cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.20017458.v1
title: Cardiorespiratory response and energy expenditure during exercise at maximal lactate steady state

description: There has been little research regarding cardiorespiratory responses during submaximal exercise at the maximal lactate steady state intensity (MLSSint) until exhaustion. The objective of this study was to investigate the responses of oxygen consumption (VO2), heart rate (HR) and oxygen pulse (O2 pulse) during exercise to exhaustion at MLSSint, and to compare energy expenditure (EE) estimated by VO2 and HR. Twelve trained athletes followed an incremental protocol on a cycle ergometer to determine maximal and submaximal parameters of aerobic metabolism. On subsequent occasions they performed 2 to 4 30-minute tests with constant load to identify MLSSint. Finally, they underwent a test to exhaustion at MLSSint. Cardiorespiratory parameters were measured continuously during all tests. During the test to exhaustion, physiological responses were compared for six points in time calculated as percentages of the time to exhaustion (TTE). Mean TTE was 55.1±10.2 min. Oxygen pulse presented significant reduction over time, decreasing to a value 9% lower than baseline at the exhaustion point. This fact was the result of increases in HR over time that was disproportional to the increase in VO2, resulting in significant differences between EE estimates. Therefore, there appears to be a gradual loss of cardiorespiratory efficiency during exercise to exhaustion at MLSSint that is shown by the reduction in O2 pulse. The direct relationship between VO2 and HR with workload presents variations over the course of exercise, leading to errors when EE is estimated using HR.
DOI: 10.6084/m9.figshare.20017459
title: Trunk stabilization exercises for healthy individuals

description: The aim of this study was to analyze the trunk muscular response during different variations of some of the most popular stabilization exercises: front-bridge, back-bridge, side-bridge, and bird-dog. Surface electromyography was bilaterally recorded from rectus abdominis, external and internal oblique and erector spinae during 25 variations of the aforementioned exercises. Compared to the conventional form of the front- and side-bridge, performing these exercises kneeling on a bench or with elbows extended reduced the muscular challenge. Conversely, performing the back-bridge with elbows extended elicited higher muscular activation than the conventional exercise. While bridge exercises with double leg support produced the highest activation levels in those muscles that counteracted gravity, single leg support while bridging increased the activation of the trunk rotators, especially internal oblique. The highest activation levels were found in three exercises: sagittal walkout in a front-bridge position, rolling from right side-bridge into front-bridge position, and side-bridge with single leg support on a BOSUTMbalance trainer. Although the exercises performed on unstable surfaces usually enhanced the muscle activation, performing the exercises on the BOSUTMbalance trainer did not always increase the trunk muscle activity. Overall, this information may be useful to guide fitness instructors and clinicians when establishing stabilization exercise progressions for the trunk musculature.
DOI: 10.6084/m9.figshare.20017459.v1
title: Trunk stabilization exercises for healthy individuals

description: The aim of this study was to analyze the trunk muscular response during different variations of some of the most popular stabilization exercises: front-bridge, back-bridge, side-bridge, and bird-dog. Surface electromyography was bilaterally recorded from rectus abdominis, external and internal oblique and erector spinae during 25 variations of the aforementioned exercises. Compared to the conventional form of the front- and side-bridge, performing these exercises kneeling on a bench or with elbows extended reduced the muscular challenge. Conversely, performing the back-bridge with elbows extended elicited higher muscular activation than the conventional exercise. While bridge exercises with double leg support produced the highest activation levels in those muscles that counteracted gravity, single leg support while bridging increased the activation of the trunk rotators, especially internal oblique. The highest activation levels were found in three exercises: sagittal walkout in a front-bridge position, rolling from right side-bridge into front-bridge position, and side-bridge with single leg support on a BOSUTMbalance trainer. Although the exercises performed on unstable surfaces usually enhanced the muscle activation, performing the exercises on the BOSUTMbalance trainer did not always increase the trunk muscle activity. Overall, this information may be useful to guide fitness instructors and clinicians when establishing stabilization exercise progressions for the trunk musculature.
DOI: 10.6084/m9.figshare.20017461.v1
title: Influence of sexual maturation on cardiorespiratory fitness in school children

