Week 11 - Physical activity and Health

Question 1

List some health outcomes of physical activity participation.

Answer 1

• Lower rates of all-cause mortality
• Decreased risk of CVD
• Improved weight management
• Improved cardiometabolic health
• A lower ris of major forms of cancer
• Decreased fall risk
• Improved brain and bone health

Question 2

What is exercise capacity a powerful predictor of?

Answer 2

mortality

1MET = 12% increase in survival

Question 3

What is the relationship between leisure time physical activity (MET-hours/week) and risk of mortality?

Answer 3

as leisure time physical activity increases the risk of mortality decreases
- Largest decrease seen with initial increase in MET-hrs/week
- No lower threshold for benefit

Question 4

What are the key recommendations for the amount of moderate intensity and vigorous intensity physical activity that adults should participate in?

Answer 4

• Move more, sit less each day
• 150-300mins of moderate-intensity PA
• 75-150mins of vigorous-intensity PA
• Moderate-to-high intensity strength activity performed 2times/week or more (focus on all major muscle groups)

Question 5

Physical health guidelines for children and young adults (5-18yrs)

Answer 5

• at least 60mins everyday
• muscle and bone strengthening activites 3x per week

Question 6

A dose-response relationship exists for most health outcomes. What does the “dose-response relationship” refer to?

Answer 6

more physical activity is generally better, leading to greater health outcomes

Question 7

What are the 5 key components to understand the dose-response relationship (dose (PA) needed to deliver the desired health effect/response)?

Answer 7

1) Potency
2) Slope: how much change in effect comes from a change in dose
3) Maximal effect
4) Variability: effect varies between and within individuals
5) Side effect

Question 8

Explain how exercise adheres to the FITT principle.

Answer 8

Frequency: days per week or day

Intensity: %V02max, %maxHR, RPE, lactate threshold

Time: number of minutes of exercise

Type: resistance, CV endurance, swimming, running, rowing

Question 9

What does the VP stand for in FITT-VP?

Answer 9

Volume: frequency x time
Progression: transition from easier to harder exercise to gain further improvements and greater benefits

Question 10

Different response outcomes to physical activity.

Answer 10

Acute response: occur with one or several exercise bouts but do not improve further

Rapid responses: benefits occur early and plataeu

Linear: gains are made continuously over time

Delayed: occur only after weeks of training

Question 11

There is no lower threshold for health outcome benefits. What does this mean?

Answer 11

achieving as much activity as possible will still improve health, even if the 150min weekly goal is not met

Question 12

Physical workloads (intensities) can be assigned in METs. How many METs is:
a) low-intensity PA
b) moderate-intensity PA
c) vigorous-intensity PA

Answer 12

a) 1.1-2.9
b) 3-5.9
c) >6

Question 13

How can physical activity volume and intensity goals be achieved?

Answer 13

through the accumulation of MET-minutes

e.g. 5METs x 30mins per day x 4 days per week

Question 14

What is the recommended minimum amount of MET-minutes associated with improved health?

Answer 14

500 weekly MET-minutes but dose-dependent health benefits accrue up to weekly 100MET-minutes

Question 15

Describe HIIT and its application to clinical populations.

Answer 15

Repeated cycles of short duration high intensity exercise interspersed with recovery periods (3-10)
- Its a time-efficient means of improving Cardiorespiratory fitness
- Caution recommended for those with disease or accumulation of CVD risk factors
- Greater effectiveness for “low responders”

Question 16

What are the potential advantages that HIIT has for health outcomes compared to MICT?

Answer 16

• Increased V02peak
• Decreases systolic and diastolic bp
• Decrease high density lipoproteins
• Decreases oxidative stress and inflammation
• Increased adiponectin, insulin sensitivity and b-cell function
• Increased maximal rate of calcium uptake
• Increased cardiac function

Question 17

How can low-intensity physical activity (LPA) be quantified?

Answer 17

step counts which can be monitored with pedometers and modern wearables, including smart watches

5,000 = sedentary
10,000+ = highly active

Question 18

Is there a risk of cardiac arrest in vigorous activity?

Answer 18

Cardiac event risk if acutely elevated during exercise but overall (exercise + rest) cardiac event risk is lower as compared to sednetary.

Low risk for acute adverse CV events with HIIT.

Question 19

a) What is the relationship between risk of death and V02max.
b) When does death risk decrease the most?

Answer 19

a) death risk inverse to V02max
b) death risk decreases most when the least fit becomes active

Question 20

Describe exercise prescription guidelines for cardiorespiratory fitness, referencing FITT.

Answer 20

Frequency - 3-5 sessions per week (5 for MIE and 3 for VIE)

Intensity - 40% to 89% HR range/V02max (MIE: 40-59%, VIE: 60-89%)

Time: 20-60mins per session

Type: dynamic, large muscle activities such as running, swimming, cycling, rowing, dancing