Exam #1 Flashcards
Why study PA?
1) humans were meant to be physically active
2) our society no longer supports our “need” for PA
3) leading causes of death/disease are influenced by our PA levels
Physical inactivity is the ___ leading cause of death in the world (2004)
4th
Term created to refer to the shift in the nature of the relationship between PA and survival
physical activity transition
Why study PA’s relationship with health and wellness?
more than just physical health is impacted by PA
definition of physical activity
any bodily movement produced by skeletal muscles that results in an increase in metabolic rate over resting energy expenditure
name 3 different types of physical activity
1) leisure time PA
2) transportation
3) work
physical fitness
an individual having the necessary skills to perform a given task
performance related fitness
athletic ability (endurance, speed, cardiorespiratory power, etc)
health related fitness
ability to perform daily activities with vigor
early conceptualizations of health
- was the idea of homeostasis
- holistic health
- we need a balance
early western cultures conceptualization of health
- biomedical model
- focused on physical health
- in the 1900’s they added mental health in the equation
- focus on the illness rather than the health
what did the world health organization state about health
that it is not merely the absence of disease
Wellness
holistic concept describing a state of positive health in the individual comprising physical, social and psychological well-being
doubly-labeled water
subjects consume water containing stable isotopes throughout the day, isotopes are secreted in urination, the rate of secretion is proportionate to the degree of metabolic CO2 production. Oxygen uptake and EE can be calculated from the difference in isotope rates
what are the pros of doubly-labeled water
- safe
- non-invasive
- doesn’t require people to wear monitors
- free from info bias
- can be used in children and pregnant women
what are the cons of doubly labeled water
- expensive
- requires respondents to be willing to collect urine
- cannot be used to differentiate intensity
- duration
- frequency of specific activities
indirect calorimetry
participants wear a mask, carry the equipment needed to analyzing expired air to measure VO2
what are the cons in indirect calorimetry
- wearing the mask is likely to affect the PA of the carrier (Hawthorne effect)
- method is cumbersome and expensive
- not appropriate for epidemiological studies
pros of heart rate monitors
- Work well in epidemiological studies
- A strong linear association exists between heart rate and VO2 at high rates of EE
cons of heart rate monitors
- Heart rate is less precise for measuring EE at low intensities
- Emotional stress, body temperature, and medication can all influence heart rate and throw off results
name 2 types of motion sensors
- pedometer
- accelerometer
pedometer cons
- Length of steps vary and different brands detect steps differently
- Daily life often involves more than just walking on a flat surface
accelerometer cons
- Many activities involve isometric muscle contraction or muscular work against some external force (weight lifting, carrying, pushing, or activities such as skating or rowing) are not detected well via accelerometers.
- Physical activity is therefore likely to be underestimated if an individual performs the above mentioned activities often.
resting metabolic rate
estimate of how many calories you would burn if you were to do nothing but rest for 24 hours, represents the amount of energy needed to keep your body functioning, including breathing and keeping your heart beating
total energy expenditure
result of posture, spontaneous and voluntary PA, resting metabolic rate, Thermic effect of feeding (EE needed for digestion, absorption, and the increase in sympathetic nervous system activity after eating a meal)
-RMR is fairly consistent within and between individuals (varies ___ to ___% in adulthood)
5-10
power consumption per unit of time
intensity
cardio-respiratory fitness
The ability of the cardiovascular and respiratory systems to supply oxygen to working muscles
watching and recording a person’s activities
behavioural observation
PA records
participants record activities and time spent doing them
what are the cons to PA records
- prone to bias
- not the method of choice for epidemiological studies, but useful for validation purposes
PA logs
provide participants with a list of specific activities to choose from when recording PA
pros of PA logs
Facilitates journal keeping for participant and aids with data processing for researcher, helps someone remember something that they did that they may not have remembered otherwise
cons of PA logs
-Lists can never be complete – low-intensity activities (household chores and spontaneous activity) tend to be underrepresented in logs
Prone to bias (can influence activity patterns)
epidemiology
the use of the scientific method to study the distribution of disease in a population , to identify risk factors that likely cause the disease, and then to change the risk factors in order to reduce sickness and death from the disease.
PA epidemiology
Studies how participation in physical activity relate to the probability of disease and injury
what are we after in epidemiological research?
The degree of change in physical activity or inactivity (independent variable) that causes some health outcome (dependent variable)
Cross-sectional survey
Measure both risk factors and the presence or absence of a health outcomes at the same time
cons of cross-sectional surveys
- Third variable problem: when two variables are related because of their common connection to another, they are often related to another variable that we are not measuring : third variable
- So, just because two things are related does not mean that one causes the other!
pros cross-sectional surveys
- quick and easy
- good for hypothesis testing
case-control studies
-People (cases) with a disease are chosen
-These people are matched with a control who is similar but doesn’t have the disease
-Attain information on history of exposure to a risk factor: why did one get cancer and the other not?
