Presence and duration of reactivity to pedometers in adults

PURPOSE: To examine the presence and duration of reactivity to wearing a pedometer and recording daily step counts in free-living adults. METHODS: On the first visit to the laboratory 90 participants (69% female, age = 26.8±13.0 years, BMI = 23.4±4.0 kg/m2), blinded to the study aim, were provided with a sealed pedometer (New Lifestyles NL-800) and informed that it was a 'Body Posture Monitor' (covert condition). Participants wore the pedometer throughout waking hours for 1 week. Upon return to the laboratory, stored step counts were recorded and participants were informed that the device was a pedometer. Participants wore the pedometer unsealed (no restriction on viewing the step count display) for 2 weeks, during which they recorded their daily step count in a diary (diary condition). Mean daily step counts recorded during the covert condition and during weeks 1 and 2 of the diary condition were compared using a repeated-measures ANOVA. RESULTS: There was a significant overall effect of study condition (P<0.001), with post hoc analyses revealing that mean daily step counts reported during the first week of the diary condition (9898±3002 steps/day) were significantly higher than those reported during the covert condition (8331±3010 steps/day) and during the second week of the diary condition (8226±3170 steps/day) (P<0.001). CONCLUSION: Reactivity to wearing unsealed pedometers and step count recording appears to last for 1 week. In the absence of any intervention material, step counts return to normal levels during the second week of monitoring, and therefore represent a more accurate estimate of habitual activity. These findings have important implications to both researchers and practitioners interested in the use of pedometers for physical activity surveillance and promotion

How many days of pedometer monitoring predict monthly ambulatory activity in adults?

PURPOSE: To determine how many days of pedometer monitoring are necessary to estimate monthly ambulatory activity in adults. METHODS: 212 adults (64% female, age=38.3±13.3 years, BMI=27.9±5.3 kg/m2) wore a pedometer (SW-200) for 28 consecutive days. 76.4% were randomly allocated to a reliability group while the remainder (n = 50) comprised a confirmation group. Mean step counts calculated over the 28-day period served as the criterion. Using the reliability group, intra-class correlations (ICCs) were computed for the entire 4 week period, for 3, 2 and 1 weeks, and for different combinations of any 6, 5, 4, 3 and 2 days. The reliability of the recommended time frame was tested in the confirmation group using regression analysis. RESULTS: In the reliability group, the ICC for any single given day was 0.41. All combinations including 6 days or more had ICCs above 0.80. The inclusion of participant characteristics into a regression, alongside mean steps reported during 1 week of monitoring, failed to strengthen the prediction. When tested in the confirmation group, there was a significant relationship between mean step counts calculated from the first week of monitoring and the criterion (adjusted R2 =0.91, CONCLUSION: It is recommended that researchers collect pedometer data over a 7-day period for a reliable estimate of monthly activity in adults. A 7-day period is recommended, as opposed to 6 days (where ICCs were >0.80) because: 1) step counts are characteristically lower on a Sunday, thus for a reliable estimate of habitual activity, Sunday activity should always be included, and 2) in the event of missing data (1 day), data collected on six days will remain sufficiently reliable to estimate mean monthly activity

Increasing our understanding of reactivity to pedometers in adults

PURPOSE: To investigate the presence of reactivity, if any, to wearing sealed and unsealed pedometers, with and without step count recording. METHODS: On the first visit to the laboratory 63 participants (41 female, 22 male: age = 23.6±9.6 years, BMI = 22.7±3.0 kg/m2), blinded to the study aim, were provided with a sealed pedometer (New Lifestyles NL-1000) and informed that it was a 'Body Posture Monitor' (covert monitoring). Participants wore the pedometer throughout waking hours for 1 week. Upon return to the laboratory, stored step counts were downloaded and participants were informed that the device was a pedometer. Participants wore the pedometer under 3 more conditions – sealed, unsealed, and unsealed plus logging daily steps in an activity diary - each having a duration of 1 week. The order of participation in each condition (sealed/unsealed/diary) was balanced across participants. Mean daily step counts recorded during the 4 conditions were compared using a repeated-measures ANOVA. RESULTS: There was a significant overall effect of condition (p<0.001) (covert monitoring = 8362±2600 steps/day; sealed condition = 8832±2845 steps/day; unsealed condition = 9176±3299 steps/day; diary condition = 9635±2709 steps/day), with post hoc analyses revealing that mean step counts were significantly higher in the diary condition than those reported during both the covert and sealed conditions (both p<0.003). No significant gender effects were observed (p=0.33) CONCLUSION: The greatest increase in step counts occurred in the diary condition, suggesting that reactivity to pedometers is greatest when participants are requested to wear an unsealed pedometer and record their step counts. This has validity implications for short-term pedometer studies investigating habitual free-living activity that require participants to provide a daily log of their step counts

