Table 3.

Reasons for stopping exercise (peak RER <1.0 vs. others)

Reason	Peak RER <1.0 (N=52)	Peak RER ≥1.0 (N=3064)	P-value
Test stopped early for ECG or BP criteria	10 (19%)	50 (2%)	<0.001
Participant removed mouthpiece early	8 (15%)	130 (4%)	<0.001
Mouthpiece discomfort/ dry mouth	10 (19%)	346 (11%)	0.07
Leg fatigue	8 (15%)	1567 (51%)	<0.001
Shortness of breath	5 (10%)	412 (13%)	0.42
Chest discomfort	0 (0%)	5 (0.2%)	0.77

Groups are compared using chi-squared test

Abbreviations: ECG, electrocardiogram; BP, blood pressure