Does muscular fitness predict cardiorespiratory fitness in adolescent girls? A 3-year follow-up study.

The main purpose of the study was to establish, whether future cardiorespiratory fitness might be predicted by the level of muscular fitness at baseline. In this 3-year follow-up study, we recruited 240 secondary school girls at the age of 15 y, who were followed until the age of 17 y. Muscular fitness included the following tests: (i) standing broad jump (cm), (ii) sit-ups in 60 s (#) and (iii) squats in 60 s (#). Cardiorespiratory fitness was split into aerobic endurance (the 800-m run test) and speed endurance (the 400-m run test). Better performances in the 800-m run and the 400-m run tests at follow-up were correlated with higher levels of standing broad jump, sit-ups and squats in 60 s measured at baseline. In regression models adjusted for fat mass and maturity offset, standing broad jump, sit-ups and squats in 60 s were positively associated with the 800-m run test, while only standing broad jump remained significantly and positively associated with the 400-m run test. These data suggest that interventions enhancing muscular fitness should be recommended, as the effects are likely to be associated with future cardiorespiratory fitness in adolescent girls.

Tracking of anthropometric characteristics from childhood to adolescence: an 8-year follow-up findings from the Czech ELSPAC study.

BACKGROUND: Although evidence suggests that obesity track well from childhood to adolescence, most of the research has been done in Western and high-income countries. Moreover, most of the studies have tracked body-mass index, as a proxy of nutritional status, while tracking characteristics of circumferences and skinfold thicknesses have been less studies. Therefore, the main purpose of the study was to explore tracking characteristics of complete anthropometric data from childhood to adolescence. METHODS: This sub-study was part of the Czech ELSPAC study. In the present 8-year longitudinal study, we collected information from pediatrician's medical records at the ages of 8 y (n = 888), 11 y (n = 1065), 13 y (n = 811) and 15 y (n = 974), including circumferences (head, chest, waist, hips, and arm), indices (body-mass index, waist-to-hip ratio and waist-to-height ratio) and skinfold thicknesses (biceps, triceps, subscapula, suprailiaca, thigh and the sum of 5 skinfolds). Participants were recruited from the two selected regions of the Czech Republic (Brno and Znojmo). Linear generalized estimating equations were conducted to analyze tracking patterns over an 8-year follow-up period for all anthropometric measurements. RESULTS: Tracking coefficients were moderate to strong, ranging from 0.40 to 0.62 for circumferences, 0.41 to 0.74 for indices and 0.72 to 0.86 for skinfolds. According to body-mass index and waist circumference standards, overweight/obese children and children with abdominal obesity at the age of 8 y were 11.31 (95% CI = 8.41 to 15.22, p < 0.001) and 10.73 (95% CI = 7.93 to 14.52, p < 0.001) more likely to remain overweight/obese and to have abdominal obesity at the age of 15 y. CONCLUSIONS: Findings show moderate to strong tracking of anthropometric characteristics, i.e. circumferences track moderately well, while strong tracking for indices and skinfold thicknesses is observed. Moreover, strong tracking of general overweight/obesity and abdominal obesity between ages 8 y and 15 y indicates that the detection of these risk factors at the beginning of primary school should be advocated.

Tracking of health-related physical fitness in adolescent girls: a 3-year follow-up study.

BACKGROUND: Evidence has shown that higher levels of physical fitness (PF) in youth have beneficial effects on adult health-related outcomes. However, the tracking of separate PF components during adolescence has been less studied. Since PF often starts to rapidly decline during adolescence, it is necessary to provide information regarding critical time-point for interventions. This study aimed to analyze the extent of tracking the components of PF through PF tests. METHODS: In this longitudinal study, we recruited 240 adolescent girls with recoded data at 2 time-points (15 y and 17 y). PF included body composition (fat mass), explosive power of lower extremities (standing broad jump), muscle endurance of the trunk (sit-ups in 60 s), flexibility (sit-and-reach test), muscle endurance of lower extremities (squats in 60 s), aerobic endurance (the 800 m run test) and speed endurance (the 400 m run test). Tracking coefficients were calculated using generalized estimating equations. Tertiles (high, moderate and low) were calculated for each fitness component. RESULTS: The highest tracking coefficients between the two time-points were found for explosive power of lower extremities (ß = 0.98), followed by flexibility (ß = 0.89), body composition (ß = 0.88), speed endurance (ß = 0.86), aerobic endurance (ß = 0.75), muscle endurance of lower extremities (ß = 0.65), and muscle endurance of the trunk (ß = 0.51). Tertile ratings remained stable across the two time-points. CONCLUSIONS: Moderate to high tracking of PF in adolescent girls suggests that interventions aiming to increase the level of PF should probably begin in early adolescence.

