Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Eur J Sport Sci ; 23(8): 1810-1820, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36971121

RESUMEN

Increasing moderate-vigorous physical activity (MVPA) through exercise requires reallocating time from other physical behaviour(s). We aimed to determine the reallocations induced by endurance exercise in physically active individuals. We also searched for behavioural compensatory responses, and explored the effect of exercise on daily energy expenditure. Fourteen participants (8 women; median age 37.8 [IQR 29.9-48.5] yr) exercised on Monday, Wednesday, and Friday mornings (cycling MVPA, 65 min/session; "exercise days"), and avoided exercising on Tuesday and Thursday ("rest days"). Time spent on sleep, sedentary behaviour, light-intensity physical activity, and MVPA was determined each day by accelerometers and logs. An energy expenditure index was computed considering minutes spent on each behaviour and fixed metabolic equivalents. We found that all participants had lower sleep and higher total (including exercise) MVPA on exercise days compared to rest days. Thus, on exercise vs. rest days, sleep was lower (490 [453-553] vs. 553 [497-599] min/day, respectively, P < 0.001), and total MVPA was higher (86 [80-101] vs. 23 [15-45] min/day, respectively; P < 0.001). No differences in other physical behaviours were detected. Notably, exercise not only induced reallocations (i.e. less time in other behaviours) but also behavioural compensatory responses in some participants (e.g. increased sedentary behaviour). This rearrangement of physical behaviours manifested in exercise-induced increases in energy expenditure from 96 to 232 MET × min/day. In conclusion, active individuals reallocated time from sleep to accommodate morning exercise. Yet exercise induced variable rearrangements of behaviours, with some individuals manifesting compensatory responses. Understanding individual rearrangements may help improve exercise interventions.


Adults are recommended to engage in moderate-vigorous physical activity (MVPA) to maintain health. But including exercise sessions within a day inevitably requires reallocating time from other physical behaviour(s): sleep, sedentary behaviour, or physical activity.We studied the time reallocations induced by 65 min/day of morning exercise (cycling MVPA) in physically active participants.Participants spent less time sleeping and higher time on total (including exercise) MVPA on days that included exercise compared to days without exercise. Thus, participants reallocated sleep time to accommodate morning exercise sessions.Some participants also spent higher time on sedentary behaviour during days that included exercise compared to days without exercise. This probably represents a behavioural compensatory response to exercise-induced fatigue.Together, time reallocations and behavioural compensatory responses led to a rearrangement of daily time spent on physical behaviours. This rearrangement was estimated to produce large interindividual variability in the increase in energy expenditure induced by exercise.


Asunto(s)
Terapia por Ejercicio , Ejercicio Físico , Humanos , Femenino , Adulto , Ejercicio Físico/fisiología , Sueño , Conducta Sedentaria , Ciclismo , Acelerometría
2.
Eur J Sport Sci ; 23(11): 2119-2128, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36779300

