Sports & Diabetes

Question 1

what are the most important fuels for muscles?

Answer 1

• carbohydrates and fat

Question 2

what are the types of muscle fibers?

Answer 2

Type I
Type IIA
Type IIB

Question 3

which type of muscle has lots of mitochondria?

Answer 3

Type I

Question 4

which type of muscle has a high content of triglycerides and high HSL (hormone sensitive lipase) activity?

Answer 4

Type I

Question 5

which type of muscle is important in aerobic endurance?

Answer 5

Type I

Question 6

which type of muscle do females have more?

Answer 6

Type I

Question 7

which type of muscle is responsible for slow contraction?

Answer 7

Type I

Question 8

which type of muscle is the fastest to contract?

Answer 8

Type IIB

Question 9

which type of muscle is known as fast-twitch fiber or fast-glycolytic fiber?

Answer 9

Type IIB

Question 10

which type of muscle fiber is important in short-duration anaerobic events and power events?

Answer 10

Type IIB

Question 11

What is the difference between type IIA and type IIB?

Answer 11

Type IIA is similar to type IIB but have a moderate oxidative capacity

Question 12

which muscle fiber is more suited for endurance exercise?

which is more suited for sprinting exercise?

Answer 12

Type I for enedurance and type II for sprinting

Question 13

Skeletal muscle is used for energy during rest for what?

Answer 13

• maintaining electrolytes and Ca gradients via ATP pumps
• maintaining amino acid gradients
• replacing fuel stores lost via oxidation

Question 14

during the fed state, what is the most important tissue for removal of blood glucose following high CHO meal?

Answer 14

Skeletal muscle

Question 15

What do skeletal muscles use as energy during rest?

Answer 15

they oxidize a mixture of fat and carbohydrates

Question 16

during the fed state, what is the main source of energy for skeletal muscles?

Answer 16

Carbohydrates

Question 17

high plasma glucose level during the fed state leads to rapid uptake of what by skeletal muscles? what does this process depend on?

Answer 17

rapid uptake of glucose by skeletal muscles (insulin dependent GLUT4)

Question 18

what is glucose uptaken by the muscles used for?

Answer 18

glycogen synthesis and energy (fuel)

Question 19

why is there no fat mobilization during the fed state in skeletal muscles?

Answer 19

because insulin inhibits lipolysis and stops fat mobilization and insulin is high during the fed state

Question 20

during the fasting state, what is the main energy source for skeletal muscles?

Answer 20

Fat (80-90%)

Question 21

why do we observe a reduction in glucose uptake in skeletal muscles when the body is in fasting state?

Answer 21

because the insulin levels are low and there are therefore less GLUT4 transporters

Question 22

when does mobilization of free fatty acids from adipose tissue occur? why?

Answer 22

during the fasting state because their are low levels of insulin which activates HSL

Question 23

What are the three different energy systems that supply ATP for skeletal muscles during exercise?

Answer 23

1. ATP-CP (creatine phosphate) system
2. Lactic acid system (anaerobic glycolysis)
3. Aerobic system (aerobic glycolysis, TCA, B-oxidation)

Question 24

what are some characteristics of the creatine phosphate or ATP-CP system?

Answer 24

• uses high energy bond of creatine P together with ATP
• muscle concentration of CP is limited and is diminished after 15-25 seconds of heavy exercise (short time period)
• beneficial for high intensity exercise for short duration (100m sprinting)

Question 25

what are some characteristics of the lactic acid system?

Answer 25

- involves glycolytic pathway and production of limited ATP by complete anaerobic breakdown of glucose to lactate - muscle glycogen is the main source of glucose - rapidly produces ATP (but limited amount) for high intensity exercise - main supplier after ATP from CP is depleted - important for high intensity events lasting from 20-75 seconds - lactic acid removed by the liver and other tissues

Question 26

what are some qualities of the aerobic system?

Answer 26

- involves the TCA cycle (carbs, fats and proteins are completely oxidized) - very efficient in producing ATP - main supplier of ATP for exercises lasting longer than 2-3 minutes - oxygen required

Question 27

what are the four major sources of fuel during exercise?

