74751
document
Metabolic and ventilatory responses during very low level exercise . 1 . Nine male and six female healthy subjects were studied during supine bicycle exercise at workloads of 12 and 37 W ; pedalling rates varied between 30 and 50 cycles/min at each workload . Measurements were made of oxygen consumption ( VO2 ) , carbon dioxide production ( VCO2 ) , minute ventilation ( VE ) , tidal volume ( VT ) , respiratory frequency ( fR ) , inspiratory and expiratory time ( TI , TE ) and mean inspiratory flow ( VT/TI ) using a non-invasive canopy-computer-spirometer system . 2 . At rest , males had greater values of VE , VT , TI , inspiratory duty cycle ( TI/TTOT ) , VCO2 and VO2 , and a lower fR , than females . 3 . At the lower workload , VO2 , VCO2 , VE , VT and VT/TI increased linearly with increasing pedalling rate , whereas at the higher workload there was a decrease in VO2 and little or no change in ventilatory parameters from 30 to 50 cycles/min except for an increase in fR in females . 4 . While performing supine exercise , there was an effect of pedalling rate on ventilatory and metabolic parameters at the low workload ( 12 W ) which diminished at the higher workload ( 37 W ) . An increase in pedalling rate appears to enhance efficiency at these low workloads . 5 . Differences between the sexes during exercise generally include : ( a ) a higher breathing frequency , ( b ) a greater mechanical efficiency , and ( c ) lower ventilatory equivalents of O2 and CO2 ( VE/VO2 and VE/VCO2 ) during the higher workload in females than males .
74752
Intervention_Physical
very low level exercise
74753
Intervention_Physical
supine bicycle exercise
74754
Intervention_Physical
supine exercise
74755
Outcome_Physical
oxygen consumption ( VO2 ) , carbon dioxide production ( VCO2 ) , minute ventilation ( VE ) , tidal volume ( VT )
74756
Outcome_Physical
respiratory frequency ( fR ) ,
74757
Outcome_Other
inspiratory and expiratory time ( TI , TE )
74758
Outcome_Other
mean inspiratory flow ( VT/TI )
74759
Outcome_Physical
VE
74760
Outcome_Physical
VT
74761
Outcome_Other
TI
74762
Outcome_Physical
inspiratory duty cycle
74763
Outcome_Other
( TI/TTOT )
74764
Outcome_Physical
VCO2
74765
Outcome_Physical
VO2
74766
Outcome_Physical
lower fR
74767
Outcome_Physical
VO2
74768
Outcome_Physical
VCO2
74769
Outcome_Physical
VE
74770
Outcome_Physical
VT
74771
Outcome_Other
VT/TI
74772
Outcome_Physical
VO2
74773
Outcome_Physical
ventilatory parameters
74774
Outcome_Physical
fR
74775
Outcome_Physical
pedalling rate on ventilatory and metabolic parameters
74776
Outcome_Other
pedalling rate
74777
Outcome_Physical
higher breathing frequency
74778
Outcome_Other
a greater mechanical efficiency
74779
Outcome_Other
lower ventilatory equivalents of O2 and CO2 ( VE/VO2 and VE/VCO2 )
74780
Participant_Condition
Nine male and six female healthy subjects were studied during supine bicycle exercise at workloads of 12 and 37 W ; pedalling rates varied between 30 and 50 cycles/min at each workload .