The purpose of the present study was to evaluate the relationship between scores achieved in physical fitness tests and outcomes of health and movement screens (HMS) in ROTC students. Twenty-eight ...students (20 males: 21.8 yrs ± 3.4 & 8 females: 20.7 yrs ± 1.8) enrolled in an ROTC branch (Army, Air Force, Navy, or Marines) completed a series of screens, including body composition analysis via Dual-Energy X-Ray Absorptiometry (DXA), balance and functional movement tasks via a lower-quarter Y-Balance test, and knee and hip joint concentric strength testing on an isokinetic dynamometer. Official ROTC PFT scores were collected from the respective military branch leadership. HMS outcomes were compared to PFT scores via Pearson Product-Moment Correlation and linear regression analyses. Across branches, total PFT scores were significantly correlated to visceral adipose tissue (r = -0.52, p = 0.01) and android:gynoid fat ratio (r = -0.43, p = 0.04). Visceral adipose tissue (R2 = 0.27, p = 0.011) and android to gynoid ratio (R2 = 0.18, p = 0.042) significantly predicted total PFT scores. No further significant correlations between HMS and overall PFT scores were observed. HMS scores revealed significant bilateral differences in lower extremity body composition (p < 0.001; d = 0.23) and strength (p = 0.002; d = 0.23). Across ROTC branches, HMS were poorly correlated with PFT performance yet indicated significant bilateral differences in lower extremity strength and body composition. The inclusion of HMS may ease the increasing injury rate among the military population by assisting in detection of movement shortcomings.
The benefits of physical activity are likely universal for all children, including children and adolescents with disabilities (CWD). The participation of CWD in physical activity, including adaptive ...or therapeutic sports and recreation, promotes inclusion, minimizes deconditioning, optimizes physical functioning, improves mental health as well as academic achievement, and enhances overall well-being. Despite these benefits, CWD face barriers to participation and have lower levels of fitness, reduced rates of participation, and a higher prevalence of overweight and obesity compared with typically developing peers. Pediatricians and caregivers may overestimate the risks or overlook the benefits of physical activity in CWD, which further limits participation. Preparticipation evaluations often include assessment of health status, functional capacity, individual activity preferences, availability of appropriate programs, and safety precautions. Given the complexity, the preparticipation evaluation for CWD may not occur in the context of a single office visit but rather over a period of time with input from the child's multidisciplinary team (physicians, coaches, physical education teachers, school nurses, adaptive recreation specialists, physical and occupational therapists, and others). Some CWD may desire to participate in organized sports to experience the challenge of competition, and others may prefer recreational activities for enjoyment. To reach the goal of inclusion in appropriate physical activities for all children with disabilities, child, family, financial, and societal barriers to participation need to be identified and addressed. Health care providers can facilitate participation by encouraging physical activity among CWD and their families during visits. Health care providers can create "physical activity prescriptions" for CWD on the basis of the child's preferred activities, functional status, need for adaptation of the activity and the recreational opportunities available in the community. This clinical report discusses the importance of participation in sports, recreation, and physical activity for CWD and offers practical suggestions to health care providers.