Normative Values for Health-Related Physical Fitness in First-Year Police Officers.

ABSTRACT: Stefan, L, Kasovic, M, and Culej, M. Normative values for health-related physical fitness in first-year police officers. J Strength Cond Res 36(9): 2530-2535, 2022-The main aim of the study was to develop normative values for health-related physical fitness tests in first-year police officers. In this cross-sectional study, we recruited 773 police officers aged 19-28 years old (mean age ± SD = 22 ± 3 years, 34% women). Health-related physical fitness included: (a) polygon backwards (agility), (b) standing broad jump (explosive power of lower extremities), (c) sit-and-reach test (flexibility), and (d) 2.4 km run (aerobic capacity). In addition, maximal oxygen uptake (V̇ o2 max) was calculated. Sex- and age-specific centile smoothed curves for the 20th, 40th, 60 th , and 80th percentiles using Cole's LMS method were created. The results showed that men performed better in all health-related physical fitness tests ( p < 0.001), compared with women. The median values for polygon backwards, standing broad jump, sit-and-reach test, 2.4 km run and V̇ o2 max were 8 seconds, 210, 15 cm, 721 seconds and 49 mlO 2 ·kg -1 ·min -1 in men and 10 seconds, 165, 10 cm, 915 seconds and 39 mlO 2 ·kg -1 ·min -1 in women. No significant interaction between age and health-related physical fitness was observed. This study provides sex- and age-specific normative values for health-related physical fitness in police officers. Findings from this study may be used in detecting a group of police officers who have lower levels of physical fitness. Thus, policies aiming to enhance the level of physical fitness could be implemented within the system.

Normative data for the 6-min walk test in 11-14 year-olds: a population-based study.

BACKGROUND: The 6-min walk test (6MWT) has become an established measure for assessing exercise capacity in children with chronic diseases. However, little evidence has been provided regarding population-based normal data in healthy children. The main purpose of the study was to provide normative data in a large sample of children. METHODS: In this cross-sectional study, 4352 children between 11 and 14 years were recruited (66% girls). The main outcome measure was the distance walked for six minutes. Sex- and age-specific percentile values (5th, 15th, 25th, 50th, 75th, 85th and 95th) for the 6MWT were created and the differences and correlations were examined by the analysis of variance and Pearson's coefficient of correlation. RESULTS: The mean distance walked in 6 min was 576 ± 93 m in boys and 545 ± 92 m in girls, respectively. The mean walking speed for boys and girls was 98 ± 5 m/min and 91 ± 6 m/min. Older boys and girls performed better, compared to their younger counterparts (p for age < 0.001). The 6MWT was significantly correlated with age (r = 0.24, p < 0.001), height (r = 0.09, p < 0.001), weight (r = - 0.13, p < 0.001) and body-mass index (r = - 0.26, p < 0.001). CONCLUSIONS: This is the first population-based study aiming to provide normative data for the 6MWT in healthy children between 11 to 14 years. Children in lower percentiles are 'target groups' for special intervention aiming to enhance the performance.

Functional endurance capacity is associated with multiple other physical fitness components in 7-14-year-olds: a cross-sectional study.

