Maximal incremental cycling test

After a 6-min warm-up at 75 W, the work rate increased continuously by 25 W every minute until volitional exhaustion despite strong verbal encouragement. After a 10-min passive rest period, a time to exhaustion test was performed by cycling at 90% of the peak power output during the incremental cycling test until exhaustion. The work rate for this time to exhaustion test was kept constant for the intermediate and post-training testing. Whole-body oxygen uptake was measured breath by breath with a metabolic system (MetaLyzer 3B; Cortex Biophysik GmbH, Leipzig, Germany), and heart rate was measured continuously (H7; Polar, Kempele, Finland). Details concerning determination of peak oxygen uptake, power output, and heart rate as well as ventilatory thresholds can be found in the Supplementary Materials.