Lecture 2 Flashcards
Justify financial support for PA promotion/ExRx
Link w decreased fitness/ex w increased disease/mortality, ageing population, reduce burden on medical system
Why prescribe ex?
Athletic performance, prevention & treatment of chronic disease, well-being, social interaction, enjoyment
Why prescribe ex – evidence
Epidemiological studies link decrease PA and/or fitness with increase rates of all-cause mortality.
PA is a modifiable risk factor of chronic disease e.g. obesity, diabetes, CVD, cancer
Physical activity:
Any bodily mvmt produced by contraction of skeletal muscle that substantially increases energy expenditure
Difference between PA and ex =
intensity
Leisure-time physical activity (LTPA):
Activities completed during free time, based on personal interests and needs. Includes formal ex programs, hiking, gardening, and sport. Result in marked energy expenditure and may vary in duration.
Dose-response:
R/ship b/w increasing PA levels on changes in a defined health parameter
Exercise:
Subcategory of LTPA in which planned, structure, repetitive bodily mvmts are performed to improve/maintain 1 or more components of physical fitness
Aerobic, anaerobic, resistance ex
Physical fitness:
Multidimensional concept. Set of attributes that relate to the ability to perform PA.
Physical fitness components =
Skill, health, physiological
Skill-related physical fitness components =
Associated mostly with sport and motor skills performance
Agility, balance, coordination, speed, power, reaction time
Health-related physical fitness components =
Associated w/ ability to perform daily activities w/ vigor; & w/ a low risk of premature dev of hypokinetic diseases
Cardiovascular endurance, muscular strength & endurance, flexibility, body comp, anaerobic power & capacity.
Physiological physical fitness component =
Non performance components that relate to biological systems influenced by habitual activity.
Metabolic fitness, morphologic fitness, bone integrity
Cardiorespiratory endurance:
Ability of circulatory & respiratory system to supply oxygen during sustained PA
body composition:
Relative amounts of muscle, fat, bone, & other vital parts of the body
muscular strength:
Ability of muscle to exert force
Muscular endurance:
Ability of muscle to continue to perform w/out fatigue
flexibility:
Range of motion available at a joint
Agility:
Ability to change position of body in space with speed & accuracy
Coordination:
ability to use the senses, e.g. sight & hearing, together w/ body parts in performing tasks smoothly & accurately
Balance:
Maintenance of equilibrium while stationary or moving
Power:
Time elapsed b/w stimulation & the beginning of the reaction to it
Reaction time:
Time elapsed b/w stimulation & the beginning of the reaction to it
Speed:
Ability to perform a mvmt within a short period of time
Epidemiology:
Study of the distribution and determinants of health-related states or events (including disease), & the application of this study to the control of diseases & other health problems
Health-related states or events:
The concept of health is viewed on a continuum; for example, consider both life quality & disease state.
Health-related outcomes:
May refer to both disease and other health-specific conditions as an absolute (disease absent or disease present) or graded (normal weight, overweight or obese).
Epidemiology can identify:
Risk factors, but not causality
Prevalence:
Number of people w/ health-related outcome at a specific time
Helpful in assessing need for health care or preventative strategies
Incidence:
Number of new occurrences of health-related outcome that develop during a specific time interval
Observational study design:
Descriptive studies – case reports/studies – Individuals
Analytical studies – Correlational – populations
Cross-sectional surveys – individuals
Case-control studies – individuals
Cohort studies – individuals
Experimental study design:
Randomized, controlled trials – individuals
Case-control study:
Comparison of disease present (case) & disease absent (control) populations seeking associations of exposure to the factors of interest
Cohort study:
Longitudinal observation of a population to assess the effect of a specific exposure or intervention
Randomized, controlled trial:
*Participants are randomly assigned to one or multiple conditional trails to quantitatively assess the effects of a specific intervention
Case study:
*Description of a single or group of individuals w/ a similar diagnosis. (large variance)
Correlational study:
Population characteristics analysed to describe the frequency and r/ship of a health-related outcome & a specific variable.
Cross-sectional survey:
Describes the prevalence of a health-related outcome within a sample in relation to personal or demographic characteristics.
Inverse dose-response r/ship between PA and:
All-cause mortality, cardiorespiratory health, metabolic health, weight loss, weight maintenance following weight loss, abdominal obesity, bone, joint & muscular health, functional health, colon and breast cancers, depression & distress.
Study: changes in PA and mortality – 4 key outcomes:
- Beginning moderately vigorous sports activity (>/ 4.5 METs) reduced mortality by 23%
- *Quitting smoking reduced mortality by 41%, however, mortality rates remained 23% higher than constant non-smoking
- Recently diagnosed hypertension is at a lower risk of death than chronic hypertension.
- Maintenance of lean body mass was associated with lower mortality than long-term, recent or previous obesity
Lean men had…
Double the risk of all-cause mortality of fit, lean men *
Unfit men…
Had a higher risk of all-cause and CVD mortality than did fit men in all fat and fat-free mass categories
Unfit, lean mean had…
Higher risk of all-cause & CVD mortality than did men who were fit and obese
Unfit men with…
Low waist girths (<87cm) had greater risk of all-cause mortality than did fit men with high waist girths (99cm)
What is the optimum amount of ex for longevity?
4200kJ/wk presents a 20-30% reduction in all-cause mortality
Vigorous activity associated with longevity
How much longer can active people expect to live?*
2 years (Peffenbarger et al.1986)
Dose-response relative risk CVD – PA & PF:
Both factors decrease relative risk
PF is sig more of a protective factor than PA
Intensity may be a link to explain the diff b/w them
Surgeon general’s report on PA and Health 1996
“Sig health benefits can be obtained by including a mode amount of PA on most, if not all, days of the wk. through a modest increase in daily activity, most Americans can improve their health and quality of life.”
Does ex improve all health and fitness parameters to the same degree?
no
Does-response to exercise:
Some activity is better than none, and more activity – up to a certain point – is better than less.
Optimal dose of PA has yet to be defined
Ex volume and total energy expenditure
Mode administered has implications for outcome achieved
PA/fitness & all-cause mortality r/ship =
Inverse r/ship
Physical capacity appears to be a protective agent
