The Training
Week.

01 / The distribution problem

The distribution problem

Running four times a week does not guarantee progress. The question is what those four sessions look like.

Most runners default to a moderate effort on every run. Hard enough to feel like real training. Not hard enough to drive the adaptations they are chasing. The result is a week full of Zone 3 running: the grey zone. You accumulate fatigue without building aerobic capacity, and without the speed and threshold stimulus that hard sessions produce.

The fix is not to run more. It is to run differently.

In practice, this means most of your runs should feel genuinely easy. Conversational. Slow enough that you could keep going. And one or two sessions per week should be genuinely hard. Not medium hard. Hard.

Zone 3 sits in between. It is hard enough to be tiring and not hard enough to produce the adaptation you want. Most runners spend most of their time there. That is the problem.

03 / Types

The four types of run

Every session in a well-structured week belongs to one of four categories. Most runners only use one, running everything at the same moderate effort.

04 / Sequencing

How to sequence your week

The session types matter. The order they appear in your week matters just as much.

06 / Progression

When life interrupts

Most training weeks do not go to plan. Work, family, illness, and weather reduce the sessions you complete. When that happens, the priority order matters.

• Long run first. Weekly aerobic volume is more important than intensity. If you can only run twice this week, make one of them your long run.
• Easy volume second. Consistent aerobic stimulus compounds faster than sporadic intensity. Four easy runs builds more base than two hard sessions.
• Hard sessions last. A missed interval session costs you almost nothing compared to a week of missed base volume.

A shorter week is not a failed week. The mistake is compensating by making the sessions you do complete harder, confusing intensity for effort. Stick to the session types even in reduced weeks.

Progression over time

Week-to-week progression works when volume increases gradually and recovery is built into the schedule.

The 10 percent rule

Do not increase your total weekly running volume by more than 10 percent from one week to the next. Larger jumps outpace adaptation and increase injury risk. Consistent small increases compound into significant fitness gains over 8 to 12 weeks.

The recovery week

Every fourth week is a recovery week. Reduce total volume by 20 to 30 percent. Keep the same session types and intensities, just reduce the duration. The recovery week is where adaptation consolidates. Skipping it pushes the body into accumulated fatigue rather than fitness gains. Most runners who plateau do so because they never pull back.

What to expect at 8 weeks

After 8 weeks of structured polarised training, easy runs feel noticeably easier at the same heart rate. Threshold pace improves without additional perceived effort. Hard sessions feel more recoverable. These are not subjective impressions. They reflect real physiological changes in mitochondrial density, stroke volume, and lactate clearance capacity. The same weekly structure scales straight into a race build, whether that is a half marathon training plan or a marathon training plan. Targeting one of the World Marathon Majors adds course-specific work on top of this same weekly skeleton.