Edit activity log later if I forget to hit “stop”?

Every so often after a recorded hike/bike, I realize I didn’t stop logging it when I jumped back in the jeep... so my hike shows me suddenly moving 25 mph back down a canyon... screws up everything.

Any way to edit & trim back the activity so I can force it to end when it should have, rather than when I remember to stop my watch?

Thanks,
Brian