While the marathon has a certain mystique and ends up on countless bucket lists every day, it's not the most popular distance. Far more people run half marathons every year. 13.1 might not have the same kind of allure 26.2 does, but there are some very good reasons why this distance resonates for so many people.
A typical marathon training cycle can easily be 16-20 weeks depending upon your current level of running fitness. This is 4-5 months of running three (or more days) a week. It's likely this routine includes cross-training, yoga, stretching, foam rolling, and more. Training for 26.2 can be a life consuming endeavor.
Training for a half marathon is not nearly as demanding. I've known many people who get into half marathon shape in 10-12 weeks from simply running 2-3 times/week. I'm not saying this approach will get you a personal best, but it can get you across the finish line.
If you want to get into great running shape and still have a balanced lifestyle, the half marathon is worth a long look.
I love the marathon. But, the truth is every serious running related aggravation and injury I've sustained has been associated with training for this distance. I'm not alone in this department. The risk of aggravation and injury spikes considerably when training for 26.2.
Just running a single stride can generate 3-7 times in impact force per footstrike. Consider doing this for 26.2 miles versus 13.1. The marathon simply asks much more of your body than a half marathon.
The half distance poses a far lower risk of aggravation and injury. I've worked with thousands of runners over the years. The aggravations and injuries I see with the half are far less frequent and far less severe than with the full.
So, if steering clear of aggravations and injuries while maintaining a high level of running fitness is one of your goals, the half marathon is worth your consideration.
The general rule of recovery for running is about a day per mile. So, if you run 3 miles, you're theoretically not 'fully' recovered from this run until three days later. This doesn't mean you can't run during this stretch, but you might need to take it a bit easier for a day or so.
If you're training for a marathon, you'll eventually stare down a 20 miler. There's a reason why the longest run (often 20+ miles) is usually three weeks out from race day during a marathon training cycle. It's because your body needs about three weeks to fully recover from a run as demanding as this.
Conversely, log a 10 miler while training for a half marathon and you're likely going to feel fully recovered in little more than a week. The half doesn't demand nearly as much as the full. So, recovering from a long run during a half marathon training cycle is going to be much faster.
If you're bound and determined to conquer 26.2, I get it. But, at least get into solid half marathon shape first. Get a few 13.1's under your belt. In the process of doing so you may just discover that the half marathon is actually your jam.