Not like "away from cops" kind of advice!
I've been running since the beginning of this year, 5km/3miles on alternative days amongst other exercises like push ups, pull ups and sit ups.
Over the past year, I have developed a pace that I feel very comfortable with, too comfortable that is. Basically, I am not improving in pace or time. When I increase my pace, it doesn't last long. However if I keep to my pace, I can go on and on and on, easily beyond 5k.
Observing other better runners, I feel that my stride isn't "light" enough. I feel that my heel is still touching the ground too much. It's amazing how those guys run like as if their bodies are feather weight, and their strides are as though they are floating in the air. I tried to mic mick them but it's felt really unnatural for me.
The reason why I want to improve my pace or stride is I want to over come this "plateau" and lose more weight! Generally, I just want to feel better. Any enlightening words?
FYI I don't know anyone personally who runs and my family are all couch potatoes.
The "normal" running shoes we buy aren't designed for toe running. The attenuation (is that correct use of word?) is all in the heel. There's nothing wrong with landing on your heel, but beware of how your foot is turning upon landing. Google "pronation" and you'll get more info. The wrong shoe might damage your knee over time.
If you want to increase your oxygen intake, I strongly suggest you run intervals. Much, much more effective. For example 4x4 intervals (which there have been several studies on, and it's very effective). 4x4 intervals is simply 4 intervals of 4 minutes, with a three minute slower-rate running in-between. In the intervals, you want to work yourself up toward max heart rate in the final interval. To reach those high heart rates, it's very effective to run in a slight hill. The three minute "breaks" are to burn milk acid in your muscles.
Intervals is extremely effective on reducing your fat percentage. That is what you want, not really "go down in weight". Who cares about their weight, it's the fat people want removed. Intervals burns fat.... that is, you're challenging your body. Why should the body change if it's not physically challenged? Push yourself. Not too much, obviously, but don't stay in the "comfort zone". Also, if you want to reduce your fat percentage, you really do need to eat correctly. Proteins are key, little fat and sufficient amounts of carbs. That worked really well for me, I lost almost 15 kg in 6 months. I went from around 85 to almost almost 70 kg. (convert yourself

)... The thing I found was that be careful of what you eat before you go to bed. Your supper should mainly be proteins. Eating enough proteins will make sure you don't burn too much muscle, but rather burn the fat. A nice, and cheap, protein source is pure chicken (not those marinated things). Fat fish (salmon, trout etc) is also a nice source. Here you get essential fatty acids as well. I ate well 6 days a weak, and allowed myself to eat "whatever I wanted" on Saturdays. The Sunday was a hard day

hehe.
This might seem like much effort for little. BUT, this is the correct way to burn fat. Pills don't take them. Any other miraculous diet, don't try it. This is guaranteed to work. It takes time, perhaps a little longer for some. It all depends on the individual. BUT, if you reduce your intake of calories, run (either intervals, long distance running, or really any activity three times a week that burn calories), and you will see result. You really get into shape, you eat well and feel the differences, you can feel you getting better times in your running. It's great. It takes, however, commitment, and kind friends who will not offer you any chocolate or other food that's not in your program. Set up what you want to eat for breakfast each day, dinner each day. What I did was to eat chicken a few days, salmon a few other days for dinner and supper. Breakfast I just ate bread with ham or something.
And remember your minerals and stuff, those are important. Perhaps pills containing the needed if you can't get it via your regular food.
If you find it hard to get enough proteins each day through your meals, then try protein powder.. Very easy, it tastes good and contains the amino acids you need.
edit: challenging your body with different types of training is very smart. Your body might "get used to" being challenged a certain way. If you have a bike, use it. If you have a pool nearby, swim. Jumping ropes are brilliant. Intensive strength training works wonders.