BM - Physical activity and exercise Flashcards
What is the difference between physical activity and exercise?
o Physical activity is -any bodily movement produced by skeletal muscles that results in increased energy expenditure
o Exercise is – planned & structured bodily movements done to improve or maintain one or more components of physical fitness. It increases heart rate
o Physical fitness is – set of attributes that people have or achieve and relate to the ability to perform physical tasks
o Wellness – an holistic concept describing a state of positive health in an individual comprising physical, social & psychological well-being
Includes structured exercise, sport and ‘lifestyle’ activities, such as walking and gardening.
History of activity and exercise?
· Claudius Galenus (Ad131) Greek Physician – On Hygiene – promoted his belief that everyone could benefit from exercise
· Scientists and physicians in China & India recognised a link between physical activity and health over 5000 years ago
· Scientific support for the belief that exercise could prevent or ameliorate disease did not emerge until 20th century
Many ancient cultures, scientists and physicians have recognised the role of physical activity in promoting the health of both body and mind. A medical document written in India between 1000and 800 bc the Ayur Veda recommended massage and exercise in the treatment of rheumatism.
· 1940s London Bus Study (Jerry Morris and colleagues)
What was the London bus study?
1st physical activity epidemiology study
London Bus Study – 1st physical activity epidemiology study – showed that London’s double decker bus conductors who climbed stairs and were on their feet through out their shifts had lower rates of coronary heart disease than bus drivers who were almost sedentary on their shifts.
The first study to show an association between physical activity and risk of heart disease. Since then many studies have confirmed these results using more sophisticated measures of PA to assess intensity, duration, type of PA.
History of interventions/progress in exercise and physical activity…
· 1940s London Bus Study (Jerry Morris & colleagues)
· 1950s cardiologist Paul Dudley White prescribed exercise as part of the treatment for people with coronary heart disease
· 1960s & 1970s popularised jogging and running led to exercise scientists to systematically explore the effects of various types, duration and intensity of endurance exercise on cardio-respiratory fitness
· 1980s onwards there has been a growing awareness of the contribution of moderate physical activity to health and fitness
Why are we programmed to be physically active?
· our genome results from millions of years of selective pressure of a hunter gatherer life
· sedentary life is very recent
· sedentarism and obesity are problems of behaviour
At least 60% of the world’s population fails to complete the recommended amount of physical activity required to induce health benefits. This is partly due to insufficient participation in physical activity during leisure time and an increase in sedentary behaviour during occupational and domestic activities. An increase in the use of “passive” modes of transport has also been associated with declining physical activity levels.
About physical activity and health
Evidence that physical inactivity is associated with many chronic conditions: Ischaemic heart disease, Diabetes, Osteoporosis, Some forms of cancer, Obesity
Levels of inactivity are high in virtually all developed and developing countries. In developed countries more than half of adults are insufficiently active. In rapidly growing large cities of the developing world, physical inactivity is an even greater problem. Urbanisation has resulted in several environmental factors which may discourage participation in physical activity:
What are the health benefits of physical activity?
20-30% reduced risk of premature death
50% reduced risk of developing chronic diseases
Improve quality of life & independence in later life
Reduced obesity
Skeletal health and growth → less falls/ injuries in the older people
Increased psychological well-being
Approximately 9% deaths could be avoided if people who are currently sedentary did at least 30 minutes of moderate exercise, five days a week. This includes over a third of all deaths due to coronary heart disease.
What are some pathways of health benefits from physical activity?
Cardiovascular benefits:
reduced risk of CV disease, reduced blood pressure, body fat, increased HDL cholesterol, increased fitness.
Psychological benefits:
reduced depression & anxiety, increased self-esteem.
Other benefits:
reduced cancer (colon/breast/prostrate), increased immune functioning, increased bone mineral density
Risks – sudden cardiac death – temporary risk during exercise benefits out weigh the risk
Related sport injuries – swimmer’s shoulder – rotator cuffs; musculo- skeletal – runners – tendons, knee injuries; in terms of addiction – 11 studies show addiction to exercise and could be a compulsive behaviour for some individuals.
What is the evidence for physical activity having positive health effects?
Functional neuroimaging of brain networks
Physical activity is one of the most effective means of behavioural intervention for prevention of chronic diseases of the body and mind, and for slowing cognitive decline associated with healthy aging.
How does physical activity and changes in aerobic fitness level affect brain and cognitive health.
Results from this research have shown that a network that is proposed to be a biomarker for normal cognitive decline and the Default Network is positively affected by aerobic exercise and that this may be part of the benefits of aerobic exercise on cognitive aging.
Brain is less active when sitting still, focussing on other things. Getting more oxygen etc during exercise.
