Chapter 13 Nutrition and Physical Activity. What is fitness? Fitness is defined as the ability to...

Chapter 13Nutrition and Physical Activity

What is fitness? Fitness is defined as the ability to perform

routine physical activity without undue fatigue.

Copyright 2010, John Wiley & Sons, Inc.


Exercise, Health and Fitness

The overload principle assumes that the body will adapt to the stresses placed on it.

Aerobic exercise includes endurance exercises such as jogging,

swimming or cycling, or any exercise that increases heart rate and requires oxygen in metabolism.

The cardiorespiratory system includes the circulatory and respiratory systems,

delivering oxygen and nutrients to the cells.


Which is true regarding the overload principle?

When you exercise, you should work harder than you think is possible.

The body will adapt to the stresses placed on it.

If people exercise too much, they will not improve fitness.

Overload is to be avoided.


Exercise, the Heart and the Muscles Regular aerobic exercise and the heart

strengthens the heart muscle increases stroke volume decreases the resting heart rate. increases ability of cells to use oxygen to produce energy increases the circulatory system's ability to deliver oxygen

The resting heart rate can be measured by counting the number of pulses per minute while at rest.

Aerobic capacity is the body’s maximum ability to generate ATP by aerobic metabolism during exercise. Aerobic capacity is also called VO2 max.


Which of the following statements about aerobic capacity is incorrect?

Aerobic capacity is the body's maximum ability to generate ATP by aerobic metabolism during exercise

Aerobic capacity is dependant on the ability of the cardiorespiratory system to deliver oxygen to cells.

Aerobic capacity is dependant on the ability of cells to use oxygen to produce energy.

The smaller a person's aerobic capacity, the more intense activity can be performed before lack of oxygen affects performance.

Excercise and muscle

Stress or overload during exercise causes muscles to adapt by increasing in size and strength. This is called hypertrophy.

When muscles are not used, they atrophy, becoming smaller and weaker.



Lifting a heavy weight stresses muscles causing an adaptation called

a) hypertrophy

b) hypotrophy

c) atrophy

d) atropic


Health Benefits of Exercise

In addition to increased flexibility and the ability to easily perform daily activities, benefits of regular exercise include:

Weight management Cardiovascular health Diabetes prevention or management Bone and joint health Possible reduction of cancer risk Psychological health


The health benefits of exercise include all of the following except

decrease blood pressure

increase HDL cholesterol.

decrease the sensitivity of tissues to insulin.

reduce the risk of osteoporosis.


Exercise Recommendations


Todd is 30 years old. If his target heart rate during aerobic activity is 60 - 90 % of his maximum heart rate, how fast should his heart rate be during exercise?

a)

60 and 90

b)114 and 171

c)

132 and 198

d)160 and 220


Target Heart Rates During Aerobic Exercise


If Dahlia exercises in such a way as to expend 300 extra kcalories and reduces her kcaloric intake by 200 kcalories a day, approximately how long will it take Dahlia to lose five pounds?

a) 1 week b) 15 days c) 35 days d) 45 days


Which is true regarding maximum heart rate?

a) When a person is fit, it takes less effort to reach his/her maximum heart rate

b) Maximum heart rate declines

with age

c) Maximum heart rate is the number of times that the heart beats per minute while a person it at rest

d) Maximum heart rate is

calculated using one's weight and height


Components of a Good Exercise Regimen


Fueling Exercise

Aerobic metabolism is metabolism in the presence of oxygen. Glucose, fatty acids and amino acids are completely broken down to form CO2 and H20 and to produce ATP.

Anaerobic metabolism is metabolism in the absence of oxygen. Each molecule of glucose produces two molecules of ATP. Glucose is metabolized in this way when oxygen cannot be supplied quickly enough to the tissues to support aerobic metabolism.

Anaerobic metabolism is also called anaerobic glycolysis.


