I suspect running for 9 or more hours a week may have a benefit far beyond running, thus trying to do so, though it's boring. Did 49 miles last week on treadmill. Not sure my knee will hold up. Trying to keep legs slightly bent yet still with a short stride. In around 2 weeks I seem to have improved about 0.5 mph. Did 5.4 mph for 58 minutes on Thursday (to begin with). Some days I take a step back, some days I really jump forward. Wonder how much slight dehydration plays a role in my heart rate.