The Centurion Thames Path 100 heads upriver from Richmond in west London to Oxford. The route follows the path beside the Thames: riverbank trail, grassy stretches, locks and riverside villages across southern England. There is no significant climbing, which makes it a very different proposition from Britain's ridge-line ultras.
The cut-off is 30 hours. The absence of climbing changes the nature of the effort, since you run more and walk less, and the loading on your legs becomes highly repetitive. Proximity to the river also means some sections turn muddy after rain.
