Oxygen consumption in the first stages of strenous work as a function of prior exercise

This study examined the extent to which 10 minutes of prior exercise (PE) at a workload adjusted to maintain a heart rate (HR) of 140 bpm could facilitate the mobilization of the O₂ transport system in a strenuous criterion task (CT). The interval between the PE and CT was 30 seconds. The CT required the S to pedal for 2 minutes at a load of 1632 kpm/min. The control treatment involved completion of the CT following 10 minutes of rest on the ergometer. Comparisons between treatments were made during the 30 seconds between PE and CT, for four 30 second periods during the CT and for the 60 seconds following the CT. VO₂ was significantly higher following PE at every stage except the second 30 second period of the CT and the 60 second post CT period. Ventilation was significantly higher following PE at every stage except the last 30 seconds of the CT and the 60 second post CT period. Ventilation was significantly higher following PE at every stage except the last 30 seconds of the CT and the 60 second post CT period. HR was significantly higher following PE at every stage. And O₂ pulse was significantly higher following PE only during the 30 second pre CT period and the first 30 seconds of the CT, indicating that the PE facilitated the mobilization of stroke volume (SV) and/or A V O₂ difference. The similar values for O₂ pulse during the last 90 seconds of the CT indicate that the higher VO₂ following PE was a function of higher HR, not higher SV or A V O₂ difference.