Questionnaires and Activity Diaries
These instruments tend to provide less accurate assessments of physical activity, but
are more suitable for large samples and are relatively less expensive. The instru-
ments rely on the ability to recall and/or record information and may be influenced
by perceived social desirability (Klesges et al. 2004 ), familial circumstances
reflected in parental education (Slootmaker et al. 2009 ), and perceptions of activ-
ities in different settings, e.g., household activities or chores in urban and rural
settings and unstructured versus structured leisure activities, games, and sports.
Questionnaires and diaries also may not capture specific details of many activities.
For example, most moderately vigorous and vigorous activities, including many
sports, are intermittent and involve substantial periods of rest. This may lead to
erroneous estimates of time and/or energy expenditure spent in activities of different
intensities (Machado-Rodrigues et al. 2011 ,2012a; Slootmaker et al. 2009 ; Trost
et al. 2002 ).
Most of the data are limited to samples 10 years of age and older. Although there
is variation by type of activity (e.g., overall, moderate-to-vigorous, and vigorous),
levels of physical activity are, on average, relatively stable in childhood but decline
during the pubertal transition through adolescence, while physical inactivity
increases during adolescence (Caspersen et al. 2000 ; Telama and Yang 2000 ). It has
been suggested that the decline in activity during adolescence may have a biological
basis (Sallis 2000 ). Boys are, on average, more active and less sedentary than girls,
though evidence indicates that the sex difference is attenuated when maturity status
is controlled in adolescents (Thompson et al. 2003 ; Machado Rodrigues et al.
2010 ). Girls tend to be less active and more sedentary than boys of the same age
due to their advanced biological maturation. Allowing for the preceding general
trends, age trends in physical activity and inactivity vary among studies, with
measurement instrument and with context of activity.
Using data from two major international surveys of youth, levels of MVPA have
been estimated for 13–15-year-old adolescents in 66 mostly low- and
middle-income countries in the Global School-Based Student Health Survey
(GSHS) and 38 countries including USA, Canada, and 36 from Europe in the
Health Behavior in School-Aged Children (HBSC). Overall, 80% of 13–
15-year-old youth in the countries surveyed did not meet the recommendation of
60 min of MVPA per day (Hallal et al. 2012 ). Boys were more active than girls, but
there was variation among countries. Among boys in 56 countries (53%), 80% or
more did not meet the MVPA guideline, while among girls in 100 countries (95%),
80% or more did not meet the recommendation (Hallal et al. 2012 ). In a previous
analysis of youth from 34 countries in the GSHS, it was estimated that only 24% of
boys and 15% of girls 13–15 years of age met the recommendation of at least
60 min of physical activity per day on at least 5 days per week (Guthold et al.
2010 ). Given the nature of the data and criteria used to estimate MVPA, the
estimates of youth not meeting the guidelines should be accepted as
74 R.M. Malina et al.