Higgins, Trevor R., Thomas Lloyd, Kenneth Manalansan, Sara McDonald, and Ben Thomas. “Comparisons in Heart Rate Readings Between the Bioconnected Wireless Exercise Earpiece and a Polar T31-Coded Chest Strap During a GXT”. Journal of Human Sport and Exercise 13, no. 3 (September 18, 2018): 530–540. Accessed April 27, 2024. https://www.jhse.ua.es/article/view/2018-v13-n3-earpiece-hr-measuring-device-bioconnected-polar-t31-.