Design of a Computer Model for the Identification of Adolescent Swimmers at Risk of Low BMD.

This paper aims to elaborate a decision tree for the early detection of adolescent swimmers at risk of presenting low bone mineral density (BMD), based on easily measurable fitness and performance variables. The BMD of 78 adolescent swimmers was determined using dual-energy X-ray absorptiometry (DXA) scans at the hip and subtotal body. The participants also underwent physical fitness (muscular strength, speed, and cardiovascular endurance) and swimming performance assessments. A gradient-boosting machine regression tree was built to predict the BMD of the swimmers and to further develop a simpler individual decision tree. The predicted BMD was strongly correlated with the actual BMD values obtained from the DXA (r = 0.960, p < 0.001; root mean squared error = 0.034 g/cm2). According to a simple decision tree (74% classification accuracy), swimmers with a body mass index (BMI) lower than 17 kg/m2 or a handgrip strength inferior to 43 kg with the sum of both arms could be at a higher risk of having a low BMD. Easily measurable fitness variables (BMI and handgrip strength) could be used for the early detection of adolescent swimmers who are at risk of suffering from low BMD.

Effects of multicomponent training and detraining on the fitness of older adults with or at risk of frailty: results of a 10-month quasi-experimental study.

The aims of this study were (1) to analyse the effects of a 6-month multicomponent training (MCT) on the physical fitness of older adults with or at risk of frailty; (2) to study the consequences of a 4-month detraining period; (3) to analyse the influence of frailty status on the training and detraining adaptations. A total of 102 robust, frail and prefrail older adults (80.1 ± 6.1 y) were divided into an intervention (TRAIN) and control group (CON). The TRAIN performed a 6-month MCT, while the CON continued with their usual lifestyle. Fitness assessment was mainly based on the Senior Fitness Test. Four evaluations were carried out; at baseline, and at 3, 6 and 10 months from baseline. Linear mixed models were performed to analyse group by time interactions and to compare differences in changes within groups between different time points. After 6-month MCT, TRAIN showed greater improvements for all fitness variables (group effects p < 0.05, except for flexibility) when compared to the CON. During the 4-month detraining period, TRAIN significantly decreased their balance, upper-limb flexibility and upper and lower-limb strength (all p < 0.05). CON only decreased upper-limb flexibility. When accounting for frailty status in the TRAIN, the frail-prefrail showed lower adaptations to the training and were more affected by detraining than the robust. The presented MCT is a good strategy to improve fitness in this population, but its positive effects are limited in time. It is, therefore, critical to avoid detraining periods.Trial registration: ClinicalTrials.gov identifier: NCT03831841.HighlightsOur 6-month MCT-program improves the physical fitness of robust, frail and prefrail older adultsA detraining period of four months partially deteriorates the physical fitness of robust, frail and prefrail older adults, so it is recommended to promote ongoing exercise programs or smaller break periodsIt seems that those older adults with a more advanced frailty status may not benefit from exercise to the same degree and will be more affected by detraining. Therefore, trainers may need to individualize training protocols to obtain the greatest exercise benefits.

Do Serum 25-Hydroxyvitamin D Concentrations Affect Body Composition, Physical Fitness, Bone Strength and Bone Biomarkers in Female Children and Adolescent Football Players? A One-Season Study.

The aim was to compare changes in body composition, physical fitness, and bone biomarkers in female children and adolescent football players with different Vitamin D levels. Twenty-two players were classified into two groups according to 25(OH)D concentrations: 11 with deficient/insufficient 25(OH)D levels (IVD; <30 ng/mL) and 11 with sufficient 25(OH)D levels (SVD; ≥30 ng/mL). Body composition parameters were measured using dual-energy X-ray absorptiometry and a peripheral quantitative computed tomography scanner. The following physical fitness tests were applied: maximal isometric knee extension (MIF), long jump, 30-m sprint, and 20-m shuttle run test (VO2max). Electrochemiluminescence immunoassays were used to analyze bone biomarkers and 25(OH)D. All variables were registered at the beginning and the end of the football season. The increase in subtotal bone mineral density (BMD) was higher in players with SVD than those with IVD (p = 0.030). Only players with SVD improved their MIF of the left leg (p = 0.005); whereas, only players with IVD decreased their 30-m sprint performance (p = 0.007) and VO2max (p = 0.046). No significant between- and within-group differences were found for bone biomarkers. SVD might cause an extra improvement of subtotal BMD in female children and adolescent football players. Moreover, it seems that the 25(OH)D concentration could be an important parameter for physical fitness improvement in this population.