description: Levels of aerobic fitness of children and adolescents are declining worldwide, which results in increased health risks. In Brazil, approximately 60% of the students present levels of fitness lower than recommended for age and sex. Our objective was to determine the influence of sexual maturation and physical activity level on cardiorespiratory fitness of schoolchildren of both sexes aged 9-14 years. This was a cross-sectional including a sample of 747 individuals (47.12% female) aged 9 to 14 years enrolled in public schools. The participants completed the Physical Activity Questionnaire for Children (PAQ-C) and a questionnaire on sexual maturation, and performed the shuttle run test. In order to verify the influence of sexual maturation on VO2max, students were categorized according to maturation stage (prepubertal, pubertal and postpubertal), sex, and interaction between sex and maturation. ANOVA was used to compare mean maturation stages and to assess whether sex and maturation affect VO2max. There was influence of maturation (p &lt;0.0001; Eta2 = 0.069, power = 1) and sex (p &lt;0.0001; Eta2 = 0.059, power = 1) on aerobic fitness. VO2max values were different between the maturation stages in both sexes, and between sexes at the same maturation stage. Maturation influenced VO2max with a decreasing linear trend (p &lt;0.0001; Eta2 = 0.221, power = 1) for females. An influence of maturation and physical activity level on cardiorespiratory fitness was observed in schoolchildren of Aracaju city.
DOI: 10.6084/m9.figshare.20017461
title: Influence of sexual maturation on cardiorespiratory fitness in school children

description: Levels of aerobic fitness of children and adolescents are declining worldwide, which results in increased health risks. In Brazil, approximately 60% of the students present levels of fitness lower than recommended for age and sex. Our objective was to determine the influence of sexual maturation and physical activity level on cardiorespiratory fitness of schoolchildren of both sexes aged 9-14 years. This was a cross-sectional including a sample of 747 individuals (47.12% female) aged 9 to 14 years enrolled in public schools. The participants completed the Physical Activity Questionnaire for Children (PAQ-C) and a questionnaire on sexual maturation, and performed the shuttle run test. In order to verify the influence of sexual maturation on VO2max, students were categorized according to maturation stage (prepubertal, pubertal and postpubertal), sex, and interaction between sex and maturation. ANOVA was used to compare mean maturation stages and to assess whether sex and maturation affect VO2max. There was influence of maturation (p &lt;0.0001; Eta2 = 0.069, power = 1) and sex (p &lt;0.0001; Eta2 = 0.059, power = 1) on aerobic fitness. VO2max values were different between the maturation stages in both sexes, and between sexes at the same maturation stage. Maturation influenced VO2max with a decreasing linear trend (p &lt;0.0001; Eta2 = 0.221, power = 1) for females. An influence of maturation and physical activity level on cardiorespiratory fitness was observed in schoolchildren of Aracaju city.
DOI: 10.6084/m9.figshare.20017464
title: Body composition in portuguese adolescents: are physical activity and maturity status sex-specific determinant factors?

description: The influence of biological maturation and physical activity (PA) on the differences of body composition in adolescents have been little studied. The purpose of this study was to examine if PA and maturity status were sex-specific determinant factors in the adolescents' body composition. Ninety-four adolescents (50 boys and 44 girls) were evaluated. All anthropometric measures were obtained according to ISAK procedures, bone age was estimated by the TW3 method, and PA was assessed with Actigraph (r) GT1M, over seven consecutive days. Maturity status explained 33% of the body mass index (BMI) and waist circumference (WC) and 31% of the sagittal abdominal diameter (SAD) in boys. In girls, maturity status explained 27% of the waist-to-hip ratio (WHR), moderate PA explained 17% of the BMI and 12% of the WC, and moderate to vigorous PA explained 11% of the SAD. These results seem to indicate that the determinant factors of the adolescents' body composition are sex-specific. Maturity status was the main predictive factor in boys and interacted with PA in girls. Our findings support the evidence that researchers need to consider biological maturity when explaining body composition changes in adolescents.
DOI: 10.6084/m9.figshare.20017464.v1
title: Body composition in portuguese adolescents: are physical activity and maturity status sex-specific determinant factors?

