Mountain biking 34:01  6.0 km (5:40 / km)
Prospect Hill. Started out on the paved from the bottom. Pretty feeble, HR at 150+ in my lowest gear. Did about 3 intervals going up, with pauses where needed. Then, continued on using paved and trails.
Part of the drivetrain is out of whack: there's a clicking when I'm on the middle chainring, but it didn't look like the chainring was bent or any teeth misaligned or the derailleur cage off-center. Further research is required.