(LACK OF) PHYSICAL ACTIVITY, SEDENTARY BEHAVIOUR AND HEALTH
DEFINITIONS
Physical activity:
- any movement of the body produced by skeletal muscles
- resulting in energy expenditure, which varies from low to high
- a positive correlation with physical fitness
- should be distinguished from problem of prolonged sitting (sedentariness)
Exercise:
- body movement produced by skeletal muscles
- resulting energy expenditure varying from low to high
- planned, structured and repetitive bodily movement
- the objective is to maintain or improve physical fitness
- exercise is very positively correlated with physical fitness
Sports: physical activity that is:
- rule governed
- structured
- competitive
- involves gross physical movement
- is characterised by physical strategy, prowess/bravery and chance
Physical fitness:
- the ability of the individual to perform muscular work
- attributes that people have or achieve that enables them to perform physical activity
- physical fitness is partly related to current physical activity levels ('attributes that
people achieve') and partly a function of heredity ('attributes that people have').
EVOLUTION IN PHYSICAL ACTIVITY/HEALTH
1. pre-agricultural period (4 000 000 BC until 8000 BC): hunting and gathering, PA high,
low CHO/fat diet à High PA: run after animals, look for berries
2. agricultural period (8 000 BC – 1800): reasonably high PA, relatively low CHO/fat diet
(but increasing)
3. industrial period (1800-1945): PA level still relatively high (still hard labor), but
overcrowding, poor diet, poor public health
à infectious diseases as major causes of death
1
, 4. nuclear/technological (1945-present): improvement in public health and medical
advances in „advanced‟ societies, but now „lifestyle related‟ premature death
(hypokinetic diseases)
à Big change: hypokinetic: dieases related to a sedentary lifesyle and less PA, we
don’t have to do any hard labor
Steps per day for adults living in a Canadian Amish
community:
- agricultural period
- Sunday: resting day (magic number: 10.000 steps)
- But most days: 20.000 à very physical active
Contemporary problem:
- A fairly new problem
- A great deal of the PA that has become necessary for health must be freely chosen in
leisure time or consciously integrated into one’s normal daily routine (active living).
à We moeten het bewust inbouwen in onze routine, ervoor kiezen om te gaan
lopen/zwemmen…
- Importance of studying psychological processes, such as motivation and decision-
making!
We know that:
- Less and less people (at least in Western societies) reach the norms for health-
enhancing physical activity (especially young women, less educated, and elderly)
- Polarization: people perform much and vigorous PA, and people who do (almost)
nothing
- Problem of sedentary behaviour is something different (≠ lack of physical activity, ≠
tv viewing)
RECOMMENDED PA FOR HEALTH
Position statements about recommended P.A. for health (WHO)
- adults: at least 30 minutes moderate P.A. a day on at least five or more days a week
(in bouts of at least 10 minutes)
- Or at least 75 minutes of vigorous-intensity aerobic physical activity throughout the
week
- children/young people: at least 60 minutes each day
à if you get to these numbers: major health benefit
2
, HEALTH BENEFITS OF PHYSICAL ACTIVITY IN ADULTS
Strong evidence of protective effects:
- All-cause mortality
- Coronary heart disease
- High blood pressure
- Stroke
- Metabolic syndrome
- Type 2 diabetes
- Breast cancer
- Colon cancer
- Depression
- Falling
High level of evidence for beneficial effects:
- Increased cardiorespiratory and muscular fitness
- Healthier body mass and composition
- Improved bone health
- Increased functional health
- Improved cognitive function
Mental health benefits of physical activity (both kinds of trainings):
- Improves mood and reduces symptoms of depression and anxiety (Ross and Hayes,
1988, Am J Epidemiol 127:762–71); (Stephens, 1988, Prev Med, 17:35–47)
- Individuals diagnosed with major depression undergoing an aerobic-exercise
intervention showed significant improvements in depression comparable to
participants receiving psychotropic treatment (Babyak et al., 2000, Psychosom Med,
62(5):633- 38)
- May prevent the onset of depression (Paffenbarger, 1994, Acta Psychiatr Scand Suppl
377:16-22)
- Health related Quality of Life appears to be improved through physical activity by
enhancing the experience of well-being and increasing physical functioning in those
with poor health (Centers for Disease Control, 2001); (McAuley and Rudolph, 1995,
Aging Phys Act, 3:67–96)
- Resistance training has been associated with improved total mood state and
reductions in confusion, anger and tension in older adults, women (McLafferty et al.,
2004, Percept Mot Skills, 93(3):947-57); (Janisse et al., 2004, Women Health,
39(1):101-16)
- Hatha yoga and African dance significant reductions in perceived stress and negative
affect (West et al., 2004, Ann Behav Med, 28(1):114-18)
3