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1.
Participation in youth sport is assumed to promote and contribute towards more physically active lifestyles among children and adolescents. The aim of this study was to examine inter-participant variability in objectively measured habitual physical activity (PA) behaviours and sedentary time among youth sport participants and their implications for health. One-hundred-and-eighteen male youth sport footballers (Mean ± s = 11.72 ± 1.60) wore a GT3X accelerometer for 7 days. Average daily PA [min · day?1, in light (LPA), moderate (MPA), vigorous (VPA) and combined moderate-to-vigorous (MVPA)] and sedentary time were calculated. Participants’ body mass index adjusted for age and sex (BMI–standard deviation score), per cent body fat (BF%), waist circumference and cardiorespiratory fitness were assessed. Results revealed that variability in daily PA behaviours and sedentary time (min · day?1) was associated with BMI–standard deviation score [VPA (?), MVPA (?)], BF% [sedentary time (+), VPA (?), MVPA (?)], waist circumference [sedentary time (+), LPA (?)] and cardiorespiratory fitness [sedentary time (?), MPA (+), VPA (+), MVPA (+)]. Whilst sedentary time and MVPA were not related to health outcomes independent of one another, associations with markers of adiposity and cardiorespiratory fitness were stronger for sedentary time. Sedentary time was also significantly positively related to waist circumference independent of VPA. Results demonstrate inter-participant variability in habitual PA and sedentary time among youth sport participants which holds implications for their health. Thus, promoting PA and, in particular, reducing sedentary time may contribute towards the prevention of adverse health consequences associated with a physically inactive lifestyle for children and adolescents active in the youth sport context.  相似文献   

2.
This cross-sectional study analysed the association of sedentary behaviour (SB) and standing with waist circumference. Finnish adults aged 30-75 years from a sub-sample of population-based Health 2011 Study used a hip-worn tri-axial accelerometer (Hookie AM20, Traxmeet, Ltd, Espoo, Finland) for seven days. Those 1405 participants (57% women) who used accelerometer at least four days, minimum of 10 hours/day, were included. SB and standing were analysed in 6s epochs using validated algorithm. Daily total time, daily number and accumulated time from bouts (30s–5min,30s–10min,30s–15min,30s 30min,>5min,>10min,>15min, >30min) as well as daily number of sit-to-stand transitions were determined. Waist circumference (cm) was measured in standardized way. Participants’ mean age was 52 years (SD 12.2). Mean waist circumference was 97cm (SD 12.3) in men and 87cm (SD 12.7) in women. According to multivariable stepwise linear regression analysis, sit-to-stand transitions [standardised regression coefficient (β)= -0.14, 95%CI -0.20 to -0.09], standing bouts of 30s–5min (β= -0.21, 95%CI -0.26 to -0.15) and number of 30s-30min SB bouts (β=0.12, 95%CI 0.06 to 0.17) were most strongly associated with waist circumference. Besides assessing total SB time, future studies should assess also different bout lengths of SB and sit-to-stand transitions and standing times should be assessed separately.  相似文献   

3.
The present study examined the sex-specific associations of moderate and vigorous physical activity (VPA) with physical fitness in 300 Japanese adolescents aged 12–14 years. Participants were asked to wear an accelerometer to evaluate physical activity (PA) levels of various intensities (i.e. moderate PA (MPA), 3–5.9 metabolic equivalents (METs); VPA, ≥6 METs; moderate to vigorous PA (MVPA), ≥3 METs). Eight fitness items were assessed (grip strength, bent-leg sit-up, sit-and-reach, side step, 50?m sprint, standing long jump, handball throw, and distance running) as part of the Japanese standardised fitness test. A fitness composite score was calculated using Japanese fitness norms, and participants were categorised according to their score from category A (most fit) to category E (least fit), with participants in categories D and E defined as having low fitness. It was found that for boys, accumulating more than 80.7?min/day of MVPA may reduce the probability of low fitness (odds ratio (ORs) [95% confidence interval (CI)]?=?0.17 [0.06–0.47], p?=?.001). For girls, accumulating only 8.4?min of VPA could reduce the likelihood of exhibiting low fitness (ORs [95% CI]?=?0.23 [0.05–0.89], p?=?.032). These results reveal that there are sex-specific differences in the relationship between PA and physical fitness in adolescents, suggesting that sex-specific PA recommendation may be needed to improve physical fitness in adolescents.  相似文献   

