Longitudinal association between fitness and metabolic syndrome: a population-based study over 29 years follow-up.

OBJECTIVES: To examine the longitudinal associations between fitness and metabolic syndrome (MetS) in community-dwelling adults over 29 years of follow-up. DESIGN: Ongoing, population-based cohort study of adults aged ≥ 33 years at baseline residing in the city of Bad Schönborn, Germany. METHODS: The sample comprised 89 persons (41 females; mean age 40.1 years at baseline) who participated at baseline (in the year 1992) and 29-years follow-up (in the year 2021). Fitness (predictor variable) was assessed using 15 standardized and validated tests that measured strength, gross motor coordination, mobility/ flexibility and cardiorespiratory fitness/ endurance, and a z-transformed fitness score was calculated for analysis. MetS (outcome of interest) was assessed through five criteria related to waist circumference, blood glucose, HDL cholesterol, triglycerides, and blood pressure, and a sum score was created for analysis. We ran partial correlations to examine the association between fitness score at baseline and MetS score at 29-years follow-up, adjusted for age, sex, socio-economic status, smoking status, sleep quality, and physical activity engagement in minutes/ week. RESULTS: A higher fitness score at baseline was significantly associated with a lower MetS score indicative of better metabolic health at 29-years follow-up (r=-0.29; p = 0.011). These associations were present in participants aged ≤ 40 years (r=-0.33; p = 0.025) as well as those aged > 40 years (r=-0.43; p = 0.045). CONCLUSIONS: Fitness may be a predictor of longitudinal metabolic health, and potentially also mediates previously reported longitudinal associations between physical activity and metabolic health. More research is needed to confirm these observations, and to also explore underlying mechanisms.

Just-in-Time Adaptive Interventions for Behavior Change in Physiological Health Outcomes and the Use Case for Knee Osteoarthritis: Systematic Review.

BACKGROUND: The prevalence of knee osteoarthritis (KOA) in the adult population is high and patients profit from individualized therapy approaches. Just-in-time adaptive interventions (JITAIs) are upcoming digital interventions for behavior change. OBJECTIVE: This systematic review summarizes the features and effectiveness of existing JITAIs regarding important physiological health outcomes and derives the most promising features for the use case of KOA. METHODS: The electronic databases PubMed, Web of Science, Scopus, and EBSCO were searched using keywords related to JITAIs, physical activity (PA), sedentary behavior (SB), physical function, quality of life, pain, and stiffness. JITAIs for adults that focused on the effectiveness of at least 1 of the selected outcomes were included and synthesized qualitatively. Study quality was assessed with the Quality Assessment Tool Effective Public Health Practice Project. RESULTS: A total of 45 studies with mainly weak overall quality were included in this review. The studies were mostly focused on PA and SB and no study examined stiffness. The design of JITAIs varied, with a frequency of decision points from a minute to a day, device-based measured and self-reported tailoring variables, intervention options including audible or vibration prompts and tailored feedback, and decision rules from simple if-then conditions based on 1 variable to more complex algorithms including contextual variables. CONCLUSIONS: The use of frequent decision points, device-based measured tailoring variables accompanied by user input, intervention options tailored to user preferences, and simple decision rules showed the most promising results in previous studies. This can be transferred to a JITAI for the use case of KOA by using target variables that include breaks in SB and an optimum of PA considering individual knee load for the health benefits of patients.

Physiological and Locomotor Profiling Enables to Differentiate Between Sprinters, 400-m Runners, and Middle-Distance Runners.

