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Endress, G1; Tracy, K1; Eisenson, H J.1; Westman, E C.1

Medicine & Science in Sports & Exercise: May 2003 - Volume 35 - Issue 5 - p S33
A-15P Free Communication/Poster Obesity

1Duke University Diet and Fitness Center, Departments of Community and Family Medicine, Duke University Health System, Durham NC

Obesity is a leading contributing cause of death and disability in the United States. The treatment of obesity generally involves caloric restriction and exercise training, but there is limited data examining baseline cardiorespiratory fitness (CRF) in individuals with extreme obesity to guide exercise recommendations.

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To describe the relationship between body mass index (BMI) and CRF in a clinical sample including extreme obesity.

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A consecutive sample of individuals attending a residential lifestyle modification program who completed a CRF test prior to program initiation were included. CRF was measured using a supervised maximal treadmill or leg/arm ergometer test to achieve 85% of age-predicted maximal heart rate, and MET Level (metabolic equivalents) was calculated for each test. Multivariable linear regression was used to assess the relationship between MET Level and demographic variables.

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The sample consisted of 108 individuals. The mean age was 52.9 (SD = 13.6) years, 61.2% were female, 100% were Caucasian. The mean BMI was 41.4 (SD = 9.1) kg/m2, mean MET Level was 7.9 (SD = 3.0), mean Exercise Time was 7.8 (SD = 2.0) minutes; 95.4% of individuals achieved 85% of age-predicted maximal heart rate. The mean MET Levels for the categories of BMI < 35, 35–50, and > 50 kg/m2 were 9.8, 7.8, and 5.7 respectively. The MET Level was lower as BMI increased (p < 0.001), as age increased (p < 0.001), and for women (p < 0.001). A decrease in MET Level of 1 corresponded to an increase in 10 years, or an increase of 40 pounds.

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Cardiorespiratory fitness assessment is important prior to initiation of a comprehensive diet and exercise program to guide a realistic and appropriate exercise regimen. While CRF generally decreases as BMI increases, even those with extreme obesity can achieve high MET levels. We conclude that poor CRF is not an inevitable consequence of extreme obesity.

©2003The American College of Sports Medicine