RESUMEN

Substantial evidence links physical activity and sedentary behaviour (SB) with cardiovascular health. However, studies usually examine time-use behaviours independently, rather than considering daily activities as a 24-hour time-use composition. This study aimed to use compositional data models to investigate how time reallocations from SB to moderate-to-vigorous physical activity (MVPA)/ light physical activity (LPA) were associated with changes in cardiometabolic biomarkers. Compositional isotemporal substitution analysis was conducted using data from a representative cross-sectional sample of adults aged 20 years or older (n = 5213 full sample; n = 2221 fasting subsample) from the 2003-2004 and 2005-2006 cycles of the National Health and Nutrition Examination Survey. Overall as well as gender- and age-specific estimates were obtained for reallocating time between the behaviours associated with cardiometabolic outcomes. Replacing SB with MVPA was associated with decreased levels of C-reactive protein (CRP), white blood cells (WBCs), red blood cell distribution width (RDW), insulin, insulin resistance homeostasis model assessment (HOMA-IR) and 2-hour glucose, and increased high-density lipoprotein cholesterol (HDL-C), except for WBCs in older adults, insulin and HOMA-IR in females and older adults, 2-hour glucose in young and older adults, and HDL-C in older adults. Substituting LPA for SB resulted in lower CRP in older adults, lower RDW in males and older adults, lower insulin in young and middle-aged adults, lower HOMA-IR in females and middle-aged adults, and higher HDL-C in males and young adults. Our findings provide new evidence for the potential benefits of LPA and MVPA in cardiovascular health and help make population-specific recommendations for physical activity.HighlightsShorter sedentary behaviour (SB) time and longer active behaviours time are associated with a lower cardiovascular disease risk profile.Although replacing SB with MVPA has stronger positive health effects, LPA, as a simpler and more feasible activity, may has greater potential in promoting cardiovascular health.The expected changes in cardiometabolic biomarkers caused by time reallocations from SB to MVPA/LPA vary with gender and age, and physical activity guidelines with specific recommendations should be tailed to the subpopulations.


Asunto(s)
Enfermedades Cardiovasculares , Conducta Sedentaria , Masculino , Persona de Mediana Edad , Femenino , Adulto Joven , Humanos , Anciano , Estudios Transversales , Encuestas Nutricionales , Acelerometría/métodos , Ejercicio Físico , Biomarcadores , Proteína C-Reactiva , Insulina , Glucosa
3.
Eur J Sport Sci ; 23(6): 1047-1055, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35658800

RESUMEN

This study aimed to compare the effectiveness of recreational football performed once (LOW) vs. twice (MOD) a week on cardiovascular risk factors in healthy, sedentary men. Body composition, resting blood pressure, blood lipid profile and maximal oxygen consumption (VO2max) were measured at baseline, after a 12-week control and training period, using an interrupted time-series study (study 1, n = 18: n = 8, LOW and n = 10, MOD) nested in a randomized parallel trial (study 2, n = 34: n = 18 LOW and n = 16 MOD). After the intervention in study 1, LDL-cholesterol (-12.3 mg·dL-1 [-22.7 to -2.0]) and VO2max (4.5 ml·kg-1·min-1 [1.2-7.8 ]) changed in LOW whereas differences were found in weight (-2.1 kg [-3.7 to -0.4]), BMI (-0.7 kg·m-2 [-1.2 to -0.1]), total cholesterol (-22.2 mg·dL-1 [-36.0 to -8.4]), no-HDL-cholesterol (-17.5 mg·dL-1 [-30.5 to -4.5]), LDL-cholesterol (-14.9 mg·dL-1 [-23.6 to -6.2]) and VO2max (5.7 ml·kg-1·min-1 [2.8-8.6]) in MOD. Study 2 showed no evidence of differences between groups. Our results therefore suggest positive health effects of recreational football even when performed at low frequency as it can happen in real context.Highlights Moderate and high amount of recreational football practice (i.e. 2 or 3 h a week) have been shown to be effective to improve health-related factors in both healthy and unhealthy people.Scarce data are present regarding the effect of a low frequency of recreational football practice (i.e. 1 h a week) that is often usual in a real context.Our results showed the practice of recreational football, once a week, is effective for improving some cardiovascular risk factors (maximal oxygen consumption and LDL-cholesterol) in sedentary, healthy middle-aged men.Moreover, practising recreational football once or twice a week seems to lead to similar positive health adaptations.


