La actividad física como herramienta para reducir el absentismo laboral debido a enfermedad en trabajadores sedentarios. Una revisión sistemática

Fundamentos: Se ha sugerido que los programas de actividad física (AF) podrían reducir el absentismo laboral por motivos de enfermedad en trabajadores sedentarios. Esta revisión tuvo como objetivo examinar la evidencia científica disponible para estudiar los efectos de la AF sobre el absentismo laboral teniendo en consideración el diseño del programa de AF. Métodos: Se realizó una búsqueda bibliográfica en 4 bases de datos (Medline, Sportdiscus, Web of Science y Embase) de ensayos clínicos y estudios observacionales publicados sobre AF y absentismo laboral, en inglés y en español, desde el inicio de indización hasta diciembre de 2017, utilizando la metodología PRISMA. Resultados: Un total de 10 estudios publicados cumplieron con los criterios de elegibilidad establecidos. Las evidencias encontradas en la revisión sugieren que la AF es efectiva como medida para reducir el absentismo laboral por motivos de enfermedad. En general, los estudios señalaron que se observan mayores probabilidades de ausentarse del trabajo en trabajadores sedentarios que en los físicamente activos. Conclusiones: La AF en general parece disminuir el absentismo laboral. En concreto, la AF vigorosa podría obtener mejores resultados que la realizada a intensidad moderada, aunque faltan estudios de intervención más rigurosos y específicos, con un mayor control sobre las variables de intervención. Background: Physical Activity (PA) programs have been suggested to lower absenteeism due to illness in sedentary employees. The aim of this review was to examine available scientific literature in order to study PA effects in workplace absenteeism taking the program design into consideration. Methods: A search through 4 databases (Medline, Sportdiscus, Web of Science and Embase), from inception to December 2017, was conducted to identify control intervention and observational studies about PA and absenteeism published in either English or Spanish language using PRISMA procedures. Results: A total of 10 published studies between 1981 and 2017 met the inclusion criteria. Evidence from the review suggested that PA is effective in reducing illness-related absence. Likelihood of being off from workplace reported with sedentary workers reach more probabilities when compared with exercisers. Conclusions: General PA is considered paramount in order to lower employees'' absenteeism, which could be more related to vigorous training. However, there is a lack of rigorous and more specific studies about the issue. More focused on PA effect on absenteeism, adjusted by intervention variables, research would be desirable

Longitudinal effects of swimming on bone in adolescents: A pQCT and DXA study

The aims of the present study were, firstly, to evaluate areal bone mineral density (aBMD), bone strength and structure during a swimming season and compare them to those of normo-active controls (CG), and secondly to ascertain whether practising an additional weight-bearing sport other than swimming might improve bone. Twenty-three swimmers who only swam (SWI-PURE; 14 males, 9 females), 11 swimmers who combined swimming with an additional weight-bearing sport (SWI-SPORT; 8 males, 3 females) and 28 controls (CG; 16 males, 12 females) participated in the present study. aBMD was assessed with dual energy X-ray (DXA). Bone mass, area, structure and strength of the non-dominant tibia and radius were measured with peripheral quantitative computed tomography (pQCT). Measurements were performed at the beginning of the swimming season and 8 months later. The only difference among groups for DXA and pQCT variables was found for arm aBMD, which was higher in the SWI-SPORT than in the CG group at both pre- and post-evaluation. Group by time interactions (GxT) were found for trochanter aBMD when comparing SWI-SPORT to CG and SWI-SPORT to SWI-PURE, favouring in both cases SWI-SPORT. No GxT were found for the radius. For the tibia, GxT were found between SWI-SPORT and CG and between SWI-PURE and CG, in both cases favouring the swimmers. A season of swimming does not confer any additional benefits to aBMD, but may confer minor benefits to structure and mass. Complementing swimming with a weight-bearing activity is beneficial to bone

Effects of active video games on health-related physical fitness and motor competence in children and adolescents with overweight or obesity: Systematic review and meta-Analysis

