Presentation on theme: "Resting Metabolic Rate (RMR)"— Presentation transcript:
1 Resting Metabolic Rate (RMR) How Do You MeasureENERGY EXPENDITURE?
2 Metabolic Rate in Various Conditions Basal Metabolic Rate (BMR)Minimum energy required to sustain life(Measured when Waking State with No Food & No Movement)Resting Metabolic Rate (RMR)Combination of…Basal Metabolism (waking state)Sleeping MetabolismArousal MetabolismExercise Metabolic RateMetabolism during Exercise + RMR
3 How Do You Measure Metabolic Rate? Substrate (CHO or Fat) + O2 + Energy (ATP) CO2 + H2O + Energy (ATP) + HeatMethod #2INDIRECT CALORIMETRYMethod #1DIRECT CALORIMETRY
4 Method #1 DIRECT CALORIMETRY Total Energy from Metabolism...~40% ATP~60% HeatSo…if you measure your body’s heat production, you can estimate energy production!
5 DIRECT CALORIMETRY How Does It Work? Insulated ChamberHeat ExchangerWater flow in the heat exchangerThe difference in the temperature of water entering and leaving the chamber reflects the person’s heat production.
6 DIRECT CALORIMETRY Problems ExpensiveNot applicable in most activitiesHighly impractical for large-scale studiesVery few pieces of equipment in nationSo…Method #2
7 Method #2 INDIRECT CALORIMETRY Complete Combustion of FoodISAchieved at the Expense of O2 Molecules.So…if you measure your oxygen uptake,you can estimate energy production!
8 INDIRECT CALORIMETRY How Does It Work? Oxygen Uptake= (VO2 IN) – (VO2 OUT)O2 InspiredO2 Expired
13 What about Protein?Protein is metabolized as either fat or carbohydrate and is therefore difficult to separate from the other twoProtein consumption is a small percentage of total metabolism during normal conditions and can be ignored
14 Respiratory Exchange Ratio (RER) CO2 producedO2 consumedActual gas exchange (RER) at the lungs can be greater or less than the RQ at the cell. It can range from slightly below 0.7 all the way to around 1.5 (lots of non-metabolic CO2)(hyperventilation vs hypoventilation?)RER =At the LUNGS
15 How Do You Use RQ or RER? Assuming RQ = RER, you can estimate the energy produced per liter of O2.e.g.RQ = 0.85 4.86 kcal/LO2(Utilizing 50.7% CHO & 49.3% Fat) Table 4.4
16 Comparing RMR Absolute Oxygen Uptake (in LO2/min) more muscle mass higher absolute VO2Not able to compare300 lbs football player and 130 lbs X-country runnerRelative Oxygen Uptake (in mlO2/kg/min)Eliminates some of the differences in muscle mass by using body mass (body composition is unaccounted for)
17 Metabolic Equivalent (MET) A MET is defined as a multiple of the Resting Metabolic Rate.e.g.If RMR (1 MET) = 3.6 mlO2/kg/min,Work requires 7.2 mlO2/kg/min of O2 uptake = 2 METS(# of METS in different activities?)
18 STPD Correction Factor Volume of Gas expressed under Standard Conditions ofTemperature (273K or 0°C)Pressure (760 mmHg or 1 atm)Dry (no water vapor)273K PBAR – PH2O273K + TA (in °C) mmHg(hot, wet condition vs cold, dry condition?)STPDCF =X
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