Cardiorespiratory Fitness and Sedentary Lifestyle in the Morbidly Obese

Abstract

Background: Sedentary lifestyles and poor physical fitness are major contributors to the current obesity and cardiovascular disease pandemic. Hypothesis: Daily physical activity and cardiorespiratory fitness are correlated in morbidly obese individuals in their free-living environment. Methods: Ten morbidly obese participants continuously wore an activity sensor that measured caloric expenditure, minute-by-minute physical activity, and steps/day over a 72-h period. Following collection of the device data, structured cardiorespiratory fitness testing was performed on each subject. Results: Mean caloric expenditure for all individuals was 2,668±481 kcal/d. On average, subjects took 3,763±2,223 steps. On average 23 h and 51.6 min per d were spent sleeping or engaged in sedentary activity (<3 metabolic equivalents [METs]) and the remaining 8.4 min were spent in moderate activity (3-6 METs). Average peak VO 2 was 16.8±4.7 mL/kg/min. Higher peak VO 2 correlated with higher total caloric expenditure (TCE; r = 0.628, p = 0.05) and trended with higher steps/day (r = 0.591, p = 0.07). Conclusions: Most morbidly obese participants in this study were markedly sedentary. These study results may provide important links between obesity, poor fitness, and cardiovascular disease.

Effect of Weight Loss on Aerobic Capacity in Patients with Severe Obesity Before and After Bariatric Surgery

“…Previous studies have shown that obesity is associated with a high expenditure of energy needed to move a greater corporal mass [13,14]. This high expenditure of energy reduces exercise capacity and shortens the duration of the test [5].…”

“…However, it remains to be determined whether poor physical fitness and sedentary lifestyle is an important characteristic of these patients [5].…”

“…One study reported that severely obese individuals have extremely reduced cardiorespiratory fitness [4][5][6]. Another reported that these patients show a reduced exercise capacity compared to non-obese individuals and suggested that metabolic demand is increased by the extramuscular work necessary to compensate for the excess in body mass [7].…”

Bariatric Surgery and Cardiovascular Risk Factors

“…45,186,187 According to 1 report, exercisers lost an average of 6.1 kg more than inactive patients, suffered less depression and anxiety, and had higher scores in general health. 187 Because severely obese individuals are often completely sedentary, 188 they should be strongly encouraged to engage in regular walking so that they can move out of the least fit, least active, "high-risk" cohort. Surgically induced weight loss can also increase peak heart rate, respiratory exchange ratio, and relative oxygen consumption (mL ⅐ kg Ϫ1 ⅐ min Ϫ1 ), augmenting the exercise capacity.…”

Counterregulation of insulin by leptin as key component of autonomic regulation of body weight

“…At this point, the attention should be brought to the fact that spontaneous locomotion and physical activity levels are, like meal-to-meal eating, under nonhomeostatic control although their interaction brings about the stability of adult body weight [284] . Cross-sectional human data show that total non-basal energy expenditure normalized for body mass is inversely related to body fat [285,286] , and that morbidly obese individuals are almost completely inactive [287] . On the other extreme, underweight subjects with anorexia nervosa are known for compulsive running, "drive for activity", and "restlessness" [288,289] .…”