Asunto(s)
Enfermedades Cardiovasculares , Fútbol Americano , Masculino , Persona de Mediana Edad , Humanos , Fútbol Americano/fisiología , Aptitud Física/fisiología , Enfermedades Cardiovasculares/prevención & control , Factores de Riesgo , Consumo de Oxígeno/fisiología , Colesterol , Factores de Riesgo de Enfermedad Cardiaca
4.
Eur J Sport Sci ; 22(6): 867-876, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33944698

RESUMEN

ABSTRACTExergaming has been proposed as a promising alternative to traditional endurance training since many experience exergaming as more enjoyable. Therefore, the aim of this trial was to determine the exergaming-induced effect on cardiorespiratory fitness. This parallel-group randomised controlled trial, investigated the effects of regular exergaming among healthy adults (aged ≥ 18 years) who were not endurance-trained. Participants allocated to the exergaming group (n = 13) used the Playpulse exergaming platform for a minimum of 45 min twice weekly for eight weeks, whereas the control group (n = 17) received no intervention. The primary outcome measure was the between-group difference in peak oxygen uptake (V̇O2peak) after the intervention. V̇O2peak increased significantly from baseline (43.9 [SD 7.0]) to after the intervention (45.3 [SD 8.2] mL kg-1 min-1) in the exergaming group, compared to the control group (42.4 [SD 7.0] to 42.0 [SD 5.7] mL·kg-1·min-1) with a between-group difference of 2.1 mL kg-1 min-1 (95% CI: 0.2-4.1; p = 0.04). The average score on the Feeling Scale reported during exergaming was 3.4 (95% CI 3.2-3.6), with 3 being "good" and 5 "very good" and was not related to the participants' exergaming skills. There were no adverse events during this trial. Two weekly sessions using the Playpulse exergaming platform can improve V̇O2peak. This finding suggests that exergaming can be an efficient form of endurance training. Furthermore, our findings indicate that participants' enjoyed exergaming irrespective of exergaming skills.Trial registration: ClinicalTrials.gov identifier: NCT04112329..


Asunto(s)
Capacidad Cardiovascular , Adulto , Terapia por Ejercicio , Videojuego de Ejercicio , Humanos
5.
Gait Posture ; 87: 6-10, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33866152

RESUMEN

BACKGROUND: The measurement of step count and distance covered are of interest in healthcare and rehabilitation medicine, so fitness trackers and smartwatches have incorporated these metrics. In 2014, the introduction of new brands of these devices peaked, although the highest number of new devices was introduced in 2015. Even though Mi Band Xiaomi was among the top 5 regarding sales, it is not at the top of the fitness bands considered in research articles. RESEARCH QUESTION: this study aimed to assess the validity of Xiaomi Mi Band 2.0, 3.0 and 4.0 for recording steps and distance covered. METHOD: The data were recorded from 26 elderly adults (71.2 ± 3.2 years old; 169.3 ± 5.8 height; 72.1 ± 9.2 weight), who covered the maximum distance possible at walking speed in a delimited outdoor space following different trajectories to compare data with the criterion measure, using three wristband devices (Xiaomi Mi Band versions 2.0, 3.0. and 4.0.). RESULTS: In step count, the average bias was small (<2.6 steps) and no statistical differences were found between instruments (p > 0.76; t=0.30). However, Xiaomi Mi Band 4.0 obtained questionable validity (ICC = 0.76) for distance estimation. SIGNIFICANCE: The accuracy of Mi Band Xiaomi 2.0., 3.0. and 4.0. may be considered as good to count the number of steps for physical activity monitoring, whereas distance estimation is considered questionable.


Asunto(s)
Ejercicio Físico , Anciano , Atención a la Salud , Monitores de Ejercicio , Humanos , Reproducibilidad de los Resultados , Velocidad al Caminar
6.
Front Public Health ; 9: 799870, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35096747

