Chapter 10 Nutrients, Physical Activity, and the Body’s Responses
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Transcript of Chapter 10 Nutrients, Physical Activity, and the Body’s Responses
Chapter 10Chapter 10
Nutrients, Physical Activity, Nutrients, Physical Activity, and the Body’s Responsesand the Body’s Responses
Nutrition: Concepts & Controversies, 12e Nutrition: Concepts & Controversies, 12e Sizer/WhitneySizer/Whitney
Learning ObjectivesLearning Objectives
Discuss the short-term and long-term benefits of achieving cardiorespiratory fitness.
Explain how the 2008 Physical Activity Guidelines for Americans can be incorporated into anyone’s lifestyle. Suggest simple ways to increase activity level throughout the day.
Learning ObjectivesLearning Objectives
Explain why it is important for an athlete to maintain blood glucose levels before, during, and after vigorous exercise.
Describe how an athlete’s body uses dietary protein during and after strenuous exercise.
Learning ObjectivesLearning Objectives
Discuss some reasons why female endurance athletes may be vulnerable to iron deficiency.
Evaluate whether conjugated linoleic acid (CLA) and other ergogenic aids are useful for obtaining an ideal body composition for sports.
IntroductionIntroduction
Physical activity and nutrition Needs
Energy-yielding nutrientsVitamins and minerals
ResultsRegulation of energy-yielding nutrientsBody compositionDaily calorie allowance
FitnessFitness
Depends on physical activity or exercise Movement, muscle contraction, & energy
expenditure Benefits
Chronic disease Longevity Disease resistance Numerous other benefits
Physical Activity GuidelinesPhysical Activity Guidelines
2008 Physical Activity Guidelines for Americans Aerobic physical activity & resistance
training Moderate vs. vigorous intensity Health-care provider advise Accumulated weekly totals Weight maintenance Sport performance
Physical Activity Guidelines for Physical Activity Guidelines for AmericansAmericans
Intensity of Physical ActivityIntensity of Physical Activity
American College of Sport Medicine’s American College of Sport Medicine’s Guidelines for Physical FitnessGuidelines for Physical Fitness
The Essentials of FitnessThe Essentials of Fitness
Components of fitness Adaptations
Athletes Muscle power Agility Reaction times Fatigue
How Do Muscles Gain in Size and How Do Muscles Gain in Size and Strength?Strength?
Activity choices Overload
Balance of activity and rest Work different muscle groups Muscles need rest
Replenish and adapt
Specific training Hormones and muscle growth
What Are the Benefits of What Are the Benefits of Resistance Training?Resistance Training?
Progressive weight training Prevent and manage chronic disease
Muscle strength & size, power, or endurance Resistance and repetitions Appearance
Mobility and bone loss Slows loss of physical mobility Maximize and maintain bone mass
How Does Cardiorespiratory How Does Cardiorespiratory Training Benefit the Heart?Training Benefit the Heart?
Enhances capacity Heart, lungs, and blood
Enhances efficiency Delivery of oxygen
VO2 max
Removal of wastes Blood lipid profile
Heart disease risk
How Does Cardiorespiratory How Does Cardiorespiratory Training Benefit the Heart?Training Benefit the Heart?
Effective training activities Elevate heart rate Sustained for longer than 20 minutes Use most of the large-muscle groups
Pulse check
The Active Body’s Use of FuelsThe Active Body’s Use of Fuels
Fuels Mixtures
Vary Excess postexercise oxygen consumption
(EPOC) High intensity activities Cardiac output
Fuel usage
Delivery of Oxygen by the Heart Delivery of Oxygen by the Heart and Lungs to the Musclesand Lungs to the Muscles
Glucose Use and StorageGlucose Use and Storage
Muscle glucose Retains glycogen for own use
Liver glucose Glycogen and endurance
High-carbohydrate diets
The Effect of Diet on Physical The Effect of Diet on Physical EnduranceEndurance
Activity Intensity, Glucose Use, Activity Intensity, Glucose Use, and Glycogen Storesand Glycogen Stores
Energy stored as glycogen Anaerobic use of glucose
Quick energy Muscle glycogen reserves
Aerobic use of glucose Energy from glucose and fatty acids
Lactate Anaerobic activity Muscle size and strength
Glucose and Fatty Acids in Their Glucose and Fatty Acids in Their Energy-Releasing Pathways in Muscle Energy-Releasing Pathways in Muscle
CellsCells
Activity Duration, Glucose Use, Activity Duration, Glucose Use, and Glycogen Storesand Glycogen Stores
Glucose use Duration of activity Intensity of activity
Blood glucose and activity Dietary strategies
High carbohydrate diet dailyConsume glucose during activityConsume carbohydrate shortly after
exercise
Carbohydrate Needs of AthletesCarbohydrate Needs of Athletes
Degree of Training Affects Degree of Training Affects Glycogen UseGlycogen Use
Muscles adapt to store more glycogen
Trained muscles burn more fat
Fat and Physical ActivityFat and Physical Activity
Body fat as fuel for activity Sources of fat Importance of strength training
Fat in the athlete’s diet Performance Omega-3 fatty acids
Intensity and duration Degree of training
Protein for Building Muscles and Protein for Building Muscles and for Fuelfor Fuel
Muscle protein synthesis Up to two days after activity Intensity and pattern of muscle contraction Muscle cells only build proteins as needed
Dietary protein Supplements High-quality proteins
Fuel for physical activity Factors that regulate protein use
How Much Protein Should An How Much Protein Should An Athlete Consume?Athlete Consume?
