https://sondreamdahl.com/2017/10/05/fastest-known-time-on-kungsleden-the-king-of-trails/
Amdahl started with Elisabet Barnes, who stopped eventually because of injury.
Normally you hike this trail in 20+ days and few people do all of it in one go. We had one week. We decided to start in the north in Abisko and go south, seeing how far we could get in that time. The challenge lies not only in the running, but in the fact that you have the boat crossings to contend with and also the road connection between Vakkotavare and Kebnats. The boat crossings are serviced by the hosts of the huts or other boat owners. Most run a fixed schedule with generally two crossings per day, some need to be pre-booked. At some crossings you can row, but the logistics present some challenges if you are trying to do this trail fast. There is a rule that there must always be at least one boat by a shore. So, if you arrive at the shore and there is only one boat there, you have to first cross once, then take a boat on tow back with you from the other side before you can finally cross. For a 4km crossing, that’s 12km of rowing, in potentially windy weather… The road stretch is serviced by one daily bus in September (two daily buses in high season). If you miss it you have to wait a day, staying in the Vakkotavare hut, or hitchhike.