Background: Childhood obesity is one of the most important public health problems. Active video games (AVGs) have been proposed as an attractive alternative to increase energy expenditure and are being investigated to determine their effectiveness against childhood obesity. Objective: The aim of this study is to summarize the existing research and draw conclusions about the effects of AVGs on health-related physical fitness and motor competence in children and adolescents with overweight and obesity. Methods: The search strategy was applied to PubMed, MEDLINE, Web of Science, and SPORTDiscus, including randomized and nonrandomized controlled trials investigating the effects of AVG programs on health-related physical fitness and motor competence in children and adolescents with overweight and obesity. To measure the risk of bias in randomized and nonrandomized controlled trials, 2 different quality assessment tools were used. In total, 15 articles met the inclusion criteria, and the variables of interest were BMI, body fat percentage, cardiorespiratory fitness (CRF), waist circumference, fat-free mass, muscular fitness, and motor competence. A meta-Analysis was performed. Results: Positive effects were found for BMI and body fat percentage, favoring the AVG group compared with a control group with no intervention (mean difference-0.209; 95% CI-0.388 to-0.031 vs mean difference-0.879; 95% CI-1.138 to-0.602). Positive effects seem to be observed for CRF. The effects of AVG interventions on muscular fitness, fat-free mass, waist circumference, and motor competence are unclear. Conclusions: AVG programs showed positive effects on BMI, body fat percentage, and CRF. AVG could be a good strategy to combat childhood obesity. © 2021. KJMIR Publications Inc.. All right reserved

Agreement of body composition methods in elite male football referees

Objective: The current literature about the body composition of elite football referees is scarce and almost non-existent. Therefore, and in order to establish the level of agreement between bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DXA) in elite football referees, the aim of this study was to compare fat mass (FM) and fat-free mass (FFM) values measured with these two different methods. Method: A total of 30 male referees belonging to 1st, 2nd and 2ndB categories, and 36 assistant referees from 1st and 2nd categories in the Spanish national league participated in this study. Total and regional FM and FFM were assessed using a portable BIA analyser TANITA BC 418-MA (Tanita Corp., Tokyo, Japan) and DXA (Hologic Corp. Software version 12.4, Bedford, MA 01730). Agreement between methods was assessed by plotting the results in Bland-Altman graphs and the presence of heteroscedasticity was also examined. Differences between methods were analysed by two-paired samples t-test. Results: For the whole group, BIA underestimated body fat percentage in 3.87 points (CI 95%=3.22-4.52; p=<0.01) and overestimated kg of total FFM in 3.56 points (CI 95%=3.08-4.05; p=<0.01), however, no heteroscedasticity was shown in any case (all p>0.05). Conclusions: The present study suggests that according to DXA, BIA values calculated with a non-specific equation are underestimating total FM and, consequently, overestimating total FFM in male elite football referees. Objetivo: La literatura científica existente sobre la composición corporal en árbitros de fútbol es todavía escasa. Por lo tanto y para establecer el nivel de concordancia entre el análisis de impedancia bioeléctrica y la absorciometría de rayos X de doble energía en árbitros de fútbol de elite, el objetivo de este estudio fue comparar los valores de masa grasa (MG) y la masa libre de grasa (MLG) medidos con ambos métodos. Método: Un total de 30 árbitros pertenecientes a las categorías de 1ª, 2ª y 2ª división B, y 36 asistentes de 1ª y 2ª división de la liga española participaron en este estudio. La MG y la MLG tanto a nivel total como regional se evaluó utilizando la impedancia bioeléctrica TANITA BC 418-MA (Tanita Corp., Tokyo, Japan) y absorciometría de rayos X de doble energía (Hologic Corp. Software versión 12.4, Bedford, MA 01730). La concordancia entre métodos se evaluó con gráficos de Bland-Altman y también se examinó la presencia de heterocedasticidad. Las diferencias entre métodos se analizaron con la prueba T de Student para muestras relacionadas. Resultados: Para el total de la muestra, la impedancia bioeléctrica infraestimó el porcentaje de MG en 3.87 puntos (IC 95%=3.22-4.52; p=0.05). Conclusión: El presente estudio sugiere que, tomando como referencia la absorciometría de rayos X de doble energía, la impedancia bioeléctrica calculada a partir de una ecuación no especifica para árbitros, infraestima la MG y consecuentemente, sobreestima la MLG en árbitros de fútbol de elite