DRI vs. other authorities Nature of
chosen activity
Do Nutrient Supplements Benefit Do Nutrient Supplements Benefit Athletic Performance?Athletic Performance?
Well-nourished athletes More food means more nutrients
Supplement timing Body use takes hours or days
Preventing deficiencies Impede performance
Nutrients of ConcernNutrients of Concern
Vitamin E Physical activity creates more free radicals Benefits of vitamin E supplements
Studies are conflicting Interference with absorption
Iron Deficiency impairs performance Groups at risk for deficiency Sports anemia
Water Losses During Physical Water Losses During Physical ActivityActivity
Water losses Breathing and sweating
Dehydration Sweat and temperature regulation Heat stroke
Potentially fatal Reduce risk
Hypothermia Symptoms
Fluid and Electrolyte Needs Fluid and Electrolyte Needs During Physical Activity During Physical Activity
Hydrate and rehydrate Thirst signal
Hourly sweat rate Water
Endurance athletes Electrolyte losses and replacement
Minerals Sports drinks vs. regular diet
Sodium Depletion and Water Sodium Depletion and Water Intoxication Intoxication
Replenishing electrolytes Crucial time Hyponatremia
Differs from dehydration Heat cramps
Sodium
Other BeveragesOther Beverages
Caffeine Moderate doses
Iced teaEnergy drinks
Carbonated beverages Alcoholic beverages
Diuretic
What Do Sports Drinks Have to What Do Sports Drinks Have to Offer?Offer?
Fluid Glucose Sodium and other electrolytes Psychological edge
Choosing a Performance DietChoosing a Performance Diet
Nutrient density Balance
Carbohydrate intakeLiquid carbohydrate supplements
Protein Milk and meat products
Nutritious High-Carbohydrate Nutritious High-Carbohydrate Meals for AthletesMeals for Athletes
Choosing a Performance DietChoosing a Performance Diet
Planning an athlete’s meals Fruit and vegetable intake Pregame meals
Easily digestedContain fluidsFinish eating 3 to 4 hours before
competition “Complete” bars and drinks
Eating Patterns for AthletesEating Patterns for Athletes
Examples of High-Carbohydrate Examples of High-Carbohydrate Pregame MealsPregame Meals
Ergogenic Aids: Breakthroughs, Ergogenic Aids: Breakthroughs, Gimmicks, or Dangers?Gimmicks, or Dangers?
Controversy 10
Ergogenic AidsErgogenic Aids
Advertorials Dietary supplements
Escape regulation Legitimate research
Large majority of ergogenic aid claims are not supported
Ergogenic AidsErgogenic Aids
Caffeine Endurance vs. high-intensity activities Adverse effects Diuretic
Carnitine Nonessential nutrient
Chromium picolinate Carbohydrate and lipid metabolism Safety concerns
Ergogenic AidsErgogenic Aids
Creatine Hypothesized benefits Confirmed effect
Weight gain
Conjugated linoleic acid (CLA) Not worth their price
Sodium bicarbonate Unpleasant side effects
Ergogenic AidsErgogenic Aids
Amino acid supplements Maximum gains
Essential amino acids in system prior to physical work
Best sourceFoodReasons against supplements
Ergogenic AidsErgogenic Aids
Whey protein and other protein supplements By product of cheese making Timing of protein intake
Complete meal replacers Fall short of ‘complete’ nutrition Risk of dental caries Nutritional uses
Pregame mealBetween-meal snack
Hormone PreparationsHormone Preparations
Anabolic steroid hormones Illegal and dangerous
Steroid alternative supplements Herbal or insect sterols
Prohormones Androstenedione DHEA
Drugs posing as supplements
Physical Risks of Taking Steroid Physical Risks of Taking Steroid Hormone DrugsHormone Drugs