Having a consistent weekly base mileage is important. One example for me when I was preparing for my first half marathon the next 2 months having a base of running non stop for 6 mes I went 1 week - 6 2nd-8 3rd-10 4th-10 5th-12 6th 8 7th-8 8th- race day half marathon you increase progression. Everyone is diff, but this is how I set mine up based on my ability. I moved through the year from 1/2 Mara to full Mara to 50k to 50 mile ultra marathon 1/2 ironman then ironman in the same year. It all comes down to how willing are you gonna work hard and staying injury free knowing when to rest and listening to your body