Exercise capacity in lean versus obese women

Abstract

The aim of this study was to assess the nature and magnitude of the differences in submaximal and maximal exercise capacity parameters between lean and obese women. A total of 225 healthy obese women 18-65 years (BMI> or=30 kg/m(2)) and 81 non-athletic lean women (BMI< or=26 kg/m(2)) were selected. Anthropometric measurements (weight and height), body composition assessment (bioelectrical impedance method) and a maximal exercise capacity test on a bicycle ergometer were performed. Oxygen uptake (VO(2)), carbon dioxide production (VCO(2)), expired ventilation (VE), respiratory quotient (RQ), breathing efficiency (VE/VO(2)), mechanical efficiency (ME) and anaerobic threshold (AT) were calculated. At a submaximal intensity load of 70 W, VO(2) (l/min) was larger in the obese women and was already 78% of their peak VO(2), whereas in the non-obese it was only 69% (P=0.0001). VE (l/min) was larger, VE/VO(2) did not differ and ME was lower in obese compared to the lean women. AT occurred at the same percentage of peak VO(2) in both lean and obese women. At peak effort, achieved load, terminal VO(2) (l min(-1) kg(-1)), VE, heart rate, RQ respiratory exchange ratio and perceived exertion were lower in obese subjects compared to the non-obese. Obese subjects mentioned significantly more musculoskeletal pain as a reason to end the test, whereas in lean subjects it was leg fatigue. Lean women recovered better as after 2 min they were already at 35% of the peak VO(2), whereas in the obese women it was 47% (P=0.0001). Our results confirm that exercise capacity is decreased in obesity, both at submaximal and peak intensity, and during recovery. Moreover, at peak effort musculoskeletal pain was an important reason to end the test and not true leg fatigue. These findings are important when designing exercise programs for obese subjects.

Use of Heart Rate Reserve and Rating of Perceived Exertion to Prescribe Exercise Intensity in Diabetic Autonomic Neuropathy

“…Such individuals exhibit an abnormal left ventricular response to isometric and dynamic exercise that is due to a de- Exercise intensity and autonomic neuropathy fective inotropic recruitment, despite the presence of a normal left ventricular contractile reserve (23). Furthermore, as noted previously, obese subjects such as the ones in this study have often been reported to attain lower heart rates and RER values during maximal efforts (15,16). In recognition of these potential risks and limitations of the subject population, the criteria for maximal effort in the present study were established as the attainment of a plateau in oxygen consumption or an RER value of at least 1.0.…”

“…Only those tests in which the subject achieved a plateau in oxygen consumption and/or an RER of Ն1.0 were included in the analyses; this minimum RER was used to allow for the decreased maximal exercise capacity that has been reported in obese individuals with BMIs similar to the subjects in the current study (15,16). HRR and VO 2 R were calculated by subtracting resting heart rate or VO 2 values from their respective peak values; accordingly, for each stage of exercise, the increment above resting for each value was divided by the calculated reserve and multiplied by 100 to get %HRR or %VO 2 R.…”

Exercise does not feel the same when you are overweight: the impact of self-selected and imposed intensity on affect and exertion

“…58 Another possibility, supported by anecdotal reports collected during the present study, is that, as the intensity increases, overweight adults tend to experience more skeletal and muscular aches and pains than normalweight adults. 30,59 These could also lead to a less pleasant or more unpleasant affective experience.…”

Influence of gender, age and BMI on lower limb muscular power output in a large population of obese men and women

“…5,6 The higher fatigability suffered by obese subjects, which are constrained to carry more weight than lean individuals as a consequence of added inert fat mass, has been attributed to several different factors, including chronic physical inactivity, concomitant diseases and chronic pain, as well as poor selfesteem. [7][8][9] Nonetheless, it has been demonstrated that obese patients actually display major motor limitations due to a reduction of both aerobic and anaerobic capabilities, which can be evidenced with adequate functional motor tests suitable for this disabled condition. [10][11][12][13] While reductions in aerobic power interfere with the capability to sustain relatively intense and prolonged exercise, anaerobic power is related to the accomplishment of short and vigorous movements more directly involved in everyday life activities (ie rapidly climbing up a flair of stairs or running to catch a bus) or even in brisk postural adjustments to prevent falls and accidental crushes.…”