Relationship between school rhythm and physical activity in adolescents: the HELENA study

The aim was to assess the relationship between school rhythm and physical activity (PA) in adolescents. The study included 2024 adolescents (12.5–17.4 years). Participants wore an accelerometer for 7 days. A short school rhythm was defined as a short time at school with short recesses and less time in teaching per day (Group 1). A long school rhythm was defined as a longer time at school with more time in teaching and recess (Group 2). Adolescents in Group 1 performed less moderate to vigorous PA (MVPA) than those in Group 2 per week (P < .0001), especially during school days (recess: 3.9 ± 4.0 vs. 9.8 ± 7.9 min · day^?1; P < .0001; teaching hours: 14.5 ± 9.8 vs. 19.1 ± 12.0 min · day^?1; P < .0001). Adolescents in Group 1 were less likely to meet the PA recommendations than were adolescents in Group 2: 30.7% vs. 34.1% (P < .0001). During school days, the percentage of adolescents who spent more than 2 h · day^?1 in sedentary activities was greater in the Group 1 (P < .001). Our results suggest that leisure-time out-of-school hours is used mainly for sedentary activities, and that school time provides a good opportunity for promoting PA.     

Calibration of context-specific survey items to assess youth physical activity behaviour

This study tests calibration models to re-scale context-specific physical activity (PA) items to accelerometer-derived PA. A total of 195 4th–12th grades children wore an Actigraph monitor and completed the Physical Activity Questionnaire (PAQ) one week later. The relative time spent in moderate-to-vigorous PA (MVPA_%) obtained from the Actigraph at recess, PE, lunch, after-school, evening and weekend was matched with a respective item score obtained from the PAQ’s. Item scores from 145 participants were calibrated against objective MVPA_% using multiple linear regression with age, and sex as additional predictors. Predicted minutes of MVPA for school, out-of-school and total week were tested in the remaining sample (n = 50) using equivalence testing. The results showed that PAQ β-weights ranged from 0.06 (lunch) to 4.94 (PE) MVPA_% (P < 0.05) and models root mean square error ranged from 4.2% (evening) to 20.2% (recess). When applied to an independent sample, differences between PAQ and accelerometer MVPA at school and out-of-school ranged from ?15.6 to +3.8 min and the PAQ was within 10–15% of accelerometer measured activity. This study demonstrated that context-specific items can be calibrated to predict minutes of MVPA in groups of youth during in- and out-of-school periods.     

In-school and out-of-school physical activity in primary and secondary school children

Abstract

The aim of this study was to compare in-school and out-of-school physical activity within a representative sample. Socio-demographic, physical activity, and anthropometric data were collected from a random sample of children (250 boys, 253 girls) aged 3–16 years attending nine primary and two secondary schools. Actigraph GT1M accelerometers, worn for seven days, were used to estimate physical activity levels for in-school (typically 09.00–15.00 h), out-of-school (weekday), and weekend periods. Physical activity as accelerometer counts per minute were lower in school versus out of school overall (in school: 437.2 ± 172.9; out of school: 575.5 ± 202.8; P < 0.001), especially in secondary school pupils (secondary: 321.6 ± 127.5; primary: 579.2 ± 216.3; P < 0.001). Minutes of moderate-to-vigorous physical activity accumulated in school accounted for 29.4 ± 9.8% of total weekly moderate-to-vigorous physical activity overall but varied by sector (preschool: 37.4 ± 6.2%; primary: 33.6 ± 8.1%; secondary: 23.0 ± 9.3%; F = 114.3, P < 0.001). Approximately half of the children with the lowest in-school activity compensated out of school during the week (47.4%) and about one-third at the weekend (30.0%). Overall, physical activity during the school day appears to be lower than that out of school, especially in secondary school children, who accumulate a lower proportion of their total weekly moderate-to-vigorous physical activity at school than younger children. As low in-school activity was compensated for beyond the school setting by less than half of children, promoting physical activity within the school day is important, especially in secondary schools.     

