Midterm 1 Flashcards
What are the top 5 chronic diseases?
- Heart disease
- Cancer
- Cerebrovascular disease
- Respiratory disease
- Diabetes
What is the Frieden pyramid?
- Lists 5 factors influencing public health from strongest contribution to fewer
1. Socioeconomic factors (increasing population impact)
2. Changing the context to make individual’s default decisions health
3. Long-lasting protective interventions
4. Clinical interventions
5. Counseling and education (increasing individual effort needed)
What are the various levels of prophylaxis?
Primary prevention ⟶ intercept the onset of disease
Secondary prevention ⟶ minimize consequences of disease through early detection and intervention
Tertiary prevention ⟶ mitigating the consequences of disease or an injury after late diagnosis
What is the definition of health promotion?
Process of understanding individual, environmental, and policy factors that influence health behaviour
What is the definition of PA?
Any bodily movement produced by contraction of skeletal muscles that increases energy expenditure above a basal level (eg. standing)
What are the classifications of PA depending on type of activity?
- Household (eg. sweeping the floor, vacuuming)
- Occupational (eg. lifting, carpentry, moving boxes, shoveling)
- Transportation (eg. commuting from place A to place B)
- Leisure-time (eg. exercise, sports, recreational activities)
- Exercise: a type of leisure-time PA that is structured and planned; done specifically to enhance fitness
What are the classifications of PA depending on intensity?
- Light (eg. slow walk, stretching)
- Moderate (eg. fast walk)
- Vigorous (eg. stationary bike)
What is the definition of intensity and the unit used to measure it?
- The amount of effort you put in to doing a physical activity
- Use Metabolic Equivalent Level (METs)
What is a MET?
- Unit is used to estimate amount of oxygen used/consumed by body during PA
- 1 MET = energy (oxygen) used by body as you sit quietly = 3.5 mL oxygen consumption/kg/min = 1 kcal/kg/hr
How do you classify intensity levels using MET values?
- Light intensity = <3 METs
- Moderate intensity =3-6 METs
- Vigorous intensity = >6 METs
What is a calorie? How many calories does a 70 kg person walking at 4 MET level burn per hour?
- Measure of energy from food (3500 kcal of food energy = 1 lb of body weight) or amount of energy expended during PA
- 280 kcal per hour (ie. 70 kg x 4.0 METs)
How do you calculate the functional capacity of someone using their maximal oxygen uptake?
- Remember 1 MET = 3.5 mL oxygen consumption/kg/min
- If someone has maximal oxygen uptake of 35 ml/kg/min, they would have a functional capacity of 10 METs
- Activities involving 10 METs would be this person’s maximum, but not recommended
What is the definition of sedentary behaviour?
Any waking behaviour with <1.5 MET value in a sitting or reclining position
Can sedentary behaviour coexist with high PA? Discuss.
- Sedentary behaviour can coexist with high PA (ie. you like to sit a lot but you have bouts of high PA)
- Sitting has negative implications even with PA (all-cause mortality, CVD mortality, CVD itself, type 2 diabetes, cancer)
What types of PA are beneficial?
- Some PA is better than none; benefits increase as amount of PA increases (intensity, duration, or frequency)
- Substantial health benefits for adults with 140-300 minutes a week of MPA
- Both aerobic and muscle-strengthening PA are beneficial
- Even LPA; best if in bouts of at least 10 minutes rather than sporadic
What are the benefits of PA?
- Lowers risk of all-cause mortality, CVD, type 2 diabetes, cancers, obesity
- Improves cognition, quality of life, sleep, physical function
- LPA is inversely associated with mortality and can benefit insulin, fat mass, and WC
Why is it important to measure PA?
- Specify which aspects of PA (eg. cardio) are effective for particular health outcomes
- Determine prevalence of PA in population
- Monitor changes in PA over time
- Monitor effectiveness of interventions!
What are important things to consider when evaluating measures of PA?
- Validity
- Whether the measure actually assesses the construct you’re trying to measure
- Eg. pedometer may count brushing hair as actual steps - Reliability
- Consistency and stability of your measurements/results - Sensitivity to change
- Being non-reactive
- If you’re trying to see if intervention works, you don’t want the PA to be due to the act of wearing the measure - Being acceptable to respondent
- Acceptable cost of administration
What do pedometers measure?
Number of steps taken with horizontal, spring-suspended lever arm that is deflected when a subject’s hip accelerates vertically with a force beyond a chosen threshold
What are the benefits of pedometers?
- Best for documenting relative changes in PA or ranking individuals
- Motivates you to exercise
- Non-invasive, simple, low cost
- Can pick up short durations of PA
- Yield accurate data for running and walking (vertical motion)
What are the cons of pedometers?