RESUMEN

Background: While mentally passive sedentary behavior such as television viewing (TV) is often related with depressive symptoms, some research shows that physical activity (PA) may attenuate this association. Thus, this study aimed to examine the associations between TV, PA, and depressive symptoms, considering sociodemographic covariates. Methods: A sample of 29,285 adults (13,943 men; 15,342 women) with a mean age of 50.9 ± 17.4 years (50.6 ± 17.3 men; 51.1 ± 17.5 women) from the European Social Survey agreed to be respondents for this study. Data for sociodemographic variables, TV watching, PA, and depressive symptoms were self-reported. Different statistical procedures were conducted to provide evidence for the association between study variables. ANCOVA was used to analyze the association between TV watching and depressive symptoms. Linear regression analysis was conducted to analyze the association between PA and depressive symptoms. General Linear Model was performed to analyze the association of TV watching and on depressive symptoms, controlling for PA. Results: European adults who responded watching more than 2 h per day showed higher scores for depressive symptoms. Higher participation in PA was negatively and significantly associated with depressive symptoms in men (ß = -0.15, 95% CI: -0.18, -0.13), and women (ß = -0.23, 95% CI: -0.26, -0.21). Men spending 1-2 h/day TV watching and engaging in PA ≥ 5 days/week presented the lowest scores on depressive symptoms. The lowest scores on depressive symptoms was observed in women engaging 2-4 days/week in PA and spending <1 h/day in TV watching. Conclusions: More time spent in TV watching is related with increased scores on depressive symptoms. However, regular PA participation can weaken this association.


Asunto(s)
Depresión , Televisión , Adulto , Anciano , Depresión/epidemiología , Ejercicio Físico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Conducta Sedentaria , Autoinforme
7.
Eur J Sport Sci ; 21(10): 1459-1468, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33108970

RESUMEN

AbstractCOVID-19 pandemic led many countries to implement lockdown measures. Italy declared lockdown from 9th March to 3rd May 2020, and universities shifted to online classes. Home confinement could prevent students from achieving the physical activity and sleep levels recommended for their psychophysical health, and medicine students are already known to be at risk of inactivity and reduced sleep due to their time-consuming curricula. This study aimed at describing medicine students' behaviours during lockdown and comparing them with pre-lockdown data and current recommendations. A cross-sectional questionnaire survey was conducted among 6th-year Italian medicine students (n = 714; age=25 ± 2 y; female: 62%; male: 38%) in October-November 2019. The same survey was repeated in 6th-year students during lockdown (n = 394; age=25 ± 2 y; female: 73%; male: 27%), and extended to 1st-5th year (total 1st-6th-year sample during lockdown: n = 1471; age=23 ± 2 y; female: 70%; male: 30%). International Physical Activity Questionnaire Short Form (IPAQ) and selected questions from Pittsburgh Sleep Quality Index were administered to evaluate physical activity, sitting and sleep time. Decreased physical activity, and increased sitting and sleep time were observed from pre- to during lockdown in 6th-year students (p<0.01). 1st-6th-year students featured 10 [8-12] hours sitting (median [Q1-Q3]) and an IPAQ score of 1170 [400-2348] MET-min/week. Even participants with higher physical activity featured high sitting time. Sleeping less than recommended (<7 h/night) was associated with more sitting time and less energies to perform daily activities. Strategies fostering compliance with current guidelines for physical activity, sedentary behaviour and sleep should be implemented, especially in case of a repeated or intermittent lockdown.


Asunto(s)
COVID-19/epidemiología , Pandemias , Cuarentena , Conducta Sedentaria , Sueño , Estudiantes de Medicina/psicología , Adulto , Estudios Transversales , Metabolismo Energético , Femenino , Humanos , Italia/epidemiología , Masculino , SARS-CoV-2 , Caminata , Adulto Joven
8.
Eur J Sport Sci ; 21(2): 250-260, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32105186

