesity]

INTRODUCTION

Intervention for childhood obesity is a public health priority. The purpose of this study was to evaluate the effectiveness of an elementary school-based intervention against obesity in children.

MATERIAL AND METHODS

Non-randomised controlled trial was conducted on children from first to fifth grade from two public schools of Avilés (Spain). The intervention lasted for 2 school years comprising healthy diet workshops, educational chats, educational meetings, informative written material, and promotion of physical activities. Primary outcome measure was body mass index z-score. Secondary outcomes included: obesity and overweight prevalence, waist circumference, dietary habits, and physical activity.

RESULTS

A total of 382 (177 girls, 205 boys) out of 526 pupils of both schools were included in the study. Complete anthropometric data were obtained in 340 of the 382 individuals. Compared to children in control group, those in intervention group decreased body mass index z-score from 1.14 to 1.02 (P=.017), and improved KIDMED score from 7.33 to 7.71 points (P=.045). The percentage of students who carried on an optimal diet increased from 42.6% to 52.3% (P=.021). There were no statistical differences in the prevalence of obesity and overweight, or in waist circumference between the intervention and control groups.

CONCLUSIONS

This school-based program resulted in modest beneficial changes in body mass index and diet quality.

The relationship between self-determined motivation and physical activity in adolescent boys

BACKGROUND

Physical education (PE) lessons and leisure-time represent two important opportunities for adolescents to accumulate moderate-to-vigorous physical activity (MVPA).

PURPOSE

Framed by self-determination theory, this study investigated how much of the observed variation in adolescent boys' MVPA levels (during PE and leisure-time) was explained by individual- and class-level motivation.

METHODS

Cross-sectional design. Adolescent boys (N = 61, M = 14.36 years, SD = .48 years) completed motivation questionnaires and wore an accelerometer during a PE lesson and across 7 consecutive days.

RESULTS

Self-determined motivation toward PE predicted MVPA during PE lessons (R(2) = .31). Self-determined motivation toward leisure-time physical activity was positively associated with MVPA during leisure-time (R(2) = .08).

CONCLUSIONS

Findings support the tenets of self-determination theory and suggest that motivation may be an important correlate of adolescent boys' MVPA in PE lessons and during leisure-time. Also, results indicated that teachers' behavior may be an important determinant of MVPA in PE lessons, while individual motivation may be more important in leisure-time.