Cardiopulmonary Exercise Testing Protocol

Cardiopulmonary exercise testing was performed using a stationary bicycle (StrengthErgo 8; Mitsubishi Electric Engineering, Tokyo, Japan) and a breath-by-breath gas analyzer (AE-300S; Minato Ikagaku Co., Tokyo, Japan). Symptomatic maximal exercise was performed using a ramp protocol of 5–30 watts (W)/min according to age and condition after 2–3 min rest and warm-up of 0–10 W lasting 2–3 min. Rating of perceived exertion (RPE) at the end of the exercise was assessed using the Borg scale (Beaver et al., 1986a (link); Takano, 2000 (link); Dekerle et al., 2003 (link); Balady et al., 2010 (link); Lenti et al., 2011 (link); Wasserman et al., 2012 ; Yen et al., 2015 , 2018 (link); Nishijima et al., 2017 (link), 2019 (link); Keir et al., 2018 (link); Korkmaz Eryılmaz et al., 2018 (link); Carriere et al., 2019 (link); Iannetta et al., 2019 (link); Nakade et al., 2019 (link)).