Performance and physiological analysis of 500 km non-stop cycling: a case study. A Spanish group has examined the change during a cycling over 500 km. Driving speed and wattage continued to go back constantly, with this decline on the rotational speed and not to lead back to the force. The heart rate also slowly decreased.In addition, a decrease in heart rate variability, a pronounced inflammation, and signs of a muscle damage.These changes remained up to 2 days after the end of the load.
Based on the case report, the authors show that a cycling over 500 km is also a very high stress for a trained athlete. The work can be found under https://pubmed.ncbi.nlm.nih.gov/29359592/