Exercise Flashcards
Exercise - History
Claudius galenus AD131 promoted his belief that everyone could benefit from exercise
Many ancient cultures recognised the role of PA in promoting health of body & mind - document written between 800-1000BC recommended massage & exercise in treatment of rheumatism
1950s- Paul Dudley White prescribed exercise as part of treatment for patients with CHD
1980s onwards - growing awareness of contribution of moderate PA to health & fitness
London Bus Stud
Morris et al 1953
First epidemiological PA study
double decker bus conductors=active, climbing stairs etc = decr risk of CHD
Drivers = mostly sedentary = incr risk of CHD
1st study to show assoc b/ PA and risk of HD
Physiological benefits of exercise
20-30% decr risk of premature death
50% decr risk of developing chronic diseases
Incr QOL & incr independence in later life
Decr obesity - link with other essay
Approx 9% deaths avoidable if sedentary people did at least 30 mins exercise 5d/wk incl >1/3 deaths due to CHD
BMJ Article Fentem 1994
Skeletal musc functions enhanced: ↑metabolic capacity & nutrient blood supply, ↑strength & contractility
Tendon & connective tissue functions enhanced: ↑strength, supportive function, joint stability
Joint functions enhanced by exercise: lubrication, range of movement and maintenance of flexibility
Cardiovascular function & cardiac function
Aim of rehab is to increase patients general capacity for physical work via a programme of regular exercise
regular exercise incr heart health in two ways:
- ↓HR w/ improvement in aerobic fitness = energy req of heart less
- Systematic arterial BP ↓ = also ↓ heart muscle workload
Maximal myocardial performance is ↑ allowing more exercise to be taken than before
Active cardiac rehab = physiologically sound
Hazard of exercise for patients but benefits outweigh the risks
Pts should be encouraged to ↑intensity of exercise cautiously. Increments every 8-10 weeks
Exercise & T2D: Colberg et al 2010
PA is key element in T2D prevention & management but many with the disease do not become/remain physically active
Participation in reg PA improves blood glucose and can orevent/delay T2D
positively affects lipids, BP, CV events, mortality and QOL
Structured interventions combining PA and modest weight loss have been shown to ↓T2D risk by ~58% in high risk pops
Exercise & T2D: Colberg et al 2010
concl.
Exercise plays a major role in the prevention and control of insulin resistance, prediabetes, GDM, type 2 diabetes, and diabetes-related health complications.
Both aerobic and resistance training improve insulin action and can assist with the management of BG levels, lipids, BP, CV risk, mortality, and QOL, but exercise must be undertaken regularly to have continued benefits and likely include regular training of varying types.
Most persons with type 2 diabetes can perform exercise safely as long as certain precautions are taken. The inclusion of an exercise program or other means of increasing overall PA is critical for optimal health in individuals with type 2 diabetes
Exercise psychological beenfits:
BDNF
BDNF plays a significant role in neurogenesis. BDNF acts on certain neurons of the CNS & PNS, helping to support survival of existing neurons & encourage the growth and differentiation of new neurons and synapses.
active in the hippocampus, cortex & basal forebrain - areas vital to learning, memory and higher thinking. It is important in long-term memory.
Serum brain-derived neurotrophic factor levels before and after 8 weeks of training- (threefold) increase BDNF synthesis in the human brain, a phenomenon which is partly responsible for exercise-induced neurogenesis and improvements in cognitive function.
BDNF Rat study
• Exercise has an anti-depressive effect - Russel Neustadt et al., 2001
• Rats assigned to 4 groups :
- Engaged in ‘voluntary running’ on a wheel
- Given anti-depressants
- Both
- 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 provides “The Feel Good Factor”
- Distraction
- Relaxation/Stress
- Healthier Coping
Cross-sectional studies have consistently associated high self-reported levels of habitual physical activity with better mental health. The correlation of habitual exercise level with low depression in adolescents (Norris, Carroll, & Cochrane, 1992) is hard to interpret because control variables were omitted.
Using a similar, but large (N = 5,061) cohort, Steptoe and Butler (1996) showed that vigorous exercise participation was related to lower emotional distress, after controlling for social class and health status.
in 16,483 university undergraduates, reported exercise correlated with lower depression, after controlling for age and sex only. (Steptoe et al 1997)
Opioid Mechanisms in effects of exercise
• Opioids – associated with increased mood and decreased pain sensations endorphins etc. – exercise increase these and is considered to be linked to post exercise mood enhancement.
