THE EFFECT OF SHORT- AND LONG-TERM AEROBIC TRAINING YEARS ON SYSTEMIC O2 UTILIZATION, AND MUSCLE AND PREFRONTAL CORTEX TISSUE OXYGEN EXTRACTION IN YOUNG WOMEN.

This study aimed to determine if systemic O2 utilization (VO2) and tissue oxygen extraction (deoxyhemoglobin [HHb]) in the vastus lateralis (VL), gastrocnemius (GAST), and prefrontal cortex were different during exercise between short-term trained (STT, 6-24 months) and long-term trained (LTT, >5 years) young women while controlling for current training load. Thirteen STT and 13 LTT participants completed ramp incremental (RI) and square-wave constant load (SWCL) tests on a cycle ergometer. In LTT compared with STT: (a) VO2 was higher during the RI (p = 0.024) and SWCL (p = 0.001) tests; (b) HHb in the VL (p = 0.044) and GAST (p = 0.027) was higher in the RI test; and (c) there were significant group x intensity interactions for VO2 in the SWCL test. The additional years of aerobic training in LTT compared with STT (LTT 7.1 ± 1.9 vs. STT 1.5 ± 0.4 years) resulted in higher VO2 and HHb in the VL and GAST. These results indicate that in young women, independent of current training load, systemic VO2 and peripheral muscle O2 extraction during exercise continues to increase beyond 24 months of aerobic training. [ABSTRACT FROM AUTHOR]