RESUMEN

ABSTRACTPhysical activity (PA) and sedentary behaviours (SB) influence health. Since most people engage in different combinations of both behaviours every day, understanding the socio-demographic characteristics of adults with distinct PA and sitting time (ST) patterns is important to contribute to evidence-based planning of public health strategies. Data from a national survey on diet and activity behaviours (IAN-AF, 2015/16) including 1724 adults (50.5% women, 18-64 years) from a representative sample of Portuguese adults was used in this study. Participants were interviewed face-to-face, and the International Physical Activity Questionnaire (IPAQ) was used. Logistic regression examined the associations between socio-demographic factors each of the four-low/high PA-ST groups. PA low/high categories were defined as in IPAQ, while ST low/high categories were defined according to ST tertiles (≤180 min/day, ≥360 min/day). A 'higher risk' behaviour pattern (low PA/high ST) was present in 37.3% of the adults and was likely associated with a middle household income, and with having 12 or more years of education. The 'lower risk' (high PA/low ST) represented 26.6% of the sample and was likely associated with middle-aged adults and with having a lower educational level. Being male, young and highly educated was related to being physically active and spending large amounts of time in ST. Besides adding to the body of mixed evidence on this theme, the identification of the socio-demographic factors associated with each PA/ST pattern will permit national public health authorities to define policies and tailored actions to promote PA and reduce ST.


Asunto(s)
Ejercicio Físico , Conducta Sedentaria , Sedestación , Factores Socioeconómicos , Adolescente , Adulto , Factores de Edad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Portugal , Factores Sexuales , Encuestas y Cuestionarios , Factores de Tiempo , Adulto Joven
9.
Eur J Pediatr ; 180(1): 109-117, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32556508

RESUMEN

This study aimed to examine the clustering of 24-h movement behaviors (moderate to vigorous physical activity, screen time, and sleep duration) and their association with cardiorespiratory fitness among adolescents. We evaluated 561 adolescents (52.1% girls; mean age, 13.0 ± 1.0 years) from Florianópolis, Brazil. A 20-m shuttle run was used to assess cardiorespiratory fitness, while a questionnaire was used to measure 24-h movement behaviors. A latent class analysis was performed to identify the clustering of 24-h movement behaviors, while linear Bayesian mixed-effect regression models were applied to identify their association with cardiorespiratory fitness. Two classes were identified: unhealthy (10.4%), characterized as a high probability of practicing less than 300 min/week of moderate to vigorous physical activity, spending more than 4 h/day in front of screens, and sleeping less than 8 h/day; and healthy (89.6%), characterized by a high probability of practicing more than 420 min/week of moderate to vigorous physical activity, spending less than 2 h/day in front of screens, and sleeping 8-10 h/day. Adolescents in the healthy class had a higher cardiorespiratory fitness level than those in the unhealthy class. Most adolescents were grouped in the healthy class and had higher cardiorespiratory fitness levels than those in the unhealthy class. These results suggest that families and professionals should work toward creating healthier lifestyles for adolescents by increasing opportunities to practice moderate to vigorous physical activity, reduce screen time, and favor healthy sleep to increase their cardiorespiratory fitness levels. What is Known: • Moderate to vigorous physical activity, screen time, and sleep duration are positively, negatively, and inconsistently associated with cardiorespiratory fitness, respectively, when analyzed separately. • Little is known about the clustering of 24-h movement behaviors and how they are associated with cardiorespiratory fitness levels in adolescents. What is New: • The 24-h movement behaviors clustered into almost opposite classes among adolescents (healthy and unhealthy classes). • Adolescents in the healthy class had greater cardiorespiratory fitness levels than those in the unhealthy class.


Asunto(s)
Capacidad Cardiovascular , Adolescente , Teorema de Bayes , Brasil , Niño , Análisis por Conglomerados , Estudios Transversales , Ejercicio Físico , Femenino , Humanos , Análisis de Clases Latentes , Masculino , Aptitud Física , Conducta Sedentaria
10.
Artículo en Inglés | MEDLINE | ID: mdl-33171963

