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2.
Front Psychol ; 15: 1377947, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38577116

RESUMEN

Introduction: Motivation plays a crucial role in determining whether or not a person adheres to an exercise program. The present study aimed to determine the motivational differences between people exercising in fitness alone, in groups/aerobics and with a personal trainer by gender and relationship status. Methods: The Exercise Motivations Inventory-2 (EMI-2) questionnaire was completed by 830 users of 20 largest fitness centers in Slovenia. Results: The Kruskal-Wallis test followed by a Dunn post-hoc test revealed that health-related motives such as ill-health avoidance were most frequently associated with exercising with a personal trainer compared to other exercise modalities, especially among females (p = 0.032, M = 4.88) and people in a relationship (p = 0.020, M = 5.18). On the other hand, intrinsic motivations such as enjoyment and stress management were mostly associated with exercising alone (p = 0.002, M = 4.98 and p = 0.021, M = 4.68, respectively). These results were also transferred to females and to some extent to people in a relationship (for enjoyment only). It is expected that intrinsic motivation is related to sustained exercise behavior. Discussion: Future studies could implement a longitudinal design to test this statement and examine the proposed relationships over a longer period to better understand whether there may be causal relationships between motivation and different exercise modalities depending on different characteristics of participants.

3.
Medicina (Kaunas) ; 60(1)2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38256386

RESUMEN

Background and Objectives: In many sports, maintaining muscle work at an optimal level despite fatigue is crucial. Therefore, it is essential to discover the most efficient way of recovery. This study aimed to evaluate and compare the acute effects of four different recovery methods on muscle neuromechanical properties. Materials and Methods: The research was conducted using a randomized, quasi-experimental, repeated-measures design. Fourteen healthy and active male students of the Faculty of Sport and Physical Education (age 25.1 ± 3.9 years) were included in this study. The tensiomyography was used to evaluate muscle responses after four different types of short-term recovery methods (passive rest, percussive mechanical, vibro-mechanical, and manual massage) on the rectus femoris muscle on four occasions: baseline, post fatigue, post recovery and prolonged recovery. Results: The ANOVA revealed that muscle fatigue decreased maximal vertical muscle displacement (Dm) and muscle contraction time (Tc) in post fatigue compared to the baseline. The most important finding shows that only the vibro-mechanical massage resulted in an increase in Tc in the prolonged recovery compared to the post fatigue (p = 0.028), whereas only manual massage showed no differences in Dm from the baseline in post-recovery (p = 0.148). Moreover, both manual and vibro-mechanical massages increased Dm and Tc in prolonged recovery, indicating no differences from the baseline (all p > 0.05), thus showing signs of muscle recovery. Percussion mechanical massage and passive rest did not show indices of muscle recovery. Conclusions: Manual massage could induce immediate positive changes in Dm by reducing muscle stiffness. In addition, vibro-mechanical and manual massage improved muscle tissue by rapidly returning Dm and Tc values to baseline at prolonged recovery measurement (5 min after the fatigue protocol). These findings can benefit sports practitioners, and physical therapists in developing the best recovery method after muscle fatigue.


Asunto(s)
Contracción Muscular , Músculo Cuádriceps , Masculino , Humanos , Adulto Joven , Adulto , Fatiga Muscular , Masaje , Estado de Salud
4.
Scand J Med Sci Sports ; 33(11): 2323-2339, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37493345