ABSTRACT: Thron, M, Woll, A, Doller, L, Quittmann, OJ, Härtel, S, Ruf, L, and Altmann, S. Physiological and locomotor profiling enables to differentiate between sprinters, 400-m runners, and middle-distance runners. J Strength Cond Res 38(8): 1419-1427, 2024-Different approaches exist for characterizing athletes, e.g., physiological and locomotor profiling. The aims of this study were to generate and compare physiological and locomotor profiles of male and female runners and to evaluate relationships between the different approaches. Thirty-four highly trained adolescent and young adult female and male athletes ( n = 11 sprinters; n = 11,400-m runners; n = 12 middle-distance runners) performed two 100-m sprints on a running track to determine maximal sprinting speed (MSS) and maximal lactate accumulation rate (cLa max ). A cardiopulmonary exercise test was performed on a treadmill to determine maximal aerobic speed (MAS) and maximal oxygen uptake (V̇ o2 max). Anaerobic speed reserve (ASR) was calculated as the difference between MSS and MAS. Group comparisons were conducted with a 2-way ANOVA (discipline × sex; p < 0.05) and Bonferroni post hoc tests and Cohen's d as effect size. Parameters were correlated by Pearson's correlation coefficients. Maximal aerobic speed and V̇ o2 max were higher in 400-m and middle-distance runners compared with sprinters ( p ≤ 0.02; -2.24 ≤ d ≤ -1.29). Maximal sprinting speed and cLa max were higher in sprinters and 400-m runners compared with middle-distance runners (0.03 ≤ p ≤ 0.28; 0.73 ≤ d ≤ 1.23). Anaerobic speed reserve was highest in sprinters and lowest in middle-distance runners ( p ≤ 0.03; 1.24 ≤ d ≤ 2.79). High correlations were found between ASR and MAS, MSS, and cLa max ( p < 0.01; -0.55 ≤ r ≤ 0.91) and between cLa max and MSS ( p < 0.01; r = 0.74). Our results indicate that athletes of different sprinting and running disciplines show differing physiological and locomotor profiles, and that the parameters of these approaches are related to each other. This can be of interest for assessing strengths and weaknesses (e.g., for talent identification) or training prescription in these disciplines.

How to select interventions for promoting physical activity in schools? Combining preferences of stakeholders and scientists.

BACKGROUND: The failure to scale-up and implement physical activity (PA) interventions in real world contexts, which were previously successful under controlled conditions, may be attributed to the different criteria of stakeholders and scientists in the selection process of available interventions. Therefore, the aim of our study was to investigate and compare the criteria applied by local stakeholders and scientists for selecting amongst suitable school-based PA interventions for implementation. METHODS: We conducted a three-round repeated survey Delphi study with local stakeholders (n = 7; Bremen, Germany) and international scientific PA experts (n = 6). Independently for both panels, two rounds were utilized to develop a list of criteria and the definitions of criteria, followed by a prioritization of the criteria in the third round. For each panel, a narrative analysis was used to rank-order unique criteria, list the number of scorers for the unique criteria and synthesize criteria into overarching categories. RESULTS: The stakeholders developed a list of 53 unique criteria, synthesized into 11 categories with top-ranked criteria being 'free of costs', 'longevity' and 'integration into everyday school life'. The scientists listed 35 unique criteria, synthesized into 7 categories with the top-ranked criteria being 'efficacy', 'potential for reach' and 'feasibility'. The top ranked unique criteria in the stakeholder panel were distributed over many categories, whereas four out of the top six criteria in the scientist panel were related to 'evidence'. CONCLUSIONS: Although stakeholders and scientists identified similar criteria, major differences were disclosed in the prioritization of the criteria. We recommend an early collaboration of stakeholders and scientists in the design, implementation, and evaluation of PA interventions.

Assessment of 24-hour physical behaviour in adults via wearables: a systematic review of validation studies under laboratory conditions.

BACKGROUND: Wearable technology is used by consumers and researchers worldwide for continuous activity monitoring in daily life. Results of high-quality laboratory-based validation studies enable us to make a guided decision on which study to rely on and which device to use. However, reviews in adults that focus on the quality of existing laboratory studies are missing. METHODS: We conducted a systematic review of wearable validation studies with adults. Eligibility criteria were: (i) study under laboratory conditions with humans (age ≥ 18 years); (ii) validated device outcome must belong to one dimension of the 24-hour physical behavior construct (i.e., intensity, posture/activity type, and biological state); (iii) study protocol must include a criterion measure; (iv) study had to be published in a peer-reviewed English language journal. Studies were identified via a systematic search in five electronic databases as well as back- and forward citation searches. The risk of bias was assessed based on the QUADAS-2 tool with eight signaling questions. RESULTS: Out of 13,285 unique search results, 545 published articles between 1994 and 2022 were included. Most studies (73.8% (N = 420)) validated an intensity measure outcome such as energy expenditure; only 14% (N = 80) and 12.2% (N = 70) of studies validated biological state or posture/activity type outcomes, respectively. Most protocols validated wearables in healthy adults between 18 and 65 years. Most wearables were only validated once. Further, we identified six wearables (i.e., ActiGraph GT3X+, ActiGraph GT9X, Apple Watch 2, Axivity AX3, Fitbit Charge 2, Fitbit, and GENEActiv) that had been used to validate outcomes from all three dimensions, but none of them were consistently ranked with moderate to high validity. Risk of bias assessment resulted in 4.4% (N = 24) of all studies being classified as "low risk", while 16.5% (N = 90) were classified as "some concerns" and 79.1% (N = 431) as "high risk". CONCLUSION: Laboratory validation studies of wearables assessing physical behaviour in adults are characterized by low methodological quality, large variability in design, and a focus on intensity. Future research should more strongly aim at all components of the 24-hour physical behaviour construct, and strive for standardized protocols embedded in a validation framework.

