exercise physiology

how does the body know what’s happening?

a response system

reaction timeline

stimulus→receptors→integrative center→process→reacts

the body responds to a stimuli in order to maintain what

homeostasis

self regulation

maintain stability

steady state

meeting demands of a stimuli

allostasis

when stability occurs through change

what does decrease leptin do

decreases the sympathetic nervous system and increases weight loss and increased appetite/food

what happens when you gain weight

leptin rises which leads to decreased eating and an increased sympathetic system

what is leptin

anoretic hormone, appetite suppressor

what happens with glucose when you eat

eat→glucose enter blood stream(beta cells from pancreas release insulin)→increased insulin

how does insulin decrease glucose levels

it talks to skeletal muscle to increase glucose uptake which ten decreases glucose levels from the bloodstream

what are alpha cells

cells in the pancreas that secrete glucagon

what does glucagon do

tells liver to make glucose

What is homeostasis compared to steady-state to allostasis?

• Homeostasis = keep things constant.

• Steady-state = temporary new balance during activity.

• Allostasis = flexible, anticipatory adjustments for survival.

What is the difference between exercise and physical activity?

Physical Activity

• Definition: Any bodily movement produced by skeletal muscles that increases energy expenditure above resting levels.

• Examples: Walking to class, cleaning your room, gardening, playing with your dog, or taking the stairs.

Exercise

• Definition: A subcategory of physical activity that is planned, structured, repetitive, and done with the goal of improving or maintaining fitness, health, or performance.

• Examples: Going for a 3-mile run, lifting weights 3x per week, attending a spin class, or practicing yoga.

metabolism

the sum of all chemical reactions

anabolic

greater/bigger→endergonic→store E

catabolic

breakdown→exergonic→ release E

bioenergetics

conversion of food stuff to energy

another name/version of energy

ATP

what does ATP do

helps regulate metabolism

enzymes

accelerate reactions to occur and lower the energy activation barrier

what regulates enzymes

ph, temperature, allostatic regulators

what does a high H+ concentration mean

low ph

what does a low h+ conc mean

high ph

what does temperature allow when it comes to enzymes

substrate to bind to active sites

what are the allosteric regulators

atp/adp (critical for energy transformation in the body)

What are the 3 basic goals of digestion and absorption

1. break down nutrients

2. extract nutrients

3. filter toxins

what begins digestion process in the mouth

carbs

what breaks down carbs

salivary amylase

how does salivary amylase get deactivated

low ph

chewing

speeds up process and increase contact time for enzymes, occurs in the mouth

what happens in the SI

carbs are absorbed via capillaries in microvilli

where does glucose travel after carb absorption

portal vein then to the liver

2 places most of the glucose goes

1. released to the general circulation

2. skeletal muscle to store as glycogen

where does the remaining glucose after muscle uptake go

liver and is stored as glycogen

. What route does the liver take to make glycogen from dietary carbohydrate?

indirect and direct pathways

indirect pathway

includes substrates that tend to be lactate, glycerol, and alanine

carb recommendations for athletes 

5-10kg/g of body weight (70%)

carb recommendation for sedentary

40-50%

carb recommendation for pa

60%

the more cho you intake, the greater what

glycogen

protein

act as hormones, enzymes, receptors, and acid base

What nutrient is mainly digested in the stomach?

protein

recommendations for post work out meal for protein 

20-25 g 

recommended protein for sedentary

0.8g/kg of body weight

recommended protein for athlete

1.2-1.6 g/kg of body weight

pepsine

helps digest protein the stomach

where does protein digestion happen

in the stomach

4 fat soluble vitamins

A,D,K,E

fat

a hunger suppressor, most energy dense nutrient

saturated fat

rises LDL(form of cholesterol), does not lower HDL

trans fats

type of saturated fat, rises LDL and lowers HDL

diet recommendations for saturated fat

less Than 7%

diet recommendations for unsaturated fats

10-20%

where does digestion start for fats

mainly in SI

bile

made in liver, but stored in the gallbladder; isolates fat from sticking together: emulsification

What is emulsification and how does it impact fat digestion?

Emulsification is the process by which bile salts break large fat globules into small droplets, increasing surface area for pancreatic lipase to efficiently digest triglycerides into absorbable molecules.

Where does most nutrient absorption take place

SI

How are fats digested

1. fat forms globules in chyme

2. fat globules go under emulsification

3. fat is absorbed by simple diffusion and secreted into the lymph system

4. enters subclavian vein

5. then general circulation

How does insulin favor fat storage?

activates lips protein lipase, helps stimulate synthesis of INTG, converts glucose into glycerol 3-P(glycolysis)

why are carbs important

for energy systems

Name the 3 stages of the cell being able to provide ATP for biological
work.

1. atp

2. PCr

3. glycolysis

hat is the enzyme involved in the CP/ATP reaction

Creatine kinase (Cr)

what does PCr donate

P to ADP, to form ATP

glycolysis

1 molecule of glucose (6 carbons) converted to 2 molecules of pyruvate( 3 carbons each)

What are 2 by-products of oxidative glycolysis

co2, h20, 30 atp

types of glycolysis

non-oxidative and oxidative

where does crab cycle take place 

mitocondria 

why feed the body cho

cho is stored as glycogen, glycogen in muscle can help with ATP, liver

where are cho primary stored

as glycogen in skeletal muscle

what is glycogen

a string of glucose molecules connected together by. alpha bonds

fiber 

connected by beta bonds 

what does the liver supply the body with

primary with blood glucose

What are the 3 ways in which CHO in the body contributes to ATP
generation?

glycolysis, glycogenolysis, oxidation

liver can produce glucose via what enzyme 

glucose -6- phosphate