RESUMEN

It is vital from the public health and educational perspective to be familiar with changes in the fitness levels of individuals and populations since fitness is associated with several health outcomes and cognition. Skill-related physical fitness refers to performance in sports or occupation and is associated with motor skill performance. The aim of the present study was to examine secular trends in skill-related physical fitness of 16 678 participants in four youth generations of Slovenian children and adolescents in years 1983 (n = 3128), 1993/94 (n = 3413), 2003/04 (n = 5497), and 2013/14 (n = 4640). Using repeated cross-sectional design, we observed fitness level of all participants divided into three age groups: 6-10, 11-14, and 15-19 years. Skill-related physical performance was measured with seven fitness tests for speed, coordination, balance, and flexibility. Analysis of covariance was used to compare differences in fitness performance between decades in each age and sex group, adjusted for body height, body weight, and body mass index. Overall, large but inconsistent changes in coordination, a small improvement in speed, and a decline in flexibility were seen. The trends over the whole examined period were not linear throughout decades. Generally, positive trends were noticed in periods 1983-1993 (range 1.4%-17.9%; except flexibility) and 2003/04-2013/14 (range 0.2%-36.4%; except age group 15-19 years) while in the period 1993/94-2003/04 there are some particularities in secular trends according to individual components as well as age groups. In general, the secular trend showed a positive direction for both genders (p < 0.05), except for gross motor coordination, which demonstrated positive trends in 1993 and 2013 compared with a decade earlier (p < 0.05) and from 1983 to 2013/14, except for the youngest boys in 2003 and the youngest girls from 1993 to 2003 (p < 0.05). Our findings call for exercise programs aimed at improving speed and gross motor coordination in both sexes and all age groups, especially in the group of 15-19 years old.

5.
Behav Sci (Basel) ; 13(6)2023 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-37366699

RESUMEN

The sustainability of fitness centers depends on two factors: member recruitment and retention, which is why these factors have received attention in recent decades. Temporal trends in fitness center membership purchase channels from 2016 to 2022 and motivation for exercise in 2022 in the Slovenian general population were investigated. The sample included 3419 participants, including 3131 participants (age 31.03 ± 11.31 years, 1430 females) and 288 participants (age 29.39 ± 10.43 years, 110 females) for the first and second objectives, respectively. Data were assessed using a web-based recruitment questionnaire and the EMI-2 motivation questionnaire. Traditional advertising strategies such as radio and flyers are the least effective (only 0.9% of memberships in 2022), while more sophisticated advertising strategies such as the internet and social media are becoming increasingly important in the advertising world (26.6% of memberships in 2022). On the other hand, word of mouth is the most influential method, attracting 51.3% of new members. Females, older members, and Eastern Slovenians were more motivated to exercise by health and esthetic motives, and males and younger members by challenge and competition. Fitness center management should focus on providing the best possible quality of service, tailoring it to the age, gender, and motivation of customers.

6.
Sports (Basel) ; 11(6)2023 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-37368560

RESUMEN

BACKGROUND: A massage is a tool that is frequently used in sports and exercise in general for recovery and increased performance. In this review paper, we aimed to search and systemize current literature findings relating to massages' effects on sports and exercise performance concerning its effects on motor abilities and neurophysiological and psychological mechanisms. METHODS: The review has been written following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines. One hundred and fourteen articles were included in this review. RESULTS: The data revealed that massages, in general, do not affect motor abilities, except flexibility. However, several studies demonstrated that positive muscle force and strength changed 48 h after the massage was given. Concerning neurophysiological parameters, the massage did not change blood lactate clearance, muscle blood flow, muscle temperature, or activation. However, many studies indicate pain reduction and delayed onset muscle soreness, which are probably correlated with the reduction of the level of creatine kinase enzyme and psychological mechanisms. In addition, the massage treatment led to a decrease in depression, stress, anxiety, and the perception of fatigue and an increase in mood, relaxation, and the perception of recovery. CONCLUSION: The direct usage of massages just for gaining results in sport and exercise performance seems questionable. However, it is indirectly connected to performance as an important tool when an athlete should stay focused and relaxed during competition or training and recover after them.

