Lab #9 Exercise Physiology Flashcards
Define aerobic metabolism
The process where oxygen is used to make energy from glucose
Define anaerobic metabolism
The process that makes glucose without oxygen’s presence.
Give an example of aerobic exercise and explain the primary source(s) of energy.
An example is running, which is an endurance exercise. The primary energy source will be fat. Fat breakdown yielding ATP is lipolysis. The rate of lipolysis is a limiting factor for acquiring ATP. As LIPOLYSIS incorporates overall muscle energy there will be a decrease as contraction INTENSITY increases. In the presence of glycogen DEPLETION, the rate of lipolysis will not be sufficient to reach the exercise’s demand. Depletion leaves few glycogen stores ready for resting muscle activity. Decreasing intensity will spare glycogen to avoid depletion.
What is the source of all muscle contractions?
ATP
When is energy released?
When it’s broken into ADP + Pi
What does ADP + Pi stand for?
adenosine diphosphate and a phosphate group
What is the limiting factor of skeletal muscles?
the ability to maintain the availability of ATP for muscle contraction
ATP is stored in large amounts in skeletal muscles (T/F)
( F ) ATP is not stored in large amounts in skeletal muscles
Where do viable sources of ATP come from?
anaerobic and aerobic means
anaerobic
does not require O2
aerobic
requires oxygen
What does the primary energy source for a given activity primarily DEPEND ON?
the INTENSITY of muscle contractions
The 2 main anaerobic sources of ATP
1) phosphocreatine (PCr)
2) anaerobic glycolysis
What are intramuscular PCr stores used for?
rapid high-intensity contractions
Con of intramuscular PCr stores.
are depleted in 8-10 seconds AND take several minutes to replenish
100 m sprint is an example of what?
PCr which provides the majority of energy
Pro of PCr stores.
ability to perform repeated bouts of near-maximal energy
What is anaerobic glycolysis?
breakdown of glucose (glycolysis) –> pyruvate
Oxygen’s effect on pyruvate.
in the ABSENCE of oxygen, pyruvate is CONVERTED to lactic acid
In muscle fibers, ___ is made available through the breakdown of muscle ___ stores.
glucose; glycogen
Anaerobic glycolysis is limited to the availability of what? aka what is the limiting factor
the accumulation of LACTIC ACID and other metabolites
Anaerobic:
Pro of anaerobic glycolysis?
ability to perform high-intensity exercise w/ duration of 1-2 minutes
Example of anaerobic glycolysis.
400 m swimmer
800 m race
What is aerobic glycolysis? (simple)
occurs when oxygen is available to breakdown pyruvate
Breakdown of pyruvate yields what?
ATP through chemical reactions that occur in the Krebs cycle & ETC
What is the similarity between anaerobic and aerobic metabolism?
glucose can be obtained from stored glycogen
Glycogen stores are plentiful, and what does this mean?
therefore glycogen DEPLETION is only a concern for athletes who are continuously exercising for more than 90 minutes or intermittent exercise over substantially longer periods of time
Who is more prone to becoming glycogen depleted?
endurance athletes, marathon runners
A phrase referred to as glycogen depletion to athletes
“hitting the wall”
How do athletes avoid glycogen depletion?
“carbo load” ahead of contest; manipulates carbohydrate content of one’s diet to MAXIMIZE glycogen stores
The most abundant energy source available to muscle fiber is ___?
fat
What is lipolysis?
the breakdown of fat to yield ATP
What is the limiting factor of fatty acids?
the rate at which lipolysis occurs to obtain ATP
Lipolysis is responsible for …. ?
resting muscle activity
Lipolysis’s contribution to overall muscle energy supply?
will DECREASE as contraction intensity INCREASES
Example of lipolysis’s responsibility
1) glycogen depletion occurs when the rate of lipolysis CANNOT meet the energy demand of exercise
2) reliance on glycolysis EXPANDS the available glycogen stores
When does exercise intensity reduce dramatically?
once glycogen depletion occurs
A small ___ ( increase/decrease ) in intensity earlier in the exercise bout would spare glycogen sufficiently to ___ ( encourage/ avoid ) depletion.
decrease; avoid
Name 3 macronutrients
carbohydrates, fat, and protein
1g carbohydrate = ___ kcal
1 g carbohydrate = 4.0 kcal
1 g fat = ___ kcal
1 g fat = 9.0 kcal
1 g protein = ___ kcal
1 g protein = 4.0 kcal
What is body composition?
relative proportion of either actively metabolizing tissues OR lean body mass & fat tissue in body
Body mass index (BMI)
finding body composition by using height-to-weight ratio
BMI examples
skinfold calipers, underwater weighing, & bioelectric impedance
The gold standard to body composition testing is ___, which is also the most expensive and inconvenient.
underwater weighing
A BMI of over ___ places a person at high risk of diseases of obesity. A BMI of under ___ is considered healthy, and a BMI in the range of ___ is optimum.
