Table 2—

Cardiopulmonary parameters during endurance exercise

VO2 L·min−10.34±0.041.36±0.301.39±0.21
fC beats·min−176.1±15.0128.4±12.0131.4±16.4
VE L·min−112.3±1.7441.9±7.6650.9±9.1
VT L0.68±0.161.47±0.461.49±0.39
fR breaths·min−118.6±3.431.3±11.233.4±11.9
tI s1.32±0.240.99±0.360.93±0.32
Ptdi cmH2O9.57±3.3117.78±4.9317.76±4.04
PTPdi cmH2O·s−1·min−1127.6±50.0300.8±77.0301.5±64.2
PTPoes cmH2O·s−1·min−186.7±34.1325.8±86.0331.2±94.7
Lactate mEq·L−11.6±0.65.1±1.4
  • Data are presented as mean±sd with the percentage of the predicted value in parentheses

  • VO2: oxygen consumption

  • fC: cardiac frequency

  • VE: minute ventilation

  • VT: tidal volume

  • fR: respiratory frequency

  • tI: inspiratory time

  • tI/ttot: duration of total breathing cycle

  • Ptdi: transdiaphragmatic pressure

  • Ttdi: tension/time index of the diaphragm

  • Ttoes: tension/time index of the oesophagus

  • PTPdi: pressure/time product of the diaphragm

  • PTPoes: pressure/time product of the oesophagus

  • #: p=0.002 versus resting

  • : p=0.03 versus mid-exercise