Mid- and Late-Life Physical Activity and Neuropsychiatric Symptoms in Dementia-Free Older Adults: Mayo Clinic Study of Aging.

OBJECTIVE: This study examined associations between physical activity (PA) and neuropsychiatric symptoms (NPS) in older adults free of dementia. METHODS: This cross-sectional study included 3,222 individuals ≥70 years of age (1,655 men; mean±SD age=79.2±5.6; cognitively unimpaired, N=2,723; mild cognitive impairment, N=499) from the population-based Mayo Clinic Study of Aging. PA (taken as a presumed predictor) in midlife (i.e., when participants were 50-65 years of age) and late life (i.e., the year prior to assessment) was assessed with a self-reported, validated questionnaire; PA intensity and frequency were used to calculate composite scores. NPS (taken as presumed outcomes) were assessed with the Neuropsychiatric Inventory Questionnaire, Beck Depression Inventory (BDI-II), and Beck Anxiety Inventory (BAI). Regression analyses included midlife and late-life PA in each model, which were adjusted for age, sex, education, apolipoprotein E ɛ4 status, and medical comorbidity. RESULTS: Higher late-life PA was associated with lower odds of having apathy (OR=0.89, 95% CI=0.84-0.93), appetite changes (OR=0.92, 95% CI=0.87-0.98), nighttime disturbances (OR=0.95, 95% CI=0.91-0.99), depression (OR=0.94, 95% CI=0.90-0.97), irritability (OR=0.93, 95% CI=0.89-0.97), clinical depression (OR=0.92, 95% CI=0.88-0.97), and clinical anxiety (OR=0.90, 95% CI=0.86-0.94), as well as lower BDI-II (ß estimate=-0.042, 95% CI=-0.051 to -0.033) and BAI (ß estimate=-0.030, 95% CI=-0.040 to -0.021) scores. Higher midlife PA was associated only with higher BDI-II scores (ß estimate=0.011, 95% CI=0.004 to 0.019). Sex modified the associations between PA and NPS. CONCLUSIONS: Late-life PA was associated with a lower likelihood of clinical depression or anxiety and subclinical NPS. These findings need to be confirmed in a cohort study.

Insights on physical behavior while working from home: An ecological momentary assessment study.

Ever since the COVID-19 pandemic, working from home (WFH) has emerged as a common alternative work environment, but the possible influence on daily physical behavior (PB) (i.e., physical activity (PA), sedentary behavior (SB)) remains unclear. This study aimed to examine daily associations between PB and the work environment (i.e., WFH, working at the office (WAO)), as well as to explore and identify patterns of PB within each work environment. An observational study using a dual-accelerometer system to continuously assess PB for at least 5 days was conducted. The sample consisted of 55 participants providing 276 days of assessment. Additional demographic, contextual, and psychological variables were measured via baseline questionnaire and several smartphone prompts per day. To analyze the effects of the work environment on PB, multilevel analyses were conducted. For the identification of patterns within each work environment, latent class trajectory modelling was applied. Associations between the work environment and various PA parameters were found, indicating that WFH has a negative effect on MVPA time, steps, and physical activity intensity (MET), but a positive effect on short PA bouts (≤5 min). No associations between the work environment and any SB parameter (i.e., SB time, SB breaks, SB bouts) were found. Latent class trajectory modelling revealed three MVPA patterns for days WFH, and two patterns for days WAO. Given the growing prevalence of WFH and the positive health effects associated with MVPA, daily-tailored solutions to enhance MPVA while WFH are urgently needed.

