Going from 3 to 4 sessions a week: when, how, and which session to add
Three sessions a week are enough to finish any distance. The fourth is the one that moves your time up a notch. But adding it at the wrong moment or with the wrong session leads straight to fatigue. Here is the rule your AI coach applies to change plan variant.
Last updated: 2026-09-19
When you are ready
Three signals, read in your Garmin data: at least eight consecutive weeks at three sessions with no missed week, a stable ACWR between 0.9 and 1.2, and a weekly feeling of 3 or more. If one is missing, the coach advises you to wait.
The fourth session is never added mid-plan: it is chosen at the start of the next plan, by changing variant. The coach reminds you of this if you ask halfway through.
Which session to add
An easy-endurance run of 40 to 50 minutes, not a quality session. The fourth session first serves to increase easy volume, which builds the base. The second quality session only arrives at five sessions a week.
The plan places it on a day not adjacent to the long run, according to the days you indicate. Weekly volume rises by about 25%; the assimilation week stays one week in four.
The first six weeks
The coach watches ACWR more closely during the transition: it brings the assimilation week forward as soon as the ratio exceeds 1.3, and proposes going back to three sessions if the feeling drops to 2 two weeks running.
- Ready: 8 stable weeks at 3, ACWR 0.9-1.2, feeling ≥ 3.
- Add an easy run, not a quality session.
- Change variant at the start of the next plan.
After six weeks at four sessions with no negative signal, the transition is done. The next plan can then consider five sessions, with the second quality session.
Frequently asked questions
Can I go straight from 3 to 5 sessions?
The coach will refuse: that doubles the number of quality sessions. Go through four for at least one full plan.
Can the fourth session be cycling?
Yes: an easy bike ride counts as a volume session in the multisport profile, with less impact. The coach accepts it as the fourth session.
How much time a week at four sessions?
Between 3 h 30 and 5 h depending on the distance prepared, long run included. At three sessions, count 2 h 30 to 4 h.
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