Exercise Physiology Introduction

Exercise Physiology Introduction

1. Energy

   • - capacity to do work
   • Internal Work
     • - total energy expended (from potential, kinetic, and thermal energy) - AKA metabolic work
     • Mechanical Work
       • - physical movement
     • Chemical Work
       • - cellular/protein work
     • Transport Work
       • - ion transporters
     • measured as heat or kcal
   • External Work
     • W=Fxd
   • First Law of Thermodynamics
     • - no energy can be created or destroyed; only transferred
   • Types:
     • Potential Energy
       • - stored in molecular bonds (chemical energy)
     • Kinetic Energy
     • Thermal Energy
       • - released energy as heat

2. Calorimetry

   • - estimate of energy expenditure by measuring heat
   • Direct
     • - put person in a box and measure the heat they produce
   • Indirect
     • - measuring O2 consumption of energy expenditure
     • measure volume of air breathed
     • measure composition of air breathed
       • VO2max
         • determined by:
           • O2 delivery
             • - CO
             • VO2max = CO x (a-v)O2
           • O2 extraction
             • - av O2 difference
   • Values
     • 1 L of O2 consumed = 5 kcal
     • Absolute VO2 (L/min) x 5 = kcal/min
     • Relative VO2 = mL/kg/min

3. Basal Metabolic Rate

   • - BMR - lowest amount of energy needed to perform all cellular processes at rest - 60% to 75% of energy you burn in a day - does not include physical activity or digestion - kcal/hour/day
   • increases as body need increases
     • - such as in trauma/healing
   • Resting Metabolic Rate
     • - RMR - same thing as BMR but in a very strict resting environment
     • average = 3.5 mL/kg/min
     • Metabolic Equivalents
       • - METs - multiples of RMR
       • 1 MET = 3.5 mL/kg/min

4. Total Daily Energy Expenditure

   • - TDEE
   • TDEE = BMR + PA + Thermal Effect of Food
     • PA found in norm table
     • Thermal Effect is 10% of caloric intake

5. Body Composition

   • "Body Size" Measurements
     • MetLife Height/Weight Tables
     • BMI
       • - kg/m^2
       • Underweight
         • < 18.5
       • Normal
         • 18.5 - 24.9
       • Overweight
         • 25 - 29.9
       • Obese
         • > 30
     • Waist Circumference
     • Waist:Hip Ratio
   • Direct Assessment
     • - chemical dissolve or dissection (cadaver)
   • Indirect Assessment
     • Hydrostatic Weighing
     • Dual Energy X-ray Absorptiometry (DEXA)
     • Bioelectrical Impedance Analysis
     • Skinfold Assessment
   • Body Fat
     • Storage Fat
     • Essential Fat