With higher age there tend to be a decrease in the autonomic regulation of the cardiovascularsystem. Exercise is hypothesized to improve autonomic function but the time and intensitynecessary for substantial improvements has not been concluded. High intensity training(HIT)training poses potential time benefits that may aid physically inactive people.
The purpose of this study was to evaluate the effects of a 6-week High intensity interval training(HIIT)-program vs a 6-week Moderate intensity exercise training (MIET)-program on autonomic function in physically in-active older adults.
Home recordings of blood pressure and heart rate variability was conducted prior to and 6-weeks in to the training period. Training was carried out in a gym setting, 2 times weekly, duringa 6-week period. Participants were randomized to either the HIIT or MIET protocol with 15 participants in the HIIT group and 15 participants in the MIET group.
There was no significant difference in Heart rate variability after a 6-week training programregardless of time and intensity of exercise. The MIET group reduced morning blood pressure parameters significantly (Mean arterial pressure mornings: 95% Confidence interval (CI)I:-5,8- -0,7, p=0,016; Morning systolic pressure: CI:-9,3- -1,3, p=0,002; Morning diastolic pressure: 95%CI:-4,2- -0,3, p=0,03), the HIIT group did not (Mean arterial pressure mornings: 95% CI: -10,3-1,8,p=0,147; Morning systolic pressure: 95% CI: -12,3-1,5, p=0,110; Morning diastolic pressure:95%CI: -9,5-2,2, p=0,196).
A 6-week training protocol is not sufficient in order to improve autonomic function in a population of older inactive adults.