Stress also activates central (and peripheral) opioid systems and this accounts for some instances of the analgesia which is caused by stress. Spontaneous exercise shares these effects, increasing endogenous opioid activity in the peripheral and central nervous system (Harber & Sutton, 1984);
Opioid mechanisms have also been implicated in mood improvement by running in regular runners; the opioid antagonists, naloxone, attenuated this effect (Allen & Coen 1987)
Determinants of exercise adherence
Higher socio-economic status
Being male
Higher levels of enjoyment of PA
Greater belief in benefits of PA = “perceived benefits” - link to health belief mofel = more likely to take action
Reporting fewer barriers to PA
Higher levels of self-efficacy towards PA -overweight people likely to believe that they cannot do it. Low self-efficacy = feelings of hopelessness
Embarrassment = Obesity linked with low self-esteem – they have low self-efficacy but may also have experienced negative reaction to them exercising e.g people staring/laughing Classical conditioning?
Having had a physically active childhood – habits/routine – watching parents – social learning
Lower BMI = lower weight= physically easier
Barriers to PA
Internal triggers: hunger/cravings/emotions & unhelpful thoughts – creating justifications like “ive worked hard, ill have a break today”
External triggers: It is starting to rain outside so don’t leave house to exercise
No time/too tired - stressful job/commuters/chronic fatigue etc
expensive to join gym/buy gymwear
Transtheoretical Model: Exercise
STAGES OF CHANGE
• Precontemplation: Not currently taking regular physical activity and have no intention to change in the next 6 months
• Contemplation: Not currently taking regular physical activity but seriously intend to change in the next 6 months
• Preparation: Intention to start taking regular physical activity towards a criterion in the next month
• Action: Increases in physical activity have occurred over the last 6 months
• Maintenance: The period after the action stage until termination has been achieved
TM PROS
- Intuitively appealing model which is popular in practice
- Broad-based and has identified many useful processes involved in physical activity behaviour change
- Predicts change in physical activity behaviour
Application of TM to Exercise
TM has allowed researchers to identify and work with sedentary populations as an individual does not need to be an exerciser to fit the model
In helping somebody to modify a behaviour their SOC would be established and then the processes of change most applicable tot hat SOC would be uses to design an intervention - provides exercise consultant with an effective way of helping an individual to adopt a physically active lifestyle
Research has demonstrated that an integration of the stages and processes of change can provide a useful guide for physical activity interventions
Woods et al 2002
Scottish Youths
Applying TM to exercise
PA levels in young adults in Scotland were low, research supports use of TM in designing PA interventions
Study used pre-post randomised control design to investigate the effectiveness of a self-instructional intervention for helping sedentary young adults to initiate PA
Post-intervention, significantly more of experimental group (68%) improved their exercise SOC from baseline (P<0.05)
Stage improvers scored significantly higher on all of the behavioral and four out of five of the cognitive processes of change
This inexpensive, self-instructional intervention, based on the TM and the `active living message’, is an effective method of assisting sedentary young adults to progress through the exercise SOC.
Theory of planned Behaviour
Ahmad et al 2014
study found that – through the application of TPB – participation of subjects in doing exercise was mostly influenced by attitude among men and subjective norm among women
. “Not motivated to perform exercise” was a specific factor that affected attitude toward exercise in men; meanwhile, family and friends were the important supporters to engage exercise among women
An understanding of these motivational forces and barriers is invaluable in the planning and implementation of effective strategies and intervention programs to gain good compliance toward exercise among elderly individuals.
Our subjective norms are infuenced by our attitudes and perceived behavioural control, which leads to our intention e.g. norms in society, then our intention influences our behaviour.
TPB Pros
- Intentions sometimes predict physical activity behaviour
- Highlights social norms
- Perceived control (e.g. childcare) often the most important factor
- Allows comparison of different aspects of physical activity behaviour e.g. perceived control for walking versus structured exercise
- Develops our understanding of attitudes and physical behaviour
TPB cons
- Does not adequately address environmental influences (e.g. access to gym), social support, adoption versus maintenance of exercise behaviour.
- Intentions often do not predict behaviour
HBM Pros
- Allows comparison of different influences on physical activity behaviours
- Identifies barriers to physical activity (e.g. lack of time, lack of social support) as being the most important, and threat as being least important.
HBM Cons
- Threat does not predict physical activity behaviour
- Leaves out emotions, habit, social norms (e.g. friend starts exercising), and other motivations (e.g. appearance)
- Has intuitive appeal, but its application to physical activity has not been clearly demonstrated
- Does not define how to test relationships between different elements in the model
How is exercise promoted in the UK?
- QA framework for GP exercise referral schemes
- Health Action Zones
- Local Policy e.g. Primary Care Trusts
- National Campaigns - free swimming, LEAP, media
- Environment restructuring
Levels of intervention
Levels of intervention:
Individual: Allows tailoring, flexible scheduling, labour intensive
Group: Added group dynamics, ‘buddying’, less tailoring, less labour intensive
Organisational/community: (e.g. schools, corporate fitness, primary care): wide impact, existing infrastructures, lack of facilities and trained staff, often favours those who need it last
Societal: (e.g. mass media campaigns, transport policy, environment, PE currFiculum, insurance incentives: widest impace
