Nutrition and Physical Activity Chapter 11

What Are the Health Benefits of Physical Activity? Nearly half of Americans lead a sedentary life Physical activity is essential for long, healthy life Physical activity Day-to-day activities Exercise

What Are the Health Benefits of Physical Activity? Improves health and fitness Overall benefits Weight management Reduced risk of cardiovascular disease, cancer, and type 2 diabetes Decreased back pain & better bone health Enhanced self-esteem, better sleep, and stress management

What Are the Health Benefits of Physical Activity? Recommendations Physical Activity Guidelines for Americans 150 minutes a week of moderate-intensity aerobic activity Two session of muscle strengthening a week

What Are the Health Benefits of Physical Activity? Components of physical fitness Health-related and skill-related components Cardiovascular fitness Muscle strength Endurance Flexibility Body composition

What Are the Health Benefits of Physical Activity? FITT principle Frequency Intensity Perceived exertion “Talk test” Monitoring heart rate Target heart rate Indirect calorimetry

Signs and Symptoms of Perceived Exertion

Maximum and Target Heart Rates

What Are the Health Benefits of Physical Activity? FITT principle Type of activity Several types of exercise Time of activity Cardiovascular fitness Lose weight or prevent weight regain Injuries

Guidelines & Goal Setting Activities for Achieving FITT Principle

How Does Energy Metabolism Change during Physical Activity? Energy expenditure at rest 1.0 to 1.5 kcal/minute Energy expenditure during activity Can increase to 36 kcal/minute

Effects of PA Level on Total Energy Requirements

How Does Energy Metabolism Change during Physical Activity? ATP generation Exercise Glucose, fatty acids, amino acids Multiple pathways Aerobic conditions Anaerobic conditions Muscle fibers convert chemical energy in ATP into mechanical energy

How Does Energy Metabolism Change during Physical Activity? ATP generation Creatine phosphate system Simplest and most rapid means Anaerobic conditions Glycolytic system Anaerobic Yields two pyruvate molecules Oxidative system Lactate

The Creatine Phosphate System

How Does Energy Metabolism Change during Physical Activity? ATP generation Oxidative system Aerobic conditions ATP generation is slow Generates many ATP Delayed onset muscle soreness

Contribution of Energy Systems to Energy Expenditure during Exercise

What Physiologic Adaptations Occur in Response to Athletic Training? Adaptation responses Hypertropy of muscles Atrophy Expansion of blood vessels Higher tolerance for lactate Training beyond body’s ability to recover Muscle soreness Joint pain Serious injury

What Physiologic Adaptations Occur in Response to Athletic Training? Strength training Movements are difficult but brief Promotes muscular growth Endurance training Low- to moderate-intensity exercise Longer duration Improves aerobic capacity

What Physiologic Adaptations Occur in Response to Athletic Training? Cardiovascular adaptations Heart rate Ventilation rate Stroke volume Maximal oxygen consumption Endurance training Increased use of fatty acids for ATP Interval training Improves endurance & anaerobic capacity

What Physiologic Adaptations Occur in Response to Athletic Training? Ergogenic aids Enhance physical performance beyond natural gains Wide range of products FDA does not approve products prior to being placed in the marketplace

How Does Physical Activity Influence Dietary Requirements? Nutritional recommendations are similar for all people Athletic people should… Consume enough water Take in enough energy to meet demands Energy requirements Mathematical formulas

Average Energy Expenditure for Selected PA

How Does Physical Activity Influence Dietary Requirements? Macronutrient intake Carbohydrates Glycogen Carbohydrate loading Protein Amount Timing of consumption Lipids Omega-3 fatty acids

How Does Physical Activity Influence Dietary Requirements? Micronutrient intake Iron Role Endurance athletes Sports anemia Hemodilution Calcium Zinc Supplementation

How Does Physical Activity Influence Dietary Requirements? Fluids and electrolytes Water Dehydration Heat exhaustion Characteristics Heat stroke Hyponatremia Prevention

Signs & Symptoms of Mild to Severe Dehydration

How Does Physical Activity Influence Dietary Requirements? Post-exercise recovery Carbohydrates Glycogen stores When and how much carbohydrate to consume Carbohydrate-to-protein ratio Proteins Muscle recovery Types of protein

How Does Physical Activity Influence Dietary Requirements? Post-exercise recovery Water Based on weight lost during work out Hydration status Urine color