Ramirez-Campillo, R, Alvarez, C, Gentil, P, Loturco, I, Sanchez-Sanchez, J, Izquierdo, M, Moran, J, Nakamura, FY, Chaabene, H, and Granacher, U. Sequencing effects of plyometric training applied ...before or after regular soccer training on measures of physical fitness in young players. J Strength Cond Res 34(7): 1959-1966, 2020-To compare the effects of short-term (i.e., 7 weeks) plyometric jump training applied before (PJT-B) or after (PJT-A) soccer practice on components of physical fitness in young soccer players, a single-blind randomized controlled trial was conducted. Postpubertal boys aged 17.0 ± 0.5 years were allocated to 3 groups: PJT-B (n = 12), PJT-A (n = 14), and control (CON; n = 12). The outcome measures included tests to evaluate 20-m speed, standing long jump (SLJ), squat jump (SJ), countermovement jump (CMJ), and drop jump (DJ), 20-m multistage shuttle run endurance (MSSRT), and Illinois change-of-direction speed (ICODT). Although the CON performed soccer-specific training, the PJT-A and PJT-B groups conducted the same soccer-specific sessions but replaced ∼11% of their time with plyometric training. The PJT-B group performed plyometric exercises after a warm-up program, and the PJT-A group conducted plyometric exercises ∼10 minutes after the completion of soccer training. Analyses of variance were used to detect differences between groups in all variables for pretraining and posttraining tests. Main effects of time (all p < 0.01; d = 0.19-0.79) and group × time interactions (all p ≤ 0.05; d = 0.17-0.76) were observed for all examined variables. Post hoc analyses revealed significant increases in the PJT-B group (SLJ: 9.4%, d = 1.7; CMJ: 11.2%, d = 0.75; 20-m MSSRT: 9.0%, d = 0.77) and the PJT-A group (SLJ: 3.1%, d = 0.7; CMJ: 4.9%, d = 0.27; 20-m MSSRT: 9.0%, d = 0.76). Post hoc analyses also revealed significant increases in the PJT-B group (20-m speed: -7.4%, d = 0.75; 20-cm DJ reactive strength index: 19.1%, d = 1.4; SJ: 6.3%, d = 0.44; ICODT results: -4.2%, d = 1.1). In general, our study revealed that plyometric training is effective in improving measures of physical fitness in young male soccer players when combined with regular soccer training. More specifically, larger training-induced effects on physical fitness were registered if plyometric training was conducted before soccer-specific training.
The purpose of this study was to investigate whether perceived motor competence and components of health-related physical fitness mediated the relationship between actual motor competence and ...physical activity in 8- to 9-year-old Iranian girls. A convenience sample of 352 girls (mean age = 8.7, SD = 0.3 years) participated in the study. Actual motor competence, perceived motor competence and children's physical activity were assessed using the Test of Gross Motor Development-2, the physical ability sub-scale of Marsh's Self-Description Questionnaire and Physical Activity Questionnaire for Older Children, respectively. Body mass index, the 600 yard run/walk, curl-ups, push-ups, and back-saver sit and reach tests assessed health-related physical fitness. Preacher & Hayes (2004) bootstrap method was used to assess the potential mediating effects of fitness and perceived competence on the direct relationship between actual motor competence and physical activity. Regression analyses revealed that aerobic fitness (b = .28, 95% CI = .21, .39), as the only fitness measure, and perceived competence (b = .16, 95% CI = .12, .32) were measures that mediated the relationship between actual motor competence and physical activity with the models. Development of strategies targeting motor skill acquisition, children's self-perceptions of competence and cardiorespiratory fitness should be targeted to promote girls' moderate-to-vigorous physical activity.
This study aimed to explore the relationship between physical fitness and the academic performance of primary school students and to predict the academic performance associated with physical fitness ...using machine learning methods. The results provide new evidence confirming the relationship between physical fitness and the academic performance of primary school students. This study provides a practical foundation for early intervention methods to improve the physical fitness and academic performance of primary school students via physical exercise.
A total of 432 fifth-grade students from five primary schools in Huai'an, China, were selected using the cluster sampling method. Their physical fitness was evaluated in terms of their body mass index, muscle strength, flexibility, speed, and aerobic endurance. The final exam scores in Chinese, mathematics, and foreign language were used to quantify their academic performance. The Mann–Whitney U test was used to investigate the differences in physical fitness between academic performance groups. The Spearman correlation analysis was used to quantify the relationship between physical fitness and academic performance. Machine learning models based on random forest (RF), support vector machine (SVM), and K-nearest neighbor (KNN) algorithms were used to predict the academic performance of primary school students. The respective prediction performances of machine learning models were evaluated using the accuracy and validated in the test sample.
