Table 2

Cardiopulmonary exercise test data

Post-COVID athletes
(n=21)
Reference athletes
(n=42)
Testing modality
 Cycle ergometer9 (43)18 (43)
 Treadmill12 (57)24 (57)
Vital signs
Baseline HR (beats per minute)86±1681±14
Peak HR (beats per minute)189±9189±9
 Percent predicted95±495±4
Heart rate recovery (beats per minute)44±1246±11
Baseline SBP (mm Hg)122±11119±11
Peak SBP (mm Hg)168±21172±24
Baseline DBP (mm Hg)75±677±8
Peak DBP (mm Hg)77±570±12†
Baseline O2 saturation (%)98±198±1
O2 saturation (%) at peak exercise96±296±2
Spirometry*
Pre-exercise FEV1 (L)3.7±1.14.1±1.0
 Percent predicted (%)86±1698±12†
 Abnormal (below 5th percentile)7 (37)3 (7)†
Pre-exercise FVC (L)4.9±1.14.8±1.1
 Percent predicted (%)98±1098±13
Pre-exercise FEV1/FVC0.74±0.110.86±0.06†
 Abnormal (below 5th percentile)7 (37)1 (2)†
Gas exchange
Respiratory exchange ratio1.17±0.091.17±0.08
Peak VO2 (L/min)3.2±0.73.4±0.9
Peak VO2 (mL/kg/min)44.6±9.146.4±9.6
 Percent predicted (%)110±30114±23
 Abnormal (<80% predicted)3 (14)1 (2)
VO2 at VT (mL/kg/min)35.7±11.336.0±10.3
Chronotropic index0.89±0.240.83±0.17
Oxygen pulse (mL/beat)16.8±4.218.1±4.9
Total VE/ VCO2 slope28.1±3.428.2±4.0
VE/ VCO2 slope through VT24.6±3.324.3±3.2
Peak VE (L/min)112±32120.±37
Breathing reserve (%)*18±2025±19
 Low breathing reserve (<10%)8 (42)5 (12)†
  • *Two post-COVID athletes’ spirometry measurements (1 male, 1 female) were excluded due to low quality.

  • †P<0.05 for post-COVID athletes versus reference athletes.

  • DBP, diastolic blood pressure; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; HR, heart rate; SBP, systolic blood pressure; VCO2, carbon dioxide production; VE, ventilation; VO2, oxygen consumption; VT, ventilatory threshold.