Weight loss but not gains in cardiorespiratory fitness after exercise-training predicts improved health risk factors in metabolic syndrome

Background and aims: To examine the relationship between changes in cardiorespiratory fitness (CRF; estimated by VO2 max) and metabolic syndrome (MetS) after an exercise training intervention to confirm/contradict the high association found in cross-sectional observational studies. Methods and results: MetS individuals (54 +/- 8 yrs old; BMI of 32 +/- 5) were randomly allocated (6:1 ratio) to a group that exercised trained for 16-weeks (EXER; n = 138) or a control sedentary group (CONT; n = 22). At baseline, MetS components, body composition and exercise responses were similar between groups (all P > 0.05). After 16 weeks of intervention, only EXER reduced body weight, waist circumference (-1.21 +/- 0.22 kg and -2.7 +/- 0.3 cm; P < 0.001), mean arterial blood pressure and hence the composite MetS Z-score (-7.06 +/- 0.77 mmHg and -0.21 +/- 0.03 SD; P < 0.001). In the EXER group, CRF increased by 16% (0.302 +/- 0.026, 95% CI 0.346 to 0.259 LO2 . min(-1); P < 0.001) but was not a significant predictor of MetS Z-score improvements (r = -0.231; (beta = -0.024; P = 0.788). Instead, body weight reductions predicted 25% of MetS Zscore changes (r = 0.508; (beta = 0.360; P = 0.001). Conclusions: In MetS individuals, the exercise-training increases in CRF are not predictive of the improvements in their health risk factors. Instead, body weight loss (<2%) was a significant contributor to the improved MetS Z-score and thus should be emphasized in exercise training programs. (C) 2018 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.