The Reliability and Validity of the Half-Squat Test to Predict Cardiopulmonary Fitness in Men

Abstract

Field tests commonly used to assess cardiopulmonary fitness, such as shuttle run and stepping tests, require either considerable space or bulky and heavy equipment. In addition, the test mode involving running/walking or stepping might not be suitable for certain populations. For example, it might increase the risk of fall in elderly, and might increase discomfort in people with obesity or people with osteoarthritis. Therefore, we attempted to develop a new testing method which can be performed in a small space and is safer when a person performs the test. PURPOSE: The study was to investigate the reliability and validity of the half-squat test to assess cardiopulmonary fitness. METHODS: Eleven healthy men (23 ±2.79 yrs) were recruited. Each subject performed a half-squat test, and a maximal exercise test to determine maximal oxygen consumption (VO2max) in a day. In order to evaluate the intra- and inter-day reliabilities, two half-squat tests were performed on a separate day within one week. When performing the half-squat test, the subject started at standing position with his elbows 90° flexed at the sides of waist. Then, with a custom-made lightweight equipment, the subject was guided to squat down to 45° knee flexion, and at the same time, both arms pushed out. The subject repeated the sequences at a rate of 120 cycles/ min for 3 minutes. Recovery heart rates (HR) (0∼30, 60∼90, 120∼150 seconds), blood pressure and ratings of perceived exertion were measured following the half squat test. The fitness index was calculated as (180*100/ (the sum of recovery HR)*2). RESULTS: The intra-class correlation coefficient (ICC, a measure of agreement) for intra-day was 0.82, indicating high reliability of the half squat test within a day. The inter-day ICC of 0.73 showed an acceptable reliability. Pearson's correlation coefficient showed a significantly high correlation between the half squat test and VO2max(ml O2/kg/min) (r=0.71, p < 0.05). CONCLUSION: The half-squat test is a valid test for evaluating fitness level in healthy men. Future studies on special populations, such as elderly or people with pathological gait, are suggested.