7.
Artículo en Inglés | MEDLINE | ID: mdl-36498298

RESUMEN

The present study investigated effects of squat resistance training on intermuscular hypertrophy of quadriceps femoris muscles (i.e., rectus femoris, RF; vastus intermedius, VI; vastus medialis, VM; and vastus lateralis, VL). Eighteen university students (age: 24.1 ± 1.7 years, 9 females) underwent 7 weeks of parallel squat training (2 days/week) preceded by a 2-week familiarization period. Squat strength (1RM) and cross-sectional area (CSA) of four quadriceps muscles were assessed at baseline and at the end of the study. At posttest, 1RM and CSA of quadriceps muscles significantly increased (p < 0.01), with moderate-to-large effect (ES = 1.25−2.11) for 1RM (8.33 ± 6.64 kg), VM CSA (0.12 ± 0.08 cm2), and VL CSA (0.19 ± 0.09 cm2) and small effect (ES = 0.89−1.13) for RF CSA (0.17 ± 0.15 cm2) and VI CSA (0.16 ± 0.18 cm2). No significant differences were found in the changes of CSA between muscles (F = 0.638, p = 0.593). However, the squat 1RM gain was significantly associated only with the changes in CSA of the VL muscle (r = 0.717, p < 0.001). The parallel squat resulted in significant growth of all quadriceps muscles. However, the novelty of this study is that the increase in strength is associated only with hypertrophy of the VL muscle.


Asunto(s)
Músculo Cuádriceps , Entrenamiento de Fuerza , Femenino , Humanos , Adulto Joven , Adulto , Músculo Cuádriceps/fisiología , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Hipertrofia , Terapia por Ejercicio
8.
Front Physiol ; 13: 874632, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35784865

RESUMEN

The main objective of present study was to evaluate inter-rater reliability and concurrent validity of Side Hop Test stopwatch vs. force plates timing, and to determine the number of sessions and trials required to minimize the effects of learning on Side Hop Test total time and limb symmetry index. Fifteen healthy male physical education students (mean ± SD: age, 23 ± 3 years; height, 181 ± 9 cm; and weight 72 ± 6 kg) participated. Side Hop Test total time (stopwatch and force plates) of left and right leg, and limb symmetry index (force plates) were obtained over seven sessions conducted 5-7 days apart. Time recordings of two raters were similar (t = -0.56, p > 0.05) with high reliability (all ICC >0.99 and CV% <0.1) and no systematic bias when compared to force plate data (p > 0.05; for rater 1 and 2, respectively). Total time improved across the Sessions (F = 25.87, p < 0.01, ω 2 = 0.18) and Trials (F = 68.15, p < 0.01, ω 2 = 0.10), with no significant interaction between factors. No between-leg differences were detected (F = 0.52, p > 0.05, ω 2 = 0.001). Limb symmetry index ranged from 0.999 to 1.055 across all sessions and trials (all p > 0.05 and ω 2 < 0.00). Due to low coefficient of correlation, high interclass correlation coefficient, and the lack in heteroscedasticity, stopwatch measurements are valid to measure total time in the Side Hop Test. Moreover, stopwatch measurements could be reliably used to measure total time in the Side Hop Test, while the test could be administrated with only one experienced rater. Unlike total times, findings on limb symmetry index suggest it could be reliably assessed after seven familiarization sessions.

9.
Eur J Appl Physiol ; 122(10): 2223-2231, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35831629

RESUMEN

The aim of the study was to investigate how the relationship between resistance training-induced hypertrophy, strength, and passive contractile adaptations is affected by contraction duration. Twenty university students (11 males) were randomly assigned to either the fast eccentric/fast concentric phase group (F/F; 1 s both phases) or the slow eccentric/fast concentric phase group (S/F; 4 s and 1 s, respectively). Both experimental groups completed a 7-week biceps curl training programme with a total of 14 sessions (2 days/week). Elbow flexor muscle thickness (MT), one-repetition maximum (1RM), and tensiomyographic (TMG) parameters (radial displacement-Dm and contraction time-Tc) were assessed. The percentage change (∆) in MT correlated significantly with the ∆1RM only in the S/F group (r = 0.712, p < 0.05). Both groups demonstrated significant negative associations between ∆MT and ∆Dm (r = 0.717-0.760, p < 0.01). Conversely, no significance was found between ∆MT and ∆Tc (F/F: r = -0.398, p = 0.255; S/F: r = 0.410, p = 0.239), ∆1RM and ∆Tc (F/F: r = -0.278, p = 0.436; S/F: r = 0.223, p = 0.536), nor ∆1RM and ∆Dm (F/F: r = - 0.131, p = 0.719; S/F: r = - 0.351, p = 0.320). The main findings indicate that the relationship between hypertrophy and strength gains is significantly stronger when resistance training was paced with slower eccentric contractions comparing to fast ones. On the other hand, reduced Dm values indicate increase in MT regardless of contraction duration, while strength gains are not correlated with corresponding TMG changes.


