Received: 15 October 2019
Accepted: 23 January 2020
First Online: 4 February 2020
Ethics approval and consent to participate
: The Ethics Committee of the Faculty of Environmental Science, Nagasaki University, approved this study. All participants signed an informed consent form before experiments began.
: All authors have approved the manuscript and agree with submission to the Journal of Physiological Anthropology.
: The authors declare that they have no competing interests.