EFFECTS OF HIGH INTENSITY INTERVAL TRAINING ON INSULIN RESISTANCE OF CYSTIC FIBROSIS INDIVIDUALS: a controlled, randomized, blinded clinical trial
Cystic Fibrosis, Insulin Resistance, Exercise, Quality of Life, Respiratory Function Tests.
The aim of this study is to investigate the effect of high intensity interval training in cystic fibrosis (CF) individuals affected by insulin resistance. This is a single-blinded randomized clinical trial conducted at the Federal University of Rio Grande do Norte and Paraíba State University. Prepubescent and pubescent boys and girls, with CF diagnose (chloride values ≥ 60 mmol/L on sweat test and/or genetic analysis) are considered eligible for the study. Individuals incapable of executing or understanding the proposed exercise and necessary procedures, pregnant women and exacerbated CF are excluded. Participants are then distributed into control and intervention groups. Both groups receive equal educational intervention through classes and paper guideline. Intervention group receives extra instructions regarding the high intensity interval training. The training program is performed at home with a cycloergometer for lower limbs, 3 times per week, every other day for 8 weeks. The program begins with a 24-minute training, increasing time every two weeks until reaching 35 minutes in the 8th week. Intensity of the exercise is monitored by frequency meter ranging from 30% to 80% of maximal heart beat and by the modified Borg scale which is kept between 5-6 during rest time and 7-8 during high intensity exercise. Individuals are pre-assessed for pubertal stage according to Tanner stages. They are also assessed at baseline, in 8 weeks and in 16 weeks for: I) Primary outcome: metabolic functions (insulin and glycemic curve); II) Secondary outcomes: pulmonary function (spirometry), exercise tolerance (TD3) and Quality of Life (QFC); III) Characterization of the sample: dyspnea (mMRC) and anthropometry. Normative data will be reported by Shapiro-Wilk test, homogeneity between groups will be estimated by OneWay ANOVA or Kruscal-Wallis test and repeated measures associated with Bonferroni will be analyzed through ANOVA to compare the effects of the exercise program. The results are expected to contribute to the treatment of CF with valid information about a monitored and effective aerobic exercise program.