There is no single correct training week, but there is a shape that works for a very wide range of runners, and departures from it should be deliberate rather than accidental.
The shape
- One long run — the aerobic backbone.
- One quality session — intervals or hills.
- One steadier effort — tempo or threshold.
- Everything else easy — genuinely easy.
- At least one full rest day — more if life demands it.
That is two to three hard efforts a week. If you are doing four, you are almost certainly doing none of them well.
Why most of it is easy
Easy running builds the aerobic system with a low recovery cost. That combination is what makes volume possible, and volume is what makes runners. Running easy runs moderately hard produces fatigue without the corresponding adaptation — the worst trade in endurance training.
If every run feels like a moderate effort, you are training the middle of the range and improving at neither end of it.
The long run
It is a session with a purpose, not a distance to survive. For most half-marathon training, 90 minutes to two hours is plenty. For a marathon, the long run becomes more specific: some of it at goal pace, and practice at eating while running.
Increase it gradually. A sudden jump in long-run duration is one of the more reliable ways to get injured.
The quality session
Intervals or hills, ideally alternating in blocks rather than in the same week. Total hard work of twenty to thirty minutes is enough for most amateurs, plus a proper warm-up and cool-down.
The steady effort
Twenty to forty minutes at threshold, continuous or broken into blocks. This is the most specific session for anything from 10K to a marathon, and the one most people skip because it is uncomfortable without being exciting.
Fitting strength in
Two sessions, attached to the hard running days. See how often runners should lift for the detail.
When to change it
Change one thing at a time, and give it four weeks. Changing three variables at once means you learn nothing about which one worked.
