Second Author: Alan Hardcastle 2.4.1/2.4.2 Nikki Griffin 2.4.3/2.4.4/2.4.5
Physiological Adaptations for Jogging
Understanding VO2 Max
VO2 max is defined as"the highestrate of oxygen consumption attainable during maximal or exhaustive exercise" (3).
The diagram below shows at what point exercise intensity continues without the oxygen consumption increasing.
VO2 Max In Athletes and Non Athletes
VO2 max varies greatly between individuals and even between elite athletes that compete in the same sport. The table below lists normative data for VO2 max in various population groups:
Genetics plays a major role in a person’s VO2 max (11) and heredity can account for up to 25-50% of the variance seen between individuals.
The highest ever recorded VO2 max is 94 ml/kg/min in men and 77 ml/kg/min in women. Both were cross-country skiers (16).
Untrained girls and women typically have a maximal oxygen uptake 20-25% lower than untrained men. However, when comparing elite athletes, the gap tends to close to about 10% (3).
Taking it step further, if VO2 max is adjusted to account for fat free mass in elite male and female athletes, the differences disappear in some studies.
Cureton and Collins (29) suggest that sex-specific essential fat stores account for the majority of metabolic differences in running between men and women.
Determining VO2 Max
VO2 max can be determined through a number of physical evaluations. These tests can be direct or indirect.
Direct Testing:
Direct testing requires sophisticated equipment to measure the volume and gas concentrations of inspired and expired air.
There are many protocols used on treadmills, cycle ergometers and other exercise equipment to measure VO2 max directly.
One of the most common is the Bruce protocol often used for testing VO2 max in athletes or for signs of coronary heart disease in high risk individuals.
Indirect Testing:
Indirect testing is much more widely used by coaches as it requires little or no expensive equipment.
There are many indirect tests used to estimate VO2 max. Some are more reliable and accurate than others but none are as accurate as direct testing.
Examples include the multistage shuttle run (bleep test), 12 minute walk test and 1.5 mile run
-The EDV is the filled volume of the ventricle prior to contraction.
-The ESV is the residual volume of blood remaining in the ventricle after ejection.
**In a typical heart, the EDV is about 120 ml of blood and the ESV about 50 ml of blood. The difference in these two volumes, 70 ml, represents the SV. Therefore, any factor that alters either the EDV or the ESV will change SV.
**SV = EDV - ESV**
-For example, an increase in EDV increases SV, whereas an increase in ESV decreases SV.
Blood pressure is the pressure of the blood against the walls of the arteries. Blood pressure results from two forces. One is created by the heart as it pumps blood into the arteries and through the circulatory system. The other is the force of the arteries as they resist the blood flow.
What do blood pressure numbers indicate?
The higher (systolic) number represents the pressure while the heart contracts to pump blood to the body.
The lower (diastolic) number represents the pressure when the heart relaxes between beats.
The systolic pressure is always stated first. For example: 118/76 (118 over 76); systolic = 118, diastolic = 76.
Blood pressure below 120 over 80 mmHg (millimeters of mercury) is considered optimal for adults.
A systolic pressure of 120 to 139 mmHg or a diastolic pressure of 80 to 89 mmHg is considered "prehypertension" and needs to be watched carefully.
A blood pressure reading of 140 over 90 or higher is considered elevated (high).
How can I tell if I have high blood pressure?
High blood pressure usually has no symptoms. In fact, many people have high blood pressure for years without knowing it. That's why it's called the "silent killer." Hypertension is the medical term for high blood pressure. It doesn't refer to being tense, nervous or hyperactive. You can be a calm, relaxed person and still have high blood pressure.
A single elevated blood pressure reading doesn't mean you have high blood pressure, but it's a sign that further observation is required.
Ask your doctor how often to check it or have it checked. Certain diseases, such as kidney disease, can cause high blood pressure.
In 90 to 95 percent of cases, the cause of high blood pressure is unknown.
*The only way to find out if you have high blood pressure is to have your blood pressure checked. Your doctor or other qualified health professional should check your blood pressure at least once every two years, or more often if necessary.
**Optimal blood pressure with respect to cardiovascular risk is less than 120/80 mm Hg. However, unusually low readings should be evaluated to rule out medical causes.**
Aerobic exercise- is defined as exercise that requires and allows the use of oxygen to replenish energy stores. Your body is working aerobically if your lungs and heart are working overtime to restore you. If it gets your heart pumping (stationary bikes, stair climbers, treadmills, etc) then it is aerobic exercise.
Anaerobic
-So if aerobic exercises uses oxygen to replenish energy, anerobic forces your body to make energy without the use of oxygen.
-Now this doesn't mean holding your breath while doing your exercise, but it means the demand is so much that your body has to get energy from your body's natural chemistry.This type of exercise is usually defined as weight or strength training.
-You are performing isolated, limited movements on specific muscles.
-A lunge, for example, requires a great deal of energy to perform and if you are doing a set of 10 to 15 lunges, you will feel your heart pick up, but you are burning more than oxygen to fill the energy deficit.
You Need Both
A balanced fitness program utilizes both aerobic and anaerobic exercise in order to maximize your fitness. This means using cardio (aerobic) for building endurance, heart and lung health as well as burning calories along with strength training (anerobic) for building muscle strength, burning calories and increasing your overall fitness.
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