The effect of aerobic training years on systemic oxygen utilisation, and peripheral O2 extraction in the vastus lateralis, gastrocnemius and pre-frontal cortex in young men

Introduction: This study was designed to determine if systemic O2 utilisation (V̇O2), and tissue O2 extraction (deoxyhemoglobin [HHb]) in the vastus lateralis (VL), gastrocnemius (GAST) and pre-frontal cortex (PFC) differed between aerobically short term trained (STT 6 – 24 months) and long term trained (LTT > 5 yr) men aged 18 – 30 years, who were matched for current training load.
Methods: Fourteen STT and 13 LTT participants completed ramp incremental (RI) and square-wave constant load (SWCL) (3 min at 25%, 80% and 25% and 20 min at 90% of ventilatory threshold [VT]) tests on a cycle ergometer.
Results: ANCOVA revealed that V̇O2 was higher in LTT compared to STT in the RI (p < 0.001) and SWCL (p = 0.004) tests. There was no difference in ΔHHb in the VL, GAST or PFC between LTT and STT during both tests. However, there was a group x intensity interaction in the GAST during SWCL. Conclusion: These results suggest that in men aged 18 – 30 years, with up to 24 months of aerobic training, additional training years can increase systemic O2 utilisation without increased current training load and that peripheral adaptations have little influence on the observed increases.