Cardiovascular Fitness Procedures Manual

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1. OVERVIEW OF CARDIOVASCULAR FITNESS

Cardiovascular Fitness in the National Health and Nutrition Examination Survey

(NHANES)

Cardiovascular disease is currently the leading cause of death in the United States for both

men and women. A sedentary lifestyle (along with elevated blood cholesterol levels, hypertension, and

smoking) is a major modifiable risk factor for cardiovascular disease. According to current data however,

only about 24 percent of American adults currently meet the physical activity recommendations outlined

in the 1996 Surgeon General’s Report.

In previous versions of NHANES, no direct cardiovascular fitness assessment components

have been included in the data collection. A cardiovascular fitness component will be included with the

current NHANES.

Cardiovascular fitness is defined as the body’s ability to uptake, transport, and utilize

oxygen. Other terminology that is sometimes used to describe cardiovascular fitness includes VO 2 max,

maximal oxygen uptake, maximal oxygen consumption, and aerobic power.

A maximal treadmill test is considered to be the most valid method of measuring

cardiovascular fitness. By collecting and analyzing expired air during the test, one can directly measure

VO 2 max. This type of testing is done in a clinical setting and is extremely expensive and time

consuming. A 12-lead electrocardiogram (ECG) is typically utilized during a maximal test. Thus,

maximal treadmill testing can be used to diagnose stress induced cardiac arrhythmias and coronary heart

disease. Due to time constraints, test setting, expense, and the large number of SPs in NHANES, it is

neither feasible nor possible to utilize this method to evaluate cardiovascular fitness.

Submaximal treadmill testing will be utilized as a means to estimate cardiovascular fitness

levels during NHANES. Based on variables including gender, age, BMI, and self-reported level of

physical activity, SPs will be assigned to one of eight treadmill test protocols, each varying in difficulty.

Each of the eight protocols was designed so that the SP could walk at all times. The goal of each protocol

is to elicit a heart rate that is approximately 75 percent of the predicted maximum (220-age) by the end of

the test. Each protocol includes a 2-minute warm-up, followed by two 3-minute stages and a 2-minute