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

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 Guidelines for Physical Activity Guidelines for AmericansAmericans

Intensity of Physical ActivityIntensity of Physical Activity

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

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

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

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

What Do Sports Drinks Have to What Do Sports Drinks Have to Offer?Offer?

Fluid Glucose Sodium and other electrolytes Psychological edge

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