•Compare the proportion of the cases exposed to the risk factor (RF) to the proportion of control exposed to the RF.
•Retrospective study: starting at the point where the person already has the disease and going back from there
prospective cohort study
Randomly select a group of people from a defined population and assess baseline information
Asks: What impact does risk factor status have on the incidence of disease?
Calculate the difference in risk between those exposed to the RF to those not to if exposure increases risk; attributable risk
Follow those people over time and incidence of disease or health outcome is tracked
randomized clinical trial
- Random assignment of people into at least two groups
- one group is exposed to a treatment and the other group is not exposed to the treatment
- Compare the intervention to the control group on the outcome to determine if they differ.
- determines cause and effect relationships
How much PA reduces mortality risk?
PA has a dose response relationship with all-cause mortality risk
“Some is good; more is better”
What is the minimal amount of PA necessary to reduce mortality risk?
15 mins. per day (90 mins. per week) moderate PA = reduced risk of all-cause and cancer-caused mortality
Adds 3 years to one’s life
Over the short term, PA is associated with ________ weight loss
a) significant
b) moderate
c) not associated
b) moderate
1 pound of body fat is equal to how many kcals?
3500 kcals
A 75 kg person needs to walk __ miles in order to lose 1 pound of fat
35
People who do high amounts of PA tend not to lose as much weight as expected because of _______________.
compensatory eating
List and explain 3 of the 5 reasons that accumulating evidence points to a causal relationship between PA and reduced mortality even though we do not have evidence from RCT’s
- Temporal sequence (Pa precedes mortality event)
- Strength of association –consistent moderate association
- Consistency of Support –findings confirmed time and again
- Biologically plausible -many biological mechanisms suggest PA should reduce mortality risk
- Dose-response –also indicative of causation
primary prevention
prevent the disease from happening
secondary prevention
once they have the disease, can PA lessen the severity
PA significantly after a cardiac event reduces risk of death by approx. ___-___%
25-30
PA = ___-___% reduction in risk of type 2 diabetes
15-25
What is the thermogenic hypothesis of why exercise can alleviate anxiety?
when your body heats up while doing exercise, your body naturally relax
explain the effects of PA on obesity
PA decreases the risk of mortality when it comes to obesity but it does not eliminate the effects of being obese
Meta-meta analysis
quantitative statistical analysis of several separate but similar experiments or studies in order to test the pooled data for statistical significance
anxiety
Pathological counterpart of normal fear, manifest by disturbances in mood, as well as thinking, behaviour, and physiological activity
what are the symptoms of anxiety?
1) Unpleasant feelings (ie: feeling of panic in ordinary situations, uncertainty over what to do, feeling overwhelmed)
2) Bodily Symptoms (ie: persistent feelings of tension)
3) Changes in cognitions (ie: difficulty concentrating)
4) Changes in behaviour (ie: difficulty sleeping)
Physical Activity and Anxiety in nonclinical populations, what do the results tell us?
the more the people were active, the less anxiety they felt
what kind of PA typically helps reduce anxiety?
aerobic, the mode does not matter, as long as it is aerobic
are there any types of PA that can increase anxiety?
Resistance training can increase anxiety at a high intensity but low or moderate is okay
what are the benefits of treating anxiety with PA as opposed to other treatments like meditation, quiet rest or pharmaceuticals?
these treatments all decrease anxiety levels but PA has so many more benefits than just the decrease of anxiety
distraction/ time out hypothesis
rhythmic movement, having a distraction, thinking of other things
non-clinical depression
Episodes of unhappiness that affect most people from time to time, to persistent low mood and inability to find enjoyment
symptoms of depression
Difficulty Concentrating Loss of Interest in all or Most Activities Lack of Energy Feelings of Guilt/Worthlessness Sustained Feelings of Sadness Thoughts of Suicide
endorphin hypothesis of reducing depression
the body produces endorphins which is the body’s natural pain killers
Mastery hypothesis for reducing depression
physiological effects from PA are correlated with a better sense of self worth (you feel good after doing PA, you accomplished something
affect regulation hypothesis
PA serves to increase positive feelings or reduce negative feelings
social interaction hypothesis for reducing depression
PA provides an opertunity to interact with other people, possibly leading to better moods
what is the difference between treating depression vs anxiety with PA
it seems as tho all types of PA may help reduce symptoms of depression as opposed to treating anxiety, only aerobic PA seems to help
Hot off the press- Zhu et al (prospective cohort study)
study on PA and cognitive function, finds that moderate/ vigorous activity has a dose-response relationship with memory and cognitive function, findings were stronger in white vs black people