description: The influence of biological maturation and physical activity (PA) on the differences of body composition in adolescents have been little studied. The purpose of this study was to examine if PA and maturity status were sex-specific determinant factors in the adolescents' body composition. Ninety-four adolescents (50 boys and 44 girls) were evaluated. All anthropometric measures were obtained according to ISAK procedures, bone age was estimated by the TW3 method, and PA was assessed with Actigraph (r) GT1M, over seven consecutive days. Maturity status explained 33% of the body mass index (BMI) and waist circumference (WC) and 31% of the sagittal abdominal diameter (SAD) in boys. In girls, maturity status explained 27% of the waist-to-hip ratio (WHR), moderate PA explained 17% of the BMI and 12% of the WC, and moderate to vigorous PA explained 11% of the SAD. These results seem to indicate that the determinant factors of the adolescents' body composition are sex-specific. Maturity status was the main predictive factor in boys and interacted with PA in girls. Our findings support the evidence that researchers need to consider biological maturity when explaining body composition changes in adolescents.
DOI: 10.6084/m9.figshare.20017465
title: Slow component of VO2 kinetics: physiological determinants and implications for performance in aerobic exercises

description: Oxygen uptake (VO2) kinetics and blood lactate response during constant workload exercise at different intensities allow characterizing the moderate, heavy and severe exercise domains. In constant-intensity exercise, the VO2response profile, analyzed by exponential fits, shows the cardiodynamic, fundamental and slow phases. The occurrence of the slow component (SC) has been associated with factors such as the recruitment of type II fibers and the accumulation of metabolites such as lactate, ions H+, inorganic phosphate and adenosine diphosphate. The SC expresses a reduction of muscular efficiency and has been associated with lower tolerance to high-intensity aerobic exercise. The present study aimed to detail the theoretical framework of its occurrence and its influence on exercise tolerance, as well as providing the different procedures used in its quantification.
DOI: 10.6084/m9.figshare.20017465.v1
title: Slow component of VO2 kinetics: physiological determinants and implications for performance in aerobic exercises

description: Oxygen uptake (VO2) kinetics and blood lactate response during constant workload exercise at different intensities allow characterizing the moderate, heavy and severe exercise domains. In constant-intensity exercise, the VO2response profile, analyzed by exponential fits, shows the cardiodynamic, fundamental and slow phases. The occurrence of the slow component (SC) has been associated with factors such as the recruitment of type II fibers and the accumulation of metabolites such as lactate, ions H+, inorganic phosphate and adenosine diphosphate. The SC expresses a reduction of muscular efficiency and has been associated with lower tolerance to high-intensity aerobic exercise. The present study aimed to detail the theoretical framework of its occurrence and its influence on exercise tolerance, as well as providing the different procedures used in its quantification.
DOI: 10.6084/m9.figshare.20017467
title: Relationship between obesity and biochemical markers in Brazilian adolescents

description: The aim of this study was to describe the prevalence of biochemical markers and associate with obesity in Brazilian adolescents enrolled in public schools in a rural area. The sample consisted of 199 adolescents between 10 to 14 years old from Piracicaba, Brazil. The obesity was measured by body mass index (BMI) and according to the World Health Organization curves. We collected blood for biochemical markers analysis (total cholesterol, high density lipoprotein, low density lipoprotein, triacylglycerol, insulin and glycemia). Mann Whitney test was used to compare continuous variables between sexes. Chi-square test was used to compare proportions. To investigate the association between the independent variables and biochemical markers a multiple logistic regression model was performed. Among 199 adolescents, 23.1% was obese and 65.8% were insufficiently active. A high prevalence of dyslipidemia (71.4%) was observed, whereas the low levels of high density lipoprotein (40.7%) were the most prevalent. An association between obesity and undesirable values for high density lipoprotein, triacylglycerol and insulin resistance was found. Obese adolescents were less likely to present a desirable value for high density lipoprotein. It is understood that obesity is detrimental to metabolic profile and should be prevented and treated even in adolescence.
DOI: 10.6084/m9.figshare.20017467.v1
title: Relationship between obesity and biochemical markers in Brazilian adolescents