Early Life Factors Associated with Lean Body Mass in Spanish Children: CALINA Study.

Early life is critical for the programming of body composition. The literature links perinatal factors with fat mass development and its future effects (e.g., obesity); however, little evidence exists between early life factors and lean body mass (LBM). This study follows up on a cohort of 416 Spanish children at ages six to eight, previously evaluated at birth in the CALINA study. Here, we studied the association between early life factors, LBM, and limb strength. Parental origin/nutritional status, maternal smoking during pregnancy, gestational diabetes/weight gain/age, birth weight (BW), early feeding, and rapid weight gain (RWG) were collected from primary care records. Bioimpedance analysis, dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and a handgrip/standing long jump test were used to assess fat-free mass index (FFMI), total lean soft tissue mass index (TLSTMI), muscle cross-sectional area index (MCSAI), and limb strength, respectively. In girls, maternal smoking, gestational age, and BW were positively associated with FFM/LSTM. In boys, the parents' BMI, BW, and RWG were positively associated with FFM/LSTM. BW was associated with handgrip strength in both. Maternal BMI in girls and RWG in boys were negatively associated with the standing long jump. Early life programming plays a key role in determining LBM in children.

Effects of an online home-based exercise intervention on breast cancer survivors during COVID-19 lockdown: a feasibility study.

PURPOSE: The strict lockdown implemented due the COVID-19 pandemic is generating a great impact on wellbeing and health-related quality of life (HRQoL) in people with cancer. We aimed to evaluate the efficacy and feasibility of an online home-based exercise intervention performed during a lockdown period analysing its effects on body composition, physical fitness, and HRQoL in breast cancer survivors. METHODS: Fifteen women with breast cancer receiving hormonal therapy (55.5 ± 6.7 years) were included in the study. The exercise intervention consisted of two weekly sessions of remotely supervised functional training (60 min per day) and two weekly sessions of unsupervised aerobic training (20-30 min/session; 60-85% of maximum heart rate) for a total of 16 weeks. DXA absorptiometry was used for the assessment of body composition. Functional assessment included cardiorespiratory fitness (CRF) by Rockport walking test, upper and lower body strength (grip strength, arm curl test, and chair stand test), walking speed (brisk walking test), and agility (8-foot up-and-go test). The HRQoL was evaluated with the QLQ-BR23 questionnaire. The adherence to the intervention was measured as the percentage of online classes attended. RESULTS: Rate of adherence for the online exercise intervention was 90 ± 17%. The exercise intervention induced significant (p < 0.05) improvements in physical fitness: CRF (+ 9%), right arm and lower limb strength (+ 10% and + 18%, respectively) and lower limbs lean mass (+ 2% and + 3.5% for left and right leg, respectively). CONCLUSION: This feasibility study suggests that an online home-based exercise intervention during COVID-19 lockdown could improve physical fitness and body composition in breast cancer survivors even in a context of heightened concern for future health.

Fat-free/lean body mass in children with insulin resistance or metabolic syndrome: a systematic review and meta-analysis.

