Boontha, Kritsana, Ubon Pirunsan, Peanchai Khamwong, and Sainatee Pratanaphon. “Reliability of Heart Rate Maximizer Test Using Jumping Jack in Assessing Cardiovascular Fitness”. Journal of Associated Medical Sciences 49, no. 3 (September 3, 2016): 344. Accessed May 16, 2024. https://he01.tci-thaijo.org/index.php/bulletinAMS/article/view/69064.