[IZ] 1/2 Marin Headlands Bike, 8/10

Dist: 16.8 miles
Time: 1:20
Avg: 12.6 MPH

HR Avg: 139

Through the Presidio, across the bridge, 1/2 way up the headlands, down the other side, through the tunnel, and home across Crissy Field.

I tried to keep a "Merriman Pace" throughout the ride, but it doesn't seem to've affected my time or HR much (except making me more tired).