BDNF - the brain’s “fertiliser”
Serum brain-derived neurotrophic factor [BDNF] levels before and after 8 weeks of training.
Exercise have been shown to markedly (threefold) increase BDNF synthesis in the human brain, a phenomenon which is partly responsible for exercise-induced neurogenesis and improvements in cognitive function.
What effect does exercise have on stress?
Improves stress tolerance
What is a study on on exercise’s effect on stress?
Rats assigned to 4 groups
1. Engaged in ‘voluntary running’
2. Given anti-depressants
3. Both
4. Neither
Rats then underwent a 2-day ‘forced swimming’ procedure
Results:
BDNF levels in untreated animals were depressed
Animals in physical training or anti-depressants had BDNF restored to baseline
Animals with both showed increase in hippocampal BDNF well above baseline
→ Exercise has an anti-depressant effect
What is the three step approach to getting more physical activity?
- Decrease time sitting down, get up more often, stretch, sit down again. Standing desk.
- Do more physical activity, find strategies to be ‘less effective’ – don’t wee, get drink and printer all in one go, get up more than once!
- Do planned exercise
What are the only active muscles at rest?
the heart and circulatory system
What are the psychological benefits of physical activity?
- Distraction
- Relaxation/stress management
- Healthier coping
- Opioids
- Reduced immune system chemicals that can worsen depression
- BDNF
Can physical activity beat the blues and help with nerves?
In line with the NICE clinical guidelines for depression, patients of all ages with mild depression should be advised of the benefits of following a structured and supervised exercise programme.
Opiods – associated with increased mood and decreased pain sensations endorphins etc. – exercise increase these and is considered to be linked to post exercise mood enhancement.
What are the recommended levels of physical activity?
· Adults: 30 mins of moderate intensity PA at least 5 days/wk or 20 min vigorous activity 3 d/wk
· Children: at least 60 minutes per day of moderate intensity PA.
· Includes PA accumulated in shorter bouts of at least 15 minutes
· Recommends a progression towards more vigorous PA
Lifestyle activity can mean walking to work, school, cycling, climbing the stairs, gardening, housework.
Moderate physical activity is defined as activity which causes an individual to feel slightly warm, breathe slight heavier and increases the heart rate.
How do we measure physical activity levels?
Objectively
e.g. activity and heart rate monitors, accelerometry, step counters, fitness measures
Self-report:
Simple questions
PA recall (e.g. Blair’s seven-day recall questionnaire)
PA diaries
Self report has problems, as type of exercise, how long really for, how intense the exercise was – they are very subjective and probably not accurate!
Measuring physical activity is difficult because it is a complex behaviour – because in fact a whole class of behaviours theoretically includes all bodily movements from fidgeting to swimming the channel - dimensions are commonly known as FITT – frequency, intensity, time & type
How active is the UK’s population?
Adults : a high proportion of men and women aged 16-64 perceived themselves to be either very or fairly physically active compared with other people in their age group (75%of men and 67%of women).
Children: more boys (72%) than girls (63%) met the government recommended targets by participating in physical activity for at least 60 minutes on all seven days per week.
However more than 27 million adults in England are not getting enough exercise and 14 million don’t complete 30 minutes a week
What are the main determinants of physical activity levels?
Ø Higher socio-economic status Ø Being male Ø Taking moderate intensity exercise Ø Higher levels of enjoyment of PA Ø Greater belief in the benefits of PA Ø Higher levels of social support for PA Ø Higher levels of motivation towards PA Ø Reporting fewer barriers to PA Ø Higher levels of self-efficacy towards PA Ø Having had a physically active childhood Ø Being younger Ø Have a lower BMI Ø Being a non-smoker
What are the psychological determinants of physical activity?
è Self efficacy è Social support è Motivation/intention è Beliefs è Barriers/benefits
What is self-efficacy?
‘How confident do you feel about sticking to your physical activity programme’:
‘When you are short of time?’
‘When you are stressed out?’
How would you increase someone’s self-efficacy for exercise?
Self-efficacy is a belief that one has the capabilities to execute the courses of actions required.
Encouraging the person. Positive reinforcement.
Unlike efficacy, which is the power to produce an effect (in essence, competence), self-efficacy is the belief (whether or not accurate) that one has the power to produce that effect. For example, a person with high self efficacy may engage in a more health related activity when an illness occurs, whereas a person with low self efficacy would harbor feelings of hopelessness.
What is the role of social support in physical activity and exercise?
‘Would your family/friends encourage you to take more physical activity?’
‘Would any of your family/friends join in your physical activity routine?’
What other ways are there of social support that would increase someone’s self-efficacy for exercise? Buddying up, council have done this with overweight people referred from GP. These people tended to maintain their health behaviour change better.
Support of a club structure – being with others who also swim, run etc