Analyzing mechanisms of interdisciplinary cooperation in promoting students' health at university.

BACKGROUND: Interdisciplinary cooperation among university actors and resulting intersectoral synergies are considered cornerstones in the process of incorporating health promotion practices in everyday university life in order to break down barriers and provide better access to health promotion services. To date, no network of a health-promoting university has been examined regarding the processes underlying tie formation, network emergence, and maintenance. OBJECTIVES AND METHODS: The goals of this study are to obtain insight into the mechanisms of cooperation between university actors in a health-promoting network and to identify the structural and attributive factors associated with establishing cooperation between actors in the observed network in order to better understand how to build and develop successful networks in the future. For this purpose, a social network analysis was carried out and exponential random graph models were estimated to test corresponding hypotheses. RESULTS: The network at hand consists of 33 actors (e.g. University Sports Center, General Student Committee) and shows a flat, non-hierarchical structure. Data reveal that attributed competence predicts cooperation (0.32; p < 0.05). Significant homophily effects among student actors (1.31; p < 0.05) and among university actors (0.59; p < 0.05) were found. All structural predictors examined were significant (0.22-5.40; p < 0.05) and are therefore essential in determining the likelihood of cooperation between actors involved in the network. CONCLUSION: The results of this study provide for a better understanding of the mechanisms of cooperation and can be used to further develop the network at hand (e.g. selection of key actors for information dissemination or integration of peripheral actors). In addition, the findings offer starting points for sustained network development at other universities (e.g. significance of network governance form or goal consensus). Knowing the factors that influence the network structure, here the conditions of cooperation, results in opportunities to encourage empowerment among actors. However, the analysis of the network undertaken does not directly bear on the success of the network.

A tool to assess fitness among adults in public health studies - Predictive validity of the FFB-Mot questionnaire.

BACKGROUND: Fitness has important implications for physical activity behavior and is associated with various health-related outcomes. It can be assessed through a test battery or a self-reported questionnaire. One example is the FFB-Mot (Funktionsfragebogen Motorik; engl. functional fitness questionnaire) which consist of 28 items to assess four components of fitness in adults: cardiorespiratory fitness/ endurance, muscular strength, gross motor coordination, and flexibility. The aims of this manuscript were to (1) provide an English-version of the FFB-Mot questionnaire (developed from the German-version using translation and back-translation) to the international community of researchers in the areas of physical activity, fitness and health in adults, and (2) examine the predictive validity of the FFB-Mot questionnaire in a large sample of community-dwelling adults. METHODS: We used data from a longitudinal study in Germany with four measurement waves over a period of 18 years, with samples ranging between 310 and 437 participants (1572 adults in total, mean ages 46-58 years). To assess predictive validity, we calculated Pearson correlations between FFB-Mot data collected in 1997 and external health-related criteria (i.e., subjective health status, physician-rated health status, back pain, physical complaints and physical activity in minutes per week) collected in 2002, 2010, and 2015, and separately for males and females. RESULTS: We observed correlations between higher FFB-Mot scores with better subjective health status (in 2002: males, r = 0.25; females, r = 0.18; in 2010: males, r = 0.29; females, r = 0.28; in 2015: males, r = 0.40), and higher physical activity (in 2002: males, r = 0.24; females, r = 0.25; in 2010: males, r = 0.30; females, r = 0.38; in 2015: females, r = 0.27). Higher FFB-Mot scores were also correlated with lower back pain (in 2002: males, r = -0.23; females, r = -0.25; in 2010: females, r = -0.22), less physical complaints (in 2002: males, r = -0.36; females, r = -0.24), and better physician-rated health status (in 2002: males, r = -0.41; females, r = -0.29, 2010: males, r = -0.38; females, r = -0.44; in 2015: males, r = -0.47). CONCLUSIONS: Our results suggest that the FFB-Mot to assess fitness in adults has predictive validity for health-related outcomes as indicated by significant correlations, albeit some effect sizes are small. The FFB-Mot may be used as one-time assessment of self-reported fitness, or for repeated testing to assess change of self-reported fitness over time and in different settings (e.g., public health research).

