Improvement or maintenance of each of these functions can have a positive impact on preventing and or delaying the onset of diseases such as diabetes and osteoporosis. Fitness testing provides an opportunity to assess the major components of fitness related health which can be used to assess an individuals risk for disease, modify exercise programs, monitor progression of fitness programs, and educate participants on their fitness levels and act as an incentive by providing an attainable goal for participants.
Before conducting fitness/field test, it is important to determine the reliability, validity, efficiency, economic feasibility, as well as safety considerations associated with conducting each test. Participants should be risk stratified and proper medical clearance should also be attained before conducting any testing. Recommendations as to when exercise testing should take place prior to beginning a physical activity program and when medical supervision is needed to conduct fitness testing are provided by the American College of Sports Medicine. It is also important that participants are well informed on the nature of the testing and informed consent gathered prior to beginning any tests.
Depending on the number of physical fitness tests being conducted for a study, one of the first measures which may be taken is body composition. Body composition refers to the percentage of bone, muscle, and fat that comprises the human body and is often expressed as the relative percentage of fat versus fat�free mass. There are a variety of ways to assess body composition that go beyond the scope of what is covered here. One of the simplest and most commonly used methods is calculating body mass index (BMI). BMI is expressed as weight in kilograms divided by height in meters squared. The BMI is then compared to cut points established by the Expert Panel on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. More complex and precise measures of body composition include underwater weight and Dual X–ray Absorpitometry (DXA). Underwater weighing is considered the gold standard of body composition assessment and can be used to validate all other assessment procedures. In between BMI and underwater weighing there are other measures such as skinfold testing, bioelectrical impedance, measures of circumference, magnetic resonance imaging (MRI) and computed tomography (CT) scans.
Cardiovascular fitness measures the efficiency of the heart, lungs, and vascular system in delivering oxygen to working muscles and is related to the ability to perform moderate�to�high intensity activity over prolonged periods of time. Cardiovascular fitness has been shown to be inversely related to obesity and metabolic risk and premature death. Cardiovascular exercise, which enhances cardiovascular fitness, has also been shown to reduce blood pressure in both hypertensive and normotensive persons (Whelton et al, 2002). In epidemiological studies, cardiovascular fitness testing has been used to show improvement as a result of intervention. Cardiovascular testing has also been used to validate physical activity assessment tools. Cardiovascular fitness can be measured by maximal or submaximal tests depending on the objective, feasibility, and safety concerns of the participant. It's important to keep in mind that for some detrained populations, submaximal testing can be maximal in effect. It's important to have the proper medical supervision for participants and follow testing termination protocols.
Muscular endurance is the ability of a muscle or group of muscles to sustain repeated contractions against a resistance for an extended period of time. Improved muscular endurance can lead to increasing or maintaining proper posture, preventing joint pain, and increasing abilities to perform activities of daily living (Katzmarzyk & Craig, 2002). Studies suggest lower muscular endurance is associated with lower back pain. Muscular endurance testing can be performed at a percentage of the participants 1 repetition maximum (1RM) which can easily be compared during baseline and post testing. Some examples of popular field tests are the flexed–arm hang, abdominal curl–up test, pull–up test, and a push–up test. Be sure to inform participants that muscle soreness may be experienced. Also be aware of proper warm–up, form, and other safety concerns in all populations.
Muscular strength is the ability of your body's muscle to generate force in a short period of time. Muscular strength is positively associated with quality of life and independence and negatively associated with premature mortality and morbidity (Warburton et al, 2001). Muscular strength can be assessed directly by participants completing a 1RM lift. An example of this would be a maximal bench press or squat test. In older or detrained populations, a 1RM lift may be ill–advised for safety concerns in which case submaximal testing is available. Participants should also be aware of the valsalva which can be a safety concern, especially in those with hypertension and therefore proper form and breathing should be stressed to avoid adverse responses.
Flexibility is the absolute range of movement in a joint or series of joints that is attainable in a momentary effort with the help of a partner or a piece of equipment. Flexibility should be important to everyone. Poor flexibility can severely limit an active lifestyle and even hinder the ability to perform activities of daily living such as zippering a dress. Increased flexibility has even been positively associated with increased mobility and independence (Warburton et al, 2001). Flexibility can be measured both directly and indirectly. Direct measures of flexibility such as the goniometer measures displacement between an adjacent segment or a reference period. Indirect methods involve linear measurements between segements. The most common indirect measures of flexibility are the Sit and Reach and the Back Scratch test.
Researchers and participants can obtain important information about their health and fitness through the use of physical fitness testing. Physical fitness testing can be performed as a battery of examinations or individual tests, depending on the study goals. If completed as a batter, the following format should be as follows:
- Body composition
- Cardiorespiratory fitness
- Muscular strength
- Muscular endurance