Aerobic and anaerobic performance before and after a short-term body mass reduction program in obese subjects

The cardiovascular response to an aerobic cycloergometer exercise test (ACE T, 15 min at 60 W, 60 rpm) and the maximally attainable muscle power output , assessed by a stair climbing test (SCT) were evaluated in 60 obese patien ts (41 females and 19 males; age: 18-68 yr; body mass index, BMI: 40.8 +/-4 .8 kg/m(2)) before and after a 3-week body mass reduction (BMR) program, en tailing integrated energy-restricted diet (1200-1500 kcal/day), low-grade a erobic exercise conditioning and individual and/or group psychological ther apy. The daily conditioning protocol (5 days/week) consisted of: 1) 30 min of indoor jogging and dynamic aerobic standing and floor exercises performe d with arms and legs, under the guidance of a therapist; 2) 30 min of cyclo ergometer exercise at 60 W; and/or 3) 4-km outdoor leisure walking on flat terrain. Three weeks of BMR program induced a significant weight loss (-4.5 %; p<0.001), a reduction of systolic (-11<plus/minus>14 mmHg, -7.3%,p<0.001 ) and diastolic (-7<plus/minus>9 mmHg, -7.3%, p<0.001) resting arterial blo od pressure, as well as a reduction of heart rate at rest (-18.6%, p<0.001) , during ACET (-11.3%,p<0.001) and 5 mill thereafter (-14.8%,p<0.001). The subjective rating of perceived exertion in terms of breathlessness and gene ral fatigue during ACET, scored on a 0-100 visual analogic scale, was signi ficantly reduced (p<0.001) after BMR program. A 11.2% decrease in SCT time (p<0.001) was also observed, corresponding to a 9.6% increase (p<0.001) in average muscle power (W) and 14.6% increase (p<0.001) in specific muscle po wer (W . kg(-1)). In conclusion, a combination of energy restricted diet, l ow intensity aerobic exercise and psychological counselling appears to sign ificantly improve both aerobic and anaerobic performance in morbidly obese subjects. Different factors tie, reduction of body mass, shift in the balan ce between parasympathetic and sympathetic activity, a weight-loss dependen t shift toward a more favourable region of the muscle power-velocity curve, acquisition of a certain degree of motor skillfulness during the condition ing program, improvement of self-esteem and motivation) might be responsibl e, alone or in combination, for these short-term positive effects of BMR pr ogram. (C) 2001, Editrice Kurtis.