Not sure what was wrong today. I have been running a lot outside so I decided I would put in some time on the treadmill (I know I am crazy to run indoors today). When I started I didn't have a set distance I wanted to run but a common workout I do is 10 miles at 10 mph. After one mile I up'd the pace to 10.1 with a 1% decline. My quads felt really tired but I thought they would feel better after I got warmed up. This didn't happen. My quads felt really tired for the entire run and I felt like I was working unusually hard for that pace (maybe I warmed up to fast?). For the first time I actually took along my heart rate monitor and surprisingly my heart rate was at about 180-185 for last three miles. Although I haven't used a monitor on a treadmill before I know for a fact that my heart rate is never that high at 10 mph, which is close to my marathon pace. I am not sure what to conclude from this. Any thoughts? I have been running often, about 6 times a week, but I really haven't been putting in many miles. What it is interesting is that I have run my best marathon times when I only ran 4-5 times a week for longer distances each day and on off days I cross trained (biking or swimmming). At least for me, I think my body responds better when I run fewer days and include more cross training. Fortunately the weather appears to be changing so I am looking forward to getting out on my road bike; my quads will be whipped into shape in no time. | 
