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Impact of Obesity on the Cardiorespiratory Response to Exercise: 9398:45 AM – 9:00 AM

Brawner, Clinton A.; Ehrman, Jonathan K. FACSM; Keteyian, Steven J. FACSM

Medicine & Science in Sports & Exercise: May 2006 - Volume 38 - Issue 5 - p S85
Presidential Closing Remarks 12:05 PM – 12:15 PM: Immediately Following President's Lectures ROOM: Ballroom 2/3 and Ballroom 1: E-17 Free Communication/Slide – Clinical Exercise Testing: FRIDAY, JUNE 2, 2006 8:00 AM – 9:45 AM ROOM: 303

Henry Ford Hospital, Detroit, MI


introduction: Although many studies have compared patients who are obese to normal weight controls, data describing peak cardiorespiratory responses across various obesity classifications and grouped by gender is lacking. This study describes the peak cardiorespiratory response to exercise in these patients.

METHODS: 239 subjects were identified through a query of the Henry Ford Preventive Cardiology Outcomes (PRECO) database. Included were subjects 18–80 yr, with no known heart disease, who performed a symptom-limited treadmill test with measured respiratory exchange ratio ≥1 .05. Subjects were grouped by standard body mass index (BMI) classifications. ANOVA was used to assess differences between BMI groups by gender.

RESULTS: Peak VO2 data are shown in table. Among men and women, peak VO2 per kg body mass, absolute peak VO2, and % predicted peak VO2 were significantly different between BMI groups. In both men and women, absolute peak VO2 increased with increasing BMI, while peak VO per kg body mass decreased. Within each BMI group, peak VO2 values (absolute and per kg body mass) were significantly lower in women compared to men. Among the four groups with BMi>25, women achieved a greater % of predicted peak VO2 than did men (99–117% vs 80–101%, respectively).



CONCLUSIONS: In patients with obesity, the absolute ability (VO2, mL/min) of the cardiorespiratory system to respond to an increased demand, such as exertion or general anesthesia during surgery, remains intact. However, in terms of fitness, absolute VO2 is misleading given the marked reductions in relative peak VO2 (mL/kg/ min) observed with higher BMI. New peak VO prediction equations are needed to better express this decrease in relative fitness.

© 2006 American College of Sports Medicine