NUTR 546 Exam 1

energy content of carbs

4 kcal/g

energy content of fats

9 kcal/gram

energy content of proteins

4 kcal/g

energy content of alcohol

7 kcal/g

total energy expenditure composed of

physical activity, thermic effect of food, resting metabolism

physical activity composed of

total energy activity: energy expenditure during exercise, non-exercise activity thermogenesis

components of resting metabolism

resting metabolic rate, basal metabolic rate

a measure of the amount of energy per unit of timer necessary to keep the body alive at complete rest

BMR

the amount of energy required by the body to maintain a non-active but alert state

RMR

RMR is what percent higher than BMR

10%

energy required for the digestion and absorption of food

thermic effect of food

thermic effect of food estimated to be what percent of total caloric intake

10%

what is the most variable aspect of total energy expenditure

physical activity

largest contributor to total energy expenditure

RMR and BMR (resting metabolism)

smallest contributor to total energy expenditure

thermic effect of food

three methods used to measure energy expenditure

1. Doubly labeled water

2. direct calorimetry

3. indirect calorimetry

4. wearable fitness devices

measures changes in heat energy

direct calorimetry

measures changes in O2 and CO2 out as oxygen consumption

indirect calorimetry rest

measures changes in O2 and CO2 out and Vo2 max

indirect calorimetry during exercise

two equations used to calculate resting metabolic rate

1. Harris benedict equation

2. Cunningham equation

what factors influence individuals resting metabolic rate

weight, age, height, FFM (body composition)`

five body composition methods used to determine fat free mass

1. hydrodenisty

2. plethysmography

3. skin fold measurement

4. bioelectrical impedance analysis

5. dual energy X-ray absorption (DEXA)

Based on low intensity X rays

DEXA

based on electrical current conductivity

Bioelectrical impedance analysis

estimates subcutaneous fat stores

skin fold measurements

uses air displacement to measure volume

plethysmography

underwater weighing

hydrodensity

measures the average amount of error in predicting the dependent variable using a regression equation. It quantifies the variability of the predicted values around the actual values.

standard error of the estimate

two hormones that regulate blood glucose

1. insulin

2. glucagon

stimulates cell to intake glucose, stimulates muscle and liver to store glucose as glycogen, stimulates storage of amino acids and fat

insulin

stimulates mobilization of amino acids and fat, stimulates gluconeogenesis, stimulates liver to release stored glucose

glucagon

Arnold had a rough year, and wants to gain more muscle in hopes of improving his performance. What state of nitrogen balance should Arnold strive to remain in?

Positive nitrogen balance

why eating fat is important

• fat soluble vitamins

• essential fatty acids (ALA and LA)

ways of measuring caloric intake

1. written food journal

2. tracking apps

3. 24 hour recall

4. food frequency questionaires

errors when measuring caloric intake

1. portion sizes

2. missing items - fluids or condiments

3. writing it down may change behavior

ISSN calorie recommendation for general physical activity 30-40 mins/day 3 times a week

25-35 kcal/kg/day

ISSN calorie recommendation for moderate levels of intense training 2-3 hours/day 5-6 times a week and high volume intense training 3-6 hours/day 1-2 session/day 5-6 times a week

50-80 kcal/kg/day

ISSN calorie recommendation for elite athletes

150-200 kcal/kg/day

ISSN calorie recommendation for large athletes

60-80 kcal/kg/day

one chemical step, fast, anaerobic, 5-10 sec duration

Creatine phosphate energy system

fatigue associated with Creatine phosphate energy system

CrP depletion

Creatine phosphate energy system used in what exercise

power high intensity events

how many ATP per CrP molecules

one

how do you load creatine

20-25 g/day for 5-6 days or 3 g/day for 1 month

what does creatine loading do

increases Cr and CrP by 20%

energy systems

1. creatine phosphate

2. anaerobic glycolysis

3. oxidative phosphorylation

rate limiting step of anaerobic glycolysis

phosphofructokinase step

where does lactate go to be recycled

liver

converts lactate produced by muscle cells during anaerobic exercise into glucose in the liver. Glucose is then released back into the bloodstream to provide energy for the muscles. Allows for the recycling of lactate and helps maintain blood glucose levels during prolonged exercise.