BACKGROUND: Although evidence suggests that functional endurance capacity is the most important component associated with future health, little is known of how it is associated with multiple other physical fitness components. Since various physical fitness aspects do not change the same as functional endurance capacity during childhood, it is necessary to establish possible associations between functional endurance capacity and other physical fitness components in children. Therefore, the main purpose of the study was to test the associations between functional endurance capacity with other physical fitness components in 7-14-year-old children, stratified by gender. METHODS: In this cross-sectional study, we recruited 1612 children [mean age ± standard deviation (SD) = 9.72 ± 2.37 years; 52.5% girls). Health-related physical fitness components included: 1) body-mass index (kg/m2) calculated from height and weight (measure of body size), 2) sit-and-reach test (measure of flexibility), 3) standing broad jump (measure of explosive strength of lower extremities), 4) sit-ups in 30 s (measure of repetitive strength of the trunk), 5) 10 × 5 shuttle run test (measure of agility) and 6) 20-m shuttle run test (measure of functional endurance capacity). The associations were performed using generalized estimating equations with beta (ß) coefficients. RESULTS: After adjusting for age, functional endurance capacity was associated with sit-and-reach test (ß = 0.13, p < 0.001), standing broad jump (ß = 0.59, p < 0.001), sit-ups in 30 s (ß = 0.53, p < 0.001) and 10 × 5 shuttle run test (ß = - 0.56, p < 0.001) in boys. In girls, functional endurance capacity was associated with body-mass index (ß = - 0.12, p < 0.001), sit-and-reach test (ß = 0.21, p < 0.001), standing broad jump (ß = 0.25, p < 0.001), sit-ups in 30 s (ß = 0.36, p < 0.001) and 10 × 5 shuttle run test (ß = - 0.40, p < 0.001). No significant associations between functional endurance capacity and body-mass index in boys were observed. CONCLUSIONS: Although significant, functional endurance capacity is weakly to moderately associated with other physical fitness components, pointing out that such measure should be tested separately from other aspects of physical fitness in school-aged children.

Carrying Police Load Increases Gait Asymmetry in Ground Reaction Forces and Plantar Pressures Beneath Different Foot Regions in a Large Sample of Police Recruits.

BACKGROUND: Although carrying external load has negative effects on gait biomechanics, little evidence has been provided regarding its impact on body asymmetry. The main purpose of the present study was to examine, whether standardized equipment produced greater gait asymmetries in ground reaction force and plantar pressure. METHODS: For the purpose of this study, we recruited 845 police recruits (609 men and 236 women; 72.1% men and 27.9% women) measured in two conditions: (i) 'no load' and (ii) 'a 3.5 kg load'. Absolute values in ground reaction forces and plantar pressures beneath the different foot regions were assessed with pedobarographic platform (Zebris FDM). Asymmetry was calculated as (xright - xleft)/0.5 × (xright + xleft) × 100%, where 'x' represented a given parameter being calculated and a value closer to 0 denoted greater symmetry. RESULTS: Significant differences in ground reaction forces and plantar pressures between the left and right foot were observed, when adding 'a 3.5 kg load'. Compared to the 'no load' condition, carrying 'a 3.5 kg load' significantly increased gait asymmetries for maximal ground reaction forces beneath the forefoot (ES = 0.29), midfoot (ES = 0.20) and hindfoot (ES = 0.19) regions of the foot. For maximal plantar pressures, only the asymmetry beneath the midfoot region of the foot significantly increased (ES = 0.19). CONCLUSIONS: Findings of this study indicate that 'a 3.5 kg load' significantly increases ground reaction force and plantar pressure gait asymmetries beneath the forefoot and midfoot regions, compared to 'no load' condition. Due to higher loads, increases in kinetic gait asymmetries may have negative effects on future pain and discomfort in the foot area, possibly causing stress fractures and deviated gait biomechanics in police recruits.

Does a Standardized Load Carriage Increase Spatiotemporal Gait Asymmetries in Police Recruits? A Population-based Study.