description: The aim of this study was to describe the prevalence of biochemical markers and associate with obesity in Brazilian adolescents enrolled in public schools in a rural area. The sample consisted of 199 adolescents between 10 to 14 years old from Piracicaba, Brazil. The obesity was measured by body mass index (BMI) and according to the World Health Organization curves. We collected blood for biochemical markers analysis (total cholesterol, high density lipoprotein, low density lipoprotein, triacylglycerol, insulin and glycemia). Mann Whitney test was used to compare continuous variables between sexes. Chi-square test was used to compare proportions. To investigate the association between the independent variables and biochemical markers a multiple logistic regression model was performed. Among 199 adolescents, 23.1% was obese and 65.8% were insufficiently active. A high prevalence of dyslipidemia (71.4%) was observed, whereas the low levels of high density lipoprotein (40.7%) were the most prevalent. An association between obesity and undesirable values for high density lipoprotein, triacylglycerol and insulin resistance was found. Obese adolescents were less likely to present a desirable value for high density lipoprotein. It is understood that obesity is detrimental to metabolic profile and should be prevented and treated even in adolescence.
DOI: 10.6084/m9.figshare.20017468
title: Morphological, maturational, functional and technical profile of young Brazilian soccer players

description: The objectives of this study were to describe and compare the anthropometric profile, physical fitness and soccer-specific skills between under-15 and under-17 Brazilian soccer players, as well as to evaluate possible differences in these variables according to biological maturation in the age categories. The sample consisted of 245 male soccer players (under-15: n=161; under-17: n=84). Anthropometric measures included weight, height and skinfolds. Biological maturation was assessed based on pubic hair development. The following tests were used for functional assessment: static and countermovement jump, Yo-Yo intermittent endurance test (level 2), RAST, 5- and 30-meter running speed, and agility T-test. Soccer-specific skills were assessed using three tests: ball control, dribbling, and kick accuracy. Descriptive statistics, t-test and analysis of variance (ANOVA) were used for statistical analysis. The results showed a larger body size (stature and body mass), longer sports experience (years of formal training) and better performance in most of the functional tests for under-17 soccer players compared to under-15 players. There were no significant differences in adiposity or soccer-specific skills between levels of competition. Significant differences as a function of maturation stage were observed in anthropometric and functional variables only in the under-15 category. In conclusion, the under-17 category differs from the under-15 category in terms of anthropometric and physical fitness characteristics. However, no difference was observed in two of the three soccer-specific skills. Physical fitness components and soccer-specific skills were associated with maturity only in the under-15 category.
DOI: 10.6084/m9.figshare.20017468.v1
title: Morphological, maturational, functional and technical profile of young Brazilian soccer players

description: The objectives of this study were to describe and compare the anthropometric profile, physical fitness and soccer-specific skills between under-15 and under-17 Brazilian soccer players, as well as to evaluate possible differences in these variables according to biological maturation in the age categories. The sample consisted of 245 male soccer players (under-15: n=161; under-17: n=84). Anthropometric measures included weight, height and skinfolds. Biological maturation was assessed based on pubic hair development. The following tests were used for functional assessment: static and countermovement jump, Yo-Yo intermittent endurance test (level 2), RAST, 5- and 30-meter running speed, and agility T-test. Soccer-specific skills were assessed using three tests: ball control, dribbling, and kick accuracy. Descriptive statistics, t-test and analysis of variance (ANOVA) were used for statistical analysis. The results showed a larger body size (stature and body mass), longer sports experience (years of formal training) and better performance in most of the functional tests for under-17 soccer players compared to under-15 players. There were no significant differences in adiposity or soccer-specific skills between levels of competition. Significant differences as a function of maturation stage were observed in anthropometric and functional variables only in the under-15 category. In conclusion, the under-17 category differs from the under-15 category in terms of anthropometric and physical fitness characteristics. However, no difference was observed in two of the three soccer-specific skills. Physical fitness components and soccer-specific skills were associated with maturity only in the under-15 category.
DOI: 10.6084/m9.figshare.20017470
title: Lower limb joint alignment and postural control in elderly women

