As a runner who wants to boost endurance, you want to make sure you're hitting the pavement at least 3 times a week, preferably 4 times a week. I like to try to avoid running 2 days in a row, just because I always end up hurt when I run too often, but I will sometimes run an easy day before a long run day or a speedwork day. Just be sure not to have 2 hard workouts, either in terms of distance or speed, on consecutive days.
If you want to build endurance, I suggest picking one day a week for a "long" run. If you normally run 3-4 miles a day, a long run would be 5-6 miles. If you normally run 1-2 miles, a long run would consist of about 3 miles. If you like to run 5-6 miles regularly, you long run would be about 10 miles. Get the idea? I typically run 3 or 4 times a week. 2-3 of those times, I run about 3-5 miles, but on my long run day, I run 6-7 miles.
The nice thing about long runs is, you get to slow down your pace a little bit. By slowing down, your heart doesn't have to work as hard and you can run for a longer amount of time. For example, I normally run an 7-8 minute mile pace on my daily runs, but on my long runs, I slow down to about a 9 minute mile. If you normally run 10 minute miles, I suggest you slow down on your long runs to a 12 minute per mile pace. Use your first mile to warm up; really focus on your breathing and your pace. Your first mile can even be a little bit slower than you planned pace. You really want to make sure your whole body is loose and ready to enjoy a great, long run.
Once you're loose, try to just settle into your pace and get in the zone. Enjoy the experience! Count your blessing. Really try to be in the moment and don't let your heart rate get too high. You should be able carry on a conversation with a friend while you run your long run pace. If you find yourself getting out of breath or fatiguing, slow down even more. Try to avoid walking if you can, but there's no shame in walking if you must, just make sure you get back to your run within a minute or 2 of walking.
Every other week, try to add another 10% to your distance. So if your first long run is 3 miles, do another long run of 3 miles the next week, then the next week try to go 3.25 miles. If your long run was 6 miles, try to go 6.5 miles 2 weeks later. If the time to increase your distance comes and you still don't feel comfortable with your previous distance, you don't have to go longer, but try not to get in a rut where you're afraid to challenge yourself. What's the worst that could happen? You have to walk? At least you're out there moving which is a lot more than most Americans can say for themselves. But beware, don't add on too much too quickly. Even if you're feeling great and think you could double your distance, hold off and just enjoy feeling great at your longer and longer paces. You don't want to end up injured. Wouldn't you rather be able to run regularly for years than run really hard for a couple of months and then be sidelines? If you're a go-getter that has a hard time holding back, just keep reminding yourself, "slow and steady wins the race. "
Other things that help me stay focused and continuing to improve my running skills are having a race to train for and having a buddy to run with. Signing up for a race gives me a goal to focus on, whether it's improving my previous time or racing a new distance. Having someone to run with gets me out there even on the days I may not feel like running, which we'll all encounter from time to time. Running buddies are great and it's good not to be picky when it comes to finding a running parter. It's ok to have running buddies of all different speeds, too. Don't be worried about always finding someone who runs at your pace. I find I like the challenge of trying to keep up with my husband on some days but also enjoy leisurely runs helping my friend try to work her way up to being able to run a 5k. Variety is the spice of life, even in running. Just get out there and move! Hopefully these tips help you as you build your distance. Keep your questions coming. I love hearing from you!