Running/Jump roping, alternating days, question

I have a question for fitness buffs out there.  I have a muscle in my leg that's just feeling a little strained, not intense or continuous pain.  I'm running roughly 2.5 miles (alternating with make a total of 4 to 5 miles a day).  I am starting to have pain in my knees towards the end of my run.  I really hate to take a day off from doing more calorie-burning exercise, but I don't want to injure myself to the point where I really have to lay off running.I generally run 2-3 days than do something different on the 4th day.  I thought about jumping rope the next day, and just wanted thoughts on if that's a good recovery workout (if I'm using the term right, probably not!) from running, but something I can still do to burn more calories than just say walking.

I run quite a bit. I jump rope several times a week. For me, continuous rope jumping is harder than easy/moderate running. If I start trying to add special patterns, or "double unders" etc., it is as hard as fast running.

Is your knee pain from poor running form? It maybe something as simple as your are reaching too far on your stride length. You might consider a running clinic.

I don't think jumping rope would be good, you certainly should try it...but it's probably too high impact.

Are you new to running, or have you recently increased your run volume? If so, the knee pain is probably a result of the increased impact, in which case, jumping rope would be one of the worst things you could do. Much better to bike or swim on your non-running days. Also, maybe cut back so you're running every other day until your knees adapt.

I started running a few weeks ago.  I was somewhat active (did workout dvds at home) but it was less intense than running.  I started running maybe 1 to 1.5 miles the first week and probably increased the distance to quickly to 2.5 miles (like within 2 weeks time).  I was also running 5x a week. 

Thanks for the advice!  I will try to go a little easier and take easier days in between running days.  I feel like I want to run as much as possible, but it won't do me good to injure myself to the point I have to lay off more intense cardio/exercise for a while. 

I don't think my dog will like me going biking instead, but that sounds fun.  I need a doggie seat on my bike.  On the other hand, we recently moved into a house with a pool so I can always do that!  I just tend to get lazy in the pool!  Floating burns calories, right?