W9 - Field based markers of health and fitness

Question 1

What is pre-intervention screening used for?

Answer 1

• Risk factors for consideration ahead of exercise testing and / or a physical activity intervention.
  
  • measures are also commonly used as outcome measures in health promotion research.
  • e.g.: family history of; diabetes, heart disease, weight status

Question 2

what are some types of anthropometry?

Answer 2

• Height
• Weight
• BMI (kg/m2) – well established that those with a BMI ≥30 kg/m2 have excess body fat (with some exceptions)
• Waist to height ratio

Question 3

What are some findings from BMI cut-points?

Answer 3

Categorise people into different groups based on BMI and weight status
- Asians tend to store more body fat at lower BMI than those of white ethnicity
- Only an estimate of body composition
- Doesn’t account for fat free mass
- Older adults lose their fat free mass (may have large amounts of body fat)

Question 4

Describe the various ways anthropometry can be used to categorise health in individuals from circumferences?

Answer 4

• Circumferences (useful to quantify body fat distribution)
  
  • Waist - provides a better measure of visceral adiposity than BMI
  • Hips
  • Waist-to-hip ratio (WHR) - useful in identifying individuals with higher amounts of abdominal fat
  • Waist-to-height ratio – waist size should be less than half height
    Android obesity (more fat on the trunk) increases risk of hypertension, metabolic syndrome, type 2 diabetes, dyslipidaemia, CVD, and premature death compared to when fat is distributed in the hips and thighs (ACSM’s Guidelines for Exercise Testing and Prescription)

Question 5

What is:

* Hydrodensitometry
* Plethysmography 
* Dual energy X-ray absorptiometry (DEXA)

Answer 5

• underwater weighing, separates a person’s fat(less dense) from fat free mass(more dense)
• air displacement
• scan someone, to see their adipose tissue (allows for fat mass estimations)

Question 6

Describe skinfold measurements:

Answer 6

• Estimates body fat percentage by determining the thickness of several folds of skin at different sites Body fat percentage determined from skinfold thickness measurements correlates well (r = 0.70–0.90) with hydrodensitometry (ACSM’s Guidelines for Exercise Testing and Prescription)
  
  • Person taking measurement needs to be highly trained

Question 7

What is Bioelectrical impedance analysis?

Answer 7

• Based on the estimation of total body water, determined by passing a small electrical current through the body and measuring the resistance to the electrical charge.
  
  • Fat-free mass is more hydrated than fat mass and bone so there is less resistance to electrical flow in a leaner individual.
  • Vasold et al. (2019) reported acceptable reliability (r = 0.92-0.99) and validity (r = 0.89-0.94) of commercially available BIA monitors relative to air displacement plethysmography

Question 8

Explain:

* Systolic pressure: 
* Diastolic pressure: 
* Pulse: 
* Pulse pressure:

Answer 8

• peak arterial pressure during ventricular systole
• minimum arterial pressure during diastole
• rhythmic pressure oscillation accompanying each heart beat
• difference between systolic pressure and diastolic pressure
  Pulse pressure lessens as the distance from the heart increases

Question 9

How is a blood pressure measurement taken?

Answer 9

• Individuals should sit quietly for at least 5 mins in a chair with back support, with feet on the floor and arms supported at heart level
• Smoking, exercise and caffeine should be avoided for at least 30 mins prior to the measurement
• An appropriately fitting cuff should be firmly wrapped around the upper arm at heart level, aligned with the brachial artery
• At least 2 measurements should be made (min 1 min apart), and the average calculated
  
  • Individual taking the measurement needs to be trained
  • Sounds listening for are faint, so decreases the accuracy of the measurement

Question 10

How can LDL and cholesterol impact a person’s chance of CVD?

Answer 10

Lipids and Lipoproteins Grundy et al. (2004):
* Low-density lipoprotein cholesterol (LDL-C) is a key risk factor for CVD
* High-density lipoprotein cholesterol (HDL-C) is strongly and inversely associated with CVD risk
* Non-fasting triglyceride levels have a stronger relationship with CVD risk than fasting levels
* HDL-C tends to attenuate the relationship between fasting triglyceride levels and CVD risk
* Issue of transporting the blood sample in a field-based measurement

Question 11

Why do we measure Glucose and glycated haemoglobin (HbA1c):

Answer 11

Glucose and glycated haemoglobin (HbA1c):
* Diabetes mellitus is a group of metabolic diseases characterized by elevated blood glucose levels, resulting from defects in insulin secretion (type 1) and/or an inability to use insulin (type 2)
* Sustained elevated blood glucose levels place individuals at risk of microvascular and macrovascular damage, leading to numerous health risks/complications
* Glycated haemoglobin (HbA1C) is a blood chemistry test that reflects mean blood glucose control over the past 2–3 months

Question 12

How is lung function assessed?

Answer 12

Lung function:
* Assessed using spirometry
* Most common measures: forced vital capacity (FVC), forced expiratory volume in one second (FEV1.0), FEV1.0/FVC ratio, and peak expiratory flow (PEF)
* Can help identify the presence of restrictive or obstructive respiratory abnormalities

Assessing Risk
- QRISK algorithm tells the estimated risk of e.g.: that person having a heart attack in the next 10 yrs

Question 13

What are the 3 field based markers of fitness?

Explain each

Answer 13

Multi-stage 20-m shuttle run test (Beep Test):
* Cardiorespiratory fitness is considered one of the most powerful markers of health
* Multi-stage shuttle run test (beep test) is a standardised field test of aerobic fitness (Léger et al., 1984)
* Highly correlated with maximal exercise performance (Mayorga-Vega et al., 2015)

The 6-min Walk Test (6MWT):
* Gained importance in the assessment of functional exercise capacity in patients with chronic respiratory disease, heart failure, and other groups.
* Correlates well with important health outcomes, including mortality (Casanova et al. 2011)

Grip strength:
* Reduced muscular strength, as measured by grip strength, is associated with an increased risk of CVD, and all-cause and cardiovascular mortality (Leong et al 2015)
* Grip strength was a stronger predictor of all-cause and CVD mortality than systolic BP (n = 139,691)
* People with lower grip strength have higher risk of cancer, CVD