discussed in the context of activity and health; it is both an outcome of activity and
a determinant of activity.
In contrast to the public health/biomedical model, physical activities are also
important avenues for learning, enjoyment, social interactions, self-understanding,
and physical and psychological development, and in many parts of the world are
essential for subsistence. A dimension of physical activity that is often overlooked
is context—the types, purposes, and settings of activity which include play,
physical education, exercise, sport, dance, physical labor, and household chores.
Contexts per se and meanings attached to them vary with age among children and
adolescents, and among and within different cultural groups (Malina 2008 ).
Physical inactivity refers to sedentary behaviors which are associated with very
low levels of energy expenditure. It is independent of physical activity and also has
multiple dimensions. Although the public health/biomedical view is critical of
excessive physical inactivity, many sedentary behaviors are highly valued by
societies—school, studying, reading, music, art, television and movie viewing,
computer games, and the like and have many educational and social benefits for the
individual and community. Potential benefits associated with engagement in
computer or video games include, for example, superior performance on a number
of cognitive and motor tasks. Motorized transport, of course, is a form of physical
inactivity that is highly valued by major segments of society, including youth.
Physically active and inactive behaviors are largely independent of each other.
They are, however, performed in a societal context, and many have high valence in
societies. There is a need for better understanding of meanings attached to and
motivations for physically active and sedentary behaviors by children and adoles-
cents and also by adults. The behaviors are of interest to education, to public health
and medicine, to parents, to sport, and to communities in general.
Sport merits special mention. School and non-school sport, both formal (orga-
nized) and informal, are major contexts of physical activity for youth, and many
youth perceive physical activity as equivalent with sport. Participation in sport has
the potential to contribute to the objectives of physical activity, but specific sports
vary in intensity and duration of activity.
In the context of“making visible the invisible,”many forms of physical activity
potentially fall into the category of the“invisible.”Organized sport, school physical
education, and specific training programs are highly visible forms of activity among
youth. On the other hand, many physical activities may not be perceived or con-
sidered as physical activity per se, e.g., walking to school, walking to the store,
shopping in a mall, informal play, household chores, herding and feeding animals,
getting animal feed, door-to-door sales of tortillas in rural Mexican communities,
and harvesting food. Such activities are often necessities and/or chores that simply
must be done. Although all entail physical activity, individuals may not recall them
as physical activity unless appropriately prompted in a questionnaire or interview.
Assume, for example, a student in a major metropolitan center who uses public
transportation to travel to and from school and lives nine blocks from the subway or
metro station. He/she walks nine blocks from home to the subway in the morning
and then back home on returning 5 days per week. The pace of walking would
68 R.M. Malina et al.