The body mass index (z = −2.046, p < 0.05) of high-score (HS) primary school students was lower than non-high-score (NHS) students, and the upper limb (z = −2.143, p < 0.05), trunk (z = −3.399, p < 0.05), and lower limb strength (z = −2.525, p < 0.05) and aerobic endurance (z = −2.105, p < 0.05) of HS students were better than NHS students. The academic performance of primary school students was negatively correlated with body mass index (r = −0.105, p < 0.05) and positively correlated with upper limb (r = 0.11, p < 0.05), trunk (r = 0.175, p < 0.05), and lower limb strength (r = 0.13, p < 0.05) and aerobic endurance (r = −0.108, p < 0.05). The average accuracy of RF, SVM, and KNN models in predicting the academic performance of primary school students in training samples were 59.4% ± 5.16%, 56.41% ± 3.81% and 57.89% ± 4.98%, respectively, which were found to be higher than baseline accuracy, as validated in the test sample.
The body mass index, muscle strength, and aerobic endurance of primary school students are significantly different between academic performance groups and are correlated with their academic performance. Machine learning methods can effectively predict academic performance associated with the physical fitness of primary school students.
•Significant differences existed in physical fitness between the primary school students in academic performance groups.•Physical fitness correlates with academic performance of primary school students.•Machine learning methods can predict academic performance associated with the physical fitness of primary school students.
There is dogma that higher training load causes higher injury rates. However, there is also evidence that training has a protective effect against injury. For example, team sport athletes who ...performed more than 18 weeks of training before sustaining their initial injuries were at reduced risk of sustaining a subsequent injury, while high chronic workloads have been shown to decrease the risk of injury. Second, across a wide range of sports, well-developed physical qualities are associated with a reduced risk of injury. Clearly, for athletes to develop the physical capacities required to provide a protective effect against injury, they must be prepared to train hard. Finally, there is also evidence that under-training may increase injury risk. Collectively, these results emphasise that reductions in workloads may not always be the best approach to protect against injury.
This paper describes the 'Training-Injury Prevention Paradox' model; a phenomenon whereby athletes accustomed to high training loads have fewer injuries than athletes training at lower workloads. The Model is based on evidence that non-contact injuries are not caused by training per se, but more likely by an inappropriate training programme. Excessive and rapid increases in training loads are likely responsible for a large proportion of non-contact, soft-tissue injuries. If training load is an important determinant of injury, it must be accurately measured up to twice daily and over periods of weeks and months (a season). This paper outlines ways of monitoring training load ('internal' and 'external' loads) and suggests capturing both recent ('acute') training loads and more medium-term ('chronic') training loads to best capture the player's training burden. I describe the critical variable-acute:chronic workload ratio-as a best practice predictor of training-related injuries. This provides the foundation for interventions to reduce players risk, and thus, time-loss injuries.
The appropriately graded prescription of high training loads should improve players' fitness, which in turn may protect against injury, ultimately leading to (1) greater physical outputs and resilience in competition, and (2) a greater proportion of the squad available for selection each week.
ABSTRACT
Introduction
Concussion has become the signature injury facing the U.S. military. However, little is understood about the relationship between military fitness and concussion recovery. The ...current study examined the recoveries of cadets at a U.S. Service Academy to determine whether preinjury physical fitness improved recovery and whether recovery was associated with post-injury physical fitness measures.
Methods
Participants were enrolled in a longitudinal study of concussion. Aerobic Fitness Test (AFT) and Physical Fitness Test (PFT) data were used to estimate cadet fitness. Survival analysis evaluated significant estimators of concussion recovery time. Linear regression models were used to explore the relationship between recovery duration and change in physical fitness scores.
Results
Between 2014 and 2017, 307 (n = 70; 22.80% Women) cadets who had sustained a concussion were enrolled. Preinjury physical fitness was not significantly associated with recovery duration (P > .05). Men and intercollegiate cadets took fewer days to reach recovery milestones. Compared to women, men had greater decrements in the Aerobic Fitness Test total score (P < .05) and increased 1.5-mile time postconcussion (P < .05). Women had greater decreases in push-ups postconcussion compared to males (P < .05). There was a trend for a negative association between days until asymptomatic and change in the Physical Fitness Test score (P = .07).
Conclusion
Preconcussion physical fitness levels do not appear to impact concussion recovery time among a highly physically fit cohort. Possible methods to reduce the effect of symptom duration on strength-related physical fitness should be investigated along with evaluating reductions in strength as a possible mechanism for postconcussion injury risk.
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