9.13.13 Kin 110 lecture- Can you design a study that answers an important question, is doable in a reasonable time for reasonable amount of $$?o Heart disease exampleo Yes, as long as you can break it up into smaller studies with each answering part of the question in order to accumulate enough evidence to answer you big question.- Take home messages?o We don’t know as much as we think we doo Definitive answers are difficult to obtaino Science is always in transition – can’t worry about the fact that caffeine is good, tomorrow its bad. Be weary of consistant data from multiple data. Isn’t always easy to do. We rely on others to do it for us- Challenges to doing research that gives clear, definitive information.o How does info get transmitted to public?o Does the public read any of these?- Public reads translated studies by media to form average people can understando Myth about exercise in time magazine by john cloudo What gets lost? What gets added?o Does public get right message?- How are we doing so far?o Metabolism is the sum total of energy transformation reactions in the body. TRUE; catabolism – breaking down, anabolism – building upo Diet is defined as the average nutrient intake over timeo Person in energy balance eats same number of kcal/day FALSE; eating same number of calories you are expending- Body extracts energy from stored reserves to accomplish tasks requiring energy:o Basic maintenance; energy required to keep heart beating, lungs respiring, ions across membraneso Energy to do nothing and be alive- Energy required to do these tasks is BMR (basal metabolic rate) or RMR (resting metabolic rate) – same thing more or less- RMR can be biggest portion of energy output depending on how active you areo 1 kcal/min = 1440 kcal/dayo range from 1000-1800 (90 lbs – 180 lbs)- What determines RMR?o Ageo Gendero Activityo Geneticso Biggest contributor is muscle masso More muscle mass = higher metabolic rateo Fat is inactive tissueo Muscle is highly active tissueo Higher number of calories to be at rest- Harris-benedict equation for RMRo Men vs womeno (9.56 *63.6) + (1.85 * 175.26) – (4.68 * 21)= 608+324-98 = 834- 2 processes of digesting and absorbing food requires energy.o Called diet induced thermogenesis (DIT) or “thermic effect of food”o Energy for DIT is about 10% of total energy needso Eat 2400 kcal/day, DIT is about 240 kcal- Why is difficult to lose weight by cutting food intakeo If energy intake goes down so does DITo Decrease from 2400 kcal/day to eating 1000 kcal/day, the DIT goes from 240 100o Meaning your daily output is 140 kcal- 3. Physical activityo most variableo major difference between people in energy output due to physical activity 0 2000 kcal/day- energy required for physical activity can vary from 0 to over 2000 kcal/day- energy must be in form adenosine triphosphate (ATP) to be used for metabolismo ATP is often called energy currency of the cello Only ATP can be used for muscles to contract, send ions across membranes…- Every day, body supply of ATP is recycled 5000 timeso Other stored fuels (CHO, PRO, FAT) used to resynthesize ATP- Analogy: gumball machineo Only takes quarters to take gumballso Human only takes CP, ATPo $1 CHO, Glycogen, Glucose (takes longer than quarters to break down)o $100 Fat, stored fat (takes longer than $1 to break down)o Visa Card Protein, functional – will lose muscle mass if you don’t pay it back. Can’t give it away very long without replacing ito Need to turn the visa, 100, and 1 into quarters- What determines quantity of energy needed?o Rest or exerciseo Intensityo Durationo Total energy needed = how many ATP required- What determines kind of energy requiredo Intensityo Durationo Availability of stored fuels (CHO, FAT, PRO)o What determined stored energy? Dieto Nutrition (habitual diet, pre-exercise meal) Post exercise nutrition During exercise as wello So energy storage partly determines human athletic performance/ The other part? Capacity to use the energy Determined by physiology- Capillaries size Determined by genetics and
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