Sub-4 hour marathon

How to run this plan

• Marathon-pace blocks inside long runs are the core session. A 30 km run with 15 km at goal pace is worth more than a 35 km jog.
• Easy pace 6:40–7:10/km. It will feel absurdly slow. That is what makes the goal-pace work possible.
• Fuelling: target 40–60 g of carbohydrate per hour and rehearse it exactly as you will do it on race day.
• Sub-4 usually fails between 32 and 38 km, and it usually fails because of the first 10 km. Start slower than goal pace and let it come to you.

Strength work. Strength: 20 min of squats, lunges, single-leg calf raises, glute bridges and planks. This is the injury insurance. Add it on an easy day or straight after an easy run — never the day before a quality session. If you want the movements themselves written out, running's supporting exercises, by muscle worked and equipment needed, is the reference.

The principle underneath the table

Roughly eighty per cent of the running in this plan is easy, and that ratio is not a compromise — it is the mechanism. Easy running builds the aerobic machinery that lets you absorb the hard sessions; hard running that is not paid for by easy running just accumulates fatigue. The most common way an amateur plan fails is that the easy days creep up to a moderate pace, the hard days consequently drift down to the same moderate pace, and the runner spends twelve weeks training one gear.

The second principle is the cutback week. Volume in this plan does not climb monotonically; every third or fourth week it drops. Adaptation happens during recovery, not during the session, and a plan without down weeks is a plan that banks fatigue until something gives.

The third is the taper. The last three weeks reduce volume sharply while keeping a small amount of intensity. It will feel wrong. Do it anyway — nothing you run in the final fortnight can make you fitter, and plenty of it can make you tired.