Influence of High-Intensity Interval Training on IGF-1 Response, Brain Executive Function, Physical Fitness and Quality of Life in Sedentary Young University Women—Protocol for a Randomized Controlled Trial

Sedentary lifestyles have become a social problem, mainly among women. A sedentary lifestyle has been associated with poorer health in this population, negatively affecting physical and mental health. Physical exercise, in particular high-intensity interval training (HIIT), has been shown to be a neuroprotective tool. The present study provides a protocol design for a parallel-group Randomized Controlled Trial (RCT), whose aim will be to compare the effect of two physical interventions, HIIT and physical activity (increasing daily steps), on Insulin Growth Factor-1 (saliva IGF-1 concentrations), executive functions, quality of life, body composition, physical fitness, and physical activity in young sedentary women. At least 77 women will be recruited and randomly assigned to either a HIIT group (12-week exercise HIIT intervention, 3 sessions/week), the HIIT + PA group (12-week exercise HIIT intervention, 3 sessions/week, plus 10,000 steps/day), or a control group (usual care). The primary outcome measure will the chronic change in IGF-1 concentration levels measured in saliva. Secondary outcome measures will be: (i) executive functions; (ii) body composition; (iii) physical fitness; (iv) physical activity; and (v) quality of life. All outcomes will be assessed at the beginning of the study, after the intervention, and after three months of follow-up. After this intervention, we will be able to determine whether HIIT together with increased physical activity could be more effective than HIIT alone in IGF-1 stimulation. Furthermore, by comparing both intervention groups, we will be able to determine the differential effects on numerous health-related variables. Consequently, the conclusions of this study could help better understand the effects of a training program on IGF-1 concentration levels and executive functions. In addition, various strategies could be proposed through physical exercise to improve cognition in this age group, as well as to improve the health status of this sedentary population.