HUN 4296 Nutrition & Health Issues Week 3 Day Physical Activity and Ergogenic Aids Chp 10 Nutrition: Concepts & Controversies,12e Sizer/Whitney Chp 10 Nutrition: Concepts & Controversies,12e Sizer/Whitney

Introduction  Physical activity and nutrition  Needs  Energy-yielding nutrients  Vitamins and minerals  Results  Regulation of energy-yielding nutrients  Body composition  Daily calorie allowance

Fitness  Depends on physical activity or exercise  Movement, muscle contraction, & energy expenditure  Benefits  Chronic disease  Longevity  Disease resistance  Numerous other benefits

Physical 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 Americans

Intensity of Physical Activity

American College of Sport Medicine’s Guidelines for Physical Fitness

The Essentials of Fitness  Components of fitness  Adaptations  Athletes  Muscle power  Agility  Reaction times  Fatigue

How Do Muscles Gain in Size and 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 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 Training Benefit the Heart?  Enhances capacity  Heart, lungs, and blood  Enhances efficiency  Delivery of oxygen  VO 2 max  Removal of wastes  Blood lipid profile  Heart disease risk

How Does Cardiorespiratory 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 Fuels  Fuels  Mixtures  Vary  Excess postexercise oxygen consumption (EPOC)  High intensity activities  Cardiac output  Fuel usage

Delivery of Oxygen by the Heart and Lungs to the Muscles

Glucose Use and Storage  Muscle glucose  Retains glycogen for own use  Liver glucose  Glycogen and endurance  High-carbohydrate diets

The Effect of Diet on Physical Endurance

Activity Intensity, Glucose Use, and 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 Energy-Releasing Pathways in Muscle Cells

Activity Duration, Glucose Use, and Glycogen Stores  Glucose use  Duration of activity  Intensity of activity  Blood glucose and activity  Dietary strategies  High carbohydrate diet daily  Consume glucose during activity  Consume carbohydrate shortly after exercise

Carbohydrate Needs of Athletes

Degree of Training Affects Glycogen Use  Muscles adapt to store more glycogen  Trained muscles burn more fat

Fat 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 for 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 Athlete Consume?  DRI vs. other authorities  Nature of chosen activity

Do Nutrient Supplements Benefit Athletic Performance?  Well-nourished athletes  More food means more nutrients  Supplement timing  Body use takes hours or days  Preventing deficiencies  Impede performance

Nutrients 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 Activity  Water losses  Breathing and sweating  Dehydration  Sweat and temperature regulation  Heat stroke  Potentially fatal  Reduce risk  Hypothermia  Symptoms

Fluid and Electrolyte Needs During Physical Activity  Hydrate and rehydrate  Thirst signal  Hourly sweat rate  Water  Endurance athletes  Electrolyte losses and replacement  Minerals  Sports drinks vs. regular diet

Hydration Schedule for Physical Activity

Sodium Depletion and Water Intoxication  Replenishing electrolytes  Crucial time  Hyponatremia  Differs from dehydration  Heat cramps  Sodium

Other Beverages  Caffeine  Moderate doses  Iced tea  Energy drinks  Carbonated beverages  Alcoholic beverages  Diuretic

What Do Sports Drinks Have to Offer?  Fluid  Glucose  Sodium and other electrolytes  Psychological edge

Choosing a Performance Diet  Nutrient density  Balance  Carbohydrate intake  Liquid carbohydrate supplements  Protein  Milk and meat products

Nutritious High-Carbohydrate Meals for Athletes

Choosing a Performance Diet  Planning an athlete’s meals  Fruit and vegetable intake  Pregame meals  Easily digested  Contain fluids  Finish eating 3 to 4 hours before competition  “Complete” bars and drinks

Eating Patterns for Athletes

Examples of High-Carbohydrate Pregame Meals

Ergogenic Aids: Breakthroughs, Gimmicks, or Dangers? Controversy 10

Ergogenic Aids  Advertorials  Dietary supplements  Escape regulation  Legitimate research  Large majority of ergogenic aid claims are not supported

Ergogenic Aids  Caffeine  Endurance vs. high-intensity activities  Adverse effects  Diuretic  Carnitine  Nonessential nutrient  Chromium picolinate  Carbohydrate and lipid metabolism  Safety concerns

Ergogenic Aids  Creatine  Hypothesized benefits  Confirmed effect  Weight gain  Conjugated linoleic acid (CLA)  Not worth their price  Sodium bicarbonate  Unpleasant side effects

Ergogenic Aids  Amino acid supplements  Maximum gains  Essential amino acids in system prior to physical work  Best source  Food  Reasons against supplements

Ergogenic 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 meal  Between-meal snack

Hormone 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 Hormone Drugs