The Effects of Varying Structured Physical Activity Duration on Young Children’s and Parents’ Activity Levels

ABSTRACT

Purpose: The purpose of this study was to examine whether structured physical activity (PA) in a family-based community exercise program affects PA of young children and parents. Method: Twenty-two children (mean ± SD; age, 4.9 ± 2.1 years) and their parents (age, 34.3 ± 7.6 years) participated in unstructured PA sessions followed by either short- or long-duration structured PA sessions, while wearing an ActiGraph GT9X activity monitor on their right hip to estimate PA. Independent t-tests compared children’s and parents’ PA during short- and long-structured PA sessions. Paired t-tests compared short- versus long-structured PA sessions. A mixed model ANOVA compared PA during unstructured versus structured sessions and between children and parents. Results: Children spent proportionately more time in moderate-to-vigorous PA (MVPA) and had higher accelerometer counts/min than parents during short-structured PA (children:60.9 ± 18.8% vs. parents:17.7 ± 6.8%, children:3870 ± 742 vs. parents:1836 ± 556 counts/min, p < .05) and long-structured PA (children:61.1 ± 20.1% vs. parents:12.6 ± 4.9%, children:3415 ± 758 vs. parents:1604 ± 633 counts/min, p < .05). No statistical differences were found between short- and long-structured PA sessions for proportion of time spent in MVPA or counts/min for children or parents (all, p > .05). Children spent proportionally more time in MVPA and had higher counts/min during unstructured PA compared to structured PA (unstructured MVPA:54.4 ± 3.9% vs. structured MVPA:38.2 ± 4.2%, unstructured counts/min:3830 ± 222 vs. structured counts/min:2768 ± 239 counts/min; p < .05). Conclusions: Children were more active than parents during both the unstructured and structured PA sessions. However, unstructured PA sessions resulted in 63–77% and 10–11% of PA recommendations for children and adults, respectively. Family-based exercise programming can provide an opportunity for children and their parents to attain MVPA during the week.     

Effects of a 15-week accumulated brisk walking programme on the body composition of primary school children

Abstract

The purpose of this study was to establish whether an accumulated brisk walking programme, performed during the school day, is effective in changing body composition in primary school children aged 5–11 years. Altogether, 152 participants (79 boys and 73 girls) took part in this repeated-measures intervention study, divided into groups of walkers and controls. The walkers took part in the intervention during school time, which involved brisk walking around the school grounds for 15 min in the morning and afternoon, at least three times a week for 15 weeks. This represented an additional 90 min of moderate physical activity per week. The controls undertook their usual school day activities. Pre- and post-intervention anthropometric and body composition measures were taken. Body fat (?1.95 ± 2.6%) and fat mass (?0.49 ± 1.0 kg) were significantly reduced in the walkers after the intervention, whereas the controls showed no significant changes in these measures. Our results show that regular accumulated bouts of brisk walking during the school day can positively affect body composition in primary school children.     

Effects of an afterschool community center physical activity program on fitness and body composition in obese youth

Physical activity (PA) promotes health in obese youth and is an important adjunct to medical weight management. Access to structured fitness programmes for obese, low-income youth is limited and potential benefits of such programmes are poorly understood. We describe an urban afterschool fitness programme for obese youth and participants’ changes in fitness and body composition. A case series of 30 youth (age: 11.5 ± 2.5 years) with BMI ≥95th percentile and physician referral received a 24-wk programme scholarship. The programme, offered 4 times a week for 90-min.session, included aerobic, strength, and self-organised PA. Primary outcomes, measured at baseline (BL) time 1 (4–8 wk) and time 2 (12–16 wk) were BMI, per cent body fat (%BF), fat-free mass (FFM), heart rate during a treadmill test, and muscular strength (one repetition maximum (1RM)) and endurance (reps at 70% of 1RM) on the leg press (LP) and chest press (CP). Average participation was 1.5 ± 0.6 visits per week for 18.7 ± 6.5 weeks. Between BL and time 2, LP and CP 1RM and endurance significantly improved (P < 0.05). Additionally, there was a significant interaction for %BF with boys losing 5.2% (P > 0.05) while girls lost 0% (>0.05). Obese youth attending an urban fitness programme for at least three months improved strength and body composition, but average attendance was below planned levels.     

