I'll let someone with more sports science knowledge chip in, but my more bog-standard physiology knowledge suggests that your pattern of exercise will likely encourage fast-twitch muscle rather than slow-twitch. In other words, my guess is that you're just cementing your anaerobic sprinting pattern. I also wonder whether your aerobic fitness generally is fairly poor. If you want to be able to run long distance, you need to start running at a slow pace (but above walking speed) rather than sprinting and stopping. If a slow run is too much, then fast walk longer distances until you can build up endurance. Again, I defer to those with true sports science training; general medical knowledge doesn't delve into the details of the pros & cons of exercise techniques much at all.
However a blend of running and walking is a way of covering large distances quickly without getting exhausted. IIRC, in the day of armies marching around the countryside, some skirmishing troops used an alternating pattern of 3 paces running and 3 paces walking to increase their maneouverability on the battlefield.
Hmmm...I used to walk from one end of DC to the other. I love walking and can walk for hours without getting tired at a nice decent pace.
If you look at pictures of sprinters vs marathon runners, they are totally different. That's what I am going for.
I probably need professional help on working out.