NUTR1023 Lecture Notes - Lecture 2: The Strongest, Bone Density, Cardiovascular Disease
NUTR1023 Health and Fitness Through Diet and Exercise
Summer Semester 2017
Module 2 – Physical Activity and Health (PART 2)
Cohort studies are common which look at the relationship between physical
activity and mortality from all causes. These studies usually follow a large group
of the population over time to measure change, by identifying and contrasting
the most and least physically active subjects. Usually, a 30% reduction of risk is
seen with physically active people. Limitations include no control over other risk
factors (as there may also be other causes or preventatives of early death).
Therefore, results from these studies are associative, not causative.
1. Watch the video Physical Activity and Cardiovascular Disease and then read pages
14-16 of the Physical Activity Guidelines Evidence Report before completing the
following activities:
• What types of studies are mostly used as evidence for the benefit of physical
activity in reducing the risk of cardiovascular disease? Describe the strengths
and limitations of these types of studies.
Randomised controlled trials.
• List the biological mechanisms through which physical activity is likely to
cause a reduction in the risk of cardiovascular disease.
Physical activity positively affects arteries, heart, clinical outcomes, metabolic,
neural pathways, hemodynamic and cardiovascular risk factors (by reducing
blood pressure, LDLs and triglycerides).
• Explain how the risk of cardiovascular disease changes with increasing
amounts of physical activity.
Risk factors include low HDLs, high LDLs, high triglycerides and high blood
pressure. Exercise has several physiological and metabolic positive effects to
lower risk of developing cardiovascular disease (20-30% reduction).
2. Watch the video Physical Activity and Diabetes and then read pages 17-20 of the
Physical Activity Guidelines Evidence Report and the Diabetes Prevention study by
Knowler et al (2002) before completing the following activities:
• What types of studies show a benefit of physical activity in reducing the risk
of developing type 2 diabetes? Comment on the strength of this evidence.
Large cohort studies show good evidence that physical activity reduces the risk of
type 2 diabetes. Randomised control trials also show good evidence.
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• How much is the risk of diabetes reduced by regular physical activity? Is there
a dose-response relationship between physical activity and a reduced risk of
developing type 2 diabetes?
There was a study conducted that compared risk factor patients with either a
placebo, a drug or life style change against cumulative incidence of diabetes
across time. Doing physical exercise and eating better reduced incidence by up to
58% compared with placebo.
• Describe the effects of physical activity in the primary, secondary and tertiary
prevention of diabetes. Which do you think is most important?
Primary: evidence from reviews of studies of healthy populations based on
samples.
Secondary: Randomised controlled trials of physical activity in people with
elevated blood glucose who are at a risk of developing diabetes.
Tertiary: Management of people with cancer.
The most important is probably the primary; preventing the disease before onset.
• Can resistance training be an effective type of exercise for people with type 2
diabetes?
Resistance training includes progressive muscle strengthening activities and
benefits bone mineral density. It helps prevent falls, CVD and diabetes risk factors
(additive effects in reducing vascular risk).
• The Diabetes Prevention study by Knowler et al (2002) is considered to be a
seminal paper in nutrition and exercise science. Explain why this study might
be considered to be so influencial.
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• Describe the lifestyle modification program used in the Diabetes Prevention
study by Knowler et al (2002).
The aim was to achieve and maintain a weight reduction of 7% initial body
weight through a healthy low-calorie, low fat diet and engage in physical activity
of moderate intensity for at least 150 minutes per week.
• Do you think it would be feasible and practical to implement a lifestyle
program similar to the one used in the Diabetes Prevention study by Knowler
et al (2002) here in Australia? Explain your answer.
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find more resources at oneclass.com
Document Summary
Nutr1023 health and fitness through diet and exercise. Module 2 physical activity and health (part 2) Cohort studies are common which look at the relationship between physical activity and mortality from all causes. These studies usually follow a large group of the population over time to measure change, by identifying and contrasting the most and least physically active subjects. Usually, a 30% reduction of risk is seen with physically active people. Limitations include no control over other risk factors (as there may also be other causes or preventatives of early death). Therefore, results from these studies are associative, not causative: watch the video (cid:858)physical activity and cardiovascular disease(cid:859) and then read pages. Describe the strengths and limitations of these types of studies. Randomised controlled trials: list the biological mechanisms through which physical activity is likely to cause a reduction in the risk of cardiovascular disease.