Fueling Exercise by the Minute


The Process of Anaerobic Metabolism


The Effect of Exercise Intensity


A major goal of precompetition meals is to

maximize glycogen stores in the liver

maximize fat stores

maximize activity in the large intestine

increase caffeine in the system


Nutrient Needs for Physical Activity


It is recommended that athletes consume diets with the following approximate proportions:

PROTEIN 10 - 15% ; FAT < 10%; CARBOHYDRATE 70 - 80%

PROTEIN 10 - 20%; FAT < 30%; CARBOHYDRATE 55 - 60%

PROTEIN 15 - 22%; FAT < 15%; CARBOHYDRATE 60 - 70%

PROTEIN 12 - 17%; FAT 2 - 5 %; CARBOHYDRATE 80 - 90 %


Relationship of Exercise to Intake The source of dietary energy can be as important

as the amount of energy in an athlete’s diet. The general proportion of energy for athletes and

healthy individuals should be: 45-65% total energy from carbohydrates 20-35% from fat 10-35% from protein

Vitamins and minerals requiring special attention from athletes:

B vitamins Antioxidant vitamins, such as vitamins C and E Iron

Sports anemia (blood volume expands to increase oxygen delivery, but the synthesis of Red Blood Cells lags behind._

Calcium Female athlete triad

Too much exercise combined with limited food intake can lead to hormonal abnormalities


Over-exercise, Under-nutrition Low energy intakes and excessive exercise

in female athletes may result in low levels of the hormone, estrogen that in turn contributes to reductions in bone mineral density

Amenorrhea has the greatest effect on which mineral in a female athlete's body? a) calcium b) fluoride c) iron D) magnesium



Fluid Needs for Physical Activity During exercise, water is needed to eliminate heat, to

transport oxygen and nutrients to the muscles and to remove waste products such as lactic acid from the muscles.

The ability to dissipate heat depends on hydration levels. At rest in a temperate climate, an adult loses about 4½ cups

of water per day through evaporation from the skin and lungs.

Even with regular consumption, it may not be possible to consume sufficient fluid to remain properly hydrated.

Failure to compensate for fluid losses can result in dehydration.

If heat cannot be lost from the body, body temperature rises and exercise performance as well as health can be jeopardized.


Fluid Needs for Physical Activity Dehydration occurs when water loss is great enough for

blood volume to decrease. Dehydration reduces the body’s ability to deliver oxygen

and nutrients to muscles.


During hot weather, athletes should consume fluids ___________ exercise.

a) before b) during c) after

d) All answer choices

are correct.

dehydration

Kids and the elderly are much more prone to dehydration… why?

Kids produce more heat Kids are less efficient at transferring heat

from muscle to skin Kids take longer to acclimatize to heat Kids sweat less than adults



Hyponatremia : abnormally low sodium in the blood

Sports drinks

What should you drink during a long workout?

Beverages containing a small amount of carbohydrate (15-20 grams or 6-8%)

Empty rapidly from the stomach Enhance intestinal absorption Facilitate water retention

500-700 mg sodium/liter for exercise lasting over an hour



Regarding weight loss in athletes, which is the false statement?

Weight loss of no more than 2 pounds a week is recommended.

Losing weight during the “off” season is usually a better idea than losing weight while training and competing.

Fluid can be safely restricted if energy is also restricted when quick weight loss is desired.

Severe calorie restriction in young female athletes can delay sexual maturation


Heat-Related Illnesses

Cold and dehydration

Dehydration may be a concern in the cold.. Why?

Cold air is drier so more evaporative losses from the lungs

Insulated clothing causes sweating Athletes may be reluctant to drink cold

beverages when its cold May limit intake to avoid removing clothing in

order to urinateCopyright 2010, John Wiley &

Sons, Inc.


Heat related illness is characterized by all of the following except:

a) decreased blood volume

b) increased blood pressure

c) rise in core body

temperature

d) reduced sweat production

As an athlete…

How much should you drink?



Recommended Fluid Intake


32 oz in 1 liter8 oz in 1 cup~4 cups in 1 liter


Food and Beverages to Maximize Performance


What Are You Getting From That Sports Bar?


Evaluating the Benefits and Risks of Ergogenic Supplements


Claims, Benefits and Risks of Popular Ergogenic Aids


Caffeine


Impact of Diet versus Supplements


Chapter 13

Copyright 2010 John Wiley & Sons, Inc.

All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information herein.

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