RESUMEN

Aging causes some unfavorable morphological and functional changes, such as the decline in bone mineral density (BMD) and physical function. Moderate-to-vigorous physical activity (MVPA) and sedentary time seem to be related with these alterations, but the impact of distinct patterns remains unclear. The aim of this study was to cross-sectionally and prospectively assess the association between objectively measured MVPA and sedentary patterns (bouts and breaks) with BMD and physical function in older adults. The study considered 151 Brazilians (aged ≥ 60 years), out of which 68 participants completed 2-year follow-up measurements. MVPA and sedentary patterns were measured by means of accelerometry, BMD-(total proximal femur and lumbar spine (L1-L4)) by means of dual-energy X-ray absorptiometry (DXA), and physical function-by means of physical tests. In older women, sedentary bouts >60 min were inversely associated with handgrip strength (ß = -2.03, 95% CI: from -3.43 to -0.63). The prospective analyses showed that changes in sedentary bouts (20 to 30 min and >60 min) were inversely associated with changes in the lumbar spine's BMD (ß = -0.01, 95% CI: from -0.01 to -0.00 and ß = -0.03, 95% CI: from -0.06 to -0.01) and the lumbar spine's T-score (ß = -0.06, 95% CI: from -0.10 to -0.01 and ß = -0.27, 95% CI: from -0.49 to -0.04), respectively. In older women, sedentary patterns are cross-sectionally associated with handgrip strength and prospectively associated with BMD independent of MVPA.


Asunto(s)
Densidad Ósea , Conducta Sedentaria , Acelerometría , Anciano , Brasil , Estudios Transversales , Ejercicio Físico , Femenino , Fuerza de la Mano , Humanos , Masculino , Estudios Prospectivos
11.
Eur J Sport Sci ; 19(10): 1404-1413, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30998435

RESUMEN

U.S. women are ageing. This is causing rises in osteoporosis prevalence and risk of fracture with related increases in health care costs. Replacing sedentary time with light physical activity may represent a cost effective public health solution to osteoporosis in elderly women. The National Health and Nutrition Examination Survey conducted over the period 2003-2006 provided cross-sectional data on bone mineral density and objectively assessed physical activity among 1,052 women aged 50-85 years old. Substitution analysis was applied to estimate increased bone mineral density and reduced osteoporosis for those women replacing 30 min of sedentary time with an equivalent amount of light physical activity. Substitution of 30 min of sedentary time with an equal amount of light physical activity was associated with increased bone mineral density of about 3 mg/cm2 and a 12% reduced risk of osteoporosis in the spine. When considering overweight women and women over 65 years of age, this association was reinforced and it extended to the pelvis, legs and trunk, resulting in a consistent bone mineral density increase of about 3-6 mg/cm2. The substitution of 30 min of sedentary time with an equal amount of light physical activity appears a possible primary prevention method to reduce osteoporosis and related increases in risk of fracture, mortality, and health care costs in women over 50 years old.


Asunto(s)
Densidad Ósea , Ejercicio Físico , Conducta Sedentaria , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Persona de Mediana Edad , Encuestas Nutricionales
12.
Eur J Sport Sci ; 18(9): 1245-1254, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29938604

RESUMEN

AIMS: Exercise combined with adipose tissue lipolytic inhibition augments intramuscular lipid and glycogen use in type 2 diabetes patients. The present study investigates the impact of adipose tissue lipolytic inhibition during exercise on subsequent postprandial glycemic control in type 2 diabetes patients. METHODS: Fourteen male type 2 diabetes patients (age 65 ± 2 years, HbA1c 6.7 ± 0.1% (50 ± 2 mmol/mol)) participated in a double-blind placebo-controlled randomized cross-over study in which subjects performed endurance-type exercise after being administered 250 mg of a nicotinic acid analogue (acipimox; ACP) or a placebo (PLA). A control experiment was included in which no exercise was performed (CON). RESULTS: Sixty minutes of endurance-type exercise (at 45% Wpeak) did not significantly lower circulating plasma glucose and insulin excursions in PLA when compared with CON (P = .300). Acipimox administration strongly reduced circulating plasma FFA concentrations during exercise (P < .001). Circulating plasma glucose and insulin excursions were substantially lower during 7.5 h of recovery from exercise (i.e. postprandial) in ACP when compared with either CON (P = .041 and P = .002, respectively) or PLA (P = .009 and P = .001, respectively). CONCLUSIONS: Collectively, exercise with adipose tissue lipolytic inhibition reduces postprandial blood glucose and insulin excursions and, as such, further improves glycemic control in male type 2 diabetes patients.