Back to school after lockdown: The effect of COVID-19 restrictions on children's device-based physical activity metrics

BackgroundThe coronavirus disease-2019 (COVID-19) pandemic and national lockdowns took away opportunities for children to be physically active. This study aimed to determine the effect of the COVID-19 lockdown on accelerometer-assessed physical activity (PA) in children in Wales.MethodsEight hundred participants (8–18 years old), stratified by sex, age, and socio-economic status, wore Axivity AX3 accelerometers for 7 days in February 2021, during the lockdown, and in May 2021, while in school. Raw accelerometer data were processed in R-package GGIR, and cut-point data, average acceleration (AvAcc), intensity gradient, and the acceleration above which the most active X minutes are accumulated (MX) metrics were extracted. Linear mixed models were used to assess the influence of time-point, sex, age, and socioeconomic status (SES) on PA.ResultsDuring lockdown, moderate-to-vigorous PA was 38.4 ± 24.3 min/day; sedentary time was 849.4 ± 196.6 min/day; mean ± SD. PA levels increased significantly upon return to school (all variables p < 0.001). While there were no sex differences during lockdown (p = 0.233), girls engaged in significantly less moderate-to-vigorous PA than boys once back in school (p < 0.001). Furthermore, boys had more favorable intensity profiles than girls (intensity gradient: p < 0.001), regardless of time-point. PA levels decreased with age at both time-points; upper secondary school girls were the least active group, with an average M30 of 195.2 mg (while in school).ConclusionThe lockdown affected boys more than girls, as reflected by the disappearance of the typical sex difference in PA levels during lockdown, although these were re-established on return to school. Upper secondary school (especially girls) might need specific COVID-recovery intervention.     

Physical Activity Practices in Elementary Schools and Associations With Physical Education Staffing and Training

Purpose: Authorities recommend that schools provide a variety of opportunities for students to obtain physical activity (PA) before, during, and after school. This study assessed the prevalence of several school PA practices—including measures of quantity and quality of physical education (PE)—in elementary schools and examined the associations of PA practices with school resources (PE staffing, training, and facilities). Method: Surveys were obtained from respondents in nationally representative samples of elementary schools from 2009–2010 to 2011–2012 (1,831 schools). Results: Few schools (20.8%) provided students with PE class every day, but most (76.3%) had an appropriate PE student-to-teacher ratio ( ≤ 25:1). Many schools (74.0%) offered 20 min of recess daily, but fewer than half offered organized opportunities for PA before or after school (e.g., sports). After controlling for demographics and school size, having a full-time PE teacher and requiring PE teachers to obtain PE-related continuing education (CE) were associated with PE practices such as offering ≥ 150 min of PE per week (for 3rd-grade students) and testing PE knowledge, skills, and fitness. Required CE was also associated with a higher likelihood of offering PA during the school day (i.e., activity breaks and PA outside of PE class) and before or after the school day (i.e., afterschool PA programs). Conclusion: Few schools offer a broad array of PA programming. However, PE staffing and CE are positively associated with many PA practices including those outside of PE, possibly indicating that PE staff serve a crucial role in promoting a whole-school PA-supportive environment.     

