PHYSICAL ACTIVITY, CHILD FITNESS, AND THE OBESITY EPIDEMIC

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• PHYSICAL ACTIVITY, CHILD FITNESS, AND THE OBESITY
  EPIDEMIC
• Greg Welk
• Weimo Zhu

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15.1 MODEL OF HEALTH RELATED FITNESS

• Physical activity and physical fitness are often
  considered to be synonymous terms but they are
  fundamentally differences and unique implications
  for health.

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Bouchard Shepard,1997
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• Definitions and Descriptions of Physical Activity
  and Inactivity
• Physical activity (PA) is typically defined as
  any bodily movement produced by skeletal muscles
  that results in energy expenditure(11).
• The term exercise is often used interchangeably
  with the term physical activity but exercise
  refers to a more structured (and planned) form of
  physical activity that is done with a specific
  purpose in mind

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• Longitudinal studies have demonstrated that
  activity levels decline by about 20-25 during
  the period from 12-18 (Kemper, Post, Twisk, van
  Mechelen, 1999) (Kimm et al., 2000) .
• In any case, there is no denying the importance
  of regular physical activity for youth.

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• Descriptions and Definitions of Physical Fitness
• Physical fitnesss current model
• morphological fitness
• cardiorespiratory fitness
• metabolic fitness
• motor fitness and
• neuromuscular fitness
• (Bouchard Shepard, 1994).

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• Cardiorespiratory fitness
• Cardiorespiratory fitness includes
• Categories of aerobic power,
• Heart functions (blood pressure)
• Lung function.

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• Participation in physical activity that
  challenges the cardiovascular system (aka aerobic
  activity) helps to improve cardiorespiratory
  fitness but the associations between habitual
  physical activity and aerobic fitness are lower
  in youth than in adults (Morrow Freedson,
  1994).

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• Morphological fitness
• Morphological fitness refers to indicators that
  represent the structure and composition of the
  body such as subcutaneous and visceral adipose
  tissue, body fat distribution, and bone mineral
  density.

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• The primary component of interest is typically
  body fatness

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• Low levels of physical activity and high levels
  of inactivity are causally associated with
  changes in overweight in children
• (Berkey et al., 2000 Gordon-Larsen, Adair,
  Popkin, 2002)

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• Metabolic fitness
• Metabolic fitness includes biochemical indicators
  that are associated with a reduced risk of
  cardiovascular disease and type II diabetes.
• These indicators are known to be influenced by
  physical activity and to relate directly to
  health. Many of the Indicators of metabolic
  fitness cluster together as part of an overall
  metabolic syndrome that predisposes individuals
  to cardiovascular disease (Lakka, Laaksonen, and
  Lakka, 2002).

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• Motor fitness
• Motor fitness, in this model, refers to
  components that can improve the ability to learn
  and perform complex skills required in some
  sports and physical activities.

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• Muscular fitness
• Muscular fitness includes the related
  dimensions of power, strength and endurance.
• Muscle endurance and muscle strength are
  typically considered to be dimensions of health
  related fitness because there are direct links to
  health.

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• Power (the combination of speed and strength), on
  the other hand, is often considered to be a
  dimension of skill related fitness (Corbin, Welk,
  Corbin, Welk, 2007)
• Speed is more genetically linked and less
  responsive to training.

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• A LIFESPAN MODEL OF PHYSICAL ACTIVITY AND HEALTH

Blair (1989)
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• An important message in the model is that
  physical activity and health-related risk factors
  can both track from childhood into adulthood.
• The relationships between physical activity and
  health outcomes are reciprocal (bi-directional
  arrows).

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• Relationships Between Physical Activity, Physical
  Fitness, and Health
• Physical activity has effects on a variety of
  physiological systems and has been shown to
  impact each of the different components of HRF.
• Activity and inactivity are both important in
  obesity prevention in youth.

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15.3THE YOUTH PHYSICAL ACTIVITY PROMOTION MODEL

• Youth Physical Activity Promotion (YPAP)
  Model is a social-ecological model that was
  developed to facilitate the targeting of
  variables known to influence childrens physical
  activity behavior (Welk, 1999).

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• (Welk,1999)???????????

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• Factors Influencing Physical Activity in Youth
  Description of the YPAP Model
• Predisposing Factors
• Predisposing factors refers to factors that may
  predispose a child to be physically active.

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• Enabling Factors
• Enabling factors refers to factors that enable a
  child to be physically active. These can include
  environmental variables such as access to
  facilities, equipment, and programs that provide
  opportunities for physical activity.

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• Reinforcing Factors
• Reinforcing factors refers to support that a
  child receives from significant others to be
  physically active. Parents, peers and
  teachers/coaches can all act to directly
  influence childrens interest and involvement in
  physical activity by providing opportunities for
  children to be active through the day.

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• Strategies for Promoting Physical Activity -
  Application of the YPAP Model
• School Based Physical Activity Promotion
• Family and Community Based Programming

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THANKS