4.
ABSTRACT

Sedentary time (ST) has been inconsistently associated with adiposity and cardiorespiratory fitness in children in previous studies. We studied cross-sectional associations of ST, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) with fat mass index (FMI) and cardiorespiratory fitness (estimated VO2max). Associations were evaluated with and without considering pattern of ST by bout length. We measured ST and activity by a wrist-worn accelerometer, FMI by bioelectrical impedance, and VO2max by Pacer test in 443 children (51.2% girls, 10.2 ± 0.6 years). Isotemporal substitution regression models estimated the effects of substituting ST, LPA, and MVPA on FMI and VO2max. Further models repeated analyses separating ST into short (<10 min) and long (≥10 min) bouts. Only replacing ST or LPA with MVPA was consistently associated with lower FMI and greater VO2max. When separated by bout length, only one unique association was found where replacing long ST bouts with short ST bouts was associated with lower FMI in girls only. In conclusion, activity pattern is associated with adiposity in girls and fitness in boys and girls. Separating ST into long and short ST bouts may be of minimal importance when assessing associations with adiposity and fitness using wrist-worn accelerometry in children.  相似文献   

5.
Abstract

The purpose of this cross-sectional study was to examine the relationship between objectively measured physical activity, sedentary time, and cardiorespiratory fitness in a diverse sample of youth. Participants were recruited from three middle schools and completed assessments of height, weight, cardiorespiratory fitness, and wore an accelerometer for a minimum of four days. Hierarchical general linear models controlling for age, body mass index (BMI) percentile, and sex were used to evaluate the association of time (minutes per day) spent sedentary, and in moderate physical activity and vigorous physical activity with cardiorespiratory fitness (i.e., heart rate response [beats per minute], dependent variable). Results indicated age (β = –0.16, P < 0.05), BMI percentile (β = 0.33, P <0.05), being male (β = 0.17, P < 0.05), sedentary time (β = 0.11, P <0.05), moderate (β = –0.03, P > 0.05) and vigorous (β = –0.22, P < 0.05) physical activity explained 29% of the variance in cardiorespiratory fitness. Evaluation of fitness among high sedentary/high vigorous, high sedentary/low vigorous, low sedentary/low vigorous, and low sedentary/high vigorous groups (defined by the median split) showed that high levels of vigorous activity removed the detrimental effect of high levels of sedentary time on cardiorespiratory fitness. These analyses suggest that the negative impact of sedentary time can be mitigated by engaging in vigorous activity.  相似文献   

6.
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7.
ABSTRACT

The purpose of this study was to describe the accelerometry-based characteristics of overall sedentary behavior (SB) and sitting among adults under free-living conditions. Thirty-six (mean age 47.6 years) volunteers carried a waist-worn accelerometer for ≥4 days with data ≥600 min/d during 14 consecutive days. A machine learning (ML) based method was used to classify the patterns of SB and sitting from raw 3D acceleration. The participants spent most (69.3%) of their waking time in SB, and a half (52.2%) of the SB was performed in a sitting posture. Men broke their overall sedentary time less often (4.1 vs. 6.1 bouts/h), but women sat more; however, women broke their sitting time as often as men (7.6 bouts/h). This study confirms that SB and sitting can be distinguished using ML methods, and more information about SB can be achieved when overall SB and sitting are analyzed separately in free-living conditions.  相似文献   