The translation of preschoolers’ physical activity guidelines into a daily step count target

This study aimed at translating the physical activity (PA) guideline (180 min of total PA per day) into a step count target in preschoolers. 535 Flemish preschoolers (mean age: 4.41 ± 0.58) wore an ActiGraph accelerometer (GT1M, GT3X and GT3X+) – with activated step count function – for four consecutive days. The step count target was calculated from the accelerometer output using a regression equation, applying four different cut-points for light-to-vigorous PA: Pate, Evenson, Reilly, and Van Cauwenberghe. The present analysis showed that 180 min of total PA per day is equivalent to the following step count targets: 5,274 steps/day using the Pate cut-point, 4,653 steps/day using the Evenson cut-point, 11,379 steps/day using the Reilly cut-point and 13,326 steps/day using the Van Cauwenberghe cut-point. Future studies should focus on achieving consensus on which cut-points to use in preschoolers before a definite step count target in preschoolers can be proposed. Until then, we propose to use a provisional step count target of 11,500 steps/day as this step count target is attainable, realistic and helpful in promoting preschoolers’ PA.     

Wrist-based cut-points for moderate- and vigorous-intensity physical activity for the Actical accelerometer in adults

Wrist-based accelerometers are increasingly used to assess physical activity (PA) in population-based studies; however, cut-points to translate wrist-based accelerometer counts into PA intensity categories are still needed. The purpose of this study was to determine wrist-based cut-points for moderate- and vigorous-intensity ambulatory PA in adults for the Actical accelerometer. Healthy adults (n = 24) completed a four-phase treadmill exercise protocol (1.9, 3.0, 4.0 and 5.2 mph) while wearing an Actical accelerometer on their wrist. Metabolic equivalent of task (MET) levels were assessed by indirect calorimetry. Receiver operating characteristics (ROC) curves were generated to determine accelerometer counts that maximised sensitivity and specificity for classification of moderate (≥3 METs) and vigorous (>6 METs) ambulatory activity. The area under the ROC curves to discriminate moderate- and vigorous-intensity ambulatory activity were 0.93 (95% confidence interval [CI]: 0.90–0.97; P < 0.001) and 0.96 (95% CI: 0.94–0.99; P < 0.001), respectively. The identified cut-point for moderate-intensity ambulatory activity was 1031 counts per minute, which had a corresponding sensitivity and specificity of 85.6% and 87.5%, respectively. The identified cut-point for vigorous intensity ambulatory activity was 3589 counts per minute, which had a corresponding sensitivity and specificity of 88.0% and 98.7%, respectively. This study established intensity-specific cut-points for wrist-based wear of the Actical accelerometer which are recommended for quantification of moderate- and vigorous-intensity ambulatory activity.     

Estimating physical activity in youth using an ankle accelerometer

This study developed and validated a vector magnitude (VM) two-regression model (2RM) for use with an ankle-worn ActiGraph accelerometer. For model development, 181 youth (mean ± SD; age, 12.0 ± 1.5 yr) completed 30 min of supine rest and 2–7 structured activities. For cross-validation, 42 youth (age, 12.6 ± 0.8 yr) completed approximately 2 hr of unstructured physical activity (PA). PA data were collected using an ActiGraph accelerometer, (non-dominant ankle) and the VM was expressed as counts/5-s. Measured energy expenditure (Cosmed K4b²) was converted to youth METs (MET_y; activity VO₂ divided by resting VO₂). A coefficient of variation (CV) was calculated for each activity to distinguish continuous walking/running from intermittent activity. The ankle VM sedentary behavior threshold was ≤10 counts/5-s, and a CV≤15 counts/5-s was used to identify walking/running. The ankle VM2RM was within 0.42 MET_y of measured MET_y during the unstructured PA (P > 0.05). The ankle VM2RM was within 5.7 min of measured time spent in sedentary, LPA, MPA, and VPA (P > 0.05). Compared to the K4b², the ankle VM2RM provided similar estimates to measured values during unstructured play and provides a feasible wear location for future studies.     

