Associate Professor Andrew Maiorana Accredited Exercise Physiologist Fiona Stanley Hospital & Curtin University.

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1 Associate Professor Andrew Maiorana Accredited Exercise Physiologist Fiona Stanley Hospital & Curtin University

2 Overview Background Group work: Exercise and obesity challenges Report back to share solution

3 Popular misconceptions Obese people are lazy )f you exercise enough you ll lose weight Better health equates to weight loss Specialised exercise equipment can guarantee weight loss

4 Exercise devices have evolved s 1970s 2000s

5 Adults are also losing the battle...

6 What is the next step in our evolution?

7 Causal factors Caloric intake > caloric expenditure Complex interaction of behavioural, lifestyle, cultural, social, genetic and medical factors Modern society = abundant food + physical inactivity Long standing positive energy balance

8 Modern conveniences Sedentary lifestyle - motorised transport - labour saving devices - passive entertainment (television, computer devices) - ready access to abundant food sources

9 Definition of obesity underweight normal weight overweight obese BMI < to to

10 Metabolic syndrome Elevated blood pressure (>130/80 mmhg) Central obesity (waist circumference > 102 cm) Dyslipedimia (high LDL and low HDL) Insulin resistance (high fasting blood glucose) Prevalence Normal (5%) Overweight (20%, 4 times the risk) Obese (60%, 12 times the risk) Associated with type II diabetes, cardiovascular disease and premature mortality Katzmarzyk et al, 2005

11 How can the problem be addressed? Prevention is better than cure Generally recommend an energy deficit (negative balance) of 500 to 1000 kcal/d 500 kcal 7 days/wk = 3500 kcal/wk ~ 0.5 kg of weight loss Done through reduced intake and increased expenditure ACSM s resource manual, 6 th ed

12 Exercise programs Energy requirements for exercise depend on intensity, body mass and duration: kkcal = METS x 3.5 x body mass (kg) * t (min) 200 ACSM s resource manual, 7 th ed

13 Wo king off a Ma s a How long does a 70 kg man need to walk at 5 km/hr to work off at Mars bar? 1 Mars Bar = 500 kcal

14 Do the calculations... Calculate VO 2 requirement (METS) for walking: VO 2 of walking on flat ground: 3.5 ml/min/kg speed* * Speed in meters per min: 5.0 km/h = 83.3 m/min VO 2 = = 11.8 ml/min/kg Convert to METS (VO 2 / 3.5) = 3.4 METS

15 Next step Calculate time based on kcal, METS and body mass kcal = METS x 3.5 x body mass (kg) * t (min) = 3.4 METs x 3.5 x 70 kg x min 200 Time = 120 mins!

16 E e ise doesn t e ual ene g e penditu e! The amount of calories used in a day (Calories Out) is more accurately termed total energy expenditure (TEE) the sum of basal metabolic rate (BMR), thermogenic effect of food (TEF), non-exercise activity thermogenesis (NEAT), excess post-exercise oxygen consumption (EPOC) and, of course, exercise. TEE = BMR + TEF + NEAT + EPOC + Exercise TEE is not the same as exercise. The overwhelming majority of TEE (95%) is not exercise but the BMR

17 Energy restriction: a critical component Very difficult to achieve a negative energy balance when overeating. Allows exercise levels that are realistic in practice to make a noticeable difference

18 Is weight loss the best measure of success in an exercise program? or... are there health benefits independent of weight reduction? ABSOLUTELY!

19 Changes in cardiorespiratory fitness Subjects: 297 men, about 50 years of age Measurements: cardiorespiratory fitness (CRF) (maximal treadmill test) and visceral (VAT) and subcutaneous (SAT) adipose tissue using imaging techniques. Classified as with or without metabolic syndrome Findings: among people with similar levels of VAT and SAT, cardiorespiratory fitness contributed to the risk of metabolic syndrome. Implication: if you improve someone s CRF, their risk of metabolic syndrome is likely to be less, even if you don t change the amount of body fat! Lee et al, 2005

20 Changes in waist circumference Pre vs. post Subjects: 24 men, some with Type II diabetes Study: 13 week exercise program. Measured visceral (VAT) and abdominal subcutaneous adipose tissue (ASAT) using imaging techniques before and after the program Lower body vs. abdo Findings: no weight change! Reduction in ASAT and VAT in all groups. Greater loss of abdominal fat compared with lower body fat. Implication: exercise training might reduce abdominal (and visceral fat), even if weight loss is not achieved! Lee et al, 2005

21 What outcomes should we be measuring? Weight / BMI Exercise capacity Waist circumference Impact on co-morbid conditions e.g. blood pressure, cholesterol, HB1a? Quality of life Burden, health care utilisation and absenteeism

22 Special considerations for exercise prescription in obese people Psychological - stigma - self conscious - denial - any activity is better than no activity! Physical limitations - musculo-skeletal pain - consider weight supported exercise cycling

23 Take home messages Not an even playing field for all Focus on activity rather than just exercise... but formal exercise may be necessary Think outside the square in considering physical activity options. Exercise is just one aspect of a multifactorial approach to weight management Improving health should be the goal rather than weight loss per se.

24 Challenge #1 Barry is a 53 yrs old male Referred for cardiac rehabilitation 3 weeks after experiencing an anterior MI Sedentary BMI = 34 Smoker

25 Your task Design a lifestyle modification program for Barry What strategies would you use to increase exercise/physical activity. What are your short, medium and long term weight loss goals. What are your short, medium and long term health goals.

26 Challenge #2 A new reality TV program The Biggest Winner is about to start filming it s first season. The Biggest Winner is like it s sister program, but is exclusively for obese people with chronic conditions. The producers have asked you to be a fitness trainer and design the exercise challenges. You need to come up with some novel and interesting exercise activities to facilitate weight loss, without putting the participants at risk of adverse event.

27 Challenge #3 - Clive Palmer wins the next federal election and appoints your group the Ministry for Built Environment Your task is to redesign Canberra so that it is more physical activity friendly What infrastructure and programs would you put in place?... You have Clive s personal wealth at your disposal!

28 Exercise Intensity Calories/½ hour Aerobics Light 120 Moderate 200 Vigorous 300 Walking 4 km/hr km/hr km/hr 370 Running 9 km/hr km/hr km/hr km/hr 550 Cycling 9 km/hr km/hr km/hr 320 Swimming 25 metres/min metres/min metres/min 345

29 Walking vs. running efficiency