NHM 315 1nd Edition Lecture 2 Outline of Last Lecture I Chapter 1 2 Outline of Current Lecture II Chapter 11 Weight and Body composition in Athletes Current Lecture Weight and Body Composition Plays a larger role in some sports and a lesser role in other Power to weight ratio is important in acrobatic sports Ex gymnastics figure skating Be Smart about Body Comp Don t pick a goal weight Body fat out of the sky Individual plans to change body composition should be set Body fat that is too low can affect health and performance Athletes are not immune to lose weight quick schemes Body Comp Terminology Body Mass Total amount of matter or material of the body Commonly interchangeable with weight Fat Mass FM Total amount off a tin the body Percent Body Fat BF The amount off at relative to body mass Fat free Mass FFM The total amount of all tissues in the body exclusive of fat which includes muscle bone fluids and organs Muscle Mass Total amount of skeletal muscle in the body All About Fat Essential Far Miniaml Amount necessary for proper physiological functioning 3 in males 12 in Females 9 is needed for proper hormonal and reproductive functions Subcutaneous and Visceral fat Should we use BMI for athletes BMI Body Mass Index These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Relationship of weight to height Used to establish a healthy weight range Body weight in kg height in m2 BMI calculations should not be used in trained athletes pregnant women or the elderly Athletes will fall into the Obese category if they do BMI Body fat cannot be directly measured unless you are dead Considerations When Estimating Body Composition Accuracy Cost Practicality and portability Subject comfort and effect Ease of use Technician training Time Hydrodensitometry or Hydrostatic underwater Weighing May be the most accurate for athletes see 2 7 Practical if space is available Requires submersion in water holding breath Takes more time to perform than most methods Subject may be uncomfortable Technician training needed Expensive Plethysmography Uses air displacement to measure volume SEE 2 2 to 3 7 Practical if space is available Takes 5 mins Subject may be uncomfortable being enclosed Minimal technician training needed Expensive Skinfold Measurements Estimates subcutaneous fat stores SEE 3 5 Practical if private area is available Takes 5 mins Subject may be uncomfortable some measurements difficult Technician training and skill is critical Inexpensive to purchase calipers Bioelectrical Impedance Analysis Base on electrical current conductivity SEE 3 5 Practical and easy Takes 5 mins Pre Measurement guidelines require substantial subject compliance Technician training is minimal Moderately expensive Dual energy x ray absorptiometry DEXA Base on low intensity x ray SEE 1 8 but more research needed to confirm Practical in some facilities Takes 5 10 mins Simple procedure Subject exposed to very small amount of radiation Technician training and licensure needed Very expensive Computed Tomography Scans and Magnetic Resonance Imaging Imaging techniqures SEE not yet established Practical in some facilities Takes 30 mins Technician training needed Very expensive Interpreting Body Composition Results Results should be given as a range May be used to determine an appropriate body weight goal Interpreting Boyd Weight Most useful for tracking hydration status Necessary to measure if weight must be certified Most athletes do not need to measure weight daily Must be interpreted correctly Decreased body weight could result from Loss of water Loss of body fat Loss of muscle mass Physical Characteristics Associated With Sports Performance Factors that any impact weight and body composition goals Sport Position played Size requirements Relative need for power and endurance Weight certification Body appearance Target Body Weight Base and Desired Body Composition Body composition must be estimated as accurately as possible Must consider genertic predisposition requirements of the sport Realistic goals achievable through diet and training Attaining or maintaining goals does not put athlete s health at risk Target body weight formula Target Body Weight Formula Target body weight current FFM 1 Desired BF The formula assumes euhydration and a constant fat free mass Increasing Muscle Mass Role of Exercise Strength training Role of Nutrition Sufficient energy intake Sufficient protein intake Rule of thumb estimates to support resistance training program Decreasing Body Fat General Principles Must create a caloric deficit Decrease kcal intake by reducing food intake Increase energy expenditure Combination of decreased kcal intake and increased energy expenditure is recommended Simultaneously Increasing Muscle Mass Decreasing Body Fat Difficult to achieve Usually more benefit to increase muscle mass first No more than 2 5 grams kg of protein daily Decreasing Body fat Role of Nutrition Do not restrict daily intake to less than 30 kcal kg body weight Low CHO intake affects muscle glycogen resynthesis consume at least 5g kg daily Low protein intake affects LBM Consume at least 1 4 g kg body weight daily Loss of body fat will be slow Plane for sufficient time off season Weight Gain in Underweight Athletes Increase dietary intake by 500kcal per day if possible Difficult to achieve How do we help athletes implement changes in body comp Nutrition counseling Stop light system in dining hall Tips when on the road Grocery store tours Competitions How many 300 lb 80 year olds do you know Offensive and defensive lineman have a 52 greater risk of dying from heart disease than the general population 2010 NFL combine More than 500 players over 300 lbs 1990 NFL Combine Only 94 players over 300 lbs Need to follow up an exit nutrition interview