AUTHOR=Sperlich Billy , De Clerck Ine , Zinner Christoph , Holmberg Hans-Christer , Wallmann-Sperlich Birgit 

TITLE=Prolonged Sitting Interrupted by 6-Min of High-Intensity Exercise: Circulatory, Metabolic, Hormonal, Thermal, Cognitive, and Perceptual Responses

JOURNAL=Frontiers in Physiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2018.01279

DOI=10.3389/fphys.2018.01279

ISSN=1664-042X

ABSTRACT=<p>The aim was to examine certain aspects of circulatory, metabolic, hormonal, thermoregulatory, cognitive, and perceptual responses while sitting following a brief session of high-intensity interval exercise. Twelve students (five men; age, 22 ± 2 years) performed two trials involving either simply sitting for 180 min (SIT) or sitting for this same period with a 6-min session of high-intensity exercise after 60 min (SIT+HIIT). At T<sub>0</sub> (after 30 min of resting), T<sub>1</sub> (after a 20-min breakfast), T<sub>2</sub> (after sitting for 1 h), T<sub>3</sub> (immediately after the HIIT), T<sub>4</sub>, T<sub>5</sub>, T<sub>6</sub>, and T<sub>7</sub> (30, 60, 90, and 120 min after the HIIT), circulatory, metabolic, hormonal, thermoregulatory, cognitive, and perceptual responses were assessed. The blood lactate concentration (at T<sub>3</sub>–T<sub>5</sub>), heart rate (at T<sub>3</sub>–T<sub>6</sub>), oxygen uptake (at T<sub>3</sub>–T<sub>7</sub>), respiratory exchange ratio, and sensations of heat (T<sub>3</sub>–T<sub>5</sub>), sweating (T<sub>3</sub>, T<sub>4</sub>) and odor (T<sub>3</sub>), as well as perception of vigor (T<sub>3</sub>–T<sub>6</sub>), were higher and the respiratory exchange ratio (T<sub>4</sub>–T<sub>7</sub>) and mean body and skin temperatures (T<sub>3</sub>) lower in the SIT+HIIT than the SIT trial. Levels of blood glucose and salivary cortisol, cerebral oxygenation, and feelings of anxiety/depression, fatigue or hostility, as well as the variables of cognitive function assessed by the Stroop test did not differ between SIT and SIT+HIIT. In conclusion, interruption of prolonged sitting with a 6-min session of HIIT induced more pronounced circulatory and metabolic responses and improved certain aspects of perception, without affecting selected hormonal, thermoregulatory or cognitive functions.</p>