BACKGROUND: Lean / Fat Free Body Mass (LBM) is metabolically involved in active processes such as resting energy expenditure, glucose uptake, and myokine secretion. Nonetheless, its association with insulin sensitivity / resistance / glucose tolerance and metabolic syndrome remains unclear in childhood. METHODS: The current investigation aimed to examine the differences in fat-free mass /lean body mass according to the presence of insulin sensitivity/insulin resistance/glucose tolerance/metabolic syndrome in children. A systematic search was carried out in Medline/PubMed, Embase, Scopus, Web of Science, and SciELO, covering the period from each database's respective start to 21 June 2021. Two researchers evaluated 7111 studies according to the inclusion criteria: original human studies, written in English or Spanish, evaluating fat-free mass/lean body mass in children and adolescents including both with and without insulin sensitivity/insulin resistance /glucose tolerance and metabolic syndrome and reported the differences between them in terms of fat free mass/lean body mass. The results of the studies were combined with insulin sensitivity, insulin, resistance, glucose tolerance and metabolic syndrome. The standardized mean difference (SMD) in each study was calculated and combined using the random-effects model. Heterogeneity between studies was tested using the index of heterogeneity (I2), leave-one-out sensitivity analyses were performed, and publication bias was assessed using the Egger and Begg tests. RESULTS: Finally, 15 studies which compared groups defined according to different glucose homeostasis criteria or metabolic syndrome out of 103 eligible studies were included in this systematic review and 12 studies in the meta-analysis. Meta-analysis showed lower fat-free mass/lean body mass percentage in participants with insulin resistance/glucose tolerance/metabolic syndrome (SMD -0.47; 95% CI, - 0.62 to - 0.32) while in mass units (kg), higher values were found in the same group (SMD, 1.01; 95% CI, 0.43 to 1.60). CONCLUSIONS: Our results identified lower values of fat-free mass/lean body mass (%) in children and adolescents with insulin resistance/glucose tolerance/metabolic syndrome and higher values of fat-free mass/lean body mass when these are expressed in kg. The evidence of the impact of lean mass on children's glucose homeostasis or metabolic syndrome is limited, so future studies research should focus on explaining the effect of fat-free mass/lean body mass on different metabolic outcomes. Moreover, it may be interesting to evaluate the quality (muscle density) or functional (muscle strength) outcomes in addition to both absolute (kg) and relative (%) values in future studies. The systematic review was prospectively registered at PROSPERO (registration number CRD42019124734; available at: http://www.crd.york.ac.uk/prospero [accessed: 05 April 2019]).

Nonspecific Resistance Training and Swimming Performance: Strength or Power? A Systematic Review.

ABSTRACT: Muniz-Pardos, B, Gomez-Bruton, A, Matute-Llorente, A, Gonzalez-Aguero, A, Gomez-Cabello, A, Gonzalo-Skok, O, Casajus, JA, and Vicente-Rodriguez, G. Nonspecific resistance training and swimming performance: Strength or power? A systematic review. J Strength Cond Res 36(4): 1162-1170, 2022-The purpose of this systematic review was to determine the type of nonspecific resistance intervention that is more effective to enhance swimming performance and to determine the nonspecific strength- or power-related variable that better predicts swimming performance. A search was conducted on PubMed, Cochrane Plus, and SportDiscus up to June 2018. Studies were distributed into 4 categories: dry-land strength (DLS), dry-land power (DLP), combination of training methods, and strength and power in start performance. From 1,844 citations, 33 met the inclusion criteria. Cross-sectional DLS studies showed positive associations between swimming performance and DLS development (especially through upper-body isometric assessments), although the efficacy of DLS training interventions remains unclear. Dry-land power training (principally through plyometrics) was a proficient, nonspecific method to enhance swimming block start performance (SBS; the start phase off the block and during the first 5-15 m), and jump assessment was the best predictor of SBS. Some pioneering nonspecific practices such as the acute exposure to high altitude or the maintenance of a high core temperature during the transition phase before competition seem to improve performance, although more research is required to confirm their efficacy. Further high-quality intervention studies are required to clarify the effect of DLP training on sprint swimming performance.

Associations between Spanish children's physical activity and physical fitness with lean body mass: The CALINA study.

The present study investigated the associations between physical activity (PA) and physical fitness (PF) with lean body mass (LBM) and evaluated whether PA mediates the association between PF and LBM. 279 children (150 boys) aged 7.5 ± 0.3 years participated in the study. PA was assessed by accelerometry and PF with handgrip and the standing long jump test. Total lean soft tissue mass index (TLSTMI), muscle cross-sectional area index (MCSAI), and fat-free mass index (FFMI) were evaluated using dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and bioimpedance analysis, respectively.Total (ß = 0.247) and vigorous PA (ß = 0.143) were associated with TLSTMI in girls. In boys, total (ß = 0.337), light (ß = 0.290), vigorous (ß = 0.200), and moderate-vigorous PA (ß = 0.189) were associated with TLSTMI. Total PA was associated with FFMI (ß = 0.299). Handgrip strength does not mediate the relationship between total PA and TLSTMI. Positive associations were found between handgrip strength and TLSTMI, MCSAI, and FFMI in both girls and boys.In children, there is a positive association between total and vigorous PA with TLSTMI. Handgrip strength does not mediate the relationship between total PA and TLSTMI. It was associated with TLSTMI, MCSAI, and FFMI.