description: The aim of this study was to test whether quiet stance body sway is associated with ankle and knee joint angles in elderly women. Joint angles were measured using a manual goniometer and body sway was assessed using a force platform and four postural tasks with a combination of feet positions and eye condition. The sample (N = 58) showed the following angle values: 102 (100-104) for the tibiotarsal joint, 176 (174-180) for the subtalar joint, 184 (181-187) for knee flexion-extension, and 13 (10-15) for the Q-angle. Q-angle was significantly correlated (p &lt; 0.05) with center of foot pressure (CP) displacement area (r = 0.36), anteroposterior (SDy, r = 0.34) and lateral (SDx, r = 0.31) CP standard deviation, and anteroposterior CP range (r = 0.38) during the closed base, eyes opened trial (CBEO). The valgus group showed statistically higher values than the normal and varus groups for SDy (0.56 vs. 0.52 and 0.46 mm; p = 0.02), SDx (0.55 vs. 0.49 and 0.36 mm; p = 0.02) and anteroposterior range (3.32 vs. 2.78 and 2.38 mm; p = 0.01), CBEO. The displacement velocity of the CP was significantly higher for the asymmetric than the symmetric Q-angle group (8.0 vs. 5.3 mm/s - closed base, eyes closed trial). Knee alignment was correlated with measures of body sway in elderly women, but ankle alignment showed no correlation. Knee morphology should be considered an associated factor for quiet stance postural control.
DOI: 10.6084/m9.figshare.20017470.v1
title: Lower limb joint alignment and postural control in elderly women

description: The aim of this study was to test whether quiet stance body sway is associated with ankle and knee joint angles in elderly women. Joint angles were measured using a manual goniometer and body sway was assessed using a force platform and four postural tasks with a combination of feet positions and eye condition. The sample (N = 58) showed the following angle values: 102 (100-104) for the tibiotarsal joint, 176 (174-180) for the subtalar joint, 184 (181-187) for knee flexion-extension, and 13 (10-15) for the Q-angle. Q-angle was significantly correlated (p &lt; 0.05) with center of foot pressure (CP) displacement area (r = 0.36), anteroposterior (SDy, r = 0.34) and lateral (SDx, r = 0.31) CP standard deviation, and anteroposterior CP range (r = 0.38) during the closed base, eyes opened trial (CBEO). The valgus group showed statistically higher values than the normal and varus groups for SDy (0.56 vs. 0.52 and 0.46 mm; p = 0.02), SDx (0.55 vs. 0.49 and 0.36 mm; p = 0.02) and anteroposterior range (3.32 vs. 2.78 and 2.38 mm; p = 0.01), CBEO. The displacement velocity of the CP was significantly higher for the asymmetric than the symmetric Q-angle group (8.0 vs. 5.3 mm/s - closed base, eyes closed trial). Knee alignment was correlated with measures of body sway in elderly women, but ankle alignment showed no correlation. Knee morphology should be considered an associated factor for quiet stance postural control.
DOI: 10.6084/m9.figshare.20017474
title: Electromyographic reaction time in older female fallers and non-fallers after postural perturbation

description: The electromyographic reaction time (ERT) reflects the magnitude and speed with which muscles are activated to perform movements, to prevent injuries, or to position a joint. This parameter can be used to analyze postural control performance after an external perturbation and can be correlated with the possibility of falls in older adults. The objective of this study was to determine the ERT of the internal oblique, rectus femoris, vastus lateralis, tibialis anterior, multifidus, gluteus maximus, biceps femoris, and lateral gastrocnemius muscles to balance threats in older adults with and without a history of falls. Twenty-nine physically active and noninstitutionalized women aged 60 years or older were divided into two groups: fallers (n=13; 72.4 ± 8.0 years) and non-fallers (n=16; 67.8 ± 6.8 years). The ERT of the muscles tested did not differ significantly between groups following forward or backward perturbations. The results suggest that the activation of the muscles tested in response to forward or backward perturbations is not a determinant factor of falls