Asunto(s)
Fuerza Muscular , Entrenamiento de Fuerza , Humanos , Hipertrofia , Masculino , Contracción Muscular/fisiología , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología
10.
Front Physiol ; 12: 709263, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34899366

RESUMEN

The aim of this study was to investigate the resistance-specific gains in muscle power and strength (1RM) following the training of maximum bench-press throws (BPT) against constant, inertial, and combined resistance. Forty-eight male participants (age 20.5 ± 2.0 years) were randomly assigned to the constant, inertial, combined resistance, or control group. Participants underwent 8 weeks of training of BPT against the loads that corresponded to the different effects of mass of 40 kg (∼50% of 1RM). The gains in average and maximum power, and 1RM were significant in all experimental groups (P < 0.01), but not in the control group (P > 0.1). Relative gains in the average (26.3 ± 9.8%) and maximum power (25.2 ± 9.8%) were larger than that in the 1RM (mean 7.2 ± 6.9%; both P < 0.001). The gains in the average (F 4, 66 = 6.0; P < 0.01) and maximum power (F 4, 66 = 4.7; P < 0.01) were higher when tested against the training-specific resistance than when tested against the remaining two resistance types. Differences in 1RM among experimental groups were not significant (P = 0.092). The most important and rather novel finding of the study is that the training against the weight and inertial resistance, and their combination results in resistance-specific gains in muscle power, although the overall gains muscle strength and power remain comparable across the training protocols.

11.
Front Public Health ; 9: 778837, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34957029

RESUMEN

There is evidence that physical activity (PA) can improve the academic performance. We recruited healthy adolescent girls, aged 11-12 years, and measured their PA with the accelerometer ActiGraph GT3X for the consecutive 5 days. Physical fitness (PF) was measured with eight motoric tests and three anthropometry measures. Academic performance (AP) was assessed for the six academic narrated school subjects. The results revealed that the girls were more physically active during the week days and less active at weekend (557 vs. 516 counts/min). Physical education grade shows the highest overall correlations with the results of the PF test battery (r = 0.53-0.95, p < 0.01). Nevertheless, correlations surprisingly decrease for the combined daily PA (r = 0.45), especially the weekend PA (r = 0.28). Grade point average and PF correlated moderately (r = 0.43-0.64), while they were moderate to high for PA (r = 0.59-0.87). Many questions arose after the completion of the present study and several new topics opened up, such as the question of how parental education affects the duration of PA and AP of the children and the influence of the place of residence AP of the children.


Asunto(s)
Rendimiento Académico , Acelerometría , Adolescente , Niño , Ejercicio Físico , Femenino , Humanos , Aptitud Física , Instituciones Académicas
12.
PeerJ ; 9: e12435, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34900415