8.
PurposeThis study was aimed to determine associations of accelerometer-determined time and bouts of sedentary behavior, light physical activity (LPA), and moderate-to-vigorous PA (MVPA) with sarcopenia and incident falls over 12 months.MethodsA total of 3334 Swedish 70-year-olds were assessed for sarcopenia, as defined by the revised definition of the European Working Group on Sarcopenia in Older People. Assessments were based on low scores for appendicular lean mass (dual-energy X-ray absorptiometry), hand grip strength, and the Timed Up and Go test. For 7 days after baseline, total time and total number of bouts (≥10 min of continuous activity at a given intensity) of activity performed at sedentary, LPA, and MVPA intensities were assessed by accelerometer. Incident falls were self-reported 6 months and 12 months after baseline.ResultsOnly 1.8% of participants had probable or confirmed sarcopenia. After multivariable adjustment for other levels of activity, only greater MVPA time was associated with a decreased likelihood of having low appendicular lean mass, low hand grip strength, and slow Timed Up and Go time as defined by the European Working Group on Sarcopenia in Older People criteria (all p < 0.05), and only MVPA time was associated with lower likelihood of probable or confirmed sarcopenia (odds ratio = 0.80, 95% confidence interval: 0.71–0.91 h/week). Similar associations were identified for total number of bouts, with no evidence of threshold effects for longer duration of bouts of MVPA. A total of 14% of participants reported ≥1 fall, but neither total time nor bouts of activity was associated with incident falls (all p > 0.05).ConclusionHigher amounts of accelerometer-determined MVPA are consistently associated with a decreased likelihood of sarcopenia and its components, regardless of the length of bouts or amounts of sedentary behavior.  相似文献   

9.
The aim of this study was to examine relationships between activPAL?-determined sedentary behavior (SB) and physical activity (PA) with academic achievement. A total of 120 undergraduates (N = 57 female; 20.6 ± 2.3 years) participated in the study. Academic achievement was measured as the grade point average obtained from all completed courses. Participants wore on the right tight an activPAL? for 7 days to determine total sedentary time, total number of sedentary breaks, sedentary bouts, standing time, light and moderate-to-vigorous physical activity (MVPA). Separate multiple linear regression models were performed to examine associations between SB variables and academic achievement. Light PA, MVPA, total sedentary time, total standing time, or total number of sedentary breaks were not related to academic achievement. Independently of PA, the amount of time spent in sedentary bouts of 10-20min during weekdays was positively related to academic achievement. Given that college students spend the majority of their workday in environments that encourage prolonged sitting, these data suggest that interruptions in prolonged periods of sitting time every 10-20min via short breaks may optimize cognitive operations associated with academic performance.  相似文献   

10.
This study examines the association between prolonged sedentary time and breaks in sedentary time with cardiometabolic risk in 10–14-year-old children. This cross-sectional design study analysed accelerometry-determined sedentary behaviour and physical activity collected over 7 days from 111 (66 girls) UK schoolchildren. Objective outcome measures included waist circumference, fasting lipids, fasting glucose, blood pressure, and cardiorespiratory fitness. Logistic regression was used for the main data analysis. After adjustment for confounders, the odds of having hypertriglyceridaemia (P = 0.03) and an increased clustered cardiometabolic risk score (P = 0.05) were significantly higher in children who engaged in more prolonged sedentary bouts per day. The number of breaks in sedentary time per day was not associated with any cardiometabolic risk factor, but longer mean duration of daily breaks in sedentary time were associated with a lower odds of having abdominal adiposity (P = 0.04) and elevated diastolic blood pressure (P = 0.01). These associations may be mediated by engagement in light activity. This study provides evidence that avoiding periods of prolonged uninterrupted sedentary time may be important for reducing cardiometabolic disease risk in children.  相似文献   