Secular changes in total steps and moderate-to-vigorous physical activity among fourth-grade students in Japan in 2003/2004 and 2016/2017

ABSTRACT

No study has investigated secular changes in both total steps and moderate-to-vigorous physical activity (MVPA) among Japanese children. This study examined the secular changes of total steps and MVPA among fourth-grade students in Japan in 2003/2004 and 2016/2017. It was performed at a school in Okayama Prefecture in Japan. A total of 452 participants (226 boys and 226 girls; mean age, 9.6 ± 0.5 years) participated in the study. We measured total steps and MVPA of the participants by using the same methods in 2003/2004 and 2016/2017. An uniaxial accelerometer was used to measure total steps and MVPA. On weekdays and weekends, the total steps and MVPA were lowered by approximately 1,000–3,000 steps/day and 10 min/day, respectively, in boys and by 1,000 steps/day and 5 min/day, respectively, in girls in 2016/2017 in comparison to 2003/2004. In both boys and girls, the percentage of children meeting 60 minutes/day of MVPA decreased in 2016/2017(weekdays: boys 21.8%, girls 6.0%; weekends: boys 3.8%, girls 4.1%) compared with 2003/2004 (weekdays: boys 48.2%, girls 11.6%; weekends: boys 7.8%, girls 7.6%). In conclusion, the results demonstrated that total steps and MVPA of fourth-grade students in Japan were lower in 2016/2017 than in 2003/2004.     

The use of the intensity gradient and average acceleration metrics to explore associations with BMI z-score in children

ABSTRACT

This study used the intensity gradient (IG) and average acceleration metrics to describe children’s activity profiles and explore associations with body mass index (BMI) z-score. Two hundred and forty-six children (n = 138 girls) aged 9.6 ± 1.4 years wore a wrist-mounted ActiGraph wGT3X-BT accelerometer for 7 days on their non-dominant wrist. Physical activity (PA) metrics captured included: the IG which describes the intensity distribution of accelerations across the 24 h monitoring period; average acceleration which provides a measure of the volume of activity; total moderate-to-vigorous PA (MVPA) and inactive time. Acceleration was averaged over 5s epochs. Finally, BMI z-score was calculated for each participant. Average acceleration was negatively associated with BMI z-score (p < 0.05) independent of age and gender but not IG. The IG was negatively associated with BMI z-score independent of potential correlates and average acceleration. Total MVPA was not associated with BMI-z score. The IG and average acceleration metrics may be used to explore the independent or cumulative effects of the volume and intensity distribution of activity upon measures of health and well-being in children to inform specific activity recommendations.     

Association of accelerometer-derived step volume and intensity with hospitalizations and mortality in older adults: A prospective cohort study

PurposeThis study aimed to examine the associations of accelerometer-derived steps volume and intensity with hospitalizations and all-cause mortality in older adults.MethodsThis prospective cohort study involved 768 community-dwelling Spanish older adults (78.8 ± 4.9 years, mean ± SD; 53.9% females) from the Toledo Study for Healthy Aging (2012–2017). The number of steps per day and step cadence (steps/min) were derived from a hip-mounted accelerometer worn for at least 4 days at baseline. Participants were followed-up over a mean period of 3.1 years for hospitalization and 5.7 years for all-cause mortality. Cox proportional hazards regression models were used to estimate the individual and joint associations between daily steps and stepping intensity with hospitalizations and all-cause mortality.ResultsIncluded participants walked 5835 ± 3445 steps/day with an intensity of 7.3 ± 4.1 steps/min. After adjusting for age, sex, body mass index (BMI), education, income, marital status and comorbidities, higher step count (hazard ratio (HR) = 0.95, 95% confidence interval (95%CI: 0.90–1.00, and HR = 0.87, 95%CI: 0.81–0.95 per additional 1000 steps) and higher step intensity (HR = 0.95, 95%CI: 0.91–0.99, and HR = 0.89, 95%CI: 0.84–0.95 per each additional step/min) were associated with fewer hospitalizations and all-cause mortality risk, respectively. Compared to the group having low step volume and intensity, individuals in the group having high step volume and intensity had a lower risk of hospitalization (HR = 0.72, 95%CI: 0.52–0.98) and all-cause mortality (HR = 0.60, 95%CI: 0.37–0.98).ConclusionAmong older adults, both high step volume and step intensity were significantly associated with lower hospitalization and all-cause mortality risk. Increasing step volume and intensity may benefit older people.     