Fitness vs Fatness as Determinants of Survival in Noninstitutionalized Older Adults: The EXERNET Multicenter Study.

BACKGROUND: Physical fitness and body composition are important health indicators; nevertheless, their combined pattern interrelationships and their association with mortality are poorly investigated. METHODS: This longitudinal study is part of the Spanish EXERNET-Elder project. Person-months of follow-up were calculated from the interview date, performed between June 2008 and November 2009, until the date of death or censoring on March 2018 (whichever came first). In order to be included, participants had to fulfill the following criteria: (a) be older than 65 years, (b) live independently at home, (c) not suffer dementia and/or cancer, and (d) have a body mass index above 18.5. Body fat and weight were assessed by a bioelectrical impedance analyzer. Fitness was measured with the Senior Fitness and the one-leg static balance tests. The Spanish Death Index was consulted for the death's identification. Cluster analysis was performed to identify Fat-Fit patterns and traditional cut-points and percentiles to create the Fat-Fit groups. Cox proportional hazards regression models were used to calculate the hazard ratios (HRs) of death in clustered Fat-Fit patterns and in traditional Fat-Fit groups. RESULTS: A total of 2299 older adults (76.8% of women) were included with a baseline mean age of 71.9 ± 5.2 years. A total of 196 deaths (8.7% of the sample) were identified during the 8 years of follow-up. Four clustered Fat-Fit patterns (Low fat-Fit, Medium fat-Fit, High fat-Unfit, and Low fat-Unfit) and 9 traditional Fat-Fit groups emerged. Using the Low fat-Fit pattern as the reference, significantly increased mortality was noted in High fat-Unfit (HR: 1.68, CI: 1.06-2.66) and Low fat-Unfit (HR: 2.01, CI: 1.28-3.16) groups. All the traditional Fit groups showed lower mortality risk when compared to the reference group (obese-unfit group). CONCLUSION: Physical fitness is a determinant factor in terms of survival in community-dwelling older adults, independently of adiposity levels.

Does Acute Caffeine Supplementation Improve Physical Performance in Female Team-Sport Athletes? Evidence from a Systematic Review and Meta-Analysis.

INTRODUCTION: Recent original research and meta-analyses suggest that acute caffeine supplementation improves exercise performance in team-sport athletes (TSA). Nonetheless, most of the studies testing the effects of caffeine on TSA included samples of male athletes, and there is no meta-analysis of the performance-enhancing effects of caffeine on female TSA. The aim of the present study was to synthesize the existing literature regarding the effect of caffeine supplementation on physical performance in adult female TSA. METHODS: A search was performed in Pubmed/Medline, SPORTDiscus and Scopus. The search was performed from the inception of indexing until 1 September 2021. Crossover randomized controlled trials (RCT) assessing the effects of oral caffeine intake on several aspects of performance in female TSA were selected. The methodological quality and risk of bias were assessed for individual studies using the Physiotherapy Evidence Database scale (PEDro) and the RoB 2 tool. A random-effects meta-analysis of standardized mean differences (SMD) was performed for several performance variables. RESULTS: The search retrieved 18 articles that fulfilled the inclusion/exclusion criteria. Overall, most of the studies were of excellent quality with a low risk of bias. The meta-analysis results showed that caffeine increased performance in specific team-sport skills (SMD: 0.384, 95% confidence interval (CI): 0.077-0.691), countermovement jump (SMD: 0.208, CI: 0.079-0.337), total body impacts (SMD: 0.488; 95% CI: 0.050, 0.927) and handgrip strength (SMD: 0.395, CI: 0.126-0.665). No effects were found on the ratings of perceived exertion, squat jumps, agility, repeated sprint ability or agility tests performed after fatigue. CONCLUSIONS: The results of the meta-analysis revealed that acute caffeine intake was effective in increasing some aspects of team-sports performance in women athletes. Hence, caffeine could be considered as a supplementation strategy for female athletes competing in team sports.