RESUMEN

BACKGROUND: The aim was to determine the relationship between the cross-sectional area of the quadriceps femoris and strength performance in the deep and parallel barbell squat. METHODS: The sample included 16 university students (seven female, 24.1 ± 1.7 years). Muscle strength was expressed as external load, including the one-repetition maximum and the body mass segments involved (calculated according to Dempster's method). The cross-sectional area of the quadriceps femoris muscles was determined using ultrasound, while leg muscle mass was measured using the Bioelectrical Impedance method. RESULTS: The cross-sectional areas of the three vastii muscles and leg muscle mass showed moderate to strong correlation with external load in both squat types (r = 0.509-0.873). However, partial correlation (cross-sectional area of quadriceps femoris muscles were controlled) showed significant association only between leg muscle mass and deep squat (r = 0.64, p < 0.05). The cross-sectional area of the vastus lateralis showed a slightly higher correlation with external load in the parallel than in the deep squat (r = 0.67, p < 0.01 vs. r = 0.59, p < 0.05). The regression analysis extracted the vastus medialis cross-sectional area as the most important factor in manifesting strength (parallel squat: R 2 = 0.569; deep squat: R 2 = 0.499, both p < 0.01). The obtained results suggest that parallel squat strength depends mainly on the cross-sectional area of the vastii muscles, while it seems that the performance in the deep squat requires an additional engagement of the hip and back extensor muscle groups.

13.
Scand J Med Sci Sports ; 31(9): 1853-1861, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33910265

RESUMEN

Low physical fitness has been found to be associated with many chronic diseases and medical conditions. Knowledge of secular trends in physical fitness is important to initiate countermeasures for addressing negative trends. The aim of this study was to analyze secular trends in health-related muscular fitness in Slovenian children and adolescents between 1983 and 2014. Data were collected as part of "The Analysis of Children's Development in Slovenia (ACDSi)" study in 1983, 1993/94, 2003/04, and 2013/14. Anthropometry (body weight, height, BMI, and triceps skinfold) and muscular fitness (standing long jump, bent-arm hang, and sit-ups 60 s test) of 18730 (9168 female) students from primary and secondary schools were recorded. The secular trend was analyzed considering anthropometry. The results showed that anthropometric measures had an increasing trend and overall muscular fitness had a decreasing trend. Leg muscle power decreased over the decades in all age groups (relative difference between -1.5% and -2.6%), being more pronounced in boys. Arm muscle strength decreased in two younger age groups (range -21.1% to -42.7%, 6-10, and 11-14 years), but not in the oldest group (15-19 years), where the increase occurred in both genders (0.4% to 9.3%). In terms of decades, the largest negative changes (-30.1%) occurred from 1993/94 to 2003/04 and the smallest changes (-4.2%) from 2003/04 to 2013/14. The overall trend in repetitive core strength surprisingly increased (1.1% to 18.3%). There is a need to promote healthy lifestyles, raise parental awareness and use all government resources to redirect the negative trend in physical fitness.


Asunto(s)
Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Aptitud Física/fisiología , Rendimiento Físico Funcional , Adolescente , Desarrollo del Adolescente , Factores de Edad , Niño , Desarrollo Infantil , Prueba de Esfuerzo/tendencias , Femenino , Humanos , Masculino , Factores Sexuales , Eslovenia , Factores de Tiempo , Adulto Joven
14.
Artículo en Inglés | MEDLINE | ID: mdl-33503856

RESUMEN

The two-point force-velocity model allows the assessment of the muscle mechanical capacities in fast, almost fatigue-free conditions. The aim of this study was to investigate the concurrent validity of the two-point parameters with directly measured force and power and to examine the generalization of the two-point parameters across the different functional movement tests of leg muscles. Twelve physically active participants were tested performing three functional lower limb maximal tests under two different magnitudes of loads: countermovement jumps, maximal cycling sprint, and maximal force under isokinetic conditions of the knee extensors. The results showed that all values from the two-point model were higher than the values from the standard tests (p < 0.05). We also found strong correlations between the same variables from different tests (r ≥ 0.84; p < 0.01), except for force in maximal cycling sprint, where it was low and negligible (r = -0.24). The results regarding our second aim showed that the correlation coefficients between the same two-point parameters of different lower limb tests ranged from moderate to strong (r -0.47 to 0.72). In particular, the relationships were stronger between power variables than between force variables and somewhat stronger between standard tests and two-point parameters. We can conclude that mechanical capacities of the leg muscles can be partially generalized between different functional tests.


