VO sub(2)max during successive maximal efforts

The concept of VO sub(2)max has been a defining paradigm in exercise physiology for >75years. Within the last decade, this concept has been both challenged and defended. The purpose of this study was to test the concept of VO sub(2)max by comparing VO sub(2) during a second exercise bout following a preliminary maximal effort exercise bout. The study had two parts. In Study #1, physically active non-athletes performed incremental cycle exercise. After 1-min recovery, a second bout was performed at a higher power output. In Study #2, competitive runners performed incremental treadmill exercise and, after 3-min recovery, a second bout at a higher speed. In Study #1 the highest VO sub(2) (bout 1 vs. bout 2) was not significantly different (3.95 plus or minus 0.75 vs. 4.06 plus or minus 0.75lmin super(&# x2212; 1)). Maximal heart rate was not different (179 plus or minus 14 vs. 180 plus or minus 13bpm) although maximal V sub(E) was higher in the second bout (141 plus or minus 36 vs. 151 plus or minus 34lmin super(&#x22 12; 1)). In Study #2 the highest VO sub(2) (bout 1 vs. bout 2) was not significantly different (4.09 plus or minus 0.97 vs. 4.03 plus or minus 1.16lmin super(&# x2212; 1)), nor was maximal heart rate (184+6 vs. 181 plus or minus 10bpm) or maximal V sub(E) (126 plus or minus 29 vs. 126 plus or minus 34lmin super(&#x22 12; 1)). The results support the concept that the highest VO sub(2) during a maximal incremental exercise bout is unlikely to change during a subsequent exercise bout, despite higher muscular power output. As such, the results support the "classical" view of VO sub(2)max.