NHM 315 1nd Edition Lecture 2Outline of Last Lecture I. Chapter 1 & 2Outline of Current Lecture II. Chapter 11- Weight and Body composition in AthletesCurrent 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 skatingBe 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 schemesBody 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 fatShould we use BMI for athletes?-BMI-Body Mass IndexThese 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 deadConsiderations When Estimating Body Composition-Accuracy-Cost-Practicality and portability-Subject comfort and effect-Ease of use-Technician training-TimeHydrodensitometry 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 -ExpensivePlethysmography-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-ExpensiveSkinfold 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 calipersBioelectrical 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 expensiveDual 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 expensiveComputed Tomography Scans and Magnetic Resonance Imaging -Imaging techniqures-SEE not yet established-Practical in some facilities-Takes 30 mins-Technician training needed-Very expensiveInterpreting Body Composition Results-Results should be given as a range-May be used to determine an appropriate body weight goalInterpreting 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 massPhysical 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 appearanceTarget 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 formulaTarget Body Weight Formula-Target body weight = current FFM/1-Desired % BF-The formula assumes euhydration and a constant fat-free massIncreasing Muscle Mass-Role of Exercise-Strength training-Role of Nutrition-Sufficient energy intake-Sufficient protein intake-“Rule of thumb” estimates to support resistance-training programDecreasing 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 energyexpenditure is recommendedSimultaneously 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 dailyDecreasing 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 achieveHow 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-CompetitionsHow 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