Association between physical activity and longitudinal change in body mass index in middle-aged and older adults.

BACKGROUND: In middle-aged and particularly older adults, body mass index (BMI) is associated with various health outcomes. We examined associations between physical activity (PA) and longitudinal BMI change in persons aged ≥ 50 years. METHODS: The sample included 5159 community-dwelling individuals aged ≥ 50 years (50.5% males, mean (SD) age 73.0 (10.2) years at baseline) who were enrolled in the Mayo Clinic Study of Aging (MCSA). Participants had information on PA within one year of baseline assessment, BMI at baseline, and potential follow-up assessments (mean (SD) follow-up 4.6 (3.7) years). Linear mixed-effect models were used to calculate the association between PA (moderate-vigorous physical activity, MVPA; and all PA composite score) and the longitudinal change in BMI, adjusted for baseline age, sex, education and medical comorbidities. In addition to interactions between years since baseline and PA, we also included 2- and 3-way interactions with baseline age to further assess whether age modifies the trajectory of BMI over time. RESULTS: We observed a decrease in BMI among participants engaging at a mean amount of PA (i.e. , MVPA: 2.7; all PA: 6.8) and with a mean age (i.e., 73 years) at baseline (MVPA: estimate = -0.047, 95% CI -0.059, -0.034; all PA: estimate = -0.047, 95% CI -0.060, -0.035), and this decline is accelerated with increasing age. Participants with a mean age (i.e., 73 years) that engage at an increased amount of MVPA or all PA at baseline (i.e., one SD above the mean) do not decrease as fast with regard to BMI (MVPA: estimate = -0.006; all PA: estimate = -0.016), and higher levels of MVPA or all PA at baseline (i.e., two SD above the mean) were even associated with an increase in BMI (MVPA: estimate = 0.035; all PA: estimate = 0.015). Finally, MVPA but not all PA is beneficial at slowing BMI decline with increasing age. CONCLUSION: PA, particularly at moderate-vigorous intensity, is associated with slower decline in longitudinal BMI trajectories. This implies that engaging in PA may be beneficial for healthy body weight regulation in middle and late adulthood.

Family predictors of physical activity change during the COVID-19 lockdown in preschool children in Germany.

The COVID-19 pandemic is associated with crucial changes in children's daily life including their physical activity (PA) and screen time (ST). Among preschool children, the family represents an important factor for sufficient PA levels by being the gatekeeper for PA. Thus, the aim of this study was to investigate the influence of the family environment, specifically SES, parental support, and having siblings on COVID-19-related changes of PA and ST behavior in 317 (170 boys, 147 girls) German preschool children using longitudinal data. Our results indicate a decline in total amount of sports-related PA, an increase in outdoor play, as well as an increase in leisure ST in preschool children. The changes in total amount of PA differed between children with different levels of parental support as well as in dependence on having siblings. Furthermore, levels of outdoor play and ST in preschool children were influenced by environmental factors like having access to their own garden. We conclude that the family environment (parental support as well as physical environment) is highly relevant for PA and ST levels in preschool children. To provide every child with PA opportunities during potential future lockdowns, restriction policies should be adapted and parents need sophisticated information about the importance of their support and thus the PA levels of their children.

Use of Lower Limb Exoskeletons as an Assessment Tool for Human Motor Performance: A Systematic Review.

Exoskeletons are a promising tool to support individuals with a decreased level of motor performance. Due to their built-in sensors, exoskeletons offer the possibility of continuously recording and assessing user data, for example, related to motor performance. The aim of this article is to provide an overview of studies that rely on using exoskeletons to measure motor performance. Therefore, we conducted a systematic literature review, following the PRISMA Statement guidelines. A total of 49 studies using lower limb exoskeletons for the assessment of human motor performance were included. Of these, 19 studies were validity studies, and six were reliability studies. We found 33 different exoskeletons; seven can be considered stationary, and 26 were mobile exoskeletons. The majority of the studies measured parameters such as range of motion, muscle strength, gait parameters, spasticity, and proprioception. We conclude that exoskeletons can be used to measure a wide range of motor performance parameters through built-in sensors, and seem to be more objective and specific than manual test procedures. However, since these parameters are usually estimated from built-in sensor data, the quality and specificity of an exoskeleton to assess certain motor performance parameters must be examined before an exoskeleton can be used, for example, in a research or clinical setting.