Asunto(s)
Tejido Adiposo/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Ejercicio Físico/fisiología , Hipolipemiantes/administración & dosificación , Metabolismo de los Lípidos , Pirazinas/administración & dosificación , Administración Oral , Glucemia , Estudios Cruzados , Método Doble Ciego , Ácidos Grasos/sangre , Glucógeno/metabolismo , Humanos , Insulina/sangre , Ácido Láctico/sangre , Masculino , Persona de Mediana Edad , Triglicéridos/sangre
13.
Eur J Sport Sci ; 18(2): 226-234, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29220206

RESUMEN

In recent years, prevalence of obesity in children and adolescents has increased. A strategy for prevention and management of obesity is aerobic training (AT) due to its effectiveness to decrease fat mass. AT increases the content of SIRT3, a mitochondrial protein that increases the expression of PGC-1α and NFR1, thereby enhances mitochondrial function and metabolic health. Resistance training (RT) provides metabolic benefits but its effect on SIRT3 content is unknown. To compare the effect of AT and RT on SIRT3, PGC-1α and NRF-1 protein levels in skeletal muscle of sedentary obese adolescents. Twenty-seven sedentary obese male adolescents (age: 16.7 ± 0.9 years; BMI: 33.7 ± 4.3 kg/m2) completed a 1-month control period prior to randomization to one of two supervised exercise protocols: AT (3 days/week, 40 min/day, 70-80% peak heart rate) or RT (3 days/week, 11 exercises, 2 sets/exercise, 12 repetitions/set) for 12 weeks. Biopsies were obtained from the vastus lateralis muscle before and after 12 weeks to analyse SIRT3, PGC-1α and NRF-1 proteins content. Peak oxygen consumption (VO2peak) and anthropometric variables were evaluated before and after training. AT increased SIRT3 content, which was associated with improvements in PGC-1α content and body fat percentage. RT did not affect SIRT3 or PGC-1α. VO2peak increased only in AT. The increase in muscle mitochondrial SIRT3 was observed only following AT. In contrast, RT increased muscle mass without improving SIRT3 in obese male adolescents.


Asunto(s)
Músculo Esquelético/metabolismo , Obesidad/metabolismo , Acondicionamiento Físico Humano , Entrenamiento de Fuerza , Sirtuina 3/metabolismo , Adolescente , Humanos , Masculino , Mitocondrias Musculares/metabolismo , Fuerza Muscular , Factor Nuclear 1 de Respiración/metabolismo , Consumo de Oxígeno , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo
14.
Eur J Sport Sci ; 17(7): 904-912, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28492342

RESUMEN

Multiple individual and neighbourhood characteristics are theorised to influence adult sedentary behaviour. The aim of this study was to examine associations between individual and neighbourhood-level characteristics in 40 deprived neighbourhoods in London, UK. A cross-sectional design was utilised with baseline data from the Well London Cluster Randomised Controlled Trial in 40 deprived neighbourhoods in London. Multilevel linear regression was used to examine associations between individual characteristics (measured by household survey), neighbourhood characteristics (neighbourhood audit, GIS and routinely available datasets) and sedentary behaviour (sitting time). Individual-level positive mental well-being and health behaviours were associated with sedentary time. Individual-level social networks were associated with decreased sedentary time in men and increased sedentary time in women. Neighbourhood-level measures of social networks and perceived neighbourhood quality were associated with reduced sedentary time. Fifteen per cent of the variance in sedentary time was attributable to differences at the neighbourhood level (intra-class correlation coefficient = 0.15). These findings suggest that social networks at the individual and neighbourhood levels, collective perceptions of neighbourhood quality, individual-level positive mental well-being and other health behaviours may be important components of interventions developed to reduce sedentary time in deprived populations.


