Chapter 1 Flashcards
Body Fat is stored as what in the body?
Triglycerides, stored both in fat (adipose) cells located between the skin and muscles all over the body, as well as within skeletal muscles.
Fit Female body fat range?
21%-24%
Fit male body fat range?
14%-17%
Normal ejection fraction? Exercise ejection fraction?
50%
100%
What is the significant limitation to exercise performance?
the capacity of muscles to extract oxygen from the bloodstream to produce energy. (Note that it is no the inability to breathe fast enough).
What is the energy used to drive the contraction?
ATP, adenosine triphosphate
3 ways the body replenishes ATP>
- Aerobic system
- Anaerobic glycolysis
- Creatine phosphate system.
Mitochondria definition
the site of aerobic energy (ATP) production. The greater the number of mitochondria in a cell, the greater the aerobic energy production capability of that cell.
How does the Anaerobic system work?
In the absence of sufficient oxygen, the muscle relies primarily on the anaerobic systems, which provide a rapidly available source of ATP. the anaerobic production of ATP occurs inside the cell, but outside the mitochondria.
Energy production at rest?
Contrast well-trained vs. non-trained person.
Since the heart is able to supply oxygen to the mitochondria of the muscle cells, both fatty acids and glucose are used to produce ATP. So, ATP is produced aerobically, using both fatty acids and glucose.The body produces about one calorie per minute at rest. About 50$ of this one calories per minute comes from fatty acids, even in an untrained person. In a well0trained endurance athlete, fatty acids provide as much as 70% of the resting caloric expenditure.
What happens when the body can no longer increase its delivery of oxgen into the mitochondria of exercising muscles to aerobically produce enough ATP?
the anaerobic system steps in to rapidly produce ATP. The Anaerobic threshold. This corresponds to the upper limit of sustainable aerobic exercise and it generally occurs in the range of 50% to 85% of maximum effort.
The primary source of anaerobic ATP production is?
What is the secondary source?
Glucose, which is carried in the blood and also is stored in muscles and the liver as glycogen (a large molecule made up of chains of glucose).
The secondary source of anaerobic ATP production is creatine phosphate, a molecule that can be quickly broken apart. There is an extreme limited supply of creatine phosphate. (only about 10 sec worth of max effort)
As long as a muscle cell is aerobic it uses what to produce ATP?
fatty acids and glucose, because the aerobic system uses fat (9 calories caloreis of energy per gram) the aerobic system produces much more ATP than the anaerobic systems.
Byproducts of Aerobic system?
Water and CO2, both are easy for the body to deal with, so aerobic energy production does not lead to muscle fatigue.
Byproducts of Anaerobic ATP?
lactic acid, heat, and hydrogen ions.
Why do we hyperventilate during Anaerobic ATP production?
When inadequate oxygen is available, the muscle signals the brain to increase the rate and depth of breathing. However, the limiting factor is not usually the ability to increase the rate and depth of breathing. It is primarily the ability to extract and use oxygen at the muscle. Hyperventilation is a futile process.
Maximal oxygen consumption definition
AKA VO2 max, the total capacity to consume oxygen at the cellular level. This represents an individual’s maximum aerobic capacity. VO2 max depends on 2 things:
1. the delivery of oxygen to the working muscles by the blood or the cardiac output
2. the ability to extract the oxygen from the blood at the capillaries and use it in the mitochondria. So VO2 max is
(cardiac output max) x (oxygen extraction max)
Client has a HR of 60 bpm, and stroke volume of 70 mL/beat, and oxygen extraction is 6 mLO2/100 mL of blood (so 6%), what is their resting VO2?
60 x 70 = 4200ml Liters per minute x 6% = 252 ml O2/min.
Note that is this patient weighs 70 kg, their VO2 would be 3.6 ml/kg/min
What is one MET?
One Metabolic equivalent is the resting VO2 of 3.5 mL/kg/min
Why does diastolic pressure decrease with exercise?
Because of the dilation of blood vesse;;s in the muscles decreases the amount of periphearal resistance in the vascular system.
Changes in VO2 max for a trained athlete?
- new capillaries are produces in the active skeletal muscles increasing the area for exchange of oxygen
- a significant increase in the mitochaondrial density, which means more of the muscle cell is occupied by mitochondria.
- Increased activity of mitochondrial (aerobic) enzymes.
4 things to consider for the correct type of aerobic exercise?
- the correct type
- the correct frequency
- a sufficient duration
- the proper intensity
Borg’s Rule?
The rate of perceived exertion (RPE)
What does a warmup do?
- increase in the temperature of the muscle and connection tissue, reducing the risk of soft tissue injury.
- allows the cardiovascular system to effectively adjust blood frlow from the abdominal area to the active muscles where the need fro oxygen is increased in response to the exercise while maintaining adequate venous return.