Comparison Of Body Composition Methods For The Assessment Of Body Fat In Adolescent Soccer Players

Anthropometry, dual energy x-ray absorptiometry (DXA) and air displacement plethysmography (ADP) are widely used for assessing body fat percentage (%BF). The accuracy among body composition methods in different kind of populations such as children, adults, obese persons, and athletes has been studied but there are some discrepancies between them. PURPOSE: To compare %BF assessed by DXA, ADP and anthropometry in adolescent soccer players. METHODS: %BF was assessed in ninety-two soccer players (64 males, 13.3 ± 0.5 y; 28 females, 13.3 ± 0.6 y) by anthropometry, DXA and ADP. Anthropometry measurements were registered following the recommendations of the ISAK. Anthropometry %BF was calculated using the equation proposed by Slaughter et al for adolescents. ADP %BF was calculated with 3 different formulas: (i) the general Siri equation (ADPSiri); (ii) the age- and sex-specific equation by Lohman (ADPLohman) and (iii) the age- and sex-specific equation by Silva (ADPSilva). Agreement and differences between methods were assessed by two-paired samples t tests and calculating the 95% limits of agreement. RESULTS: In the whole sample, ADPSiri ADPLohman ADPSilva and anthropometry underestimated %BF by 2.0, 6.9, 6.2, and 6.0% respectively compared to DXA (all p<0.05). The 95% limits of agreement ranged from ±5.91% to ±10.78%. Similar results dividing by sex were found. CONCLUSION: Although the 3 used methodologies have been several times described as valid for the assessment of %BF, based in our data it seems that ADP, anthropometry and DXA are not interchangeable for the assessment of %BF in adolescent soccer players

Longitudinal Effects Of Swimming On Bone Mass, Structure And Strength

PURPOSE: To investigate the changes over a swimming season in bone mineral density (BMD), bone mineral content (BMC), bone strength and bone structure in adolescent swimmers and compared them to normo-active controls (CG). METHODS: BMD and BMC were measured longitudinally (8 months) by Dual Energy X-ray Absorptiometry at the whole body, lumbar spine and non-dominant hip. Bone strength was measured at the midshaft radius and tibia with peripheral quantitative computed tomography (pQCT). Swimmers were divided into two groups; swimmers that swam and performed an extra-weight bearing sport (SWI-SPORT; n=11) and swimmers that only swam (SWI; n=23). Both groups were compared between them and to CG (n=28). ANCOVA for repeated measures x 2 (time) were performed between pre- and post-intervention to determine the effects of swimming on BMC and BMD values adjusting by change in height and subtotal lean, initial age and final Tanner stage and calcium intake for DXA values. For pQCT the same analyses were performed adjusting by change in object length, initial age and final Tanner stage. RESULTS: Eight months of swimming training had no effect on BMD or BMC, as no differences were found between SWI-PURE and CG acquisition. Nevertheless, practicing an extra-weight bearing sport in addition to swimming seemed to positively stimulate bone mass acquisition as SWI-SPORT was the only group that improved all measured skeletal sites and also a group by time interaction was found for the trochanter and total hip BMD when comparing SWI-SPORT to CG (p<0.05). Regarding pQCT measures, no group by time interactions were found for the radius. For the tibia, SWI-SPORT presented higher improvements in cortical thickness, resistance to fracture load (X-axis), and polar strain index than CG (all group by time interactions p<0.05). SWI-PURE also presented higher improvements in polar strain index when compared to CG (group by time interaction p<0.05). CONCLUSION: Swimming seems to be a neutral sport to practice regarding BMD and BMC acquisition. Nevertheless, it might entail some minor improvements in bone strength. Practicing a weight bearing sport in addition to swimming improves both bone mass acquisition and bone strength

