AES 242 Exam 1 Study Guide With Complete Solution

Units of measure (metric system and system international units) - Answer metric system: the standard system of measurement for scientists, used to express mass, length and volume system international (SI) units: for standardizing units of measurements Units for quantifying human exercise to SI units mass, distance, time, force, work, energy, power, velocity, torque - Answer mass-kilogram (kg) distance- meter (m) time- second (s) force- newton (N) work- joule (J) energy- joule (J) power- watt (W) velocity- meters per second (m x s^-1) torque- newton-meter (N x m) How to calc work - Answer work=force x distance in SI units: J=N x m How to calc power - Answer power=work/time in SI units: W=J/s Ergometry and ergometer - Answer ergometry: measurement of work output ergometer: device used to measure work (bench step ergometer, cycle ergometer, arm ergometer, treadmill) Can you calc work performed while a subject is on a horizontal treadmill? How is quantifiable work calculated? How is incline of a treadmill expressed? - Answer Not really possible even though it requires energy Normally done when walking or running up a slope Expressed in percent grade, amount of vertical rise per 100 units of belt travel (10% grade means 10m vertical rise for 100m of belt travel) Treadmill calc of work - Answer 1) vertical displacement=% grade x distance 2) work=body weight x total vertical distance Direct calorimetry 1 kcal=how many calories 1 kcal= how many J and kJ - Answer -measurement of heat production as an indication of metabolic rate -commonly measured in calories -1 kcal=1000 claories -1 kcal= 4,186 J or 4.186 kJ Indirect calorimetry What is the aprx caloric expenditure for every liter of oxygen that is consumed during exercise? Open circuit spirometry - Answer -measurement of oxygen consumption as an estimate of resting metabolic rate (food stuff+ O2--> heat + CO2 +H2O) -5 calories -open circuit spirometry: determines VO2 by measuring amount of O2 consumed, VO2=volume of O2 inspired- volume of O2 expired -to convert L per min to kcal per minute multiple 5 x kcal L MET - Answer 1 MET= resting metabolic rate 3.5 ml x kg x min ex: VO2/3.5=METs Estimation of energy expenditure (the VO2 equations for walking and running) - Answer -O2 requirement increases as a linear function of speed (m min) -walking: VO2= (.1 x m min) + 3.5 -running: VO2= (.2 x m min) +3.5 Calc of exercise efficiency - Answer -net efficiency: ratio of output divided by energy expended above rest % net efficiency= (work output/energy expended above rest) x 100 -net efficiency of cycle ergometry: 15-27% -efficiency decreases with increasing work rate (curvilinear relationship) Factors that influence exercise efficiency - Answer 1) exercise work rate (efficiency decreases as work rate increases) 2) speed of movement (there is an optimum speed and any deviation reduces efficiency) 3) muscle fiber type (higher efficiency in muscles with higher percentage of slow fibers) Running economy - Answer -oxygen cost of running at a specific speed -lower VO2 at the same speed indicates a better running economy -individual differences (elite runners are ~10% more economic when compared to less trained runners -20% differences between most and least economical runners What are the primary factors in determining the energy system and metabolic mixture that predominate exercise - Answer intensity and duration The aerobic system predominates in (blank) intensity with (blank) serving as the primary fuel source Carbs have energy transfer capacity how many times more rapid when compared with fat and proteins - Answer low, fat 2 times *the liver increases release of glucose to muscle as exercise progresses form low to high intensity** 3 different systems: their power and duration - Answer high energy phosphates: high power and short duration lactic acid system: moderate power and limited duration aerobic system: lowest power and very long duration Substrates, enzymes and most relevant muscle fibers for the 3 systems - Answer high energy phosphates: ATP pC, creatine kinase, fast twitch glycolytic fibers lactic acid system: glycogen and glucose, glycolytic enzymes, fast twitch fibers aerobic system: glucose, glycogen, fatty acids and amino acids, glycolytic and aerobic respiration enzymes, fast twitch oxidative and slow twitch fibers For all out power activities, what portion of the systems do we use - Answer 1) intramuscular PC 2) intramuscular ATP 3) lactic acids source (anaerobic glycolysis) 4) aerobic metabolism- barely any ATP PCr system - Answer -used during short duration and high intensity activity -quantity of intramuscular phosphagens substantially influences all out energy for brief durations -creatine kinase regulates the rate of phosphagen breakdown