30; 27; 23-25
According to the American Heart Association, a waist-to-hip ratio above ___ for MEN and above ___ for WOMEN is associated with an INCREASED risk of cardiovascular disease
1.0; 0.8
BMI calculations
BMI= body weight (kg) / height2 (m2)
1 kg = ___ lbs
1 kg = 2.2 lbs
1m = ___ inches
1m = 40 inches
1 lb body weight = ___ kcal
1 lb body weight = 3500 kcal
location of ATP production in anaerobic metabolism
CYTOSOL of muscle cell
location of ATP production in aerobic metabolism
MITOCHONDRIA of muscle cell
ATP-PCr: what substrate is used for energy?
PCr
anaerobic glycolysis: what substrate is used for energy?
glucose
aerobic glycolysis: what substrate is used for energy?
glucose, amino acids, and fatty acids
ATP-PCr: where is the substrate stored?
muscle
anaerobic glycolysis: where is the substrate stored?
blood glucose, liver storage, & muscle storage
aerobic glycolysis: where is the substrate stored?
liver, muscle, adipose tissue, & triglycerides muscle
ATP-PCr and anaerobic glycolysis are both which rate of ATP production?
FAST
aerobic glycolysis is which rate of ATP production?
SLOW
Give an example of anaerobic exercise and explain the primary source(s) of energy.
An example is sprinting, which is a high-intensity exercise. The primary energy source will be carbohydrates. Carbohydrates such as glucose will be made available via glycogen stores and depend on lactic acid accumulation
Using your resources, give three reasons why an elite athlete or a trained individual has a higher metabolism than a person who is sedentary or a couch potato.
An elite athlete or trained individual utilizes more fat substrates as their primary fuel source from their aerobic respiration. This holds their endurance for long durations, allows their body to find cadence and rhythm quickly, and meet the body’s oxygen demand. On the other hand, a couch potato would utilize carbohydrate substrates as their primary fuel source from anaerobic respiration. This is due to their inability to deliver proper oxygen levels. An elite athlete/trained individual would also have a higher cardiac output during exercise.
1) digest and convert macronutrients fast to be utilized at any time and at a maximum output of energy
2) exercising builds muscle mass and increases resting metabolic rates
3) increases amounts of mitochondria in muscle cells (location for ATP production in aerobic energy system), increasing energy metabolism
Using your weight data from the semester, calculate if there was weight loss or weight gain. After determining that, given that 1 lb of body weight is equal to approximately 3500 kcal, how many calories did you lose or gain over the course of this semester? Show your work.
Given:
1lb body weight = 3500 kcal
Old weight: 161.70 lbs
New weight: 169.89 lbs
Weight loss/gain = (x) kcal
I gained 28,665 kcals over the course of this semester.
Calculate BMI
Given:
BMI = weight (kg) / height2 (m2)
Height: 1.60 m
Weight: 77.06 kg
1 foot = 12 inches
1 m = 40 inches
1 kg = 2.2 lbs
BMI = (x) kg/m2
1.6 m x 1.6 m = 2.56 m2
77.06 kg / 2.56 m2 = 30.01 kg/m2
BMI = 30.10 kg/m2
Calculate waist-to-hip ratio
Given:
waist at navel: 98 cm
hips at greatest circumference: 107 cm
waist circumference by hip circumference ratio: (x) cm
0.92 cm
Estimate BMR (way 2)
Given:
weight (kg) * (females multiply by 0.7 kcal/kg/hr, males by 1.0)
weight: 77.06 kg
53.94 kcal/hr
Answer from “slide 68” * 24 (hours/day)
1294.56 kcal
Anaerobic energy system:
ATP-PCr duration of energy availability
short duration, 8-10 seconds
Anaerobic energy system:
anaerobic glycolysis duration of energy availability
short duration, 1-2 minutes
Aerobic energy system:
aerobic glycolysis
long duration, greater than 90 minutes
Carbohydrates
-break down into glucose
-source: glucose in plasma (from liver storage) & glycogen in muscle (muscle storage)
Fat
-breaks down into fatty acids in plasma
-source:
-storage: adipose tissue in muscle triglycerides
Protein
breaks down into amino acids
-source: muscle storage of amino acids
What are the best sources of carbohydrates for your nutrition?
Brown rice, potatoes, vegetables, and whole grains
What are the best sources of fat for your nutrition?
Vegetable oils, nuts, and fish
What are the best sources of protein for your nutrition?
Meat, poultry, and eggs
Your patient wants to lose 2 lbs per week.
1. How many calories per day would you need to reduce to lose 2 pounds per week.
2 lbs. 3500 kcals
——- —— = 7000 kcals
(x) kcals. 1 lb body weight
7000 kcals. 1 week
—————– ————— = 1000 kcals/day
1 week 7 days
