Lab 1: Body Composition Overview

Lab 1: Body Composition

• Two main compartments: Fat Mass (FM) and Fat-Free Mass (FFM)
• FM includes all fatty tissues in the body
• FFM includes everything else (muscles, organs, fluid, bone)
• Direct assessment measures body composition by analyzing physical components (invasive, time-consuming, special equipment)
• Indirect assessment uses other variables like weight, height, skinfold thickness, and electrical conductivity (practical, widely used, less invasive)
• Essential body fat range: Men (2-4%), Women (10-12%)
• Skinfold method: Inexpensive, simple, non-invasive, widely available, accuracy depends on the measurer, doesn't account for visceral fat
• BIA (Bioelectrical Impedance Analysis): Non-invasive, quick, easy, small device, tracks over time, relies on hydration, food intake, and skin temperature
• Hydrostatic weighing: Gold standard, highly reliable, requires special equipment (water tank), time-consuming
• Bod Pod: Very accurate, non-invasive, expensive, and not widely available, affected by clothing, hair, and movement
• BMI (Body Mass Index): Simple, inexpensive, widely used, non-invasive, doesn't differentiate between fat and lean mass
• Waist-to-hip ratio: Non-invasive, easy, inexpensive, useful for assessing fat distribution, provides indirect estimates of body fat, accuracy depends on measurement techniques
• Calculate BMI, FFM, FM, and ideal body weight (IBW)
  • BMI: Weight (kg) / Height (m²)
  • FFM: Body weight × (1 - body fat percentage)
  • FM: Body weight × body fat percentage
  • IBW: Men = 50 + (2.3 × (height (inches) - 60)), Women = 45.5 + (2.3 × (height (inches) - 60))
• Apple vs. Pear body shape differences in fat distribution (apple shape has more abdominal fat, increasing cardiovascular disease risk)

Lab 2: Aerobic Capacity

• VO2 Max: Maximum volume of oxygen consumption, measures the body's maximum oxygen utilization during maximal exercise
• Classifying VO2 Max as maximum: Plateau in VO2 increase, despite workload, maximal heart rate within ±10 bpm of predicted maximal HR, exhaustion, blood lactate concentration 4 mmol/L, RER 2.10
• Astrand Rhyming Test—Submaximal aerobic fitness test to estimate VO2 max using heart rate and workload data. Based on principles of submaximal effort, linear relationship, steady-state heart rate and workload adjustment, and use of nomograms
• Limitations of submaximal tests: General assumptions, heart rate variability, population averages, limited for extremes, and dependence bias
• Anaerobic vs. Aerobic: Anaerobic—fast, high-intensity, short duration; Aerobic—slower, more efficient, sustained energy
• Sex Differences in VO2 max—Men typically have higher VO2 max due to physiological, anatomical, and hormonal differences

Lab 3: Caloric Expenditure

• Purpose of graphing VO2/heart rate to estimate VO2 max
• Assess efficiency by analyzing slope (cardiovascular efficiency)
• Track progress
• Evaluate response
• Direct calorimetry: Measures heat produced by the body to determine energy expenditure
• Indirect calorimetry: Measures energy expenditure by measuring oxygen consumption and carbon dioxide production
• RER: Respiratory Exchange Ratio—ratio of carbon dioxide produced to oxygen consumed (CO2/O2) during metabolism

Lab 4: Muscular Power

• Work = Force × Distance
• Power = Work/Time
• Factors affecting muscle power output: Muscle fiber type, muscle cross-sectional area, muscle length, motor unit recruitment, rate of neural firing, contraction velocity, motor unit synchronization, force-length relationship, force-velocity relationship, energy availability (ATP and creatine phosphate), fatigue resistance, enzyme activity, load or resistance, and biomechanics (body position, leverage)
• Energy systems: Phosphogen (ATP-PC) system, Anaerobic Glycolysis (lactic acid system), Aerobic system (oxidative phosphorylation) and their roles in different exercises