Run,bike or walk to (T) Slussen on the Green line (TB1) and Red line (TB2) ...
https://api.sl.se/fordonspositioner#TB1
https://api.sl.se/fordonspositioner#TB2
About 10K or 5K ...
You can Bike or Run if you don't Walk ...
You can bring the Bike to/from Stockholm Södra:
https://api.sl.se/fordonspositioner#PT
NB that a few of the runners will need to bring the DS if they want to have that...