Análisis del efecto a largo plazo de un programa de estimulación cognitiva en mayores con deterioro cognitivo leve en Atención Primaria: ensayo controlado aleatorizado / Long-term effect analysis of a cognitive stimulation program in mild cognitive impairment elderly in Primary Care: A randomized controlled trial

Objetivo: Aportar evidencias de la eficacia de una intervención comunitaria en salud a través de un programa de estimulación cognitiva (PEC) implementada con el paso del tiempo en mayores con deterioro cognitivo leve en la comunidad. Diseño: Seguimiento de un ensayo controlado aleatorizado (normas grupo CONSORT). Emplazamiento: Centro de salud San José Norte-Centro y Fundación La Caridad (Zaragoza). Participantes: Veintinueve personas ≥65 años, con 24-27 puntos en el MEC-35 que completaron el ensayo a los 48 meses, 15 aleatorizados en el grupo intervención y 14 en el grupo control. Intervenciones: Se realizaron 10 sesiones, 45min/semana, durante 10 semanas, con el cuaderno rojo de activación mental que ejercita: memoria, orientación, lenguaje, praxis, gnosis, cálculo, percepción, razonamiento lógico, atención y funciones ejecutivas. Mediciones principales: MEC-35, Set-test, Barthel, Lawton-Brody, subescala de ansiedad Goldberg y Yesavage abreviado (GDS-15). Resultados: Analizando los incrementos sobre el nivel basal para MEC-35, el grupo intervención obtiene, de media: postintervención 3,14 puntos, a los 6 meses 3,76 puntos y a los 12 meses 2,26 puntos más que el grupo control, siendo estos incrementos estadísticamente significativos. A los 48 meses el grupo intervención sigue obteniendo 2 puntos más que el control, sin ser significativos. La intervención no mejoró el desempeño en fluidez verbal, actividades de la vida diaria ni estado de ánimo. Conclusiones:Nuestro PEC podría ser eficaz en la mejora de la cognición general, medida con el MEC-35, en postintervención, a los 6, 12 y 48 meses. No se evidencian mejoras en fluidez verbal, actividades de la vida diaria ni estado de ánimo.(AU)

Objective: To provide evidence about the efficacy of a community health intervention through a cognitive stimulation program at long term in older people with mild cognitive impairment. Design: Randomized controlled trial (CONSORT group norms). Location: San José Norte-Centro Primary Care Center and La Caridad Foundation (Zaragoza, Spain). Participants: Twenty-nine people over 65 years old with a 24-27 MEC score that completed 48 months follow up. They were randomized between the intervention group (15) and the control group (14). Interventions: The intervention was applied in 10 sessions of 45min for 10 weeks using the red notebook tool for mental activation that works memory, orientation, language, praxis, gnosis, calculation, perception, logical reasoning, attention and executive functions. Main measurements: The main outcome variables were MEC-35, Set-test, Barthel index, Lawton-Brody scale, Goldberg anxiety scale and Yesavage geriatric depression scale short form. Results: Increases of the main result variable over the baseline level of MEC-35 were analyzed. On average, the intervention group obtained higher scores than control: 3.14 points post intervention, 3.76 points after 6 months and 2.26 points more than control group after 12 months. All the differences were statistically significant. After 48 months the intervention group obtained 2 points more than control group. The intervention did not improve verbal fluency, activity daily living and mood. Conclusions: Our cognitive stimulation program seems to improve cognitive performance, measured with the variable MEC-35 at post intervention, 6, 12 and 48 months. There is no evidence of improvement in verbal fluency, activity daily livings and mood.(AU)

[Long-term effect analysis of a cognitive stimulation program in mild cognitive impairment elderly in Primary Care: A randomized controlled trial]. / Análisis del efecto a largo plazo de un programa de estimulación cognitiva en mayores con deterioro cognitivo leve en Atención Primaria: ensayo controlado aleatorizado.

