Marathon Training Basics
How a training block is actually structured, and why the long run isn't the only thing that matters.
A marathon block typically runs 12-20 weeks and moves through phases: base (building aerobic volume), build (adding tempo and threshold work on top of that base), peak (highest combined volume and intensity), and taper (a planned 2-3 week volume cut so you race fresh).
The long run gets outsized attention, but it's one piece. What matters more than any single run is consistent weekly mileage over months — the aerobic system adapts to accumulated stress, not to any one heroic effort. A runner who logs 30 consistent miles/week for 16 weeks will usually out-race someone chasing 20-mile long runs on an inconsistent 20 miles/week base.
Race-pace practice matters specifically for the marathon because the distance is long enough that pacing errors compound brutally. Some long runs should include miles at or near goal marathon pace, not just easy effort — this trains both the legs and the pacing discipline.
The taper is not optional and it is not laziness. Cutting volume 40-60% over the final 2-3 weeks while keeping some intensity lets your body absorb months of training and show up fresh. Runners who skip the taper because they feel undertrained almost always race worse, not better.
This is educational content, not medical advice — talk to a doctor about anything specific to your health or an existing injury.