11.
BackgroundWhether or not there is targeted pharmacotherapy for dementia, an active and healthy lifestyle that includes physical activity (PA) may be a better option than medication for preventing dementia. We examined the association between leisure-time sedentary behavior (SB) and the risk of dementia incidence and mortality. We further quantified the effect on dementia risk of replacing sedentary time with an equal amount of time spent on different physical activities.MethodsIn the UK Biobank, 484,169 participants (mean age = 56.5 years; 45.2% men) free of dementia were followed from baseline (2006–2010) through July 30, 2021. A standard questionnaire measured individual leisure-time SB (watching TV, computer use, and driving) and PA (walking for pleasure, light and heavy do-it-yourself activity, strenuous sports, and other exercise) frequency and duration in the 4 weeks prior to evaluation. Apolipoprotein E (APOE) genotype data were available for a subset of 397,519 (82.1%) individuals. A Cox proportional hazard model and an isotemporal substitution model were used in this study.ResultsDuring a median 12.4 years of follow-up, 6904 all-cause dementia cases and 2115 deaths from dementia were recorded. In comparison to participants with leisure-time SB <5 h/day, the hazard ratio ((HR), 95% confidence interval (95%CI)) of dementia incidence was 1.07 (1.02–1.13) for 5–8 h/day and 1.25 (1.13–1.38) for >8 h/day, and the HR of dementia mortality was 1.35 (1.12–1.61) for >8 h/day. A 1 standard deviation increment of sedentary time (2.33 h/day) was strongly associated with a higher incidence of dementia and mortality (HR = 1.06, 95%CI: 1.03–1.08 and HR = 1.07, 95%CI: 1.03–1.12, respectively). The association between sedentary time and the risk of developing dementia was more profound in subjects <60 years than in those ≥60 years (HR = 1.26, 95%CI: 1.00–1.58 vs. HR = 1.21, 95%CI: 1.08–1.35 in >8 h/day, p for interaction = 0.013). Replacing 30 min/day of leisure sedentary time with an equal time spent in total PA was associated with a 6% decreased risk and 9% decreased mortality from dementia, with exercise (e.g., swimming, cycling, aerobics, bowling) showing the strongest benefit (HR = 0.82, 95%CI: 0.78–0.86 and HR = 0.79, 95%CI: 0.72–0.86). Compared with APOE ε4 noncarriers, APOE ε4 carriers are more likely to see a decrease in Alzheimer's disease incidence and mortality when PA is substituted for SB.ConclusionLeisure-time SB was positively associated with the risk of dementia incidence and mortality. Replacing sedentary time with equal time spent doing PA may be associated with a significant reduction in dementia incidence and mortality risk.  相似文献   

12.
Improving sedentary measurement is critical to understanding sedentary-health associations in youth. This study assessed agreement between the thigh-worn activPAL and commonly used hip-worn ActiGraph accelerometer methods for assessing sedentary patterns in children. Both devices were worn by 8–12-year-olds (N = 195) for 4.6 ± 1.9 days. Two ActiGraph cut-points were applied to two epoch durations: ≤25 counts (c)/15 s, ≤75c/15s, ≤100c/60s, and ≤300c/60s. Bias, mean absolute deviation (MAD), and intraclass correlation coefficients (ICCs) tested agreement between devices for total sedentary time and 11 sedentary pattern variables (usual bout duration, sedentary time accumulated in various bout durations, breaks/day, break rate, and alpha). For most sedentary pattern variables, ActiGraph 25c/15s, 75c/15s, and 100c/60s had poor ICCs, with bias and MAD >20%. ActiGraph 300c/60s had a better agreement than the other cut-points, but all ICCs were <0.587. ActiGraph underestimated sedentary time in longer bouts and usual bout duration, and overestimated sedentary time in shorter bouts, breaks/day, and alpha. For total sedentary time, ActiGraph 25c/15s, 300c/60s, and 75c/15s had good/fair ICCs, with bias and MAD <20%. Sedentary patterns derived from two commonly used ActiGraph cut-points did not appear to reflect postural changes. These differences between measurement devices should be considered when interpreting findings from sedentary pattern studies.  相似文献   

