On May 19 Lucy, Ralph and I walked 5.5 miles starting at a new trail access at Willamette Blvd. going down the crest to Swan Island. A new pedestrian overpass carried over the rails at this point. Further on we exited Swan Island at Emerson St., crossing the tracks to a short trail up the crest back to Willamette Blvd. This area is marked Mock's Crest and Mock's Bottom on older maps.
The New York Times Magazine (May 12, 2013) published "The Scientific 7-Minute Workout," 12 exercises and you're done. I tried it. Got a sweat in 7 minutes and increased heart rate. A PDF of the workout is HERE for a short time.