BIO 105-03

Bio 105 Lecture 14 Notes

I. Energy Imbalance

A. Negative Energy Imbalance
B. Positive Energy Imbalance
II. Factors that Affect Body Weight
A. Hunger and Appetite
B. Physiology
1. Physiological feedback mechanisms
a. Basic info
b. Hormones
c. Other physiological feedback mechanisms
C. Genetics
1. Basic info
2. Genetics Differences Found
D. Environment (American)
III. Weight Loss
A. Reasonable rate
B. Long-Term Weight Loss
1. Basic info
2. Diet
3. Physical Activity
4. Behavior
C. Fad Diets
1. Basic info Fad Diets
2. Sensational claims and hype
3. Low-carb Diets
D. Maintaining Weight Loss
E. Extreme Obesity
1. Basic info
2. Treatment
a. Very-low-calorie diets
b. Medication
c. Gastric bypass and gastric banding
d. Liposuction
IV. Healthy Weight Gain
V. Disordered Eating
A. Disordered eating definition
B. Eating Disorders
1. Basic info
2. Anorexia Nervosa
3. Bulimia Nervosa
4. Other Eating Disorders
a. Binge eating disorder
b. Night eating syndrome
5. Treating Disordered Eating Behaviors

Clicker Questions

When would the stomach stop producing ghrelin?
1.Shortly before a meal
2.During a meal
3.Shortly after a meal

A reasonable weight loss goal for an overweight man who weighs 240 pounds is:
1.4 lbs per month
2.6 lbs per month
3.8 lbs per month
4.10 lbs per month

When you eat higher-volume food, what hormone do you increase the amount of time it is released?
1.Insulin
2.Ghrelin
3.CCK
4.Leptin

Jason wants to lose 10 pounds of body fat by increasing his physical exercise. How many calories would he need to burn off to achieve his goal?
1.3,500
2.7,500
3.17,500
4.35,000

Mark wants to gain 5 pounds by increasing his caloric intake. How many extra calories would he need to eat to achieve his goal?
1.3,500
2.7,500
3.17,500
4.35,000

A distorted body self-image is commonly seen in what eating disorder?
1.Anorexia nervosa
2.Bulimia nervosa
3.Binge eating disorder
4.Night eating syndrome
Feedback Loops

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Bio 105 Lecture 15 Notes

I. What Is Fitness?

A. Basic Info
– good health or physical condition, primarily result of exercise and proper nutrition
– exercise is NOT the same as physical activity
– has 5 basic components
B. Fitness Components
– cardiorespiratory endurance
— ability to sustain cardiorespiratory exercise for extended time
— cardiovascular and respiratory systems must provide enough oxygen and energy to muscles
– muscle strength
— ability to produce force for brief time
– muscle endurance
— ability to exert force for a long period of time w/o fatigue
– flexibility
— range of motion around a joint
– body composition
— proportion of muscle, fat, water and other body tissues which make up body weight
C. Fitness Benefits
– fitness provides numerous benefits
— overall health & physical fitness
— reduces risk of cadiovascular disease and type 2 diabetes
— improves body composition, bone health and immune system
— improves sleep and reduces stress
– over half of adults in US do not meet regular physical activity recommendations
D. Fitness Program
1. Cardiorespiratory exercise
– improves cardiorespiratory endurance and body composition
– continuous activities that use large muscle groups
— examples: high impact aerobics, stair climbing, brisk walking
– primarily aerobic because it uses oxygen
— heart rate and stroke volume increased to maximize blood flow delivery to muscles = increased cardiac output
2. Weight training
– improves muscle strength, muscle endurance, and body comp
– to increase muscle strength, low # of repetitions using heavy weights
– to increase muscle endurance – high # of repetitions using lighter weights
3. Stretching
– improves flexibility
4. FITT
a. What it stands for
Frequency / Intensity / Time / Type (see chart in book)
b. Measuring intensity
– RPE: rate of perceived exertion; measure of intensity for cardio exercise
II. Nutrient Use During Exercise
A. Basic energy use
During first few minutes of physical activity
– energy provided by anaaerobic energy production from breakdown of
— adenosine triphosphate (ATP)
— creatine phosphate
– limited amt. stored in cells
As exercise continues
– oxygen intake and aerobic energy production increases
– glucose and fatty acids broken down to yield ATP energy via cell respiration
B. Carb Use During Exercise
1. Basic info
– primary energy source during high-intensity exercise
— liver glycogen maintains normal blood glucose
— muscle glycogen supplies muscles
— blood glucose and stored glycogen lasts for about 2 hours of moderate exercise
2. Intensity effects
– lactic acid is produced at high exercise intensities and shuttled to other tissues
— used for energy during low-intensity exercise
– intensity affects how much glucose and glycogen you use
— glucose and glycogen use increases as intensity increases
– how much carb you need for exercise depends on duration of activity
C. Fat Use During Exercise
1. Basic info
– primary energy source during low-to-moderate intensity exercise
— 2 forms: fatty acids (from triglycerides) in adipose tissue and in muscle tissue
– converting fatty acids into energy is slow and requires more oxygen compared with carbohydrate
— not used very often for high-intensity
2. Intensity effects
– intensity and training affect how much fat you use
— lo-intensity exercise uses mostly fat from adipose tissue
— moderate-intensity exercise also uses fatty acids from muscle triglycerides
— well-trained muscles burn more fat than less trained muscles
— body uses less glycogen and more fat, increases endurance
3. Fat vs. carbs
– fat-burning zone: 65-73% of max heartrate
– “cardio” zone: >73% of max heartrate
– not necessary to stay in fat-burning zone to lose weight
— need to burn calories to produce overall calorie deficit
— hi-intensity exercise burns calories more quickly but can exercise longer with lower-intensity workout
D. Protein Use During Exercise
– protein is primarily needed to build and repair muscle
— muscle damage results from exercise, esp. in weight or str. training
— amino acids needed to promote muscle growth and recovery
– body can use protein for energy if needed
— prefers carb and fat as main energy sources
E. Calorie and nutrient use

