Fig. 1.
Effects of training in the fasted state (F) vs. training in the carbohydrate-fed state (CHO) on intramyocellular lipid (IMCL) content during a 2-h constant-load exercise bout. Data provided are means ± SE (F: n = 9; CHO: n = 9) and represent values before (pretest) and after (posttest) a 6-wk training period in either the fasted state (F) or with ample carbohydrate intake before and during the training sessions (CHO). Intramyocellular lipid content was measured before and at the end of a 2-h constant-load cycling bout. The workload was 175 ± 6 W and corresponded to 65% of V̇o2max in the pretest vs. 60% of V̇o2max in the posttest. Panel Basal IMCL content (A) and net IMCL breakdown (B) in type I (top) and type IIa (bottom) fibers. Fiber type-specific IMCL content was determined by fluorescence microscopy on Oil-Red-O-stained muscle cross sections [arbitrary units (AU)]. *P < 0.05 vs. pretest. #P < 0.05, significant IMCL breakdown during exercise.