Answer 27

- muscle glycogen - plasma glucose - plasma fatty acids - intra-muscular triglycerides

Question 28

what does the contribution of the 4 sources for fuel during exercise depend on?

Answer 28

- intensity and duration of exercise - level of exercise training - initial muscle glycogen level - supplementation with CHO during exercise

Question 29

A very intense exercise would require more of which source of fuel?

Answer 29

more glycogen

Question 30

the longer the exercise is the more you will need of this fuel source?

Answer 30

glycogen

Question 31

As exercise intensity increases, utilization of what fuel sources increases?

Answer 31

utilization of CHO and fat as energy sources increases

Question 32

As exercise intensity increases up to 65%, oxidation of what increases? what happens to VO2 max?

Answer 32

Fat (tiglycerides) | VO2 max then decreases

Question 33

when do oxidation of both plasma glucose and muscle glycogen increase?

Answer 33

as exercise intensity increases from low to moderate to high

Question 34

At higher exercise intensity, which fuel source provides more than 50% of energy used by muscle?

Answer 34

glycogen

Question 35

ingestion of CHO source (mixture of glu & fru) ________ glucose oxidation.

Answer 35

INCREASE

Question 36

how is intensity of muscular work defined?

Answer 36

can be defined relative to maximum aerobic capicaty (VO2 max)

Question 37

what is VO2 max?

Answer 37

VO2 max = max volume of O2 consumption

Question 38

what is the VO2 max for low intensity, moderate and high intensity exercises?

Answer 38

low intensity= 25% (2-30%) moderate =60% high= 80%

Question 39

in low intensity exercise where does most energy come from?

Answer 39

from muscle triglycerides and blood free fatty acids

Question 40

if a low intensity exercise goes on for an over extended period of time (ex: 2hours) what replaces plasma fatty acids?

Answer 40

plasma fatty acids are replaced by fatty acids mobilized from adipose tissue

Question 41

Fatty acids are the favored energy substrates for intensities up to what % of VO2 max?

Answer 41

up to 50%

Question 42

what happens during a moderate intensity exercise (65% VO2 max) ex: running for 1-3 hours?

Answer 42

- total fatty acid oxidation increases due to oxidation of muscle triglycerides - plasma fatty acid and muscle triglycerides contribute equally to energy expenditure - fat can't be oxidized rapidly enough to provide needed energy - carbohydrates provide half of required energy

Question 43

what happens during strenuous exercise (85% VO2 max)?

Answer 43

- sharp increase in the contribution of carbohydrates (more) - blood glucose and muscle glycogen become the main sources of ATP - blood glucose lvl decreases during exercise due to rapid uptake by muscle and depletion of liver glycogen - hypoglycemia postponed by inhibiting muscle glucose uptake - high rate of carbohydrate catabolism can lead to lactate accumulation due to insufficient oxygen supple

Question 44

what is diabetes?

Answer 44

A disease when the body is unable to metabolize glucose

Question 45

what are the two types of diabetes?

Answer 45

- Insulin-dependent diabetes mellitus (TYPE 1) | - non insulin dependent diabetes mellitus (NIDDM) (TYPE 2)

Question 46

which is the most common type of diabetes?

Answer 46

TYPE 2

Question 47

what are the characteristics of type 2 diabetes?

Answer 47

- target tissues are resistant to insulin (post-binding abnormalities) - compromised synthesis or mobilization of cell's glucose transporters - in skeletal muscles, glucose transporters fail to trans-locate to the plasma membrane - in adipose tissues, depletion in mRNA of glucose transporters - Insulin resistance in obesity is similar to that in adipocytes - at later stages of NIDDM, pancreas losses its ability to produce insulin

Question 48

what are the characteristics of type 1 diabetes (IDDM)?

Answer 48

- inability of B cells (pancreas) to produce and secrete insulin - and autoimmune disease (B cells are targeted by immune response)