The Association between Obesity Indices and Physical Fitness

ABSTRACT

BACGROUND Physical fitness is defined as the ability to carry out work necessary for muscle exercise satisfactorily. Generally, obese person have been considered to have low physical performance. In addition, obesity has been known to be a risk factor of cardiovascular disease such as hyperlipidemia, hypertension, and coronary arterial disease. Based on previous epidemiologic studies, abdominal obesity, especially, visceral obesity, is thought to be more important risk factor for cardiovascular disease rather than obesity itself. Therefore, the interest on assessment of abdominal visceral fat has been increasing. The aim of this study was to see the difference in physical fitness and blood pressure according to obesity degree assessed by BMI, and compare the anthropometric obesity indices with abdominal visceral fat accumulation measured by abdominal CT (Computed Tomogram). METHODS: Four hundred thirty-two subjects, who participated in the exercise program for more than one month duration at the 'Clinic for Obesity' in St. Mary's Hospital from November 1998 to June 2000, were included in the analysis. They were categorized into 4 groups [severe obesity group (BMI 30), obesity group (25 BMI <30), overweight group (23 BMI<25), normal group (BMI<23)] according to their BMI. Blood pressure, anthropometric obesity indices and physical fitness (V02 max, back muscle strength, sit up, forward bending, vertical jump, side step, balance) were measured by one skillful exercise trainer. Among them, one hundred thirty-one subjects performed abdominal CT to assess visceral fatness. We compared anthropometric indices (waist to hip ratio, body mass index, abdominal circumference, skin foldness) with abdominal visceral fat accumulation measured by CT. RESULTS: Blood pressure, cardiovascular endurance, muscular endurance, muscle strength, speed and balance were significantly different among the four groups categorized by BMI in both sexes, but flexibility and agility were not significant. In women, the correlation coefficients between visceral fat area measured by abdominal CT and each of waist to hip ratio, BMI, abdominal circumference, and skin foldness adjusted for age were 0.487, 0.479, 0.464, 0.31, respectively (P<0.01). However in men, there were no significant correlations. CONCLUSION: Obesity tended to increase blood pressure, and reduce physical performance. Only in women, obesity related indices reflected the abdominal visceral fat accumulation.