The Data-Driven Runner: My Base Phase Recap
A reflection of my base-building phase and a training block preview as I attempt a Chicago qualifier
It’s been four months since I set off on my grand running experiment to run a qualifying time for the 2025 Chicago Marathon. After 16 weeks, it’s time to transition from my base-building phase to my training phase in preparation for the Cleveland Marathon in May, where I will make my first attempt at a qualifier. It’s time to dive into some numbers, and evaluate the impact of base building, and what is to come in training.
Reflections On My Base-Building Phase
The last four months have primarily focused on easy running, in what most would call Zone 2 training. Speed was sprinkled into my weekly runs occasionally, but was not a main concern of mine. I also incorporated some long runs, gradually increasing mileage so that when training began, I wouldn’t be inappropriately increasing my training load. During this phase, I capped my long run at 8 miles.
So, how did all of this affect my projected race times? Let’s take a look at the numbers.
Projected race times across all distances decreased over the base building phase, with the 10k distance showing the most improvement at just…