Asunto(s)
Pierna , Músculo Esquelético , Fenómenos Biomecánicos , Humanos , Rodilla , Movimiento
15.
Obes Rev ; 22(2): e13160, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33462934

RESUMEN

A systematic search of the literature was performed to compare the effects of interventions that targeted sedentary behaviours or physical activity (PA) or physical fitness on primary prevention of obesity in 6- to 12-year-old children. The search identified 146 reports that provided relevant data for meta-analysis. Point estimates in % body fat were higher for fitness interventions compared with PA interventions (standardized mean difference = -0.11%; 95% CI = -0.26 to 0.04, and -0.04%; 95% CI = -0.15 to 0.06, respectively). Including sedentary behaviour to a PA- or fitness-oriented intervention was not accompanied by an increase in intervention effectiveness, as the point estimates were slightly smaller compared with those for PA- or fitness-only interventions. Overall, the effects tended to be larger in girls than in boys, especially for PA + sedentary behaviour interventions. There was some evidence for inequality, as the effects on body mass index were seen when interventions were delivered in the general population (standardized mean difference = -0.05, 95% CI = -0.07 to -0.02), but not in groups of disadvantaged children (standardized mean difference = -0.01, 95% CI = -0.29 to 0.19). In conclusion, school-based PA interventions appear to be an effective strategy in the primary prevention of childhood obesity among 6- to 12-year-old children, but targeting sedentary behaviour in addition to PA or fitness does not increase the effectiveness of the intervention.


Asunto(s)
Ejercicio Físico , Obesidad Infantil , Aptitud Física , Conducta Sedentaria , Niño , Investigación sobre la Eficacia Comparativa , Femenino , Promoción de la Salud , Humanos , Masculino , Obesidad Infantil/prevención & control , Instituciones Académicas
16.
Artículo en Inglés | MEDLINE | ID: mdl-35010686

RESUMEN

Health policies rely on physical activity (PA) and sedentary behavior data collected through PA questionnaires (PAQs). Validity of international PAQs varies among countries. Therefore, it is important to know the validity of the national versions of the PAQs to properly evaluate the results. We conducted a validation study of the Slovenian versions of the International PAQ Short Form (IPAQ-SF), the Global PAQ (GPAQ), and the PAQ used in the European Health Interview Survey (EHIS-PAQ) on 306 healthy adults. The most valid and reliable constructs in all tested were sedentary behavior and vigorous PA (VPA), however the criterion validity of these constructs was low (Spearman's ρ 0.38-0.45 for sedentary behavior and 0.34-0.42 for VPA). Moderate to vigorous PA (MVPA) had low validity (0.26-0.29) despite being used as a standard measure of PA behavior. Participants over-reported MVPA for 17 to 156 min and underreported the sedentary behavior for more than two hours. The test-retest study found high reliability for sedentary behavior (0.69-0.81) and low to moderate reliability for PA behavior (0.42-0.76). The Slovenian versions of the observed PAQs are a useful tool for national PA surveillance, but for qualitative assessment of individual health-related PA behavior they should be combined with accelerometer-based devices.


Asunto(s)
Ejercicio Físico , Conducta Sedentaria , Adulto , Humanos , Actividad Motora , Reproducibilidad de los Resultados , Encuestas y Cuestionarios
17.
Sci Rep ; 10(1): 11022, 2020 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-32620828

RESUMEN

The aim of this study is to describe trends in overweight and obesity among Slovenian youth for the period 1989-2018. Nearly all schoolchildren in Slovenia had their height and weight measured annually, which lead to a total of 6,738,510 data-points during the 30-year period. The IOTF cut-off points and Joinpoint regression were used to examine annual percent change (APC) in overweight and obesity prevalence across 3 age groups (7-10, 11-14 and 15-18 years). Obesity approximately tripled, while overweight doubled between 1989 and late 2000s in both genders. Since then overweight has been steadily decreasing in all 3 age groups for boys and in 7-10-year-old girls. Obesity has also been declining since 2009, but only in the youngest boys and girls (APC = - 1.9, 95% CI = - 3.2 to - 0.6 and APC = - 1.6, 95% CI = - 3.0 to - 0.2, respectively). Unfavourable trends were noted only in 15-18-year-old girls, with obesity rising at an unchanged rate over the past 30 years (APC = 4.8, 95% CI = 4.5-5.1). Overweight and obesity among Slovenian youth has increased dramatically over the last 3 decades. Still, during the last decade this rise has been reversed or at least stopped. This reversal of trends was more marked in boys than in girls, and in young children compared to adolescents.