Effects Of Playing Surfaces On Volumetric Bone Mineral Density In Adolescent Male Soccer Players

It has been well recognized that impact loading in sporting activity is highly associated with bone accretion. Recently, Carmona et al. showed that bone mass accretion was similar bone in prepubescent soccer players independently of the playing surface (artificial turf vs. non-grass ground surface). However, the osteogenic effects on volumetric bone mineral density (vBMD) generated by four different playing surfaces of the same sport are unknown. PURPOSE: to investigate the effects over a soccer season in vBMD of male soccer players by playing surface. METHODS: A total of 71 male soccer players (12.7±0.6 y) volunteered to participate in the study. 26 participants were training and playing on 2nd generation artificial turf, 16 on a 3rd generation artificial turf, 10 on a non-grass ground surface and 19 on natural grass (NG). vBMD, at 4 and 38% of the non-dominant tibia, was measured before and after season by peripheral quantitative computed tomography (Stratec XCT-2000 L pQCT scanner). Analysis of variance for repeated measures×2 (time) were performed to determine the effects of playing surface on vBMD controlling for pubertal status. Effect size were calculated according to the methods proposed by Cohen (small (f=0.1), medium (f=0.2), or large (f=0.4)). RESULTS: A group by time interaction was found for vBMD at 38% of the distal tibia (p=0.029 and f=0.38). When pairwise comparisons were carried out, NG showed group by time interactions compared to 2nd generation artificial turf (782 to 804 mg/cm3 vs. 790 to 798 mg/cm3; p=0.007 and f=0.50), and to 3rd generation artificial turf (782 to 804 mg/cm3 vs. 784 to 788 mg/cm3; p=0.027 and f=0.35). CONCLUSION: Soccer players training and playing in NG pitch showed better values in vBMD acquisition than those on 2nd and 3rd generation artificial turf. Despite previous studies presented no differences on bone mass accretion independently of the playing surface. Our results suggest that NG is the most recommended playing surface to improve vBMD in the non-dominant tibia

The muscle-bone unit in adolescent swimmers

Most researchers adjust bone by lean mass when comparing swimmers with controls. This adjustment is done under the assumption that lean affects bone similarly in both groups. Nonetheless, we found that the muscle-bone association is uncoupled in swimmers, and consequently, researchers should avoid this adjustment when evaluating swimmers’ bone. Introduction: To examine the functional and structural muscle-bone unit in adolescent swimmers. Methods: Sixty-five swimmers (34 girls/31 boys) and 119 controls (51 girls/68 boys) participated in the study. Muscle cross-sectional area (MCSA), bone mineral content (BMC), and polar strength-strain index (SSIPOL) were measured in the non-dominant radius by peripheral quantitative computed tomography (pQCT). Subtotal BMC and lean mass were evaluated with dual-energy X-ray absorptiometry (DXA). Handgrip and isometric knee extension (IKE) tests were performed to determine muscle force. The effect of MCSA, lean and force on SSIPOL, and BMC were tested, and the functional and structural muscle-bone ratios of swimmers and controls were compared. Results: Both muscle size (MCSA and lean) and muscle force (handgrip and IKE) influenced BMC and SSIPOL in swimmers and controls similarly. Swimmers presented normal MCSA and lean values for their height, but when compared with controls, swimmers presented a higher amount of lean and MCSA for the same BMC or SSIPOL (structural muscle-bone unit). For the functional muscle-bone unit, different results were found for the lower and upper limbs, as no differences were found for the upper limbs, while for the lower limbs, swimmers presented higher muscle force for the same amount of BMC. Conclusions: The contradictory results regarding BMC in swimmers found in previous studies could partly be explained with the findings of the present study that reinforce the idea that swimming is not an effective sport to practice regarding bone mass and that the muscle-bone unit is different in swimmers than in controls

