Protocol Study: Resistance Training Program, Nutritional, Sleep, and Screen Use Recommendations in Schoolchildren from Educational Centers in the Extreme South of Chile.

BACKGROUND: Childhood obesity has tripled, reaching critical levels of malnutrition. This factor is directly associated with a poorer health-related quality of life of the child and adolescent population. This article presents the study protocol of the project "Strong schoolchildren with a healthy lifestyle" (EF-Salud), which seeks to analyze the effects of a multicomponent program based on muscle strength exercises, sleep nutritional recommendations, and the use of screens in Chilean educational centers with extremely cold weather. METHODS: The study protocol of a randomized controlled trial with a pre- and post-test conducted according to the CONSORT statement is reported. The total sample (n = 144) will be schoolchildren from six different school years, four of which will perform an intervention and two control. Intervention group 1 (from two different school years) will receive a muscular strength exercise program in the classroom once a day from Monday to Friday for six months and nutritional, sleep, and use of screens recommendations once a week. Intervention group 2 (from two different school years) will receive a program of nutritional, sleep, and use of screens recommendations once per week for six months. The control group (from two different school years) will carry out their usual school day in relation to physical education classes. Before and after the intervention, the investigators will evaluate the cardiovascular risk, physical condition, and lifestyle related to sleep and use of screens. EXPECTED RESULTS: The schoolchildren in intervention group 1 will obtain significant results in increased strength, decreased cardiovascular risk, improved sleep habits, and fewer hours of screen use compared to the other two groups.

The Role of Job Crafting and Psychological Capital in the Relationship between Job Autonomy and Work Engagement: A Serial Mediation Model.

Work engagement is a scientifically consolidated variable, due to its fundamental role in business practice. To increase work engagement in companies, it is necessary to know which variables are antecedents and how they relate to each other. These variables include job autonomy, job crafting, and psychological capital. This research evaluates the relationships between job autonomy, job crafting, psychological capital, and work engagement. Specifically, based on the job demands and resources model and the conservation of resources theory, the study examines these relationships in a sample of 483 employees, through a serial mediation model. The results show that job crafting, and psychological capital mediates the relationship between job autonomy and work engagement. These results have practical implications for interventions to promote employee work engagement.

The Role of Job Crafting and Psychological Capital in the Relationship between Job Autonomy and Work Engagement: A Serial Mediation Model

Work engagement is a scientifically consolidated variable, due to its fundamental role in business practice. To increase work engagement in companies, it is necessary to know which variables are antecedents and how they relate to each other. These variables include job autonomy, job crafting, and psychological capital. This research evaluates the relationships between job autonomy, job crafting, psychological capital, and work engagement. Specifically, based on the job demands and resources model and the conservation of resources theory, the study examines these relationships in a sample of 483 employees, through a serial mediation model. The results show that job crafting, and psychological capital mediates the relationship between job autonomy and work engagement. These results have practical implications for interventions to promote employee work engagement. (AU)

Stress, subjective wellbeing and self-knowledge in higher education teachers: A pilot study through bodyfulness approaches.

Work-related stress is a major cause of health problems worldwide. Faculty in educational institutions, including universities, also face high levels of stress, which undoubtedly affects their performance, level of personal satisfaction and wellbeing, and the relationship with students. Training interventions based on embodied learning can promote self-knowledge, emotional regulation and stress reduction, thereby increasing levels of psychological well-being. The present pilot study analyzed the impact of body awareness training in 31 university teachers using a controlled, randomized pre-post experimental design, with two experimental groups and a control group (n = 10). The two interventions were: Hatha Yoga (n = 11) and Dance Movement Therapy/Body Mind Centering (n = 10), which we have termed Body Movement Awareness. Variables related to body awareness, mindfulness, wellbeing, life satisfaction and stress were measured using self-perception tests. Cortisol levels, heart rate variability and sleep quality were also analyzed. Finally, participants' reflections were analyzed according to a qualitative approach. The results showed significant differences between the control group and the Hatha Yoga group in terms of stress reduction and wellbeing. The Body Movement Awareness group exhibited evidence of contributions on self-knowledge, communication and kinesthetic empathy, key elements in the educational field. Despite the inherent limitations of the study, the conclusions are encouraging and open new lines of research from embodied approaches that introduce creative movement and group experience as part of the process of emotional regulation and self-knowledge.

Association of Physical Fitness, Screen Time, and Sleep Hygiene According to the Waist-to-Height Ratio in Children and Adolescents from the Extreme South of Chile.

OBJECTIVE: To analyze the perception of physical fitness, screen time, and self-reported sleep hygiene in children and adolescents (CA) from the extreme south of Chile and its associations with waist-to-height ratio (WtHr). MATERIAL AND METHODS: An observational cross-sectional study was conducted in a sample of 594 schoolchildren from 5th to 8th grade of primary education, belonging to municipal educational establishments in the Magallanes region, Chile. Cardiorespiratory fitness was assessed through the 20-m shuttle run test, muscle strength through handgrip and the standing broad jump test, physical fitness perception through the International Fitness Scale, and central obesity through the waist-to-height index. In addition, sleep hygiene and screen time were measured. RESULTS: More than 92% of CA spent more than two hours a day watching or using screens. In addition, CA with excess central adiposity had a lower perception of physical fitness, and lower muscle strength and cardiorespiratory fitness compared to CA with normal values of adiposity. CONCLUSIONS: CA of the present study spent a high number of hours watching or using screens and had poor sleep quality. In addition, excessive central adiposity was associated with lower physical fitness.