- May be inaccurate for activities
- Can’t pick up all types of movements (horizontal motion)
- People may get obsessive
- Will not capture intensity
- Less data storage capacity than accelerometers
- Can induce reactivity
- Varying sensitivity between brands
What do accelerometers measure?
- Measures acceleration (how quick body changes speed)
- Single-axis ⟶ measure vertically
- Triaxial ⟶ measure anterior-posterior (forward/backward) + medial-lateral (side/side)
What is the unit used for accelerometers? What is the significance of the unit?
- Unit = “counts”
- Translated into a metric of interest that can be biological (eg. energy expenditure) or PA patterns (Eg. stationary)
- The higher the number of counts, the greater the intensity of activity
What are the benefits of accelerometers?
- Accurate
- Able to capture large amounts of data
- Easy
- Good for young children
- High validity
What are the cons of accelerometers?
- Expensive
- Require technical expertise
- Can induce reactivity
- Does not provide contextual information
- Cannot differentiate body position (eg. sitting, lying, standing)
What are the direct outputs from accelerometers?
- Volume Indicators
- Steps/day (accumulated or only for a specific time of day)
- Total activity counts/day - Rate Indicators
- Cadence (steps/min)
• Relates to intensity
• Time-stamping capability tells you the time of day you did the activity
- Activity counts/min
• Not meaningful without a reference frame
• Can be converted by researchers to classify exercise as light, moderate, or vigorous
What are the derived outputs from accelerometers?
Generated by later processing.
- Peak Effort Indicators
- Peak cadence (rate) ⟶ sum up your most active steps/min - Time Indicators
- Time-stamped step accumulation patterns ⟶ analyzing the steps taken for each minute over a period of time (eg. for a 30 minute walk, seeing for each minute, which category you fit in)
• You can see how many minutes you are walking in a each category of idensity (sedentary, low PA, LPA, MPA, VPA) rather than looking at steps you are taking per day or your most active steps/minute
- Time-stamped activity count accumulation patterns - Event Counts
- Looks at breaks/transitions in sedentary time
What factors influence your choice of motion detector?
- Attachment site (wrist, waist, thigh, ankle)
- Metric (output) choice
• Eg. if you’re interested in steps, you’ll choose a pedometer not an accelerometer because it picks up on PA other than walking - Epoch choice (time period)
• Eg. children engage in intense bursts of sporadic behaviour so it’s best to collect at fine-tuned epoch interval levels (eg. 30 seconds) - Monitoring frame (# and types of day)
• May want to include weekday and weekend collection to get an idea of overall PA - Reactivity
• May choose not display data ⟶ seal or cover device; familiarization so they’re less likely to pay attention to it
What are the pros and cons of PA and sedentary questionnaires?
- Easy to collect and analyze, low cost and participant burden
- Only for general information, not sufficient for informing strategies for interventions, possibility of recall bias
What does the International PA Questionnaire (IPAQ) assess?
Asks # of days in the past 7 days you did an activity + duration (hrs, mins) on a typical day
LONG VERSION:
- Work-related PA
- Transportation PA
- Domestic and gardening (yard) PA
- Leisure-time PA
- Time spent sitting
SHORT VERSION:
- Vigorous PA
- Moderate PA
- Walking
- Sitting on weekdays
What does the PA Recall Questionnaire assess?
- List of common activites and “others”
- Asks whether they did activity, # of days, and # of mins on a typical day they did activity
- Go on compendium of PAs for assigned MET values
- Calculate # of MET-mins/week for MVPA
- For MET-hours, just divide by 60
What does the Godin & Shephard Leisure-Time PA Questionnaire assess?
Indicate how many times/week you did exercise for 15 minutes:
- Strenuous
- Moderate
- Mild
Multiply with assigned MET for total weekly leisure activity (in “units”)
What does the Behavioural Risk Factor Surveillance System Questionnaire assess?
- By Center for Disease Control (CDC)
- Adults are interviewed on the phone
“Do you do MPA for at least 10 minutes at a time? How many days per week? How long do you do it?”
What does the Youth Risk Behaviour Surveillance System Survey (YRBSS) assess?
- By Center for Disease Control (CDC)
- Youth complete a self-administered survey
- Eg. “During the past week, on how many days were you physically active for a total of at least 60 minutes per day?”
What does the Sedentary Behaviour Questionnaire assess?
“On a typical WEEKDAY/WEEKEND, how much time do you spend (from when you wake up until you go to bed) doing [SEDENTARY ACTIVITY]?”
OR:
“Amount of time spent sitting or lying down on average in last 7 days in [SETTING; eg. meals]”
What does the Past-Day Adults Sedentary Time (PAST) questionnaire assess?
“Estimate total time yesterday you spent sitting down or lying down while ___”:
- Work
- Travel
- TV watching
- Computer
- Reading
- Hobbies
- Other purposes
What are some considerations to keep in mind when measuring sedentariness with accelerometers?