Asunto(s)
Obesidad Infantil/epidemiología , Adolescente , Índice de Masa Corporal , Peso Corporal , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Vigilancia de la Población , Prevalencia , Eslovenia/epidemiología
18.
PLoS One ; 15(3): e0229305, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32160216

RESUMEN

This study analyses the changes of moderate-to-vigorous physical activity (MVPA) in a cohort of boys and girls aged 11 (n = 50) and 14 (n = 50). Physical activity was assessed with Bodymedia SenseWear Pro Armband monitor for 6 days in October 2013 and October 2016, considering 90% of daily wear time (21h and 40min). The initial sample (n = 160) included the children who wore the monitors at age 11 but the final analyzed sample included only those children from the initial sample (n = 50), whose data fulfilled the inclusion criteria at age 11 and 14. Physical fitness and somatic characteristics of the final sample (n = 50) were compared to a representative sample of Slovenian schoolchildren at ages 11 (n = 385) and 14 (n = 236) to detect possible bias. Changes in MVPA were controlled for maturity using the timing of adolescent growth spurt as its indicator. The average MVPA decreased more than one quarter (34.96 min) from age 11 to age 14. Children were significantly more active at age 11 than at age 14 (p < 0.01, d = 0.39). The timing of puberty onset in girls was significantly earlier (12.01 ± 1.0 years) (p < 0.01) than in boys (13.2 ± 0.75 years) (p < 0.01, d = 1.35). There was a significant gender difference in moderate-to vigorous physical activity at age 14 (p < 0.05, η2 = 0.12) and between moderate-to vigorous physical activity at age 11 and 14 (η2 = 0.11). After controlling for the timing of adolescent growth spurt the girls at age 11 showed significantly higher level of physical activity than at age 14 (p < 0.01, η2 = 0.17). Early adolescence is crucial for the development of physical activity behaviours, which is especially pronounced in girls. The significant decline of MVPA between ages 11 and 14 in Slovenia are likely influenced by environmental changes since the timing of adolescent growth spurt did not prove as a factor underlying the decline of MVPA.


Asunto(s)
Salud del Adolescente , Ejercicio Físico , Maduración Sexual , Adolescente , Niño , Estudios de Cohortes , Femenino , Humanos , Masculino , Factores Sexuales , Eslovenia
19.
Chemistry ; 19(51): 17456-63, 2013 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-24227705

RESUMEN

The synthesis of asymmetrically substituted 2,2':6',2''-terpyridines is reported. First, palladium-catalyzed C-H arylation of pyridine N-oxides with substituted bromopyridines gave 2,2'-bipyridine N-oxides, which were further arylated in a second step to form 2,2':6',2''-terpyridine N-oxides. Yields of up to 77% were obtained with N-oxides bearing an electron-withdrawing ethoxycarbonyl substituent in the 4-position. Pd(OAc)2 with either P(tBu)3 or P(o-tolyl)3 was used as the catalyst. Cyclometalated complexes derived from Pd(OAc)2 and these phosphines were also effective. K3PO4 as the base gave better results than K2CO3. Subsequent deoxygenation with H2 and Pd/C as the catalyst gave the asymmetrically substituted 2,2':6',2''-terpyridines in near quantitative yield. This reaction sequence significantly reduces the number of steps required in comparison with known cross-coupling methods and therefore allows convenient and scalable access to substituted terpyridines.

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