13.
The World Health Organisation’s (WHO) physical activity guidelines recommend 150min/week of moderate- to vigorous-intensity physical activity (MVPA) accumulated in 10 min bouts. To see whether people performing habitual exercise for recreation meet these guidelines, 25 long-distance runners [mean 67 km/wk], 25 joggers [mean 28 km/wk], and 20 sedentary adults wore an ActiGraph GT3X+ accelerometer for 7 days. Sedentary time and bouts were similar in runners and sedentary adults (p > 0.46). Sedentary adults performed 20 ± 16 min/day of MVPA (usual bout duration (W50%): 9.53 ± 3.45min), with joggers and runners performing 45 ± 31min (W50%: 16.92 ± 9.53min) and 83 ± 58min (W50%: 20.35 ± 8.85min), respectively (p ≤ 0.001 versus sedentary group). Data showed that 65% of the sedentary group, 32% of joggers and 4% of long-distance runners did not meet the WHO guideline for MVPA. Failure to meet the guideline was most prominent in, but not restricted to, runners who reported ≤50km running per week. Self-reported running does not ensure adults meet physical activity guidelines or offset daily sedentary behaviours. On the other hand, the sedentary group was very close in accumulating recommended bouts of MVPA in incidental activities. Future studies should assess whether modification of work and leisure physical activity would be more fruitful than encouraging recreational exercise per se in meeting physical activity guidelines.  相似文献   

14.
目的:检验学龄前儿童不同簇集特征体力活动与体质健康是否存在剂量-效应关系。方法:不同簇集特征体力活动通过连续7天佩戴加速度传感器进行测量。根据持续时间不同,分为零星中高强度体力活动(MVPA)(2~4 s)、短时持续MVPA(5~9 s)和长时持续MVPA(≥10 s)3类。体质测试包括心肺耐力、肌肉力量和速度灵敏素质。将男、女童不同簇集特征体力活动和体质健康综合得分分别按四分位数进行分类(Q1~Q4组),并定义体质健康得分最高的Q4组为高体质健康水平(HPH)。采用逻辑回归和线性回归探讨不同簇集特征MVPA与HPH间的关系。结果:共265名受试者纳入最后统计分析(男童149名,女童116名;月龄,57.19±5.33月)。男童中,校正混杂因素后,以活动量最少的Q1组为参照,活动量最多的Q4组中零星、短时持续和长时持续MVPA达到HPH的比值比(OR)分别为:11.72(95%CI:2.27,60.53)、7.53(95%CI:1.83,30.90)和8.98(95%CI:1.78,45.39);女童中也得到类似结果,分别为11.85(95%CI:2.33,60.19)、12.34(95%CI:2.47,61.57)和8.58(95%CI:1.70,43.41)。此外,研究发现,合计(零星+持续)MVPA与HPH在男童中存在非线性关系。当合计MVPA≤65 min/天时,每增加1 min的合计MVPA,达到HPH的OR增加19%(OR=1.19,95%CI:1.03,1.37);合计MVPA>65 min/天时,达到HPH的OR无显著变化。女童中未发现此非线性关系。结论:学龄前儿童累积不同簇集特征MVPA越多,达到HPH的比率越高,呈现出显著的剂量-效应关系。而在男童中,每日累积的MVPA超过65 min后达到HPH的比率不再显著增加。  相似文献   

15.
A study was conducted to assess the validity of the Global Physical Activity Questionnaire (GPAQ) for measuring sedentary behaviour (SB) in the Chilean adult population. About 217 adults (93/124 male/female, 43.8 ± 15.75 years) who were randomly selected during National Health Survey 2009–2010 completed the protocol. The participants wore an ActiGraph GT3X (AG) for 7 consecutive days and then completed the GPAQ (single-item question for measuring time spent sitting in a usual day). Validity was examined using Spearman’s correlation, mean bias and limits of agreement (LoA), with AG (vertical axis <100 counts · min?1) as the reference standard for estimates of SB in bouts of 1 (AG1), 5 (AG5) and 10 (AG10) min. Agreement between the GPAQ and AG for classifying data into quartiles and tertiles was assessed with kappa method. The GPAQ showed fair correlation with AG1, AG5 and AG10 (range = 0.23–0.26), with large mean biases (range = ?293.9, ?76.12 min · day?1). Agreement between the GPAQ and AG1, AG5 and AG10 was poor for categorising time spent in SB into tertiles and quartiles. The single question from the GPAQ has shown fair validity for measuring SB and poor ability for correctly classifying individuals into tertiles or quartiles of SB in a Chilean population.  相似文献   