Effective playing time affects physical match performance in soccer: An analysis according to playing position.

This study aimed to analyse the influence of effective playing time on physical match performance according to playing position in professional soccer. Official match data from 267 matches (3,731 single observations) during the 2018/2019 season of the German Bundesliga were used and the effective playing time (duration of play after subtracting the time taken up by stoppages, substitutions, injuries, and goals) was captured for each match. The physical match performance parameters total distance, high-intensity distance, sprinting distance, maximum velocity, and accelerations were analysed. Players were categorized as central defender, wide defender, central defensive midfielder, central offensive midfielder, wide midfielder, and forward. Effective playing time influenced physical match performance, with total distance and accelerations (r = 0.48-0.61) being the most and high-intensity distance, sprinting distance, and maximum velocity (r = -0.17-0.03) the least affected parameters. Players covered on average 10% more total distance and performed 13% more accelerations, while sprinting 7-10% less in matches with long (> 65 min) compared to short (< 50 min) effective playing times. The influence of effective playing time was rather similar between playing positions. Still, physical performance of wide midfielders and forwards partly deviated from the pattern observed in the other positions. Coaches and practitioners should be aware that effective playing time influences physical match performance in the German Bundesliga, while special attention should be given to wide midfielders and forwards. Effective playing time and its general and position-specific effects should be taken into account when interpreting physical match performance, thereby facilitating load management practices and training design.

The geospatial and conceptual configuration of the natural environment impacts the association with health outcomes and behavior in children and adolescents.

BACKGROUND: Studies investigating associations between natural environments and health outcomes or health behaviors in children and adolescents yielded heterogenous results to date. This may be the result of different geospatial configurations of the natural environment and confounding characteristics of the study population. Thus, we investigated how the relationship between the natural environment and mental health, muscular fitness, and physical activity varies depending on the geospatial configuration of nature and children's and adolescents' characteristics. METHODS: Data were derived from the German Motorik-Modul (MoMo) cohort study (2018-2020) that investigates physical activity, muscular fitness, and health parameters in a national sample of children and adolescents (N = 2843) between four and 17 years (Mage = 10.46 ± 3.49 years; 48.3% girls). Mental health was assessed via questionnaire, muscular fitness via standing long jump, and physical activity with 7-day accelerometer measurement. Using geographic information systems, land cover, and land use data, three different nature definitions were applied. Both circular buffers (100-1000 m) and street-network buffers (1000-5000 m) were created for each of the nature definitions. Associations were explored with linear regression models, and interaction analysis was used to investigate how those relationships vary by gender, age, and socio-economic status. RESULTS: The relationship between the three outcomes and the natural environment varied considerably depending on the nature definition, buffer size, and buffer type, as well as socio-demographic characteristics. Specifically, when comparing youth with a high socio-economic status to those with a medium socio-economic status, smaller circular buffer distances were related to less physical activity, but larger street-network buffer distances were related to greater mental health problems. Distinct relationships also occurred for youth with low socio-economic status in those relationships, with the pattern being less clear. CONCLUSIONS: For future health research studies that investigate the role of the natural environment, we argue for the development of an a-priori model that integrates both geospatial considerations (nature definition, buffer type, and buffer size) and conceptual considerations (health outcome/behavior, sample characteristics) based on potentially underlying mechanisms that link the natural environment and the health outcome or behavior under investigation to theoretically underpin the geospatial configuration of the natural environment.

Community networks of sport and physical activity promotion: an analysis of structural properties and conditions of cooperation.

BACKGROUND: The importance of intersectoral cooperation networks among community organizations located in people's immediate environments in addressing population health problems such as physical inactivity has come into focus in recent years. To date, there is limited evidence on how and why such networks emerge. Therefore, the aims of this study were (a) to analyze the structural properties and (b) to identify the conditions of cooperation in interorganizational community networks of sport and physical activity promotion. METHODS: Survey data on cooperative relationships and organizational attributes of sports and physical activity providers as well as sports administrating organizations in two community networks located in urban districts in southern Germany were collected (Network I: n = 133 organizations; Network II: n = 50 organizations). Two quantitative descriptive procedures - network analysis and stochastic analyses of network modeling (exponential random graphs) - were applied. RESULTS: Similar structures and conditions of cooperation were found in the networks (e.g. low density, centralization). The community sports administrations had the most central positions in both networks. Exponential random graph modeling showed that cooperation took place more frequently in triangular structures (closure effect) and revolved around a few central actors (preferential attachment effect). Organizations from different sectors cooperated more often than organizations from the same sector (heterophily effect). CONCLUSION: The study provided valid and robust findings on significant mechanisms and conditions of interorganizational cooperation in community networks focused on sport and physical activity promotion. Based on the results, implications for the development and most efficient governance of these networks can be derived.

