MODULE ONE: Introduction to Physical Activity and Health
Exercise physiology: the study of how the body structures and functions are altered by acute bouts of exercise or physical activity, how the body adapts to the chronic stress of physical training, and how it maintains homeostasis
Key Points:
• Physical Activity is the merging of two fields o Kinesiology and Epidemiology
• Exercise physiology – study of how the body responds to physical activity
• Epidemiology – study of the distribution of causes of health and disease Key points:
• The study of PA and health began in earnest in mid 20th Century
• Several seminal studies – London Bus Drivers, US Postal Workers, Longhsoreman
• Unequivocal evidence that PA is good for health Key Points:
• Guidelines are used to promote and monitor physical activity levels
• Current guidelines reflect the minimum dose of PA to improve health
• Adults should accumulate 150-300 min (1 ½ to 5 hours) of mode intensity PA or 75- 150 min (1 ¼ to 2 ½ hours) of vigorous intensity PA, or an equivalent combination of both moderate and vigorous activities, each week
• What is ‘physical activity’: bodily movement that is produced by the contraction of skeletal muscle and that substantially increases energy expenditure
MODULE TWO: Health Benefits of Physical Activity
Key Points:• There have been no clinical trials of the association between physical activity/fitness and mortality
• BUT findings from observational studies CONSISTENTLY show an association between PA/fitness and mortality
• AND PA/fitness has shown to be associated with intermediate health outcomes including blood pressure, lipids, glucose, etc
• 1000kcal/week of mod-to-vig PA results in 20-30% reduction in mortality (Lee &
Skerrett, 2001).
Definitions:
• Cardiovascular Disease: a group of diseases of the heart and surrounding blood vessel’s
o Coronary Heart Disease (CHD) – heart attack/heart failure o Stroke
o Hypertension
o Also, rheumatic fever, congenital heart defects, congestive heart failure, peripheral vascular disease
Key Points
• 24% reduction in risk of colon cancer
• 20% reduction in risk of breast cancer
• Possible reduction in risks for lung and endometrial cancer
• Biologically plausible pathways proposed but not confirmed
• More than 30 min and up to 60 min of MVPA may be required a day Key Points
• PA has a role to pay in primary, secondary and tertiary prevention of diabetes
• Randomized controlled trails provide the best level of evidence Definitions:
• Obesity – a condition of excessive fat accumulation to the extent that health is impaired
• Body Mass Index (BMI) – a simple index of weight for height (kg/m2) o Normal range – 18.5-24.9
o Overweight - > 25 o Obese - > 30
• Waist circumference – a measurement of abdominal circumference used to characterize levels of abdominal obesity
Key Points
• The current obesity epidemic seems to be due in large part to changes in incidental physical activity
• Some evidence that PA is associated with the prevention of weight gain
• Little evidence that PA is an effective strategy for weight loss but once weight loss has been achieved PA seems crucial for promoting weight loss maintenance
• For prevention of weight gain, and weight loss more than 150 minutes of PA is required
Key Points:
• Physical activity can prevent and treat depression
• Physical activity may play a role in preventing and treating anxiety
• Physiological and cognitive explanations have been used to explain improvements in mental health resulting from PA however exact mechanisms remain unknown
MODULE THREE: Risks and Injury Associated with Physical Activity
Key Points:
• Injuries are an unfortunate ‘side effect’ of PA
• Research into PA related injuries is limited by a) difficulties in defining injury and b) an unknown denominator
• Both activity type and dose are important determinants or injury
Key Points:
• Sudden cardiac arrest is a serious consequence of participation in physical activity
• Risk is higher when participating in vigorous physical activity and in those who have low levels of habitual physical activity
• Risks can be reduced by encouraging participation in moderate intensity physical activity and following standard principles of exercise training
MODULE FOUR: Understanding Physical Activity
Key Points:• Correlates are factors that directly or indirectly influence or associated with a particular behaviour or set of behaviours (e.g. PA)
• Knowledge of correlates is important for understanding why some people are active/inactive and for informing intervention design
• Theories are interrelated constructs that explain & predict a behaviour and are important in PA intervention design
Key Points:
• Intra-personal (individual) theories explain health behaviour & health behaviour change by focusing on individual factors
• Intra-personal models: TRA/TPB, TTM
MODULE FIVE: Introduction to Promoting Physical Activity
Key Points:• Approaches to physical activity can be informational, behavioural, social, environmental or policy focused
• Recognising that physical activity is a complex behaviour with multiple levels of influence, the best interventions will use a combination of approaches
MODULE SIX: Physical Activity in Underserved Groups
Key points• Socioeconomically disadvantaged groups are risk of lifestyle-related diseases
• Disadvantaged groups more likely to be physically inactive than more advantaged groups
• Such groups face many barriers to PA (complex)
• Hard-to-reach group…but equally important!
Key points
• Indigenous Australians have poorer health outcomes than non-indigenous = PA important modifiable behaviour.
• The prevalence and trends of indigenous PA tends to vary by age and geographical locale.
• The influences of indigenous PA participation may be multifactorial –important to acknowledge Australia’s history of ‘colonisation’.
MODULE SEVEN: Measuring Physical Activity
Why do we want to measure PA?• Monitor trends in PA in populations
• Determine relationships between PA and health (including 'dose' of PA for specific outcomes)
• Document the prevalence and distribution of PA in defined population groups
• Identify biological, psychosocial, and environmental factors that influence PA
• Evaluate the efficacy of programs to increase PA in defined groups or entire populations
Summary
• Physical activity is a complex behaviour
• Self-report vs objective measures
• Consider the desirable attributes of instruments
MODULE 8: Sedentary Behaviour and Inactivity Physiology
Sedentary behaviour defined as:Behaviours that require minimal amount of energy to perform (approx. 1-1.5 METs):
• Television viewing
• Computer use
• Electronic games use
• Sitting: reading, talking on phone, socialising, car/transport, relaxing/resting, listening to music
Key points
• Physical activity & Health @ Deakin
• Sedentary behaviour is NOT equivalent to physical inactivity
• Increasing trends in sedentary behaviour (both children and adults)
• The Physical activity guidelines now include a set of sedentary behaviour guidelines
MODULE NINE: Physical Activity in Older Adults
What happens when we age?
• Reduced muscle mass
• Reduced coordination & balance
• Reduced joint flexibility & mobility
• Reduced cardiovascular & respiratory function
• Reduced bone strength
• Increase body fat levels
• Increased susceptibility to mood disorders
• Reduced cognitive functioning
• Increased risk of disease
Key Points
• Aging population
• Burden on healthcare system
• Successful again = more than absence of disease
• Most older adults have ≥ chronic health condition
Benefits of PA in Older Adults
• Reduced risk of
o CVD, certain cancers, type 2 diabetes, anxiety & depression, overweight &
obesity
• Age specific benefits o Improved QOL
o Improvements in mental health (anxiety and depression) o Improved cognitive function
o Reduced risk of falling
o Improved ability to perform ADL (physical functioning) o Improved or maintained bone mineral density
Key Points
• PA is linked to improved physical health in older adults
• It is particularly important for improving QOL, cognitive functioning and reducing risk of falls