16.
BackgroundStructured vigorous physical activity (VPA) can improve cognitive control in children, but studies relating daily physical activity (PA) to cognitive control have yielded conflicting findings. While objectively measured daily PA summarizes all occurrences of PA within a registered period, a minimum duration of continuous PA is required for registration of a PA bout. Because brief bouts of high-intensity PA can account for a large proportion of children's daily activity-related energy expenditure, this study assessed whether daily and bouted VPA were selectively related to cognitive control in preadolescents relative to other PA intensities.MethodsA total of 75 children between the ages of 8 and 10 years (49% girls) wore an ActiGraph wGT3X+ on the hip for 7 days. The acceleration signal from the vertical axis was summarized over 1 s, 5 s, and 15 s epochs. Daily and bouted moderate PA, moderate-to-vigorous PA, and VPA were measured. PA bouts were expressed as the frequency and time spent in 2 different continuous PA bouts, one lasting ≥10 s and the other lasting ≥30 s at a given intensity. Inhibitory control was assessed using behavioral responses to a modified flanker task (mean reaction time (RTmean) and accuracy). Attentional resource allocation and cognitive processing speed were measured using the amplitude and latency of the P3 component of event-related brain potentials, respectively. Associations between PA, behavioral indices of inhibitory control, P3 amplitude, and latency were assessed using hierarchical regression models.ResultsDaily VPA was not related to RTmean or accuracy on either congruent or incongruent trials. In contrast, more time spent in VPA bouts lasting ≥30 s predicted shorter P3 latency across epochs and flanker congruencies (all β ≤ –0.24, all p ≤ 0.04). The associations between shorter P3 latency and the time spent in moderate-to-vigorous PA bouts lasting ≥30 s were less consistent and largely limited to congruent trials (congruent: β (–0.31, –0.34)). No significant associations were observed upon correction for false discovery rate.ConclusionThe pattern of uncorrected associations aligns with the dose–response literature and suggests that brief VPA bouts may yield the greatest benefits to cognitive processing speed in preadolescents. Future studies using measures of brain structure and function are needed to understand the mechanisms linking bouted VPA to neurocognitive function during childhood.  相似文献   

17.
Cardiorespiratory fitness (CRF) is associated with health benefits in children, improving cardiac morphology, cardiovascular disease risk factors, and biological outcomes. This study aimed to examine the substitution effects of displaying a fixed duration of sedentary time with a fixed duration of physical activity (PA) at different intensities on children’s CRF. A total of 315 children (136 boys) were assessed (age: 10.6 ± 0.6 years old). Outcomes at baseline and follow-up (16-months) were CRF determined using a maximal cycle test and sedentary time and PA measured with accelerometers. Data were analysed by isotemporal substitution analyses estimating the effect of reallocating 30 min/day of sedentary time by light (LPA), moderate (MPA) and vigorous physical activity (VPA) on CRF. VPA was positively and significantly associated with CRF cross-sectional (β = 0.026, p < 0.001) and prospectively (β = 0.010, p < 0.001). Reallocating 30 min/day of sedentary time into VPA was positively cross-sectionally (β = 0.780, p < 0.001) and prospectively (β = 0.303, p < 0.05) associated with CRF. Conversely, relocating 30-minutes of sedentary time into 30 minutes of LPA and MPA was not associated with CRF. These results suggest that reallocating an equal amount of time from sedentary into VPA is cross-sectional and prospectively associated with a favourable CRF.  相似文献   

18.
The GT3X+ worn at the wrist promotes greater compliance than at the hip. Minutes in SB and PA calculated from raw accelerations at the hip and wrist provide contrasting estimates and cannot be directly compared.

