Energy Expenditure I Energy Balance Energy Balance Total caloric intake Total energy expenditure A O Energy Balance B Positive energy balance C Negative Energy Balance D 3500 3600 kcal 1 lb body fat 1 weight loss of 1 lb per week 500 kcal day deficit 2 1 II Total Energy Expenditure TEE Thermic effect of a meal Physical activity Basal metabolic rate A Thermic effect of a meal 1 energy expended to digest and absorb food TEE Thermic effect of a meal Physical activity Basal metabolic rate B Physical Activity 1 varies with 2 general guidelines a Sedentary b Light c Moderate d Heavy TEE Thermic effect of a meal Physical activity Basal metabolic rate C Basal Metabolic Rate 1 energy expended to carry out essential body functions 2 2 BMR varies depending on a Lean body mass b Hormones c Stress 3 To measure BMR via gas exchange a Awake b Laying down Harris Benedict Equation Men BMR 66 5 13 7 w 5 H 6 8 A Women BMR 655 1 9 56 w 1 85 H 4 7 A W body weight in kilograms H height in cm A age in years BMR Example Male 22yrs 6ft 200lbs 3 III Changes in weight A Weight gain 1 want positive energy balance intake total energy expenditure B Weight loss 1 want negative energy balance intake total energy expenditure C Weight loss of 1lb per week 3500 kcal deficit per week or 500 kcal day D Calorie Restriction a USDA 2000 2500 kcal d IV Fed versus Fasting Fed Promote Storage Fasting Energy Production Metabolic Pathways 4 e g n a h C e v i t l a e R 0hrs 12hrs Fasting V Integration of Cycles Notes on overheads Krebs cycle amphibolic pathway involved in both the catabolism and biosynthesis of carbohydrates fats and proteins Acetyl CoA pyruvate dehydrogenase reaction is not reversible 5 Fed primary hormone Insulin Carbohydrate Fat Protein Glucose Fatty acids Amino acids Fasting Initially Glucose levels drop Glycogen stores are broken down to maintain glucose Fasting first few days use glucogenic aa s to keep up levels of glucose to supply brain CNS and RBCs Fasting early weeks Body looks to conserve energy Lowers body temp blood pressure kidney function 6 Fasting Several weeks Immune system severely diminished Fat stores nearly depleted Fasting near death VII Refeeding Syndrome aka Hypophosphatemia A At risk individuals 1 severely malnourished B What is it C Symptoms complications 1 myocardial dysfunction 2 tachycardia 3 hypotension 4 respiratory failure 7 D Why does this happen 1 During starvation body uses fat for energy glucagon is predominant hormone 2 begin to aggressively refeed a insulin to cover CHO influx c High insulin levels induce glucose uptake into cells at the same time phosphorus is driven into cells potassium magnesium are also pulled into cells E Organ Specific Heart increase cardiac workload Gut atrophy with starvation F Treatment 8 VIII Metabolic Syndrome A cluster of symptoms 1 Elevated waist circumference 2 Elevated triglycerides 3 Reduced HDL 4 Elevated blood pressure 5 Elevated fasting glucose B Insulin resistance 1 Hyperinsulinemia a more insulin released from pancreas to regulate blood glucose 2 Tissues a muscle insulin no longer stimulates glucose uptake b adipose tissue unregulated free fatty acid release c liver retains insulin sensitivity d kidney retains insulin sensitivity C Treatment 1 medications for symptoms 2 weight loss 9 VI Diets A Low fat 1 is it high CHO and low pro 2 10 fat 3 Examples 4 Advantages 5 Metabolism B Low CHO diets 1 tend to be protein and fat 2 some as low as 5 CHO 3 examples 4 Advantages 5 Metabolism IV Exercise A muscle 1 Type I a lots of mitochondria 2 Type IIa a White muscle 3 Type IIb a Less mitochondria 10 B Energy sources 1 ATP CP system creatine phosphate 2 lactic acid system anaerobic glycolysis 3 aerobic system aerobic glycolysis oxidation Krebs cycle a muscle glycogen b plasma glucose C Energy metabolism shifts the amount of energy each supplies varies 1 ATP 2 CP 3 4X greater CP than ATP in muscle cell 3 anaerobic system 4 aerobic systems glycolysis beta oxidation D Endurance Training 1 increase size and number of mitochondria 2 cardiovascular and lung capacity 3 hypertrophy of type I muscle fibers 4 increased fat usage for energy thus sparing muscle glycogen 11 E Carbohydrate Loading 1 elevating muscle glycogen to above normal levels 2 effective in distance events 13 miles 3 exercise five days of training in which you taper down the intensity rest on 6th day 4 diet days 1 3 days 3 6 12
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