TABLE 1

Regressions proposed to calculate predicted ventilation/carbon dioxide production slope

First author, year (study) [reference]Subjects (male/female)MalesFemalesAge yearsErgometer
Salvioni, 2020 [29]1136 (773/363)Y=0.095 * age +20.2Y=0.052 * age +23.813–83Cycle ergometer
Koch, 2009 (SHIP) [35]534 (253/281)Y= (−1.5*age+0.5*age2+2.5sex−0.5*age*sex)+22#25–80Cycle ergometer
Kleber, 2000 [34]101 (45/56)Y=0.13*age +19.9Y=0.12*age+24.416–75Treadmill
Neder, 2001 [36]120 (60/60)Y=0.12*age+21Y=0.08*age+25.220–80Cycle ergometer
Poulin, 1994 [37]224 (128/96)Y=0.29*age+7.69Y=0.20*age+10.0855–86Treadmill
Sun, 2002 [24]474 (310/164)Y=(0.082*age−0.0723*height)+34.3837–74Cycle ergometer/ Treadmill

Data are presented as n or range, unless otherwise stated. Reproduced and modified from [29] with permission. #: age was graded in five classes (25–34, 35–44, 45–54, 55–64 and ≥65 years) and coded for the calculation.