OBJECTIVE: To provide evidence about the efficacy of a community health intervention through a cognitive stimulation program at long term in older people with mild cognitive impairment. DESIGN: Randomized controlled trial (CONSORT group norms). LOCATION: San José Norte-Centro Primary Care Center and La Caridad Foundation (Zaragoza, Spain). PARTICIPANTS: Twenty-nine people over 65 years old with a 24-27 MEC score that completed 48 months follow up. They were randomized between the intervention group (15) and the control group (14). INTERVENTIONS: The intervention was applied in 10 sessions of 45min for 10 weeks using the red notebook tool for mental activation that works memory, orientation, language, praxis, gnosis, calculation, perception, logical reasoning, attention and executive functions. MAIN MEASUREMENTS: The main outcome variables were MEC-35, Set-test, Barthel index, Lawton-Brody scale, Goldberg anxiety scale and Yesavage geriatric depression scale short form. RESULTS: Increases of the main result variable over the baseline level of MEC-35 were analyzed. On average, the intervention group obtained higher scores than control: 3.14 points post intervention, 3.76 points after 6 months and 2.26 points more than control group after 12 months. All the differences were statistically significant. After 48 months the intervention group obtained 2 points more than control group. The intervention did not improve verbal fluency, activity daily living and mood. CONCLUSIONS: Our cognitive stimulation program seems to improve cognitive performance, measured with the variable MEC-35 at post intervention, 6, 12 and 48 months. There is no evidence of improvement in verbal fluency, activity daily livings and mood. Clinicaltrials.gov Identifier: NCT03831061.

Impact of the COVID-19 Pandemic on Teacher Quality of Life: A Longitudinal Study from before and during the Health Crisis.

BACKGROUND: Prior to the COVID-19 pandemic, teachers were already reporting a low quality of life (QoL) perception, with a significant impact on mental and physical health due to various stress factors associated with work overload. The objective of this study was to evaluate the QoL impact on Chilean teachers before and during the COVID-19 pandemic. The analysis was performed following a longitudinal design on a sample of 63 Chilean teachers in pre-pandemic and COVID-19 pandemic timeframes. QoL perception, along with teachers' sociodemographic data, was evaluated via the Short-Form 36 Health Survey (SF-36) questionnaire. Sociodemographic variables presented no significant variations in pre-pandemic and pandemic comparisons. QoL, however, showed a significant decrease during the pandemic compared to the pre-pandemic measurement (p < 0.01). In each gender, there were significant differences between pre-pandemic and pandemic timeframes, with a greater impact among women in the mental and physical component summary variables and seven of the eight QoL scales (p < 0.01). Between age categories, people under 45 presented significant differences (p < 0.05) between pre-pandemic and pandemic timeframes in all summary dimensions and measurements. In conclusion, Chilean teachers' QoL perception has been affected by the COVID-19 pandemic. These findings could be related to work overload due to teleworking or feelings of uncertainty, loneliness, and fear that the pandemic and its associated confinements will worsen.

How important is current physical fitness for future quality of life? Results from an 8-year longitudinal study on older adults.

INTRODUCTION: A vast amount of research has focused on the effects of physical fitness (PF) on mortality, with little research evaluating the effects of PF on future expected health related quality of life (HRQoL). AIM: To evaluate how current PF influences future HRQoL measured in a prospective 8-year study in older adults. METHODS: A total of 617 (157 males) older adults (>65y) participated in the study. PF was assessed with the EXERNET battery in 2008-2009 (baseline) and 2016-2017 (follow-up). HRQoL was assessed using the EQ-5D-3L questionnaire in both evaluations. PF tertiles were developed from baseline PF variables: FIT (highest PF values), REGULAR and UNFIT (lowest PF values) taking into account age and sex. Follow-up HRQoL values were compared to sex and age-specific expected values. Logistic regressions were performed to test differences between PF tertiles regarding future expected quality of life. Linear regressions were developed to test whether baseline PF could predict future HRQoL scores. RESULTS: The FIT group showed higher probabilities of an improved HRQoL when compared to the UNFIT group. All PF variables seemed to be important at some point of the study except upper extremities flexibility. Aerobic endurance was the variable that showed to be significant for most of the HRQoL predictions. CONCLUSION: PF influences future HRQoL in older adults who accordingly should try to remain fit to maintain an increased age-adjusted HRQoL.

Quantitative peripheral computed tomography to measure muscle area and assess lean soft tissue mass in children.

