The Effects of Eight-Week High-Intensity Intermittent Training on Body Composition, Aerobic and Anaerobic Performance, Lipid Profile and Hematological Indices in Sedentary Healthy Overweight Adolescent: A Comparison of Volume

Background: Research on the effects of high-intensity intermittent training (HIIT) with different volumes on cardiovascular risk factors is limited. Objectives: The current study aimed to determine the effects of eight-week of high-intensity intermittent training and to compare the volumes of training programs on body composition, fitness factors, and cardiovascular risk factors in overweight students. Methods: There were thirty overweight boys (13 - 16years) as the participants of the study who were randomly divided into three groups, including the control group (n = 10), HIIT-1 (n = 10), and MIIT-2 (n = 10). The HIIT-1 group program included 2 × 8 - 15 sets (100 - 110% MAV), and the HIIT-2 group training program included 4 × 4 - 6 sets (100 - 110% MAV). These training programs continued three times a week for eight weeks. Yo-Yo recovery test, RAST test, and ELISA technique were applied to measure aerobic and anaerobic performance, lipid profile, and hematological indices, respectively. Results: The findings showed that except for anaerobic performance and hematological variables in the HIIT-1 group and hematological variables in the HIIT-2 group, other research variables of the two training groups were significantly different from the pre-test (P < 0.05). Besides, in between-group comparison, the findings revealed that there was a significant difference between VO2max, HDL, and TG as well as anaerobic performance between the HIIT-1 and HIIT-2 groups (P < 0.05). Conclusions: The results suggest that HIIT-1 program is suitable to increase aerobic performance and reduce cardiovascular risk factors, while HIIT-2 program may be applied to increase anaerobic performance because the volume of exercises plays a decisive role in possible adaptation resulting from such exercises.