Asunto(s)
Cognición , Conductas Relacionadas con la Salud , Características de la Residencia , Conducta Sedentaria , Conducta Social , Adolescente , Adulto , Anciano , Estudios Transversales , Demografía , Femenino , Humanos , Modelos Lineales , Londres , Masculino , Persona de Mediana Edad , Apoyo Social , Adulto Joven
15.
Eur J Sport Sci ; 17(2): 222-230, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27817249

RESUMEN

The aim of this study is to determine changes in sedentary behaviour in response to extensive aerobic exercise training. Participants included adults who self-selected to run a marathon. Sedentary behaviour, total activity counts and physical activity (PA) intensity were assessed (Actigraph GT3X) for seven consecutive days during seven assessment periods (-3, -2, and -1 month prior to the marathon, within 2 weeks of the marathon, and +1, +2, and +3 months after the marathon). Models were fitted with multiple imputation data using the STATA mi module. Random intercept generalized least squares (GLS) regression models were used to determine change in sedentary behaviour with seven waves of repeated measures. RESULTS: Twenty-three individuals (mean ± Sx: 34.4 ± 2.1y, 23.0 ± 1.9% fat, 15 women, 8 men) completed the study. Marathon finishing times ranged from 185 to 344 minutes (253.2 ± 9.6 minutes). Total counts in the vertical axis were 1,729,414 lower one month after the race, compared with two months prior to the race (peak training). Furthermore, counts per minute decreased by 252.7 counts·minute-1 during that same time period. Daily sedentary behaviour did not change over the seven assessment periods, after accounting for age, gender, per cent body fat, wear time, marathon finishing time, and previous marathon experience. This prospective study supports the notion that PA and sedentary behaviours are distinct, showing that sedentary behaviour was not impacted by high levels of aerobic training.


Asunto(s)
Ejercicio Físico/fisiología , Resistencia Física/fisiología , Carrera/fisiología , Conducta Sedentaria , Acelerometría , Femenino , Humanos , Masculino , Estudios Prospectivos
16.
Eur J Sport Sci ; 17(3): 360-368, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27912681

RESUMEN

Wearable activity trackers have become popular for tracking individual's daily physical activity, but little information is available to substantiate the validity of these devices in step counts. Thirty-five healthy individuals completed three conditions of activity tracker measurement: walking/jogging on a treadmill, walking over-ground on an indoor track, and a 24-hour free-living condition. Participants wore 10 activity trackers at the same time for both treadmill and over-ground protocol. Of these 10 activity trackers three were randomly given for 24-hour free-living condition. Correlations of steps measured to steps observed were r = 0.84 and r = 0.67 on a treadmill and over-ground protocol, respectively. The mean MAPE (mean absolute percentage error) score for all devices and speeds on a treadmill was 8.2% against manually counted steps. The MAPE value was higher for over-ground walking (9.9%) and even higher for the 24-hour free-living period (18.48%) on step counts. Equivalence testing for step count measurement resulted in a significant level within ±5% for the Fitbit Zip, Withings Pulse, and Jawbone UP24 and within ±10% for the Basis B1 band, Garmin VivoFit, and SenseWear Armband Mini. The results show that the Fitbit Zip and Withings Pulse provided the most accurate measures of step count under all three different conditions (i.e. treadmill, over-ground, and 24-hour condition), and considerable variability in accuracy across monitors and also by speeds and conditions.


Asunto(s)
Monitores de Ejercicio/normas , Monitoreo Ambulatorio/instrumentación , Monitoreo Ambulatorio/normas , Adulto , Anciano , Ejercicio Físico , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Caminata , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA