Sports & Diabetes Flashcards
what are the most important fuels for muscles?
- carbohydrates and fat
what are the types of muscle fibers?
Type I
Type IIA
Type IIB
which type of muscle has lots of mitochondria?
Type I
which type of muscle has a high content of triglycerides and high HSL (hormone sensitive lipase) activity?
Type I
which type of muscle is important in aerobic endurance?
Type I
which type of muscle do females have more?
Type I
which type of muscle is responsible for slow contraction?
Type I
which type of muscle is the fastest to contract?
Type IIB
which type of muscle is known as fast-twitch fiber or fast-glycolytic fiber?
Type IIB
which type of muscle fiber is important in short-duration anaerobic events and power events?
Type IIB
What is the difference between type IIA and type IIB?
Type IIA is similar to type IIB but have a moderate oxidative capacity
which muscle fiber is more suited for endurance exercise?
which is more suited for sprinting exercise?
Type I for enedurance and type II for sprinting
Skeletal muscle is used for energy during rest for what?
- maintaining electrolytes and Ca gradients via ATP pumps
- maintaining amino acid gradients
- replacing fuel stores lost via oxidation
during the fed state, what is the most important tissue for removal of blood glucose following high CHO meal?
Skeletal muscle
What do skeletal muscles use as energy during rest?
they oxidize a mixture of fat and carbohydrates
during the fed state, what is the main source of energy for skeletal muscles?
Carbohydrates
high plasma glucose level during the fed state leads to rapid uptake of what by skeletal muscles? what does this process depend on?
rapid uptake of glucose by skeletal muscles (insulin dependent GLUT4)
what is glucose uptaken by the muscles used for?
glycogen synthesis and energy (fuel)
why is there no fat mobilization during the fed state in skeletal muscles?
because insulin inhibits lipolysis and stops fat mobilization and insulin is high during the fed state
during the fasting state, what is the main energy source for skeletal muscles?
Fat (80-90%)
why do we observe a reduction in glucose uptake in skeletal muscles when the body is in fasting state?
because the insulin levels are low and there are therefore less GLUT4 transporters
when does mobilization of free fatty acids from adipose tissue occur? why?
during the fasting state because their are low levels of insulin which activates HSL
What are the three different energy systems that supply ATP for skeletal muscles during exercise?
- ATP-CP (creatine phosphate) system
- Lactic acid system (anaerobic glycolysis)
- Aerobic system (aerobic glycolysis, TCA, B-oxidation)
what are some characteristics of the creatine phosphate or ATP-CP system?
- 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)
what are some characteristics of the lactic acid system?
- 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
what are some qualities of the aerobic system?
- 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
what are the four major sources of fuel during exercise?
- muscle glycogen
- plasma glucose
- plasma fatty acids
- intra-muscular triglycerides
what does the contribution of the 4 sources for fuel during exercise depend on?
- intensity and duration of exercise
- level of exercise training
- initial muscle glycogen level
- supplementation with CHO during exercise
A very intense exercise would require more of which source of fuel?
more glycogen
the longer the exercise is the more you will need of this fuel source?
glycogen
As exercise intensity increases, utilization of what fuel sources increases?
utilization of CHO and fat as energy sources increases
As exercise intensity increases up to 65%, oxidation of what increases? what happens to VO2 max?
Fat (tiglycerides)
VO2 max then decreases
when do oxidation of both plasma glucose and muscle glycogen increase?
as exercise intensity increases from low to moderate to high
At higher exercise intensity, which fuel source provides more than 50% of energy used by muscle?
glycogen
ingestion of CHO source (mixture of glu & fru) ________ glucose oxidation.
INCREASE
how is intensity of muscular work defined?
can be defined relative to maximum aerobic capicaty (VO2 max)
what is VO2 max?
VO2 max = max volume of O2 consumption
what is the VO2 max for low intensity, moderate and high intensity exercises?
low intensity= 25% (2-30%)
moderate =60%
high= 80%
in low intensity exercise where does most energy come from?
from muscle triglycerides and blood free fatty acids
if a low intensity exercise goes on for an over extended period of time (ex: 2hours) what replaces plasma fatty acids?
plasma fatty acids are replaced by fatty acids mobilized from adipose tissue
Fatty acids are the favored energy substrates for intensities up to what % of VO2 max?
up to 50%
what happens during a moderate intensity exercise (65% VO2 max) ex: running for 1-3 hours?
- 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
what happens during strenuous exercise (85% VO2 max)?
- 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
what is diabetes?
A disease when the body is unable to metabolize glucose
what are the two types of diabetes?
- Insulin-dependent diabetes mellitus (TYPE 1)
- non insulin dependent diabetes mellitus (NIDDM) (TYPE 2)
which is the most common type of diabetes?
TYPE 2
what are the characteristics of type 2 diabetes?
- 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
what are the characteristics of type 1 diabetes (IDDM)?
- inability of B cells (pancreas) to produce and secrete insulin
- and autoimmune disease (B cells are targeted by immune response)