BACKGROUND: Skeletal muscle is one of the main components of lean soft tissue mass (LSTM). Low levels in children affect locomotion, posture, and increase the risk of metabolic syndrome. AIM: (1) To evaluate the association between muscle cross-sectional area (MCSA) of the lower left leg measured by peripheral quantitative computed tomography (pQCT) and total LSTM; namely, total left leg and left lower leg LSTM assessed by dual-energy X-ray absorptiometry (DXA) in a group of children, (2) to examine if MCSA is a predictor of LSTM, (3) to determine the ability of pQCT to identify children with low LSTM. SUBJECTS AND METHODS: Lower left leg MCSA and LSTM were measured using pQCT and DXA, respectively, in 396 children. RESULTS: Statistically significant positive correlations were found between the lower leg MCSA - total LSTM (r² = 0.789), total leg LSTM (r² = 0.79), and lower leg LSTM (r² = 0.791) (p < .01). MCSA explained 64-68% of the variance in LSTM. Receiver operator characteristic (ROC) curves determined the capacity of the lower left leg MCSA to identify low LSTM in girls (AUC 0.95) and boys (AUC 0.87). CONCLUSIONS: Our results showed that lower left leg MCSA, measured using pQCT, could be a tool to predict low LSTM in children.

The finger flexors occlusion threshold in sport-climbers: an exploratory study on its indirect approximation.

Blood flow partially determines specific climbing endurance (SCE) as it mediates oxygen bio-availability in the finger flexors. Blood flow is related to occlusion threshold (OT), which is defined as the contraction intensity at which intramuscular pressure exceeds perfusion blood pressure resulting in the cessation of local blood flow. The OT is represented as an inflection point on a force-time graph when isometric force is registered and applied through maximal and continuous tests. Endurance time (ET) to exhaustion is influenced by the relative isometric applied force and is different for each climber. The aim of this study was to explore whether an approximation of the finger flexors OT in sport climbers through records of ET to exhaustion at different isometric relative intensities was possible. We measured maximum finger hang ETs at 6 intensities ranging from 85% to 35% maximal force in 34 sport climbers of advanced and elite level. The values obtained were analysed by two different methods in an attempt to determine a change in the shape of the curve in the intensity-ET relationship graphs that approximated the OT for each climber. The results suggest that the finger flexors OT could be different among climbers, regardless of their strength and ability level. The presented methods do not accurately reflect the OT, but could indicate the intensity at which blood flow is restored in the active muscles. This is the first study to indirectly approximate the finger flexors OT in sport-climbers, a parameter that could be essential to assess SCE.

Low interest in physical activity and higher rates of obesity among rural teachers.

BACKGROUND: Few studies have evaluated the causes of physical inactivity in rural teachers from South America. Determining the causes and effects of physical inactivity in rural teachers could be the base for future intervention studies aiming to improve physical activity (PA) engagement in this population. OBJECTIVES: To examine the levels of PA in rural teachers and evaluate the associations between their jobs, interest in PA, body composition and practice of PA. METHODS: Body mass index (BMI) and body fat % (BF) of rural teachers from the Valparaiso Region in Chile were measured; interviews regarding PA habits, interests and PA practice were conducted. The relationship between BF% and interest in PA and the practice of sports was analysed stratifying by sex. RESULTS: Around 71% were overweight/obese and 80% of the teachers reported not practicing any PA. These figures are higher than the Chilean national average for adults (64.5% overweight/obese). Moreover, females presented a higher BF% than male teachers (35.98% vs. 26.44%, p < 0.05). The main causes of not performing PA were: firstly, the lack of time (51.8%), and secondly, fatigue after work and/or finishing work late. In addition, rural teachers claim that in their free time they continue to finish tasks that they were not able to complete during their working hours. CONCLUSIONS: Rural Chilean teachers show a high prevalence of obesity and low PA levels. Moreover, rural teachers have a work overload stemming from their jobs, and this could be an important link to an overall sedentary lifestyle. Further studies should focus on the relationship between teacher obesity, physical activity, nutrition and work overload.

Role of Dietary Intake and Serum 25(OH)D on the Effects of a Multicomponent Exercise Program on Bone Mass and Structure of Frail and Pre-Frail Older Adults.

