HIGH-INTENSITY INTERVAL VS. CONTINUOUS ENDURANCE TRAINING: PREVENTIVE EFFECTS ON HORMONAL CHANGES AND PHYSIOLOGICAL ADAPTATIONS IN PREDIABETES PATIENTS

Safarimosavi, S, Mohebbi, H, and Rohani, H. High-intensity interval vs. continuous endurance training: Preventive effects on hormonal changes and physiological adaptations in prediabetes patients. J Strength Cond Res 35(3): 731-738, 2021-The aim of this study was to examine the effects of a 12-week high-intensity interval training (HIIT) intervention, or an isocaloric continuous endurance training (CET) intervention on insulin resistance indices and change in irisin and preptin in patients with prediabetes. Thirty-two prediabetic male patients (age = 38.7 +/- 4; body mass index = 26.9 +/- 1.4 kg.m(-2); and (V)over doto(2)peak = 2.49 +/- 0.22 L.min(-1)) were randomly assigned into 3 training groups (N = 8). These groups were matched based on the required energy expenditure (EE) for completing each protocol: (a) HIIT (10 x 60 seconds at 90% peak oxygen uptake [(V)over doto(2)peak], 1: 1 work to recovery at 50 W), (b) CET at an intensity equivalent to maximal fat oxidation (Fatmax) (CETFAT) (pedaling for a duration that expends an equivalent EE to an HIIT session [E approximate to HIIT]), (c) CET at an intensity equivalent to anaerobic threshold (CETAT) (E approximate to HIIT), and (d) the control group (CON): continued to perform their daily activities. After intervention, blood glucose levels were significantly (p < 0.05) lower in the HIIT group compared with CETAT group. Exercise training improved the insulin resistance index by 35, 28, and 37% in CETFAT, CETAT, and HIIT groups, respectively. Irisin concentrations in the HIIT and CETAT groups was significantly (p < 0.05) decreased compared with the pre-training values. Also, HIIT and CETFAT resulted in significant (p < 0.05) changes in preptin concentration compared with baseline. This study demonstrated that both HIIT and CETFAT protocols had similar effects on the insulin resistance index of prediabetic patients. Also, the intensity and type of exercise were effective factors in changing irisin and preptin concentrations.

Automated summary

The study showed that high-intensity interval training (HIIT) and isocaloric continuous endurance training (CETFAT) have similar effects on improving the insulin resistance index of prediabetes patients. Additionally, the intensity and type of exercise were found to be crucial factors in changing irisin and preptin concentrations.