The reduction by training of CO2 output during exercise.

5 men underwent a 10-wk endurance training programme which resulted in an 18% increase in max VO2 from a mean of 3.1 l/min. Measurements were made at 2 submaximal O2 intakes of 1.2 and 2.0 l/min to examine the physiological interdependence of mechanisms changed by training. At both levels of VO2, reductions were observed following training in cardiac frequency (fc), CO2 output (VCO2), respiratory exchange ratio (R), ventilation (VE), …