You should vary your running distance and take breaks. You will get more out of the runs. Weight training and something like yoga on the other days, plus a day or two of rest. I use to run all the time, now at 48 a lot of stuff has broken down. It happen to a lot of my running friends. It happens to most everyone between 40-50, time undefeated and still champion.

I am 43 and have been a runner since HS. 7 marathons. I have never taken time off from running and never had a running injury.

I have always lifted weights and I think this has really stabilized my knees. You need to equal quad and hamstring...I do it on the machines..and some squats.

I now am bored from solely running so I do two days of cross-fit variant class (UXF) at my gym and run the other 4 days. I take one day off. I lift weights 2 of the days I don't do the UXF class.

OP-- I know EXACTLY what you mean. No other exercise makes me feel like I do when I run. It is a mental health thing (I don't run with headphones--just clear my head) and it also keeps me regular. Spinning classes are closest thing to giving me the runner's high. Maybe try those in between running days.

Agree with the suggestins to cross-train. Bike (or spin), weight train, swim, yoga - anything that works the muscles or joints differently. I also need cardio to maintain my sanity. Running works best but I only do it 3-4 days/week.

Running without weight training is a recipe for knee pain. running really develops your hamstrings and not your quads. Balance it with some squats at the bare minimum. (I am a heavier runner - 200 or so - that likes to do long distances and if I slack off on strength training, my knees hurt within a week or two)

OP have you had your knees checked? YOu may have a torn meniscus as I do, which means RICE - Rest Ice Compression and Elevation until (maybe) they heal. You can't keep pounding on them or you will wind up needing surgery. Take a few days off - if they still hurt, go see an orthopaedic doctor.

I've run every day for over 10 years. Go to a specialty, locally owned running store and have them for your for shoes. The wrong shoe can destroy your gait and cause all kinds of pain.

maybe try swimming? no impact on your knees

also, for joint pain maybe try:
http://www.mayoclinic.com/health/glucosamine/NS_patient-glucosamine

I would also try something like an ashtanga yoga class. it's pretty intense, great for flexibility, and can almost be almost aerobic.

i suggest biking. or maybe walking uphill very fast. that will give you the exercise you crave without hurting your knees.

Agree with taking days off. I'm a new runner, but I'm up to running about 30 minutes every other day. I take one day off completely (though I may go walking), and others days I do some other work at the gym - weight training, elliptical, uphill walking.

In order to sustain your knees and joints, it's important that you have off days and vary your exercise. Maybe try swimming for lower impact workouts?

What about weightlifting? You can still get an intense workout and exhaust your body, but you can pick exercises that don't put strain on your knees.

agree with PP. Especially if you are running on the sidewalk or pavement, instead of dirt trails.

On your off days, go for a fast hike instead.

You can't run every day -- your body needs rest days. You will get injured. It sounds to me like the exercise is helping you with some kind of underlying issue like depression or anxiety. Running can be helpful in that way. But when you HAVE to run to keep symptoms at bay, especially when you are running to the point of injury, you need to step back and address those underlying issues.

Hello friends i am new in this forum. I run 5 km everyday in the morning. If i don't run i get nightmare and will be unable to sleep in night. So i run in-order to do more physical. My problem is that i am worried about my knees . It pain me too much. So please suggest me any alternatives.