Download EXPLANATION OF TEST PROTOCOLS Maximal Oxygen

UNIVERSITY OF COLORADO AT BOULDER
COMMUNITY WELLNESS AND PROACTIVE OCCUPATIONAL HEALTH PROGRAM
Department of Integrative Physiology
Campus Box 354, Boulder, CO 80309-0354
Phone: 303.492.0137 or 303.492.7629
Fax: 303.492.4009
EXPLANATION OF TEST PROTOCOLS
Maximal Oxygen Consumption (with ECG)
Maximal oxygen consumption (VO2MAX) is the maximum amount of oxygen that can be used
by the body during high-intensity exercise. Since the body uses oxygen to convert food into
energy, the more oxygen you can consume, the more energy, power, and/or speed you can
produce. Put simply, VO2MAX defines an individual’s aerobic ceiling, or the size of his or her
"engine." Research has shown that VO2MAX is very strongly associated with performance in
endurance-based events such as cycling, triathlon, running, and Nordic skiing. Of course,
VO2MAX is also positively associated with cardiovascular health.
A VO2MAX test involves an incremental increase in exercise effort until the participant is
unable to continue increasing his or her workload. A metabolic cart calculates oxygen
consumption (VO2) by collecting and analyzing the participant's inspired and expired air.
As exercise intensity increases, more muscle mass is employed and more oxygen is
consumed. VO2 will thus increase linearly with exercise intensity until the body reaches
its maximum ability to consume oxygen. At this point, VO2will level off, or plateau,
when the subject reaches his or her VO2MAX.
Concomitant electrocardiogram (ECG) and blood pressure measurements will provide
information about the heart during exercise
Blood Pressure
Blood pressure (BP) is the force exerted against the arterial walls during a cardiac cycle.
Systolic BP occurs during ventricular contraction (systole) as the heart pumps 70-110mL
of blood into the aorta. Diastolic BP occurs when the ventricles relax (diastole), the
arteries recoil, and arterial pressure declines as the heart refills with blood. Normal
resting BP is 110-140mmHg (systolic) / 60-90mmHg (diastolic).
Hypertension (high blood pressure) is a very common condition in modern society. It has
been estimated that one in five U.S. adults suffer from hypertension. In general more men
than women have hypertension. Approximately 5% of hypertension cases are caused by
kidney problems, but causes of the remaining 95% of cases are unknown. Risk factors for
hypertension include race, age, obesity, stress, smoking, and lack of exercise.
The relationship between resting BP and the risk for cardiovascular disease is continuous,
consistent, and independent of other risk factors. Prolonged hypertension damages the
lining of artery walls and accelerates the process of atherosclerosis (hardening and
narrowing of the arteries). The heart must then work harder to compensate for the
narrowed arteries and over time this causes the heart to thicken and stretch. Eventually
the heart fails to function normally, causing fluid to back up into the lungs and reducing
blood flow to vital organs. Reduced blood flow to the heart can cause angina (chest pain)
and eventually the flow may be stopped completely (heart attack). Hypertension can also
lead to kidney failure, stroke, brain damage, and/or impaired vision. Regular monitoring
of resting BP is therefore crucial in the early detection and treatment of hypertension.
Assessment of exercising BP can help diagnose abnormal heart function.
Pulmonary Function Test
Pulmonary function tests (PFTs) provide objective, quantifiable measures of lung
function. They are used to evaluate and monitor diseases that affect heart and lung
function, to monitor the effects of environmental, occupational, and drug exposures, to
assess risks of surgery, and to assist in evaluations performed before employment or for
insurance purposes.
Spirometry, the most widely used PFT, is the measurement of the movement of air into
and out of the lungs during various breathing maneuvers. Spirometric testing is
recommended for all smokers over the age of 45 and in any person presenting with
dyspnea, chronic cough, wheezing, or excessive mucus production.
In a spirometry test, a person breathes into mouthpiece that is connected to an instrument
called a spirometer. The spirometer records the amount and the rate of air that is breathed
in and out over a specified time. Some of the test measurements are obtained by normal,
quiet breathing while other tests require maximal forced inhalations or exhalations.
There are several types of lung diseases. Obstructive-type pulmonary diseases refer to
pathophysiologies in which the exhaled airflow is decreased by a narrowing or blockage
of the airways, such as asthma, emphysema, and chronic bronchitis. Restrictive-type
pulmonary diseases refer to a decrease in the total volume of air that the lungs are able to
hold, often due to a decrease in the elasticity of the lungs themselves or caused by a
problem related to the expansion of the chest wall during inhalation.
Body Composition Analysis
Body composition is the technical term used to describe the different components of the
human body that, when added together, make up a person's total body weight. These
components include lean muscle mass, organ mass, bone mass, and adipose (fat) tissue.
In particular, knowledge of the relative amount of body fat is helpful in many regards.
There is a strong association between excess body fat and increased risk for hypertension,
hyperlipidemia, heart disease, the metabolic syndrome, type 2 diabetes, and certain types
of cancer. On the other hand, a very low level of body fat may also be detrimental and
indicative of disordered eating patterns.