Repeated Sprint Protocols With Standardized Versus Self-Selected Recovery Periods in Elite Youth Soccer Players: Can They Pace Themselves? A Replication Study.

PURPOSE: Replicating the studies of Gibson et al and Brownstein et al to assess performance, and physiological, and perceived variables during a repeated sprint protocol (RSP) with standardized versus self-selected recovery in youth soccer players. METHODS: Nineteen male soccer players (age 13.1 [1.3] y) completed 2 separate RSPs. RSP1: 10 × 30-m sprints with 30-second recovery and RSP2: 10 × 30-m sprints interspersed with self-selected recovery periods. Mean time of both 10 × 30-m RSPs and self-selected recovery periods of RSP2 were assessed. Heart rate, blood lactate concentration, and rates of perceived exertion were measured following RSPs. RESULTS: RSP2 revealed longer recovery periods (RSP1: 30.0 [0.0] s; RSP2: 39.0 [7.7] s; P < .001; effect size d = 1.648) with shorter repeated sprint time (mean 30-m sprint time: RSP1: 4.965 [0.256] s; RSP2: 4.865 [0.227] s; P = .014; d = 0.414). Blood lactate concentration (P = .002-.005; d = 0.730-0.958), heart rate (P < .001; d = 1.353), and rates of perceived exertion (RSP1: 14.9 [1.9]; RSP2: 12.9 [2.1]; P = .016; d = 1.046) were higher following RSP1. CONCLUSION: In contrast to the original studies, the present replication study demonstrated that self-selected recovery periods during a RSP leads to better repeated sprint performance compared with standardized recovery periods in youth soccer players. The better repeated sprint performance with individual recovery durations in RSP2 was achieved with less physiological and perceived effort.

Soccer-Specific Agility: Reliability of a Newly Developed Test and Correlates of Performance.

ABSTRACT: Altmann, S, Neumann, R, Ringhof, S, Rumpf, MC, and Woll, A. Soccer-specific agility: reliability of a newly developed test and correlates of rerformance. J Strength Cond Res 36(5): 1410-1416, 2022-The purpose of this study was to examine the reliability of a newly developed soccer-specific agility test and to determine the correlation of different performance parameters with overall agility performance as measured by the total time. Twenty-two amateur soccer players (age, 25.1 ± 4.0 years) completed a newly developed agility test on 2 separate occasions. The test required the players to conduct 2 changes of direction, one in a preplanned manner and one in response to a stimulus that was provided by a live tester who performed different soccer-specific passing movements. Regarding reliability, very large Pearson's r and intraclass correlation coefficient values were obtained for the total time and the movement time, with moderate and large-to-very large values being evident for the response time and the decision-making time, respectively. The usefulness to detect moderate performance changes was rated as "good" for the total time, the response time, and the movement time. The decision-making time was rated as "OK." The movement time showed a very large relationship with overall agility performance as measured by the total time, while the response time and the decision-making time showed small to moderate relationships. In conclusion, the newly developed soccer-specific agility test is a reliable tool to assess the agility performance of soccer players and can be used by coaches and researchers to detect moderate performance changes. Because physical aspects, represented by the movement time, showed the greatest influence on total agility performance, they are advised to be included in soccer-specific agility training programs of amateur players.

Are Physical Activity, Screen Time, and Mental Health Related During Childhood, Preadolescence, and Adolescence? 11-Year Results From the German Motorik-Modul Longitudinal Study.

