Fatigability and Physiological Insights into Upright Standing Postural Control of Endurance Athletes Following Different High Intensity Interval Trainings

The primary aim of this study was to investigate the acute dose response of 4 different individualized high intensity interval training (HIIT) prescriptions on upright standing postural control. Further, due to the similarity between the factors contributing to the change in postural control and fatiguability, the secondary aim of this study was to evaluate the correlation between upright standing postural control and parameters of performance [electromyographic fatigue threshold (EMG_FT)] and perceived fatiguability [rate of perceived exertion (RPE), motivation, muscle soreness] in endurance athletes.

For this purpose, a sample of 40 trained endurance athletes (age: 21.47 ± 2.61 years; height: 164.77 ± 7.3 cm; weight: 57.53 ± 6.3 kg; BMI: 21.18 ± 7.4 kg/m²) was recruited for the study and randomly allocated into 4 groups. After assessing the demographic, physiological [height, weight, heart rate, blood pressure, maximal oxygen consumption (VO_2max), velocity at onset of blood lactate accumulation (vOBLA)] and fatigability parameters, different groups were assigned individualized HIIT sessions with varied recovery interval intensity and duration in between the pre- and post-postural control assessments.

All HIIT protocols caused a significant increment in the postural sway in all four directions (front, back, left, and right) which was not significantly different from each other. A strong negative correlation between the change in postural control was reported with VO_2max, EMG_FT and a strong positive correlation with height, weight, body mass index, RPE, while the correlation coefficient revealed a moderate positive correlation with vOBLA.

This study concludes that all the four HIIT prescriptions have similar acute effect on the upright standing postural control and it is strongly correlated with fatiguability.