Comparison of children’s free-living physical activity derived from wrist and hip raw accelerations during the segmented week

This study assessed children’s physical activity (PA) levels derived from wrist-worn GENEActiv and hip-worn ActiGraph GT3X+ accelerometers and examined the comparability of PA levels between the two devices throughout the segmented week. One hundred and twenty-nine 9–10-year-old children (79 girls) wore a GENEActiv (GAwrist) and ActiGraph GT3X+ (AGhip) accelerometer on the left wrist and right hip, respectively, for 7 days. Mean minutes of light PA (LPA) and moderate-to-vigorous PA (MVPA) per weekday (whole-day, before-school, school and after-school) and weekend day (whole-day, morning and afternoon–evening) segments were calculated, and expressed as percentage of segment time. Repeated measures analysis of variance examined differences in LPA and MVPA between GAwrist and AGhip for each time segment. Bland–Altman plots assessed between-device agreement for LPA and MVPA for whole weekday and whole weekend day segments. Correlations between GAwrist and AGhip were weak for LPA (r = 0.18–0.28), but strong for MVPA (r = 0.80–0.86). LPA and MVPA levels during all weekday and weekend day segments were significantly higher for GAwrist than AGhip (p < 0.001). The largest inter-device percent difference of 26% was observed in LPA during the school day segment. Our data suggest that correction factors are needed to improve raw PA level comparability between GAwrist and AGhip.     

Technical variability of the Vivago® wrist-worn accelerometer

Abstract

The aim was to assess the technical variability of a new wrist-worn accelerometer under controlled conditions with a shaker device and during normal daily physical activities (PAs). In the first experiment, 10 wrist-worn accelerometers (Vivago^® Wellness, Paris, France) were attached to the shaker device. Variability was tested at five shaking frequencies (1.1, 2.1, 3.1, 4.1, and 10 Hz) for 10 min at each frequency. In the second experiment, 21 participants wore wrist-worn accelerometers and performed six consecutive 10-min periods of activity at increasing levels of intensity from sedentary to vigorous. Results from the first experiment show a modest inter- and intra-instrument reliability at low frequencies and that reliability improved as frequency increased. The inter-instrument coefficient of variation (CV) was 2.6–18.3%. The intra-instrument CV was 4.1–23.2%. Variability was similar in the second experiment with a CV inversely related to PA intensity. The inter- and intra-instrument CV varied from 24.2% and 19.9% for sedentary activities to 3.7% and 4.3% for vigorous PA, respectively. Results suggest that reliability was higher at high intensities, corresponding to moderate and vigorous PA, intensities generally recommended for public health purposes.     

SHAPE America’s 50 Million StrongTM: Critical Research Questions Related to Youth Physical Activity

SHAPE America – Society of Health and Physical Educators has targeted youth physical activity (PA) as 1 of its 4 goals within the 50 Million Strong^TM campaign. Only 27.1% of youth met the target of all students (preK–12) participating in at least 60 min of PA that increases their heart rate enough to breathe hard at least some of the time for 7 days/week. Thus, improvements for child and adolescent engagement in PA need to be made now through 2029 and beyond. The need for these improvements warrants research related to PA and youth. We present a plethora of research questions within 3 general areas: PA and school PA programs, PA and sedentary behavior measurement, and PA and social justice imperatives. Each question is framed within the social-ecological framework levels of learning, opportunity, policy, and population health.     

