Effects of short-term, integrated body mass reduction program on maximal oxygen consumption and anaerobic alactic performance in obese subjects

Abstract

The study investigated the effect of a short-term (3-week) body mass reduction program, combining energy-restricted diet, nutritional education, psychological counselling and aerobic exercise training (DEP-AT) on maximal oxygen consumption (VO2max) and anaerobic alactic performance evaluated with different techniques in obese patients (grade II and III). Fifty-three (14 males, 39 females) obese subjects [average +/- SD body mass index (BMI): 41.6 +/- 4.2 kg/m2] were tested before and after the DEP-AT program characterised by a daily conditioning protocol of aerobic exercise on cycloergometer, treadmill and armergometer for a total duration of 35 min at an intensity corresponding to 50% of individual VO2max during the first week of the program and at 60% in the following 2 weeks. VO2max was determined with the cycloergometric indirect method. Short-term alactic anaerobic performance was evaluated with: a) jumping test (5 consecutive jumps with maximal effort, Bosco technique), b) short sprint running test (8m), and c) stair climbing test (modified Margaria test). The DEP-AT program induced a significant weight loss (-4.57 +/- 1.26%, p < 0.001) and a significant VO2max increase (14.1 +/- 20.5%, p < 0.001). After the DEP-AT program, lower limb alactic anaerobic power output, calculated on a per kg body mass basis, increased significantly both in jumping and in stair climbing (20.1 +/- 24.8%, p < 0.001 and 13.5 +/- 19.75%, p < 0.001, respectively), as well as average horizontal velocity during short sprinting (7.2 +/- 17.6%, p < 0.01). Power output was a major determinant of the motor performance, being significantly correlated with: a) vertical displacement of the centre of gravity (R2 = 0.884, p < 0.001) in jumping test, b) vertical velocity (R2 = 0.348, p < 0.001) in stair climbing test, and c) horizontal velocity (R2 = 0.394, p < 0.001) in short running test. In conclusion, short-term DEP-AT program induces significant improvements in both aerobic capabilities and anaerobic performance, possibly through the combination of a number of contributory mechanisms, such as exercise-mediated training, shift in the balance between parasympathetic and sympathetic activity, a weight-loss dependent shift toward a more favourable region of the muscle power-velocity curve, acquisition of a certain degree of motor skill during the conditioning program, improvement of self-esteem and motivation.