Chapter 15, Section 2

Objectives Define anaerobic exercise, and describe its main effects on the body Explain how anaerobic exercise can produce muscle fatigue and an oxygen debt Define aerobic exercise and its main effects on the body Name two ways that exercise can change body composition Describe an exercise plan that can lead to physical fitness

Key Terms Physical fitness Anaerobic exercise Muscle fatigue Oxygen debt Aerobic exercise Endurance Flexibility

Physical Fitness Having a heart, lungs, and skeletal muscles that are strong and work efficiently Maintaining an appropriate weight for your height and build Having a body that is flexible and able to endure prolonged physical activity

A Regular Exercise Program Exercise involves any physical activity that requires your body to do work and uses energy The energy is obtained from the foods you eat Oxygen reacting with carbohydrates, fats, and proteins in your body to release this energy There are two basic types of exercise Aerobic and anaerobic

Anaerobic Exercise The body requires energy at different rates Short or quick bursts of energy cannot wait for the oxygen to burn the nutrients that provide the energy There are reactions that release energy but do not require large amounts of oxygen These reactions are inefficient and create more “waste products” than oxygen rich reactions

Anaerobic Exercise Only about 2% of the energy in food can be converted in this way The reactions can only last for about seconds. These exercises increase the size and strength of skeletal muscles This type of exercise causes muscle cells to become thicker and stronger

Anaerobic Exercise Training your muscles involves working the muscles against a load, (weightlifting) One chemical reaction in this type of training converts Glucose, (a simple sugar found in the blood), into lactic acid, (causes soreness) Lactic Acid causes pain and muscle fatigue, ( a warning to stop before injury results) Lactic Acid removal requires oxygen, the amount of oxygen needed is your oxygen debt

Aerobic Exercise A slower, steadier form of exercise It is more efficient than anaerobic exercise, 50% versus 2% of food energy is used This is due to the food molecules being broken down in the presence of oxygen This type of exercise strengthens the heart, (cardiac muscles), and increases your endurance

Aerobic Exercise The benefits Strengthens and increases the size of the heart A larger and stronger heart increases blood flow The heart has to beat less, (50 versus 70 bpm) Reduces the risk of heart disease and stroke

New Exercise Programs Begin slowly, adding variety a little at a time Using Exercise To obtain flexibility: there are many stretching exercises that can help ligaments, tendons and muscles become more flexible To reduce body fat: converting body fat, (energy), to muscle requires anaerobic exercise To develop endurance: alternate training styles from day to day

Summary Anaerobic exercise is powered by chemical reactions that do not require oxygen, It increases the size and strength of skeletal muscles Aerobic exercise is powered by chemical reactions that require oxygen, It makes the heart stronger, improves oxygen uptake, and increases endurance Physical fitness increases the body’s flexibility and muscle mass while decreasing the amount of fat

Definitions Physical fitness is the ability to carry out moderate physical tasks without becoming tired Anaerobic exercise is an exercise that is powered by energy releasing reactions that do not require oxygen Muscle fatigue is the loss of muscle strength due to prolonged exercise

Definitions Oxygen debt is the extra amount of oxygen needed to return muscles to their normal condition after anaerobic exercise Aerobic exercise is an exercise that is powered by energy releasing reactions that require oxygen Endurance is the ability to continue exercising before becoming completely exhausted Flexibility is the ability of the body to move at its joints