Fundamental Movement Skill Proficiency and Health Among a Cohort of Irish Primary School Children

Purpose: This study aimed to investigate the relationship between fundamental movement skills (FMS) and markers of health among a cohort of Irish primary school children. Methods: Participants (N = 296, mean age: 7.99 ± 2.02 years) were senior infant (n = 149, mean age: 6.02 ± 0.39 years) and 4th class (n = 147, mean age: 9.97 ± 0.40 years) students from three primary schools in Cork, Ireland. FMS proficiency (TGMD-2) and markers of health (BMI percentile, waist circumference percentile, blood pressure percentiles, resting heart rate, cardiorespiratory fitness, objectively measured physical activity; PA) measurements were recorded. Correlation and hierarchical stepwise multiple linear regression analyses were conducted to investigate the relationship between FMS and markers of health. Results: A small, positive relationship was found between FMS (Gross Motor Quotient; GMQ) and cardiorespiratory fitness with small negative correlations between GMQ and 550 m time SDS among 6-year-olds (r(129) = ?.286, p < .05) and 10-year-olds (r(132) = ?.340, p < .05). A moderate, positive correlation was found between GMQ and light PA (r(71) = .400, p < .05). Small positive correlations were revealed between GMQ and moderate PA (r(71) = .259, p < .05) and between GMQ and total PA (r(71) = .355, p < .05). After adjusting for age, sex, the interaction effect of age and sex, and school attended, FMS explained 15.9% and 24.8% of the variance in 550 m time SDS among 6- and 10-year-olds, respectively, and 6% and 6.5% of the variance in light PA and moderate PA, respectively. After adjusting for age and sex, FMS explained 11.6% of the variance in total PA. Conclusion: A wide range of FMS is important for children’s cardiorespiratory fitness and PA.     

Impact of the choice of threshold on physical activity patterns in free living conditions among adolescents measured using a uniaxial accelerometer: The HELENA study

Abstract

The aim of this study was to assess the impact of the choice of threshold on physical activity patterns measured in adolescents under free living conditions (FLC) using a uniaxial accelerometer. The study comprised 2043 adolescents (12.5–17.5 years) participating in the HELENA Study. Participants wore a uniaxial accelerometer for 7 days. The PA patterns were assessed using thresholds determined from six different studies. For each of the thresholds used, the number of adolescents fulfilling the recommendation of 60 min of moderate to vigorous PA (MVPA) per day was also calculated. A significant difference was found between thresholds regardless of the activity level: differences of 38%, 207%, 136%, and 2780% for sedentary, light, moderate, and vigorous intensity PA, respectively (P < 0.001). Time of MVPA varied between methods from 25.3 to 55.2 min · day^–1. The number of adolescents fulfilling the recommendation varied from 5.9% to 37% according to the thresholds used. The kappa coefficient for concordance in the assessment of the number of adolescents achieving the PA recommendations was generally low. The definition of the threshold for PA intensity may considerably affect the PA patterns in FLC when assessed using a uniaxial accelerometer and the number of participants fulfilling the recommendations.     

Influence of moderate intensity physical activity levels and gender on conditioned pain modulation

This study examined the potential influence of moderate intensity physical activity (PA) levels and gender on central pain modulation using conditioned pain modulation (CPM) in healthy men and women. Twenty four individuals (12 men and 12 women) who reported engaging in the moderate intensity PA for 150 min or more per week and 24 individuals (12 men and 12 women) who reported engaging in moderate intensity PA for 60 min or less per week completed a self-report PA questionnaire and a 7-day PA assessment using an accelerometer. Furthermore, the participants completed the CPM testing to evaluate the efficiency of central pain modulation. The active individuals scored higher on the PA questionnaire and spent more minutes for light, lifestyle, moderate and vigorous intensity PA than the less active individuals. The active men and women exhibited comparable magnitudes of CPM, and showed a greater magnitude of CPM when compared to their less active counterparts. However, these beneficial effects of higher dose moderate intensity PA disappeared when time spent for vigorous intensity PA was statistically controlled for. These results suggest that the higher dose moderate intensity PA does not add to the benefits from vigorous intensity PA to further improve central pain modulatory systems.