INTRODUCTION: Although the effects of carrying loads on gait biomechanics have been well-documented, to date, little evidence has been provided whether such loads may impact spatial and temporal gait asymmetries under the different foot regions. Therefore, the main purpose of the study was to examine the effects of carrying a standardized police equipment on spatiotemporal gait parameters. MATERIALS AND METHODS: In this population-based study, participants were 845 first-year police recruits (age: 21.2 ± 2.3 years; height: 178.1 ± 10.2 cm; weight: 78.4 ± 11.3 kg; body mass index: 24.7 ± 3.2 kg/m2; 609 men and 236 women; 72.1% men and 27.9% women) measured in 2 conditions: (i) "no load" and (ii) "a 3.5 kg load." Spatiotemporal gait parameters were derived from the FDM Zebris pressure platform. Asymmetry was calculated as (xright-xleft)/0.5*(xright + xleft)*100%, where "x" represented a given parameter being calculated and a value closer to 0 denoted greater symmetry. RESULTS: When compared to "no load" condition, a standardized 3.5 kg/7.7 lb load significantly increased asymmetries in spatial gait parameters as follows: gait phases of stance (mean diff. = 1.05), load response (mean diff. = 0.31), single limb support (mean diff. = 0.56), pre-swing (mean diff. = 0.22), and swing (mean diff. = 0.90) phase, while no significant asymmetries in foot rotation, step, and stride length were observed. For temporal gait parameters, we observed significant asymmetries in step time (mean diff. = -0.01), while no differences in cadence and gait speed were shown. CONCLUSIONS: The findings indicate that the additional load of 3.5 kg/7.7 lb is more likely to increase asymmetries in spatial gait cycle components, opposed to temporal parameters. Thus, external police load may have hazardous effects in increasing overall body asymmetry, which may lead to a higher injury risk and a decreased performance for completing specific everyday tasks.

Allometric normalization of handgrip strength in older adults: Which body size parameter is the most appropriate?

BACKGROUND: Although absolute handgrip strength has been associated with health-related outcomes in older adults, little evidence has been provided regarding its adjustment by a variety of body size dimensions. Therefore, the main purpose of the study was to establish the most appropriate normalization of handgrip strength by different body size parameters in a large sample of noninstitutionalized older adults. METHODS: In this cross-sectional study, we enrolled 643 men and women aged > 60, who were part of the rehabilitation center facility program. Handgrip strength was objectively measured using a Jamar Plus* + Digital Hand Dynamometer. Body size parameters included body weight and height, body mass index, waist circumference, waist-to-height ratio, fat mass and fat-free mass. The most appropriate parameter associated with handgrip strength was identified using allometry. RESULTS: Findings showed that the most appropriate body size parameter for handgrip strength normalization was height (allometric exponent: 0.85), compared to fat-free mass (0.26) and body mass (0.12). Other body size variables were not significantly associated with handgrip strength and were omitted from further analyses. The correlations between normalized handgrip strength were significant when handgrip strength was normalized by body mass and fat-free mass, while no significant correlations were found, when handgrip strength was normalized by body height. CONCLUSION: Based on the study results, body height seems to be the best body size parameter for handgrip strength normalization in older adults, omitting the influence of body size on strength performance. If handgrip strength is measured, body height may help normalize strength for large-scale research.

Effects of Load Carriage on Postural Sway and Relative Ground Reaction Forces in Special Police Officers: A Cross-Sectional Study.

Although excessive load carriage results in biomechanical gait changes, little evidence has been provided regarding its impact on postural sway. Therefore, the main purpose of this study was to determine whether heavier loads have effects on changing foot stability and postural sway in special police officers. Thirty male special police officers (age = 40 ± 6 years, height = 180 ± 5 cm, weight = 89 ± 8 kg) were assessed in four conditions: (1) carrying no load, (2) carrying a 5 kg load, (3) carrying a 25 kg load, and (4) carrying a 45 kg load. Foot characteristics during standing were assessed with Zebris pedobarographic pressure platform. Heavier loads increased the center of pressure (COP) path length and average velocity, length of minor and major axis, and 95% confidence ellipse area, while a decrease in angle between Y and major axis was observed. Relative forces beneath the left forefoot and right backfoot regions decreased and an increase in relative forces beneath the left backfoot and right forefoot was observed. When carrying heavy loads, static foot parameters rapidly changed, especially in COP path length and average velocity.

Maternal Pre-Pregnancy Nutritional Status and Physical Activity Levels and a Sports Injury Reported in Children: A Seven-Year Follow-Up Study.