The effects of standing desks within the school classroom: A systematic review

© 2016 The Authors. Background: The school classroom environment often dictates that pupils sit for prolonged periods which may be detrimental for children's health. Replacing traditional school desks with standing desks may reduce sitting time and provide other benefits. The aim of this systematic review was to assess the impact of standing desks within the school classroom. Method: Studies published in English up to and including June 2015 were located from online databases and manual searches. Studies implementing standing desks within the school classroom, including children and/or adolescents (aged 5-18 years) which assessed the impact of the intervention using a comparison group or pre-post design were included. Results: Eleven studies were eligible for inclusion; all were set in primary/elementary schools, and most were conducted in the USA (n = 6). Most were non-randomised controlled trials (n = 7), with durations ranging from a single time point to five months. Energy expenditure (measured over 2 h during school day mornings) was the only outcome that consistently demonstrated positive results (three out of three studies). Evidence for the impact of standing desks on sitting, standing, and step counts was mixed. Evidence suggested that implementing standing desks in the classroom environment appears to be feasible, and not detrimental to learning. Conclusions: Interventions utilising standing desks in classrooms demonstrate positive effects in some key outcomes but the evidence lacks sufficient quality and depth to make strong conclusions. Future studies using randomised control trial designs with larger samples, longer durations, with sitting, standing time and academic achievement as primary outcomes, are warranted

Reactivity: an issue for short-term pedometer studies?

OBJECTIVES: To investigate the influence of wearing a pedometer and recording daily step counts on ambulatory activity. METHODS: During the first visit to the laboratory, 50 healthy volunteers, blinded to the study aim, were provided with a sealed pedometer (New-Lifestyles NL-2000) and informed that it was a “body posture monitor” (sealed condition). Participants wore the pedometer throughout waking hours for one week. Upon returning to the laboratory step counts were downloaded and participants were informed that the device was actually a pedometer. They were requested to wear it unsealed for a second one-week period, and to record their step counts in an activity log (unsealed condition). RESULTS: Mean (SD) daily step counts reported in the sealed condition (9541 (3186) steps/day) were significantly lower than step counts reported in the unsealed condition (11385 (3763) steps/day) (p<0.001). CONCLUSIONS: Step counts increased significantly in the unsealed condition. Possible mechanisms for this include the knowledge of wearing a pedometer, the visible step count display and the completion of the activity log. This has validity implications for short-term studies (duration ⩽1 week) investigating habitual pedometer-determined activity levels

Four-week pedometer-determined activity patterns in normal-weight, overweight and obese adults

OBJECTIVE: To assess pedometer-determined ambulatory activity in normal-weight, overweight and obese UK adults. METHODS: 86 normal-weight (BMI<25 kg/m2) (age = 34±12.1 years), 91 overweight (BMI 25–29.9 kg/m2) (age = 40.6±13.6 years), and 75 obese (BMI≥30 kg/m2) (age = 41.2±12.4 years) participants, from the East Midlands, provided four-weeks of continuous pedometer-determined activity data, during the winter in 2006. Activity levels and patterns were assessed for all three groups. RESULTS: The normal-weight group had a significantly higher mean step count (10247 steps/day) than the overweight (9095 steps/day) and obese (8102 steps/day) participants (p<0.05). No differences in step counts were observed between the overweight and obese groups. A consistent reduction in activity was observed on Sundays in all groups, with this reduction being two-fold greater in the overweight and obese groups (~2000 steps/day) when compared with the normal-weight group (~1000 steps/day). CONCLUSIONS: With the increasing prevalence of obesity in the UK, changes in the activity levels of those at risk are needed. The issuing of pedometers to overweight and obese individuals, with the instruction to increase their ambulatory activity on all days of the week, with particular emphasis on Sunday activity, could be a good starting point in tackling the problem of obesity in the UK

Summer to winter variability in the step counts of normal weight and overweight adults living in the UK

BACKGROUND: This study investigated whether pedometer-determined activity varies between summer and winter in normal-weight and overweight adults. METHODS: Forty-five normal-weight (58% female, age = 39.1 ± 12.4 years, BMI = 22.2 ± 2.1 kg/m2) and 51 overweight (49% female, age = 42.1 ± 12.5 years, BMI = 29.3 ± 4.5 kg/m2) participants completed a within-subject biseasonal pedometer study. All participants completed 2 4-week monitoring periods; 1 period in the summer and 1 period the following winter. Changes in step counts across seasons were calculated and compared for the 2 BMI groups. RESULTS: Both BMI groups reported significant summer to winter reductions in step counts, with the magnitude of change being significantly greater in the normal-weight group (–1737 ± 2201 versus –781 ± 1673 steps/day, P = .02). Winter step counts did not differ significantly between the 2 groups (9250 ± 2845 versus 8974 ± 2709 steps/day, P = .63), whereas the normal-weight group reported a significantly higher mean daily step count in the summer (10986 ± 2858 versus 9755 ± 2874 steps/day, P = .04). CONCLUSION: Both normal-weight and overweight individuals experienced a reduction in step counts between summer and winter; however, normal-weight individuals appear more susceptible to winter decreases in ambulatory activity, with the greatest seasonal change occurring on Sundays. Effective physical activity policies should be seasonally tailored to provide opportunities to encourage individuals to be more active during the winter, particularly on weekends