F. Timing between nutrient use and exercise
– after exercise, body is in catabolic state
— catabolic = break down
— muscle and liver glycogen stores low
— muscle protein broken down
– nutrients needed to change into anabolic state necessary for optimal fitness
— anabolic = build up
1. Before exercise
– carbohydrate 15-30 min before
— gives muscles immediate energy, spares glycogen stores, helps reduce muscle damage
– consuming protein before:
— increases muscle glycogen synthesis and protein synthesis after exercise is over
– high-fat foods should be avoided before exercise
— takes longer to digest
2. During exercise
– for exercise >1hr, begin carb intake shortly after start and every 15-20 min
— glucose, sucrose, maltodextrin are best choices for quick absorption
– consuming both carb and protein is best for muscle maintenance and growth
3. After exercise
– carb: protein ratio of 3:1
— ideal to promote muscle glycogen and protein synthesis
— promotes faster recovery time
– after exercise meal, withing 2hrs
— hi-carb
— moderate protein
— lo-fat
III. Vitamins and Minerals’ Role in Fitness
A. Basic info
– vitamins and minerals play major role in metabolism for energy during exercise
— don’t themselves supply energy
– multivitamin/minerals supplements and athletic performance
— taking more than RDA will not improve performance during exercise
B. Vitamins’ Role in Fitness
– more oxygen -> more free radicals
— cellular damage caused by exercise
– antioxidants neutralize free rad.
— antioxidant vitamins E & C supplements NOT shown to improve ath. performance
– vitamin C is important for making collagen
— connective tissue can be damaged by exercise
C. Minerals’ Role in Fitness
1. Iron
– low iron levels can reduce hemoglobin (anemia)
– hemoglobin necessary in red blood cells to transport oxygen to cells
– lo hemo causes early fatigue during exercise
– female athl. more at risk for iron-deficiency anemia
– sports anemia: decreased hemo can result from strenuous training due to increased blood volume, but low Red Blood Cells
— not same as iron-deficiency anemia and is self-correcting
2. Calcium
– important to reduce risk of bone fractures
– needed in muscle contraction
– calcium is lost in sweat
– supplements not recommended unless food intake is inadequate
IV. Fluid Intake and Fitness
A. Water/basic info
– water is lost thru sweat and exhalation
– sodium and chloride are electrolytes lost in sweat
— some potassium lost too
— electrolyte imbalance can cause heat cramps, nausea, lowered blood pressure, edema
– evaporation of sweat helps cool body
B. Sports Drinks
– contain:
— 6-8% carb
— sodium & potassium
– beneficial in long endurance events
— quickly replace fluid & eletrolytes
— for events <60 min, water is sufficient to replace fluids and food to replace eletrolytes
– should be avoided as daily beverage
— damages tooth enamel
— can provide unwanted calories
C. Dehydration
– acute dehydration
— not adequately hydrated before sternuous exercise
– chronic dehydration
— not adequately hydrated over extended period of time
— fatigue, muscle sorness, poor recovery from workout, headaches, nausea, dark urine
V. Dietary Supplements

A. Basic info

B. Creatine

C. Caffeine

D. Anabolic steroids

E. Growth hormone

F. Erythropoietin and blood doping

G. Sports bars, shakes, and meal replacements

H. Disease of day: Female Athlete Triad

Clicker Questions

For moderate health benefits, it is recommended that at least __ minutes of moderate-intensity physical activity most days.
1.20
2.30
3.60
4.90

Weight training can improve all of the following except:
1.Body composition
2.Flexibility
3.Muscle endurance
4.Muscle strength

Much of the energy production during cardio-respiratory exercise is aerobic because it uses:
1.ATP
2.Oxygen
3.Creatine
4.Lactic acid

To lose fat, you need to stay within an optimal “fat-burning zone.”
1.True
2.False

After the first 20 minutes, the main fuel your body uses during low-intensity exercise is:
1.Amino acids
2.Fat from adipose tissue
3.Fat from muscle triglycerides
4.Muscle glycogen

Taking a multivitamin/mineral supplement gives you extra direct energy.
1.True
2.False

Overhydration resulting in dangerously low levels of sodium in the blood is called:
1.Hypernatremia
2.Acute dehydration
3.Hyperkalemia
4.Hyponatremia

Which dietary supplement is likely to enhance physical performance the most?
1.Caffeine
2.Steroids
3.Growth hormone
4.Creatine

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