The multicomponent training (MCT) effect on bone health in frail and pre-frail elders, which is influenced by dietary intake, is still unknown. The objective of this non-randomized intervention trial was to assess the effects of a 6-month MCT on bone structure in frail and pre-frail elders, and to analyse the influence of dietary intake and serum vitamin D (25(OH)D) in these changes. Thirty MCT (TRAIN) and sixteen controls (CON), frail and pre-frail completed the information required for this study. Peripheral quantitative computed tomography measurements were taken at 4% and 38% of the tibia length and dietary intake was registered. The 25(OH)D values were obtained from blood samples. Analyses of covariance (ANCOVA) for repeated measures showed significant decreases for CON in total bone mineral content at 38% of tibia length. One factor ANOVAs showed smaller decreases in bone mineral density and cortical thickness percentage of change in TRAIN compared to CON. Linear regression analyses were performed to study the influence of nutrients and 25(OH)D on bone changes. Alcohol showed a negative influence on fracture index changes, while polyunsaturated fatty acid and vitamin A showed a positive association with some bone variables. The 25(OH)D only affected positively the cortical bone mineral density. In conclusion, our MCT seems to slow down some of the bone detriments associated with ageing in frail and pre-frail older adults, with alcohol showing a negative effect on the bone and apparent limited effect of nutrients and serum 25(OH)D on training related changes.

Can elastic band resistance training programs mitigate holiday weight gain and improve hand-grip strength in older women? / ¿Pueden los programas de entrenamiento de resistencia con banda elástica mitigar el aumento de peso durante las vacaciones y mejorar la fuerza de agarre de las manos en mujeres mayores?

SUMMARY: This study evaluated the effect of resistance exercise training (RET) on body composition and muscle strength in 16 older women during summer holidays (70.5 ± 8.4 years old; Range 60-87). Exercise sessions were carried out for twelve weeks, two sessions per week, with 60 minutes of exercise per session. We measured body mass index (BMI), fat mass percentage (FM%, by bioimpedance) and grip strength with a dynamometer before and after the intervention. The participants showed a significant increase in BMI (p<0.05), FM% (p<0.001), and a significant gain in grip strength (p<0.05). The RET program could be an important strategy for improving strength for older women, but we would suggest combining it with other interventions, such as aerobic exercises with gradually increasing intensity and nutrition interventions, in order to maintain a steady weight during holiday periods.

RESUMEN: Este estudio evaluó el efecto del entrenamien- to con ejercicios de resistencia (EER) sobre la composición corpo- ral y la fuerza muscular en 16 mujeres adultas mayores durante las vacaciones de verano (70,5 ± 8,4 años; Rango 60-87). Las sesio- nes de ejercicio se llevaron a cabo durante doce semanas, dos ve- ces por semana, con 60 minutos de ejercicio por sesión. Se evaluó el índice de masa corporal (IMC), el porcentaje de masa grasa (% MG, por bioimpedancia) y la fuerza de presión con un dinamómetro manual antes y después de la intervención. Las participantes mos- traron un aumento significativo en el IMC (p< 0,05), % de MG (p<0,001) y un incremento significativo en la fuerza prensil (p <0,05). El programa de EER podría ser una estrategia importante para mejorar la fuerza de mujeres adultas mayores durante el periodo estival. El EER se sugiere combinarlo con otras variables, como ejercicios aeróbicos con intensidad gradualmente creciente y una intervención nutricional, para mantener un peso constante durante los períodos de vacaciones.

The effects of Age, Organized Physical Activity and Sedentarism on Fitness in Older Adults: An 8-Year Longitudinal Study.

The aims of the present study were (1) to describe the changes in physical fitness during an 8 year follow-up in a large sample of Spanish adults aged 65 or over that are initially engaged in organized physical activity (OPA), (2) to compare fitness changes according to different age groups (65 to 69 vs. 70 to 74 vs. ≥75 years-old), (3) to evaluate the independent and combined effects of changes in OPA engagement and sitting time (ST) on physical fitness. A total of 642 (147 males) non-institutionalized over 65 years-old participants completed the EXERNET battery fitness tests and completed a validated questionnaire from which information regarding OPA and ST were collected. All participants completed evaluations in 2008-2009 and in 2016-2017. An impairment of fitness-related variables happens after 65 years of age in both males and females, with the older participants (≥75), showing the largest decreases. Males who continued performing OPA demonstrated lower decreases in balance, leg flexibility and agility when compared to those who stopped performing OPA during the follow-up. Females who continued performing OPA demonstrated lower decreases of all variables except for balance when compared to those who stopped performing OPA during the follow-up.