- May have error (eg. misclassifying active sitting as weight lifting)
- Should be worn longer than PA for accurate estimations of sedentariness
- When aggregating sedentary time, use a minimum bout length of at least 5 continuous minutes for PROLONGED SITTING; shorter bouts may mask interruptions of sedentariness
- Caution is needed when interpreting results about sedentary breaks in relation to health outcomes
What are the PA guidelines from the Public Health Agency of Canada?
- Children = 90 minutes of MVPA (60 min M; 30 min V)
- Youth = “
- Adults = 30 minutes of MPA, 4 days/week
- Older Adults = 30-60 minutes of MPA most days
What are the PA guidelines from the Canadian Society of Exercise Physiology for the early years?
- Infants (<1) should be physically active several times daily (particularly through interactive floor-based play)
- Toddlers (1-2) and preschoolers (3-4 years) should accumulate at least 180 minutes PA at any intensity spread throughout the day including:
• Variety of activities in different environments
• Activities that develop movement skills
• Progression toward at least 60 minutes of energetic play by 5 years of age
More daily PA provides greater health benefits
What are the PA guidelines from the Canadian Society of Exercise Physiology for children and youth?
Canadian 24-Hr Movement Guidelines for Children & Youth (5-17)
- Accumulate at least 60 minutes of MVPA daily
• VPA and muscle- and bone-strengthening PA incorporated at least 3 days/week - Several hours of a variety of structured and unstructured light PAs (eg. walking)
What are the PA guidelines from the Canadian Society of Exercise Physiology for adults?
18-64:
- Accumulate at least 150 minutes of MVPA (aerobic) per week, in bouts of 10 mins or more
- Beneficial to add muscle- and bone-strengthening PA using major muscle groups, at least 2 days/week
- More PA provides greater health benefits
What are the PA guidelines from the Canadian Society of Exercise Physiology for older adults?
65+:
- “
- Those with poor mobility should perform PAs to enhance balance and prevent falls
What are the sedentary guidelines from the Canadian Society of Exercise Physiology for the early years?
0-4:
- Minimize time spent being sedentary during waking hours
- Under 2 years = screen time is not recommended
- 2-4 years = screen time should be limited to under 1 hour per day
What are the sedentary guidelines from the Canadian Society of Exercise Physiology for children and youth?
Canadian 24-Hr Movement Guidelines for Children & Youth (5-17)
- 9-11 hours of sleep per night for 5-13 year olds and 8-10 hours for 14-17 year olds
- No more than 2 hours/day of recreational screen time; limited sitting for extended periods
What are the sedentary guidelines from the Canadian Society of Exercise Physiology for adults?
No Canadian guidelines for adults!
What do the Australia’s Sedentary Behaviour Guidelines for Adults say?
18-64:
- Minimize amount of time spent in prolonged sitting
- Break up long periods of sitting as often as possible
Why are sedentary guidelines so vague?
Vague because research is not at a stage where you can say “x” amount of sitting is bad!
What do the PA Guidelines for Americans (PAGA) say for preschool-aged children?
3-5:
- Should be physically active throughout the day
- Adult caregivers should encourage active play that includes variety of activity types
What do the PA Guidelines for Americans (PAGA) say for school-aged children and adolescents?
- 60 minutes or more of MVPA daily
- For aerobic PA, most of the mins either MPA/VPA
- Include VPA at least 3 days a week
- Muscle-strengthening PA at least 3 days a week
- Bone-strengthening PA at least 3 days a week
What do the PA Guidelines for Americans (PAGA) say for adults?
- Should move more and sit less throughout the day
Substantial benefits:
- At least 150-300 minutes a week of MPA
- Or 75-150 minutes a week of VPA
- Or equivalent combination of MPA and VPA
- 1 min VPA = 2 min MPA
- Preferably, aerobic PA should be spread throughout the week
Additional benefits:
- PA beyond equivalent of 300 minutes a week of MPA
- Muscle-strengthening PA that is moderate or greater intensity on 2 or more days a week
No guidelines for flexibility
- Research on health benefits are unknown
What do the PA Guidelines for Americans (PAGA) say for older adults?
- Same as adults
Additional guidelines:
- Do multi-component PA (eg. balance training; aerobic and muscle-strengthening PA)
- Consider fitness level and whether chronic conditions affect safety
- Be as physically active as abilities and conditions allow
How do the PAGA guidelines compare to Canada?
- If you don’t have time, you can cut your PA in half by increasing intensity
- More recent (2018 compared to 2012); current research suggests that every minute counts
• American guidelines have no minimum bout time - Someone who may meet American guidelines may fall short using Canadian guidelines
• “The % of population that are sufficiently active” depends on guidelines used