If you are new to distance running, a key element is endurance. It's a factor that can easily be improved upon so regardless of your background, you shouldn't be afraid to give it a go. The first person I ever coached was my sister. She was around 11 years old and I was away competing at St John's. She told me that she wanted to get into running and I, wanting to be a coach, decided to make her my project. I designed a training plan to introduce her into the sport.
At the time she had dancing as a background, but never actually went for a jog ever, so had no idea where to start. I took her out one day when I was home from college and had her jog. I timed her as I stayed by her and she was able to jog for a couple of minutes at a slow pace before needing a break. During her break, we walked a little until she felt she was ready to jog again and we started jogging. We repeated this process until we got through about half of an hour of on and off jogging and walking. We decided to call it a day and I wrote up a plan for her. I told her to pick any 3-days during the week and try to jog for as long as she can and walk when she needed to. I told her to do this for 30-minutes just as we did on day 1 and repeat that for all 3-days. I had her jog as slow and comfortable as she wanted. By the end of the week, I checked-in with her and she was able to accomplish jogging/walking for 30-minutes a day for 3-days that week. The following week I had her do the same thing but for 4-days that week. The following week she was able to do 5-days of it.
After the first 3-weeks, I had her focus on running more and walking less during the 30-minute period. She was capable of jogging 10-minutes at a time and only needing to walk about 1 or 2-minutes before being able to jog for an additional 10-minutes or so. I kept her doing this for 5-days a week taking 1 day off in the middle of the week and 1 at the end of the week. Each following week, I challenged her to push herself to jog for a longer amount of time. Within 2-months she was able to go for 50-minutes to 1-hour runs without needing to stop and walk and she was able to do this 3-5 days a week at the young age of 11. By that time I had her on a schedule of 1-day a week going for a 1-hour jog, 2-days at 45-minutes, and 2-days at 30-minutes.
Assuming that you have never run before and are brand new to this sport, I suggest testing yourself by just jogging slowly and see how long you can do it before getting tired. Regardless of what you accomplish on your first day, it's a success simply because you are out there giving it an attempt. If you are only able to jog for 10-seconds and have to stop and walk, that is fine. The next day, get out there and aim for 15 seconds. Then aim for 20-seconds. Work your way up, there isn't a rush. Stopping to walk is not bad, take your time. Jogging 30-seconds and walking for 2-minutes on and off is perfectly ok. It's your first time trying this, so any work is good work. Be diligent and hold yourself accountable to jogging 3-days a week. Work your way up to being able to jog consecutively for 20-minutes. 20-minutes too much? Then start at 10-minutes. 10-minutes too much? Start at 5-minutes....there is no standard to start, just get out there and start.
My advice though is work your way up to the point where you can maintain 20-minutes of jogging without needing a break. Work your way up to being able to do that 3-days a week. When you are capable of doing that, add a 4th day per week. Then improve to a 5th day a week. I'm a believer that being able to run more days consistently throughout your week, is more important than running for long amounts of time. 20-minutes a day for 5-days a week is better than 1-hour of running only once a week. Your body needs to adapt to running and the stresses on the body that come with it. It will adapt quicker if it does it more often. So start with short runs more frequently during the week.
After you are capable of running for 20-minutes without having to stop for 5-days a week, then start working your way up to running longer. Start with 25-minutes per day. Then 30-minutes and so on until you can jog for 1-hour. When you get to the 1-hour mark, then you are ready to start workouts if you choose. A sample training week is as follows:
Day 1 - 45-minute run
Day 2 - 30-minute run
Day 3- 45-minute run
Day 4 - Off
Day 5 - 30-minute run
Day 6 - 1-hour run
Day 7 - Off
If you want to add workouts, a nice introductory into workouts are runs that are called Fartleks. Fartlek running is regular running with short amounts of speed bursts thrown into them. Time yourself for a 20-minute jog. Then when you get to the 5-minute mark, sprint for 10-seconds and then go back to slow jogging for another 5-minutes and repeat this process until you complete your 20-minute run. In this scenario, you would have had 3 sets of 10-second sprints within your 20-minute run. Want to push yourself more? Increase the amount of time sprinting to 20-seconds, then 30-seconds. When you're capable of sprinting for 30-seconds, if you are still looking to challenge yourself in workouts, decrease the amount of time spent on slow jogging in-between the sprints. Bring it down to 4-minutes, then 3-minutes. Gradually increase the amount of time sprinting while gradually decreasing the amount of time jogging in-between each sprint. Get to the point where you can jog for 3-minutes and sprint for 30-seconds on and off for a 20-minute run (That would have given you a total of 5-6 30-second sprints during your 20-minute run). For beginners, I only recommend doing these workouts twice a week. Once in the beginning of the week, and once somewhere after the half-way point (maybe on day 2 and 5 for instance).
When you are capable of doing this, the next level would be to increase this workout to be for a total of 30-minutes of running. Increase total time running so that you are increasing the number of 30-second sprints that you are doing during your workout. When you are comfortable with jogging for 30-minutes, where you can sprint for 30-seconds after every 3-minutes of your run, then I would start to begin gradually increasing your sprint time and decreasing your recovery time. Get yourself to eventually being able to run 2-minutes of easy jogging followed by 1-minute of faster running throughout a 30-minute run. This workout is giving you 10 sets of 1-minute sprinting with double the time for recovery (2-minutes) for a 30-minute run....you are sprinting for 1/3 of the run, great job!
To fit these workouts into a weekly training plan, I advise something similar to the following:
Day 1 - 30-45 minutes of easy jogging followed by 15-20 minutes of stretching out
Day 2 - 30-minute Fartlek run followed by 15-20 minutes of stretching out
Day 3 - 30-45 minute easy run followed by 15-20 minutes of stretching out
Day 4 - Off
Day 5 - 30-minute Fartlek run followed by 15-20 minutes of stretching out
Day 6 - 1-hour long run followed by 15-20 minutes of stretching out
Day 7 - Off
Make sure you are stretching out after you run!