OBJECTIVE: Our aim was to analyze dose-response associations between maternal pre-pregnancy body mass index and physical activity levels with childhood sports injury rates. METHODS: Participants included pre-pregnant mothers (n = 4811) and their children at the age of 7 years (n = 3311). Maternal anthropometry (height, weight, and body mass index), time spent in physical activity, and education level were recorded. All sports injuries were defined as injuries reported in the past year by the children at the age of 7 years. RESULTS: Children whose mothers were overweight/obese in the pre-pregnancy period were 2.04 (OR = 2.04, 95% CI = 1.12-3.71) times more likely to report a sports injury at the age of 7 years. Underweight mothers exhibited a 74% decrease in the odds of their children reporting a sports injury at follow-up (OR = 0.26, 95% CI = 0.10-0.68). Finally, an increase in maternal physical activity across the last three quartiles was associated with a lower odds of sports injuries. CONCLUSIONS: The risk of reporting a sports injury was greater for children whose mothers were overweight/obese in the pre-pregnancy period. However, there was a lower risk with both maternal underweight status and increasing minutes of physical activity.

Longitudinal associations between sport participation and fat mass with body posture in children: A 5-year follow-up from the Czech ELSPAC study.

The main purpose of the study was to examine longitudinal associations between sport participation and fat mass with body posture in children. We used data from children recruited in the Czech European Longitudinal Study of Pregnancy and Childhood (CELSPAC) at the ages of 11 y (n = 1065), 13 y (n = 811) and 15 y (n = 974). Information on body posture, practicing sport in a club and at a competitive level, and skinfold thicknesses (biceps, triceps, subscapula, suprailiaca and thigh) from pediatrician's medical records were collected. Body posture was inspected by a pediatrician. The sum of 5 skinfolds was used as a proxy of fat mass. The 85th and 95th percentiles defined 'overfat' and 'obese'children. Practicing sport in a club and at a competitive level were included as 'yes/no' answers. General linear mixed models with risk ratios (RR) and 95% confidence intervals (95% CI) were calculated. Overall, 35.6% of children and adolescents had impaired body posture; the prevalence of 'incorrect' body posture increased by age (from 41.0% to 28.0%, p<0.001). Practicing sport in a club and at a competitive level decreased by follow-up (p<0.001), while the level of 'overfat' and 'obese' children increased (p<0.01). In separate models, 'incorrect' body posture was associated with non-practicing sport in clubs (RR = 1.68; 95% CI 1.43-1.97, p<0.001) or at competitive level (RR = 1.61; 95% CI 1.37-1.88, p<0.001) and with being 'overfat' (RR = 2.05; 95% CI 1.52-2.75, p<0.001) and 'obese' (RR = 2.15; 95% CI 1.68-2.75, p<0.001). When all variables were put simultaneously into the model additionally adjusted for sex, self-rated health and baseline body posture, similar associations remained. This study shows, that not participating in sport and being overfat/obese are longitudinally associated with 'incorrect' body posture. Therefore, the detection of these risk factors in childhood, through the development of school- and community-based interventions, should be advocated.

Tracking of Maternal Physical Activity and Sport Participation over 11 Years: Findings from the Czech ELSPAC Study.

Purpose: Tracking of physical activity (PA) and sport participation (SP) during motherhood is poorly understood. The purpose of the study was to analyze the extent of tracking of maternal PA and SP. Methods: In this investigation, data were collected from the Czech ELSPAC study subsample of 4811 and 2609 women measured postnatally (1991-1992) and after 11 years of follow-up (2002-2003), respectively. The structured questionnaire was used to assess the participation and average weekly time spent in PA, and the frequency of engaging in different sports (running, cycling, strength training, racket sports, swimming, and team sports). Tracking was calculated using generalized estimating equations (GEE) with beta coefficients (ß), odds ratios (ORs), and 95% confidence intervals (95% CI). Results: Moderately high tracking coefficients were observed for cycling (ß = 0.69, 95% 0.67-0.72), strength training (ß = 0.59, 95% 0.56-0.63), and weekly time spent in PA (ß = 0.53, 95% 0.38-0.66); meanwhile, moderate tracking coefficients were generated for swimming (ß = 0.48, 95% 0.44-0.52), team sports (ß = 0.44, 95% 0.39-0.48), racket sports (ß = 0.44, 95% 0.39-0.48), and running (ß = 0.35, 95% 0.30-0.40). Mothers who did not participate in PA at baseline were 81% more likely not to participate in it at follow-up (OR = 1.81, 95% CI 1.53-2.13). Conclusion: Cycling- and strength-related activities and weekly PA were tracked moderately-to-moderately high during motherhood. Moreover, the strong tracking of physical inactivity indicates that the detection of this risk factor before pregnancy should be advocated.

