The effect of HIIT on running economy tested on well-trained runners and triathletes

Background: Running economy is one of the key factors to achieve top performance in endurance events. Little evidence exists for improving running economy using high-intensity interval training while running. Objectives: The purpose of this study was to examine how HIIT affects running economy and VO2max. Method: 14 well-trained athletes (age 35 ± 8,9 years, height 175 ± 11,7 cm and weight 69 ± 12,2 kg) were divided into two separate groups (HIIT and Control). HIIT group performed 3 HIIT exercises every week for 4 weeks and Control group continued with their separate training programs consisting of mostly traditional endurance training. Results: Running economy showed no improvement in HIIT (pre 38,62 and post 38,62 ml/kg/min, p=1.00) but Control improved (pre 45,41 and post 43,37 ml/kg/min, p=0,03). VO2max decreased in HIIT (mean 61,32 to 60,84 ml/kg/min) and in Control (mean 61,99 to 58,47 ml/kg/min)