Wear-time for the wrist (15.6 to 17.4 h.d?1) was greater than the hip (15.2 to 16.8 h.d?1) across several wear-time criteria (all P < 0.05). Moderate-strong associations were found between time spent in SB (r = 0.39), LPA (r = 0.33), MPA (r = 0.99), VPA (r = 0.82) and MVPA (r = 0.81) between the two device placements (All P < 0.001). The wrist device detected more minutes in LPA, MPA, VPA and MVPA whereas the hip detected more SB (all P = 0.001). Estimates of time in SB and all activity outcomes from the wrist and hip lacked equivalence.

One hundred and eighty-eight 9–12-year-old children wore a wrist- and hip-mounted accelerometer for 7 days. Data were available for 160 (hip) and 161 (wrist) participants. Time spent in SB and PA was calculated using GGIR.

This study examined the compliance of children wearing wrist- and hip-mounted ActiGraph GT3X+ accelerometers and compared estimates of sedentary behaviour (SB) and physical activity (PA) between devices.  相似文献   

19.
Abstract

Walking is a safe, accessible and low cost activity, amenable to change and known to have great potential to increase physical activity levels in sedentary individuals. The objective of this study is to estimate the proportion of the 2009 adult population of England who would attain or exceed vigorous intensity activity (>70% maximum heart rate [HRmax]) by walking at 3 mph. We conducted predictive impact modelling using participants' (n = 1741, aged 25–64 years) cardiovascular fitness data from treadmill walking tests. We combined this data with English population estimates adjusted for age and sex to estimate the numbers of individuals that would exceed 70% HRmax (an intensity considered sufficient for fitness gains) when walking at 3 mph (4.8 km · h?1). We estimate 1.5 million men (95% confidence interval [CI] 0.9–2.2 million) (from 13.4 million corresponding to 11.6% (95% CI 7.0–16.2%)) and 3.9 million women (95% CI 3.0–4.8 million) (from 13.6 million corresponding to 28.6% (95% CI 22.0–35.1%)) in England aged 25–64 years would benefit from regularly walking at 3 mph. In total, a projected 5.4 million individuals (95% CI 3.9–6.9 million) aged 25–64 (from 26.97 million corresponding to 20.1% (95% CI 14.6–25.7%)) could benefit from walking at 3 mph. Our estimates suggest a considerable number of individuals in the English population could receive fitness and health benefits by walking regularly at 3 mph. Physical activity messages that promote walking at this speed may therefore have the potential to significantly impact national fitness levels and health in England.  相似文献   

20.
Abstract

The present study compared the changes in markers of muscle damage after bouts of resistance exercise employing the Multiple-sets (MS) and Half-pyramid (HP) training systems. Ten healthy men (26.1±6.3 years), who had been involved in regular resistance training, performed MS and HP bouts, 14 days apart, in a randomised, counter-balanced manner. For the MS bout, participants performed three sets of maximum repetitions at 75%-1RM (i.e. 75% of a One Repetition Maximum) for the three exercises, starting with the bench press, followed by pec deck and decline bench press. For the HP bout, the participants performed three sets of maximum repetitions with 67%-1RM, 74%-1RM and 80%-1RM for the first, second and third sets, respectively, for the same three exercise sequences as the MS bout. The total volume of load lifted was equated between both bouts. Muscle soreness, plasma creatine kinase (CK) activity, myoglobin (Mb) and C-reactive protein (CRP) concentrations were assessed before and for three days after each exercise bout, and the changes over time were compared between MS and HP using two-way repeated measures ANOVA. Muscle soreness developed significantly (P<0.01) after both bouts, but no significant difference was observed between MS and HP. Plasma CK activity and Mb concentration increased significantly (P<0.01) without significant differences between bouts, and CRP concentration did not change significantly after either bout. These results suggest that the muscle damage profile is similar for MS and HP, probably due to the similar total volume of load lifted.  相似文献   

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