Acute Responses to Resistance Training on Body Composition, Muscular Fitness and Flexibility by Sex and Age in Healthy War Veterans Aged 50-80 Years.

Background: Although evidence suggests that resistance training should be prescribed as a method to enhance or maintain physical fitness, these findings are mostly based on research on younger men. Studies investigating responses by sex and age to resistance training, especially in war veterans aged ≥50 years, are lacking. Therefore, the main purpose of this study was to examine whether a 4-week resistance training program would have similar effects on body composition, muscular fitness, and flexibility in men and women aged 50−80 years. Methods: Seven-hundred and sixty-four participants were recruited and categorized into two groups each of men and women aged 50−64 and 65−80 years. The training intervention lasted 4 weeks and consisted of three 60 min sessions per week. All participants were tested for each of the following physical fitness components: body composition, push-ups in 30 s, chair-stands in 30 s, sit-ups in 30 s, and a sit-and-reach test. Results: Over the intervention period of 4 weeks, body weight (p = 0.002) and the percent of fat mass (p < 0.001) decreased, while the percent of lean mass (p < 0.001) in push-ups in 30 s (p < 0.001), chair-stands in 30 s (p < 0.001), sit-ups in 30 s (p < 0.001), and sit-and-reach (p < 0.001) increased. Significant time*age interactions were shown for push-ups in 30 s (F1,763 = 4.348, p = 0.038) and chair-stands in 30 s (F1,763 = 9.552, p = 0.002), where men and women aged 50−64 years exhibited larger time-induced changes compared to their older (65−80 yr) counterparts. Effect sizes were similar between sex- and age-specific groups. Conclusions: The 4-week resistance training produced similar pronounced positive effects on body composition, muscular fitness, and flexibility, while men and women aged 50−64 years displayed significantly larger improvements in upper and lower muscular fitness compared with their 65−80-year-old counterparts.

The associations between health-related physical fitness and fasting blood glucose in war veterans: a population-based study.

The main purpose of the study was to analyze the associations between health-related physical fitness and fasting blood glucose in war veterans. In this cross-sectional study, we recruited 764 men and women aged 45-75 years, who were part of the Homeland War between 1990 and 1995 (33.5% women). Health-related physical fitness included: (1) fat mass and fat-free mass (body composition), (2) push-ups in 30 s (muscular dynamic endurance of upper extremities), (3) sit-ups in 30 s (repetitive upper body strength), (4) chair-stands in 30 s (lower body strength), (5) sit-and-reach test (flexibility) and (6) the 2-min step test (cardiorespiratory function). Laboratory measurement of fasting blood glucose was performed according to standardized procedures in resting seated position after a 12-h overnight fast. Generalized estimating equations with multiple regression models were used to calculate the associations between health-related physical fitness and fasting blood glucose. In men, fasting blood glucose was significantly correlated with fat-free mass (ß = - 0.25, p < 0.001), push-ups in 30 s (ß = - 0.55, p < 0.001), chair-stands in 30 s (ß = - 0.50, p < 0.001), sit-ups in 30 s (r = - 0.45, p < 0.001), the sit-and reach test (r = - 0.46, p < 0.001) and the 2-min step test (r = - 0.19, p < 0.001), while fat mass was positively correlated with fasting blood glucose (ß = 0.14, p = 0.004). In women, fasting blood glucose was significantly correlated with fat mass (ß = 0.20, p = 0.002), fat-free mass (ß = - 0.15, p = 0.014), push-ups in 30 s (ß = - 0.49, p < 0.001), chair-stands in 30 s (ß = - 0.43, p < 0.001), sit-ups in 30 s (ß = - 0.52, p < 0.001), the sit-and reach test (ß = - 0.40, p < 0.001) and the 2-min step test (ß = - 0.35, p < 0.001). This study shows that fasting blood glucose may be predicted by health-related physical fitness test in war veterans.

Defining Optimal Cut-Points for Cardiorespiratory Fitness Associated With Overweight/Obesity in Children: A School-Based Study.

The main purpose of the study was to define optimal criterion-referenced cut-points for cardiorespiratory fitness (CRF) associated with overweight/obesity. In this cross-sectional study, participants were 1,612 children aged 7-14 years (mean age ± SD = 9.7 ± 2.4 years; 52.5% girls). CRF was assessed by the Maximal multistage 20-m shuttle run test, from which maximal oxygen uptake (VO2max) was estimated. Anthropometric indices included body-mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR). Receiver operating characteristic (ROC) curves were performed to determine cut-off points. In boys, the optimal cut-off points of CRF in defining overweight/obesity for BMI, WC, and WHtR were 44.6, 46.4, and 46.9 mlO2/kg/min. The areas under the curves (AUC) were 0.83 (95% CI 0.78-0.88, p < 0.001), 0.77 (95% CI 0.71-0.83, p < 0.001), and 0.90 (95% CI 0.86-0.93, p < 0.001). In girls, the optimal cut-off points were 41.0, 40.8, and 40.7 mlO2/kg/min for BMI, WC, and WHtR, with the AUCs of 0.86 (95% CI 0.82-0.90, p < 0.001), 0.83 (95% CI 0.79-0.88), and 0.88 (95% CI 0.84-0.93, p < 0.001). In conclusion, our newly developed cut-off points for CRF assessed by the Maximal multistage 20-m shuttle run test may adequately detect primary school-aged boys and girls with general and abdominal obesity.

Normative Data for Musculoskeletal Fitness in 13,217 Children and Adolescents: The Croatian Fitness (CROFIT) Study.

Purpose: The main purpose of the study was to establish normative data for health-related musculoskeletal fitness. Method: We recruited 13,217 children and adolescents aged 11-18 years (6,181 boys and 7,036 girls; 57% of girls). To evaluate musculoskeletal fitness, the following field tests were applied: standing broad jump (cm), sprint 20 m (sec), medicine-ball throw (dm), sit-ups in one minute (#), sit-ups in one minute (short, #), and squats in one minute (#). Curves for the 10th, 20th, 30th, 40th, 50th (median), 60th, 70th, 80th, and 90th percentiles were calculated using the Lambda (L), Mu (M), and Sigma (S) method. The LMS method assumes that the data can be normalized by using a power transformation and removing the skewness. Results: Median scores for standing broad jump, sprint 20 m, medicine-ball throw, sit-ups in one minute, sit-ups in one minute (short) and squats in one minute were 185.00 cm, 3.66 sec, 80.00 dm, 46.00 x, 56.00 x and 49 x in boys and 160.00 cm, 4.01 sec, 60.00 dm, 40.00 x, 49.00 and 43 x in girls. Effect sizes (ES) showed that boys performed better in all physical fitness tests (ES = 0.50-1.05), compared to girls. In general, age-related physical fitness changes showed the plateau between ages 15 and 16 in boys, while in girls, the plateau was reached at the age of 14. Conclusions: This study shows standards for musculoskeletal tests in youth.

Associations between Fat Mass and Fat Free Mass with Physical Fitness in Adolescent Girls: A 3-Year Longitudinal Study.

The main purpose of the study was to examine the longitudinal associations between fat mass and fat free mass with health-related physical fitness. Two-hundred and forty 15-year old adolescent girls were measured at the baseline and after a period of 3 years (17 years). Health-related physical fitness included the following tests: (1) explosive power of the lower extremities (standing broad jump); (2) muscle endurance of the trunk (sit-ups in 60 s); (3) flexibility (sit-and-reach test); (4) muscle endurance of the lower extremities (squats in 60 s); (5) aerobic endurance (the 800 m run test); and (6) speed endurance (the 400 m running test). Fat mass and fat free mass were assessed using the bioelectrical impedance method. Longitudinal associations were analyzed with linear mixed model estimates. After adjusting for body mass index, fat mass was negatively associated with standing broad jump (ß = −1.13, p < 0.001), sit-ups in 60 s (ß = −0.27, p < 0.001), and squats in 60 s (ß = −0.27, p < 0001), while positive associations with the 800 m running test (ß = 0.02, p < 0.001) and the 400 m running test (ß = 0.02, p < 0.001) were observed. On the other hand, fat free mass was positively associated with standing broad jump (ß = 1.14, p < 0.001), sit-ups in 60 s (ß = 0.28, p < 0.001), and squats in 60 s (ß = 0.28, p < 0001), while the 800 m running test (ß = −0.02, p < 0.001) and the 400 m running test (ß = −0.02, p < 0.001) exhibited negative associations. This study shows that fat mass and fat free mass components are longitudinally, but oppositely associated with health-related physical fitness in adolescent girls.

Spatio-Temporal Gait Parameters in Association with Medications and Risk of Falls in the Elderly.

Purpose: The aim of this study was to analyze factors affecting spatio-temporal gait parameters in elderly people of both genders and different ages with different risks of fall, fall history, and medications. Patients and Methods: A total of 210 community-dwelling older adults (156 females, 54 males; mean age 72.84±6.26 years) participated in this study. To assess the risk of falls, the Downton Fall Risk Index was used. An additional question about medication intake (all prescribed drugs) was asked. To assess the spatio-temporal gait parameters, the Zebris FDM platform was used. Gait parameters and Downton Fall Risk Index, stratified by participants' history of falls, multiple medication use (0/1/2+), gender, age, and medication categories, were statistically analyzed using the Mann-Whitney U-test and Kruskal-Wallis test. Results: When comparing different medication categories, a Downton Fall Risk Index score indicating a high risk of falls was observed in the psychotropic medication category (3.56±1.67). A gait velocity suggesting a higher risk of falls (≤3.60 km/h) was observed in the psychotropic (2.85±1.09 km/h) and diabetes (2.80±0.81 km/h) medication categories, in the age groups 70-79 years (3.30±0.89 km/h) and 80+ years (2.67±0.88 km/h), and in participants using two or more medications (3.04±0.93 km/h). Conclusion: The results of this study confirm previous observations and show that higher age and multiple medication negatively affect the gait, and that the higher risk of falls is associated with psychotropic and diabetes medication use. These results provide important information for future fall preventive programs for the elderly that would be especially beneficial for elderly people taking psychotropic and diabetes medication.

Electromyographic analysis of the knee using fixed-activation threshold after anterior cruciate ligament reconstruction.

The aim of this study was to establish whether there are any electromyographic (EMG) differences after two different surgical techniques in two years follow-up after anterior cruciate ligament (ACL) reconstruction. Study participants were divided into three groups. The control group included healthy athletes (C), the first study group (E1) consisted of injured athletes who were treated by ACL reconstruction using patellar tendon graft and the second study group (E2) comprised injured athletes treated by gracilis and semitendinosus tendon graft. The threshold of muscle activity was defined as 30% of maximum amplitude of EMG signal medial envelope of individual muscles in the control group. Two years after reconstruction, the E2 group achieved the maximum amplitude of biceps femoris muscle signal in the takeoff phase statistically significantly later than the E1 group (0.0166, p = 0.05 and 0.015152, p = 0.05/3 = 0.016), whereas the rectus femoris muscle in the flight phase in the E2 group improved statistically significantly earlier than in the C group (0.0393, p = 0.05 and 0.025974, p = 0.05/3 = 0.016). The results of this study show particularly statistically significant differences between observed surgery techniques, which led to the change of the neuromuscular pathway during simple and controlled knee movements even two years after ACL reconstructions in athletes who returned to active training. These disturbances of muscle work coordinations in the knee joint could be tied to the function and location from which the graft was taken rather than the quality of the transplant itself. This may result in an increased risk of repeated knee injury, including potential permanent health consequences in athletes. Based on the results of this research, we were unable to establish which of the presented ACL reconstruction techniques is more appropriate. This study may be useful for athletes and their coaches, who could plan, programme and adequately adjust their training process, thereby improving knee function in the best possible way, which in turn would maintain and extend athletes' respective sports careers.