Cori Cycle

fast, anaerobic, 1-2 min duration

anaerobic glycolysis

fatigue associated with what in anaerobic glycoclysis energy system

decreased blood pH

how many ATP per glucose and per glycogen

2 ATP via glucose and 3 ATP via glycogen

slowest, potentially limitless duration, aerobic

oxidative phosphorylation (fats only)

predominant energy system in endurance exercise

oxidative phosphorylation (fats, CHO)

predominant energy system in high intensity exercise

anaerobic glycolysis

how many ATP per palmitate (16 C FFA)

113

how many ATP per glucose and glycogen in oxidative phosphorylation

32 ATP via glucose and 33 via glycogen

fatigue associated with what in CHO oxidative phophorylation

depleted muscle glycogen

types of oxidative (aerobic) phosphorylation

1. fatty acids (triglycerides) - lipolysis/ boxidation- krebs - ETC

2. carbohydrates (glucose or glycogen) krebs - ETC

3. protein (amino acids) krebs - ETC

ACSM activity factors

1.8-2.3

starch and glycogen is broken down into what

maltose

where does starch and glycogen begin to be broken down

in the mouth

where does lactose, maltose and sucrose begin to get broken down

small intestine

how does glucose/galactose get absorbed in digestive tract

SGLT carrier protein

how does fructose get absorbed in digestive tracts

carrier protein GLUT-5

what does glucose metabolism depend on

1. type of cell

2. enzymatic capability of the cell

3. intensity of exercise

4. energy state

5. training history

where is more glycogen stored in muscle or liver

muscle

athletes have higher glycogen levels about how much more at rest

20-30%

how can excessive CHO be turned into fat

1. gluconeogenesis

2. overlap during oxidation phosphorylation

3. lipogenesis takes place in liver or adipocytes

overall sports nutrition goal

1. avoid hunger

2. delay fatigue

3. minimize GI distress

4. prevent hypohydration

CHO intake before exercise recommendation

1. avoid fiber

2. moderate protein

3. avoid high fat

4. high carbs

how many g/kg CHO before exercise

1-4 g/kg 1-4 hours before

CHO intake after exercise timing, meal size and type of CHO

asap within 2 hours, smaller more frequent meals, food or bev mostly glucose and/or sucrose

specific g/kg/h CHO recommendations after

1-1.2 g/kg/hr for first 4 hours

what percent CHO solution of CHO do you want during exercise

6-8% CHO solution

how much CHO do you want when exercising

30-60 g/hour

what kinds of CHO

combination of glucose, and fructose

essential amino acids

Phenylalanine

Valine

Tryptophan

Threonine

Isoleucine

Methionine

Histidine

Lysine

Leucine

(PVT TIM HLL)

quality of protein PDCAAS

Protein

Digestibility

Corrected

Amino

Acid

Score

quality of protein DIAS

digestible

indispensible

amino

acid

It indicates the state of protein metabolism and can be positive (anabolic) or negative (catabolic). Positive balance occurs during growth or muscle building, while negative balance may result from illness or inadequate protein intake.

Nitrogen Balance

net protein balance

Net protein balance refers to the difference between protein synthesis (anabolic process) and protein breakdown (catabolic process) in the body. A positive net protein balance indicates that protein synthesis exceeds protein breakdown, leading to muscle growth and tissue repair. Conversely, a negative net protein balance indicates that protein breakdown exceeds protein synthesis, resulting in muscle loss and tissue damage. Net protein balance is influenced by factors such as exercise, nutrition, and overall health status.

occurs when synthesis of proteins is greater than their breakdown

anabolic state (MPS)

breakdown of complex molecules into simple ones

catabolic state

consumption of sufficient kcal (CHO and fat) protect protein from being used as energy

protein sparing effect

the academy daily protein need range

1.2-2.0 g/kg/day

ISSN recommendation of protein for general fitness

0.8-1.0 g/kg BW

ISSN recommendation of protein for older individuals

1.0-1.2 g/kg BW

ISSN recommendation of protein for moderate amount of intense training

1.0-1.5 g/kg BW

ISSN recommendation of protein for high volume intense training

1.5 -2.0 g/kg BW

newer recommendations suggests how much protein every 3-5 hours

0.3 g/kg

urea synthesis ___________ be increased in response to exceptionally high protein intake

cannot

high protein intake can lead to

elevated blood ammonia levels because urea synthesis cannot be increased

up to how much protein without adverse effects

2.5 - 3.5 g/kg day

more research needed for protein recommendations …

before and during exercise

how much protein after

20 g protein with CHO 30 mins post exercise

how much essential AA within 2 hours after exercise

10 g

which amino acid is an independent stimulator

leucine h

how much leucine per meal

3-4 g per meal

what protein is high in leucine content

whey protein