In recent years, online lectures and conferences have become widespread, but problems such as stress and adjustment disorders caused by watching long videos have become a problem. Few studies have objectively evaluated the minute changes in stress associated with such prolonged viewing. This study aimed to determine the effects of prolonged video viewing on physical and mental stress. Twenty-six students (10 males and 16 females, aged 21–24) from University A participated in this study. The subjects watched both a high-interest and a low-interest video for 90 minutes each and then subjectively?evaluated the video content. Heart rate variability analysis was used to assess heart rate and autonomic nervous system changes during video viewing and saliva samples were collected before, during, and after viewing the videos to measure the concentration of stress markers in the saliva. This study was approved by the Gunma University Medical Ethics Review Committee for Human Subjects. The results of the subjective evaluation showed that scores for concentration, comprehension, and interest were significantly higher, while the fatigue score was lower for the high-interest video than for the low-interest video. Both videos caused a decrease in heart rate and low sympathetic nerve activity, and an increase in parasympathetic nerve activity; however, the changes were more pronounced with the high-interest video. In addition, the differences in subjective scores between the high- and low-interest videos were more pronounced in women, with salivary chromogranin A also showing opposite trends for the two videos. This study demonstrates that watching two different types of videos for extended periods affects autonomic nervous system activity, heart rate, and stress hormones in saliva. Since trends differ depending on the type of video and the participant’s sex, attention should be paid to the video content and the individual subject when examining stress during video viewing.

The authors have declared no competing interest.

Yes

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Not Applicable

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

This study was approved by the Gunma University Medical Ethics Review Committee for Human Subjects (approval number: HS2020-147).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Not Applicable

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Not Applicable

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Not Applicable

All relevant data are within the manuscript and its Supporting Information files.