This study investigated the responses in substrate and energy based properties to repetitive days of prolonged submaximal exercise and recovery. Twelve untrained volunteers (VO_2peak=44.8±2.0 ml.kg^-1.min^-1, mean±SEM) cycled (~60 VO_2peak) on 3 consecutive days followed by 3 days of recovery. Tissue samples were extracted from the vastus lateralis both pre (Pre) and post (Post) exercise on day 1 (E1), day 3 (E3) and during recovery, (R1, R2, R3) and analyzed for changes in metabolism, substrate, enzymatic and transporter responses. For the metabolic properties (mmol.kg-1 dry wt), exercise on E1 resulted in reductions (P0.05) in PCr (80±1.9 vs 41.2±3.0), and increases (P0.05), in IMP (0.13±0.01 vs 0.61±0.2) and lactate (3.1±0.4 vs 19.2±4.3). At E3, both IMP and lactate were lower (P0.05) during exercise. For the transporters, the protocol resulted in a decrease (P0.05) in GLUT1 (29% by R1) and an increase in GLUT4 (29% by E3) and increases (P0.05) were observed for both monocarboxylate transporters (for MCT1, 23% by R2; MCT4, 18% by R1). Of the mitochondrial and cytosolic enzyme activities examined, cytochrome oxidase (COX), and hexokinase (HEX) were both reduced (P0.05) by exercise at E1 and in the case of HEX and phosphorylase by exercise on E3. With the exception at COX, which was lower (P0.05) at R1, no differences in enzyme activities existed at rest between E1, E3 and recovery days. The results suggest that the glucose and lactate transporters are among the earliest adaptive responses of the substrate and metabolic properties studied to the sudden onset of regular low-intensity exercise.