Physical Activity and Mental Health in Undergraduate Students.

Most research support positive relationships between physical activity and mental health. However, possible moderating variables of these relationships have also been identified, such as age, gender, level of physical activity, and the scope of physical activity. This study aimed to analyze the relationships between physical activity and mental health levels in undergraduate students, assessing whether these associations can change depending on the level of physical activity (low, medium, or high) and the setting (occupational, commuting, or leisure time physical activity) in which it was performed. A descriptive and cross-sectional study was conducted. The sample comprised 847 undergraduate students. Physical activity and mental health were measured by the Global Physical Activity Questionnaire (GPAQv2) and the General Health Questionnaire (GHQ-12). We found relationships between students' physical activity level and their mental health status. The higher the total physical activity, the better their mental health scores. High levels of commuting and leisure time physical activity is also associated with better mental health, while only moderate levels of occupational physical activity are associated with better mental health status. Regarding the possible associations between physical activity and vulnerability to mental health problems, with the fully adjusted regression model, leisure time and occupational physical activity remain protective of a poor state of mental health. Leisure time physical activity, performed at a high level, and moderate occupational physical activity seems to be the best combination of physical activity to reduce students' vulnerability to potential mental health problems.

Overweight/Obese Schoolchildren with Low Muscle Strength Have a Lower Cardiorespiratory Capacity and Greater Cardiovascular Risk: Results of the School Health Survey of the Extreme South of Chile 2019.

OBJECTIVE: To compare cardiovascular risk and cardiorespiratory capacity in schoolchildren from a region in the extreme south of Chile according to nutritional status and muscular strength. METHODS: An analytical cross-sectional study was performed on a sample of 594 schoolchildren from 5th to 8th grade in the extreme south of Chile. Based on body mass index and lower limb muscle strength, participants were divided into four groups: high strength-normal weight, high strength-overweight/obese, low strength-normal weight, and low strength-overweight/obese. Then, waist-to-height ratio and cardiorespiratory capacity, measured with the 20 m shuttle run test, were assessed to determine their cardiovascular risk, comparing the four groups. RESULTS: The overweight/obese group with high muscular strength presented better indicators in anthropometric variables (waist circumference and waist-to-height ratio) than their peers with low muscular strength. Additionally, the overweight/obese group with low muscular strength presented a lower cardiorespiratory capacity than their peers with high muscular strength. Both results were observed in boys and girls. CONCLUSION: The results of this study suggest that overweight/obese schoolchildren with high muscle strength present healthier anthropometric indicators and greater cardiorespiratory capacity than their peers with low muscle strength. These results confirm the relevance of measuring muscle strength in schoolchildren and its usefulness to assess functionality. These results encourage the scientific community to continue studying the role that muscle strength plays in modulating the effects of overweight and obesity on respiratory and cardiovascular conditions in childhood.

Time to Exhaustion at the Respiratory Compensation Point in Recreational Cyclists.

The time to exhaustion (tlim) at the respiratory compensation point (RCP) and whether a physiological steady state is observed at this workload remains unknown. Thus, this study analyzed tlim at the power output eliciting the RCP (tlim at RCP), the oxygen uptake (VO2) response to this effort, and the influence of endurance fitness. Sixty male recreational cyclists (peak oxygen uptake [VO2peak] 40-60 mL∙kg∙min-1) performed an incremental test to determine the RCP, VO2peak, and maximal aerobic power (MAP). They also performed constant-load tests to determine the tlim at RCP and tlim at MAP. Participants were divided based on their VO2peak into a low-performance group (LP, n = 30) and a high-performance group (HP, n = 30). The tlim at RCP averaged 20 min 32 s ± 5 min 42 s, with a high between-subject variability (coefficient of variation 28%) but with no differences between groups (p = 0.788, effect size = 0.06). No consistent relationships were found between the tlim at RCP and the different fitness markers analyzed (RCP, power output (PO) at RCP, VO2peak, MAP, or tlim at MAP; all p > 0.05). VO2 remained steady overall during the tlim test, although a VO2 slow component (i.e., an increase in VO2 >200 mL·min-1 from the third min to the end of the tests) was present in 33% and 40% of the participants in HP and LP, respectively. In summary, the PO at RCP could be maintained for about 20 min. However, there was a high between-subject variability in both the tlim and in the VO2 response to this effort that seemed to be independent of fitness level, which raises concerns on the suitability of this test for fitness assessment.

Impact of rider position and pedaling cadence on power output and bilateral asymmetry in indoor cycling.