Mental health (MH) and behavioral health are fundamental to a good quality of life. Only a few studies have investigated the association between behavioral health (e.g., physical activity (PA), screen time (ST)) and MH from childhood to adolescence. Therefore, we investigated the relationships of PA and ST with MH by sex in an 11-year longitudinal cohort study of German schoolchildren during 2003-2017. A subsample (n = 686; 55.2% female) of participants from the German Motorik-Modul (MoMo) Longitudinal Study who participated in all 3 measurement phases (mean ages: time 1 (baseline; 2003-2006), 5.57 (standard deviation (SD), 1.00) years; time 2 (wave 1; 2009-2012), 11.85 (SD, 1.03) years; time 3 (wave 2; 2014-2017), 16.86 (SD, 1.04) years) were analyzed with regard to PA, ST, and MH (emotional symptoms, conduct problems, hyperactivity/inattention, peer relationship problems, prosocial behavior, and overall strengths and difficulties). Path panel prediction models were fitted with time 1, time 2, and time 3 PA, ST, and MH indicators. PA predicted less television (TV)/video watching in females, and TV/video watching predicted personal computer (PC)/Internet use in both sexes. Behavior and MH results suggested that, for females, higher TV/video watching and PC/Internet use was related to higher MH challenges over the course of maturation. Some preadolescent males' MH challenges increased ST (TV/video watching and PC/Internet use) in adolescence. Researchers should explore innovative and effective methods for reducing childhood ST, especially among females with early signs of MH issues, and addressing preadolescent males' MH challenges.

The relationship of self-reported and device-based measures of physical activity and health-related quality of life in adolescents.

BACKGROUND: Physical activity (PA) has beneficial effects on health and health-related quality of life (HRQoL), which is a protective factor of illness and mortality. The purpose of this examination was to investigate if self-reported and device-based measures of PA were related to HRQoL in adolescents. METHODS: Participants (N = 1565; 54.3% female; Mage = 14.37 years, SDage = 1.99) were recruited from 167 sample points across Germany. Adolescents self-reported their PA, supplemented by a 1-week examination of device-based PA using accelerometry. Additionally, they completed the multidimensional KIDSCREEN-27 to assess HRQoL. RESULTS: Results showed that self-reported PA was correlated with overall HRQoL, Physical Well-Being, Psychological Well-Being, Social Support & Peers, and School Environment, whereas device-based PA was only correlated with Physical as well as Psychological Well-Being. Further, self-reported PA significantly predicted all facets of HRQoL except for Autonomy and Parent Relations, whereas device-based PA solely heightened the amount of explained variance in the Physical Well-Being subscale. CONCLUSIONS: Findings demonstrate the importance of self-reported PA as it is related to almost all facets of HRQoL. Both measures of PA are not congruent in their relationship with HRQoL and thus implications have to be carefully considered. Future studies should investigate the direct effect of PA on HRQoL and health in a longitudinal approach to account for the causality of effects.

Predictive value of physical fitness on self-rated health: A longitudinal study.

BACKGROUND: The self-rated health of adolescents and young adults is important for estimating future morbidities and mortality. Little is known about how physical fitness in younger populations predicts self-rated health. This longitudinal study (2003-2017) aims to explore the effects of physical fitness on self-rated health on the basis of the German population-based study KiGGS and its in-depth study, MoMo. METHODS: Self-rated health was assessed using a one-item scale, and physical fitness was measured with seven test items covering the dimensions of coordination, muscular fitness, and cardiorespiratory fitness. Longitudinal analyses were conducted using the structural equation modeling approach in Mplus 8.0 using the maximum likelihood estimator. RESULTS: The longitudinal samples of the KiGGS/MoMo study (T1, n = 2376; T2, n = 2821; and T3, n = 2047) had a mean age of 8.5, 14.8, and 20.0 years at T1, T2, and T3, respectively. All measurement and structural models had excellent model fits. While the results of the latent regression analysis indicated moderate-to-high stability for the coordination and muscular fitness dimensions, only low-to-moderate stability coefficients were found for cardiorespiratory fitness and self-rated health. Furthermore, small significant cross-lagged regression coefficients revealed that coordination and muscular fitness predicted self-rated health at later measurement points. CONCLUSION: To the best of our knowledge, this is the first longitudinal study to demonstrate the positive predictive value of two dimensions of physical fitness, coordination and muscular fitness, on self-rated health at a later stage. The public health implications are highlighted.