I chopped 30 minutes off my previous time by running on the descent, setting a new PR of 5.5 hours. Couch 2 5k is paying off, plus all those low weight squats. I could feel the freshness of my quads the whole way down, passing loads of hikers leaning on trekking poles (I left mine in the car). This is a very clean trail and easy to run. On the downside (or upside, if you will), my rate of ascent was only 1,300 ft/hr, about 30 ft/hr faster than my last hike. I'm not sure if this is statistically significant, but I'd say probably not. My performance was hampered by the hot weather but helped by a slightly lighter pack. Increasing rate of ascent takes a long time.