BACKGROUND: This study examines the effects of pedaling cadence and the rider's position on power output and pedaling asymmetry during indoor cycling. METHODS: Participants were 25 male indoor cycling instructors (32.4±4.8 years; 75.7±4.9 kg; 174±4.2 cm) with at least 3 years of cycling experience. In a single session, participants completed 9 training intervals consisting of different combinations of position (standing, sitting), pedaling cadence (75, 100, 120 rpm) and training intensity (75, 80, 85% maximum heart rate, HRmax). RESULTS: During standing intervals, power output was lower (132.4±72.6 W vs. 197.5±53.5 W; P<0.05) and the bilateral leg asymmetry index was greater (52.2±76.6% vs. 12.4±9%; P<0.05) than when subjects pedaled while sitting for a similar work intensity. In contrast, higher power outputs (238.1±46.3 W vs. 153±52.7 W; P<0.05) and lower asymmetry indices (30.4±39.2% vs. 12.6±11%; P<0.05) were recorded in intervals performed at 75 rpm versus 120 rpm despite similar exercise intensities. CONCLUSIONS: Our findings indicate that at similar training intensities, pedaling while standing during indoor cycling generates fewer watts and greater asymmetry than pedaling while sitting. We also observed that a slower pedaling cadence (75 rpm) gives rise to greater generated power and a lower asymmetry index than a faster pedaling cadence (120 rpm).

Effects of Polarized Training on Cardiometabolic Risk Factors in Young Overweight and Obese Women: A Randomized-Controlled Trial.

Introduction: Volume and intensity are major variables governing exercise training-mediated beneficial effects in both athletes and patients. Although polarized endurance training optimizes and maximizes physiological gains in highly trained individuals, its cardiometabolic protective-effects have not been established. The purpose of the present single site, randomized-controlled trial was to compare the effects of 12-weeks of high-intensity interval training (HIIT), moderate-intensity continuous training (MICT), and polarized volume training (POL) programs on cardiometabolic risk factors in young overweight and obese women. Materials and Methods: A total of 64 overweight/obese young women (age 23.3 ± 3.8 years, body mass index 33.8 ± 3.8 kg/m2) were randomly assigned to four groups: control group (CTRL), polarized volume training group, moderate-intensity endurance training group, and HIIT group. The cardiorespiratory capacity, glycemic and lipid profiles, whole-body substrate utilization, and body composition were assessed before and after the intervention. Results: After the intervention, VO2peak and power output at VO2peak increased in all exercised-groups (time effect: p < 0.0001). Power output at VT1 was increased only in the POL group compared to the CTRL group (p = 0.019). Relative fold changes in fasting plasma glucose concentrations decreased only in POL group (p = 0.002). Training induced a significant increase in relative fat oxidation in all the groups (time effect: p < 0.001). Relative fat oxidation increased only in the POL group compared to the CTRL group (training effect: p = 0.032). Conclusion: Twelve-weeks of polarized volume training showed overall superior effects on cardiorespiratory fitness, basal glycemic control, and substrate oxidation in comparison to MICT and HIIT training modalities. These data suggest that polarized volume training is an effective non-pharmacological treatment strategy for reducing cardiovascular disease risk factors in young overweight and obese women. The trial is registered at ISRCTN, number ISRCTN34421723.

Novel Resistance Training-Specific Rating of Perceived Exertion Scale Measuring Repetitions in Reserve.

The primary aim of this study was to compare rating of perceived exertion (RPE) values measuring repetitions in reserve (RIR) at particular intensities of 1 repetition maximum (RM) in experienced (ES) and novice squatters (NS). Furthermore, this investigation compared average velocity between ES and NS at the same intensities. Twenty-nine individuals (24.0 ± 3.4 years) performed a 1RM squat followed by a single repetition with loads corresponding to 60, 75, and 90% of 1RM and an 8-repetition set at 70% 1RM. Average velocity was recorded at 60, 75, and 90% 1RM and on the first and last repetitions of the 8-repetition set. Subjects reported an RPE value that corresponded to an RIR value (RPE-10 = 0-RIR, RPE-9 = 1-RIR, and so forth). Subjects were assigned to one of the 2 groups: (a) ES (n = 15, training age: 5.2 ± 3.5 years) and (b) NS (n = 14, training age: 0.4 ± 0.6 years). The mean of the average velocities for ES was slower (p ≤ 0.05) than NS at 100% and 90% 1RM. However, there were no differences (p > 0.05) between groups at 60, 75%, or for the first and eighth repetitions at 70% 1RM. In addition, ES recorded greater RPE at 1RM than NS (p = 0.023). In ES, there was a strong inverse relationship between average velocity and RPE at all percentages (r = -0.88, p < 0.001), and a strong inverse correlation in NS between average velocity and RPE at all intensities (r = -0.77, p = 0.001). Our findings demonstrate an inverse relationship between average velocity and RPE/RIR. Experienced squatter group exhibited slower average velocity and higher RPE at 1RM than NS, signaling greater efficiency at high intensities. The RIR-based RPE scale is a practical method to regulate daily training load and provide feedback during a 1RM test.