Higher levels of physical fitness are associated with a reduced risk of suffering sarcopenic obesity and better perceived health among elderly. The EXERNET multi-center study

Objective: To evaluate the associations between physical fitness levels, health related quality of life (HRQoL) and sarcopenic obesity (SO) and to analyze the usefulness of several physical fitness tests as a screening tool for detecting elderly people with an increased risk of suffering SO. Design: Cross-sectional analysis of a population-based sample. Setting: Non-institutionalized Spanish elderly participating in the EXERNET multi-centre study. Participants: 2747 elderly subjects aged 65 and older. Measurements: Body weight, height and body mass index were evaluated in each subject. Body composition was measured by bioelectrical impedance. Four SO groups were created based on percentage of body fat and relative muscle mass; 1) normal group, 2) sarcopenic group, 3) obesity group and 4) SO group. Physical fitness was evaluated using 8 tests (balance, lower and upper body strength, lower and upper body flexibility, agility, walking speed and aerobic capacity). Three tertiles were created for each test based on the calculated scores. HRQoL was assessed using the EuroQol visual analogue scale. Results: Participants with SO showed lower physical fitness levels compared with normal subjects. Better balance, agility, and aerobic capacity were associated to a lower risk of suffering SO in the fittest men (odds ratio < 0.30). In women, better balance, walking speed, and aerobic capacity were associated to a lower risk of suffering SO in the fittest women (odds ratio < 0.21) Superior perceived health was associated with better physical fitness performance. Conclusions: Higher levels of physical fitness were associated with a reduced risk of suffering SO and better perceived health among elderly. SO elderly people have lower physical functional levels than healthy counterparts

Do 6 Months Of Whole Body Vibration Training Improve Bone Mass Acquisition Of Adolescent Swimmers?

Whole body vibration (WBV) training has been suggested to be an effective type of training for improving bone mass. PURPOSE: To determine the effects of WBV training on bone mass acquisition in adolescent swimmers. METHODS: Sixty-four swimmers were followed over 8 months. Participants were divided in to two groups: The first group consisted of forty-one swimmers (14.2±1.8 y) who completed a WBV protocol 15 minutes of training 3 days per week during 6 months (WBV training increased each month starting with a peak acceleration of 3.6 g and ending at 11.6 during the last month) while continuing with their habitual water training (VIB). The second group consisted of twenty-three swimmers (15.0±2.2 y) who continued with their regular swimming training (SWI) (both groups performed an average of 10 hours per week of water training). Bone mineral density (BMD) and content (BMC) were measured longitudinally (8 months) by Dual Energy X-ray Absorptiometry at the whole body, lumbar spine and non-dominant hip. Analysis of covariance (ANCOVA) for repeated measures x2 (time) were performed to check differences within groups between pre and post intervention and to determine the effects of the intervention on BMD and BMC values adjusting by change in height and subtotal lean, initial age and final Tanner stage and calcium intake. RESULTS: Six months of WBV training had little effect on bone mass, as no differences were found between VIB and SWI for absolute change or percentage change for BMD values. For BMC, VIB presented higher absolute and percentage changes in both trochanter (7% increase in VIB vs. 3% in SWI) and total hip (6% increase in VIB vs. 3% in SWI) than SWI, although there was no group by time interaction. CONCLUSION: WBV training might entail minor benefits to BMC acquisition in adolescent swimmers. A minimum compliance of sixty percent was needed to improve BMC, which in the present study consisted of attending at least 2 of the 3 weekly days of training. Future studies using WBV should try to perform more sessions per week at higher intensities to determine if this type of training could be highly beneficial to bone or if other high-impact trainings might be more suitable to improve bone mass in this population