Influence of thigh activation on the VO₂ slow component in boys and men

Methods: Eight boys (mean age 11.4 ± 0.4) and eight men (mean age 25.3 ± 3.3 years) completed repeated step transitions of unloaded-to-very heavy-intensity (U → VH) exercise on a cycle ergometer. MRI scans of the thigh region were acquired at rest and after VH exercise up to the [Formula Presented]O2Sc time delay (ScTD) and after 6 min. T2 for each of eight muscles was adjusted in relation to cross-sectional area and then summed to provide the area-weighted ΣT2 as an index of thigh recruitment.