The number of steps/minute (i.e., cadence) that equates to moderate intensity in adolescents is not known. To that end, 31 adolescent females walked on a treadmill at 5 different speeds while wearing an ActivPAL accelerometer and oxygen uptake was recorded by indirect calorimetry. The relationship between metabolic equivalents (METs) and cadence was explored using 3 different analytical approaches. Cadence was a significant predictor of METs (r=.70; p<.001). Moderate intensity (3 METs) corresponded to 94 or 114 steps/minute based on the mixed model and ROC analysis, respectively. These two values, and a practical value of 100 steps/minute, were cross-validated on an independent sample of 33 adolescent females during over-ground walking at 3 speeds. The sensitivity and specificity of each value correctly identifying 3 METs were 98.5% and 87.2% for 94 steps/minute, 72.9% and 98.8 for 114 steps/minute and 96.5% and 95.7% for 100 steps/minute. Compromising on a single cadence of 100 steps/minute would be a practical value that approximates moderate intensity in adolescent females and can be used for physical activity interpretation and promotion.
Deirdre M. Harrington, Kieran P. Dowd, Catrine Tudor-Locke and Alan E. Donnelly
Kieran P. Dowd, Helen Purtill, Deirdre. M. Harrington, Jane F. Hislop, John J. Reilly and Alan E. Donnelly
This study aims to determine the minimum number of days of monitoring required to reliably predict sitting/lying time, standing time, light intensity physical activity (LIPA), moderate-to-vigorous intensity physical activity (MVPA) and steps in adolescent females.
195 adolescent females (mean age = 15.7 years; SD = 0.9) participated in the study. Participants wore the activPAL activity monitor for a seven day protocol. The amount of time spent sitting/lying, standing, in LIPA and in MVPA and the number of steps per day were quantified. Spearman-Brown Prophecy formulae were used to predict the number of days of data required to achieve an intraclass correlation coefficient of both 0.7 and 0.8.
For the percentage of the waking day spent sitting/lying, standing, in LIPA and in MVPA, a minimum of 9 days of accelerometer recording is required to achieve a reliability of ≥ 0.7, while a minimum of 15 days is required to achieve a reliability of ≥ 0.8. For steps, a minimum of 12 days of recording is required to achieve a reliability of ≥ 0.7, with 21 days to achieve a reliability of ≥ 0.8.
Future research in adolescent females should collect a minimum of 9 days of accelerometer data to reliably estimate sitting/lying time, standing time, LIPA and MVPA, while 12 days is required to reliably estimate steps.
Deirdre M. Harrington, Marie Murphy, Angela Carlin, Tara Coppinger, Alan Donnelly, Kieran P. Dowd, Teresa Keating, Niamh Murphy, Elaine Murtagh, Wesley O’Brien, Catherine Woods and Sarahjane Belton
Physical activity (PA) is a key performance indicator for policy documents in both the Republic of Ireland and Northern Ireland. Building on baseline grades set in 2014, Ireland’s second Report Card on Physical Activity for Children and Youth allows for continued surveillance of indicators related to PA in children and youth.
Data and information were extracted and collated for 10 indicators and graded using an international standardized grading system.
Overall, 7 grades stayed the same, 2 increased, and 1 decreased. Grades were assigned as follows: Overall PA, D (an increase); Sedentary Behavior (TV), C-; Physical Education, D-; Active Play, Incomplete/Inconclusive (INC); Active Transportation, D; School, D (a decrease); Home (Family), INC; Community and the Built Environment, B+ (an increase); and Government, INC. Unlike 2014’s report card, different grades for the Republic (C-) and Northern Ireland (C+) were assigned for Organized Sport Participation.
Although the grade for Overall PA levels increased to a D, this may reflect the increased quality and quantity of data available. The double burden of low PA and high sedentary levels are concerning and underscore the need for advocacy toward, and surveillance of, progress in achieving targets set by the new National Physical Activity Plan in the Republic and obesity and sport plans in the North.
Deirdre M. Harrington, Sarahjane Belton, Tara Coppinger, Muireann Cullen, Alan Donnelly, Kieran Dowd, Teresa Keating, Richard Layte, Marie Murphy, Niamh Murphy, Elaine Murtagh and Catherine Woods
Physical activity (PA) levels are a key performance indicator for policy documents in Ireland. The first Ireland Report Card on Physical Activity in Children and Youth aims to set a robust baseline for future surveillance of indicators related to PA in children and youth.
Data collected between 2003−2010 on more than 35,000 7- to 18-year-old children and youth were used and graded using a standardized grading system for 10 indicators.
Grades assigned for the indicators were as follows: overall physical activity levels, D-; sedentary behavior (TV viewing), C-; organized sport participation, C-: physical education, D-; active play, inconclusive (INC); active transportation, D; school, C-, community and the built environment, B; family, INC; and government, INC.
PA recommendations exist in Ireland but this Report Card has shown that participation is still low. A number of promising policies, programs and services are in place but these require thorough evaluation and adequate resourcing. Agreement and implementation of a common framework for the systematic surveillance of indictors related to PA of children and youth is necessary to monitor change over time and ensure the impact of promising work is captured.