Office workers' objectively measured sedentary behavior and physical activity during and outside working hours

OBJECTIVE: To examine objectively determined sedentary behavior and physical activity (PA) during and outside working hours in full-time office workers. METHODS: A total of 170 participants wore an ActiGraph GT1M accelerometer for 7 days. Time spent sedentary (<100 counts/min), in light-intensity PA (100 to 1951 counts/min), and moderate-to-vigorous PA (≥1952 counts/min) was calculated for workdays (including working hours and nonworking hours) and nonworkdays. RESULTS: Participants accumulated significantly higher levels of sedentary behavior (68% vs 60%) and lower levels of light-intensity activity (28% vs 36%) on workdays in comparison with nonworkdays. Up to 71% of working hours were spent sedentary. Individuals who were most sedentary at work were also more sedentary outside work. CONCLUSIONS: Those who are most sedentary at work do not compensate by increasing their PA or reducing their sedentary time outside work. Occupational interventions should address workplace and leisure-time sedentary behavior

UK adults exhibit higher step counts in summer compared to winter months

Background: Seasonal differences in step counts have been observed in a limited number of studies conducted on US adults. Due to the diverse global climate, assessment and interpretation of seasonal patterns in ambulatory activity may vary between countries, and regionally specific studies are necessary to understand global patterns. Currently, no studies have assessed whether a seasonal trend is present when ambulatory activity is measured objectively in adults living in the UK. Aim: To investigate whether pedometer-determined step counts of adults living in the UK vary between summer and winter. Subjects and methods: Ninety-six adults (52% male, age = 41.0 ± 12.3 years, BMI = 26.1 ± 5.1 kg/m2) completed a within-subject bi-seasonal pedometer study. All participants completed two four-week monitoring periods; one during the summer and one the following winter. The same Yamax SW-200 pedometer was worn throughout waking hours during both seasons, and daily step counts were recorded in an activity log. Intra-individual seasonal changes in mean daily steps were analysed using a paired samples t-test. Results: Summer mean daily step counts (10417 ± 3055 steps/day) were significantly higher than those reported during the winter (9132 ± 2841 steps/day) (p < 0.001). A follow-up study conducted the subsequent summer in a sub-sample (n = 28) reinforced this trend. Summer step counts were significantly higher than winter step counts on all days of the week (p ≤ 0.001). A significant day of the week effect was present in both seasons, with step counts reported on a Sunday being on average 1,500 steps/day lower than those reported Monday through to Saturday. Conclusion: Step counts in the sample of UK adults surveyed decreased significantly in the winter compared to the summer, suggesting future pedometer surveillance studies should capture step counts throughout the year for a non-biased reflection of habitual ambulatory activity. Public health initiatives should target these seasonal differences and opportunities should be provided which encourage individuals to increase their activity levels during the colder, darker months of the year

Sitting time and step counts in office workers

BACKGROUND: Technological advances mean that many adults are now employed in sedentary occupations. Given evidence linking prolonged sitting to chronic disease risk, understanding sitting and physical activity in and outside the workplace may usefully inform effective interventions. AIMS: To assess sitting time and physical activity during and outside working hours in fulltime office workers. METHODS: Participants wore a pedometer and recorded sitting times and step counts during and outside working hours for seven days. Participants were divided into tertiles based on the proportion of time spent sitting at work. Sitting times and step counts reported outside work were compared between groups, using one-way analysis of variance. RESULTS: There were 72 participants. Almost two thirds (65%) of time at work was spent sitting. The sample accumulated 3742±2493 steps at work and 5159±2474 steps outside work on workdays. Participants in the highest tertile for workplace sitting reported sitting for longer than those in the lowest tertile during transport (64±59 vs 21±16 mins), after-work (154±30 vs 126±51mins) and at weekends (382±133 vs 288±124mins, all p<0.05). Work duration and steps reported outside work did not differ between groups. CONCLUSIONS: Office workers who sit for a large proportion of their working day also report sitting for longer outside work. They do not compensate for their sedentary behaviour at work by being more active outside work. Occupational health interventions should focus on reducing workplace and leisure-time sitting in sedentary office workers