20K trail on 4 sessions a week: how many weeks of preparation?

For an athlete at intermediate level, Endu builds a 11-week preparation. If your race is closer, the plan compresses phases while keeping the taper; if it's further away, it lengthens the preparation, and when the gap is large the preparation starts right away, gently and at your current volume, before building up.

How many sessions per week?

This example has 4 sessions per week. You choose 3 to 7 training days and the exact days (e.g. Tue, Thu, Sat, Sun): the plan sticks to them.

Can I follow sessions on my watch?

Yes, on Garmin and COROS. On Garmin, the Endu app (Connect IQ Store) shows today’s session and starts it as a guided workout. On COROS, link your account from your profile: your running, trail and cycling sessions land in the watch calendar. Other brands are not supported yet.

How much does it cost?

14-day free trial, then €7.99/month with no commitment or €59.88/year (€4.99/month). Unlimited objectives and sports.

20K trail plan, 4 sessions a week

20 km · 800 m D+

You have 4 slots a week. 11 weeks, 4 sessions a week, up to 5 h and 650 m of climbing a week at the peak, long run up to 2h15. Here is how Endu spreads a 20K trail preparation over 4 sessions: the long run is protected, the quality session comes next, easy runs fill what is left.

Create my plan for 20K trail

weeks: 11
sessions: 43
sessions / week: 4
peak week: 5 h

Plan structure

Periodised in phases: build the base, move to race-specific work, then taper before the race.

Base
Weeks 1–4 · 4 wk
Build
Weeks 5–7 · 3 wk
Specific
Weeks 8–9 · 2 wk
Taper
Weeks 10–10 · 1 wk
Race week
Weeks 11–11 · 1 wk

Volume progression

Week by week: lighter recovery weeks are built in to absorb the load.

Wk	Phase	Hours	km	Elev.
1	Base	2.9 h	21	272 m
2	Base	3.2 h	23	312 m
3	Base	3.4 h	25	352 m
4	Base	3.7 h	27	392 m
5	Build	4 h	29	399 m
6	Buildrecovery	3.1 h	23	275 m
7	Build	4 h	29	513 m
8	Specific	4.5 h	32	581 m
9	Specific	5 h	36	648 m
10	Taper	2.8 h	20	252 m
11	Race week	2.4 h	20	11 m

Sample week — week 7 (Build)

Real sessions from the plan with their targets. Each session is detailed step by step, and can be sent to a Garmin or COROS watch.

MondayEasy
28 min easy
28 min · 3.7 km
TuesdayVery hard
10 × 1 min 30 s uphill
recover on the way down, 2 min 15 s
1 h 03 · 8.4 km
FridayEasy
28 min easy
28 min · 3.7 km
SundayEasy
Long run 1 h 59
1 h 59 · 13 km

Example generated for a intermediate-level profile (MAS 15 km/h, 4 days available per week). Your plan will depend on your level, availability and feedback.

This plan’s check-up

Pass

A 11-week build (recommended minimum: 8); a longest run never more than 10% above the previous month’s; volume rising at most 13% from one week to the next; 93% of the time at easy effort; a taper cutting volume by 51% in race week.

3 worth knowing · 14 checks passed

Remarks

Lighter weeks — 5 loading weeks in a row without a lighter week (up to week 5).
Strength training — No strength session.
Fueling — Long sessions (up to 135 min in this plan) are where race fueling is rehearsed.

The 14 checks passed, in detail

Length of the build — 11 weeks: enough for this race (recommended minimum: 8).
Sessions per week — 4 sessions a week: the minimum for this race is met.
Volume progression — Running volume rises at most 13% from one week to the next (a signal appears beyond 20%).
Long run increase — Each week, the longest run is at most 10% longer than the longest of the previous month (benchmark: 10%).
Weight of the long run — The long run keeps a reasonable share of the week.
Intensity distribution — About 93% of the time at easy effort: the most common distribution among trained endurance athletes.
Demanding sessions — No more than 2 demanding session(s) a week: suited to the level.
Hard days back to back — Demanding sessions are separated by easy days.
Rest days — At least one rest day a week.
Climbing in training — The plan prepares the climbs and descents (32 sessions with elevation).
Taper — Volume drops 51% in race week.
Intensity during the taper — Short race-pace efforts remain in the last two weeks.
Frequency during the taper — The number of sessions stays close to usual (88%).
Climbing in the busiest week — The busiest week climbs 648 m, for 800 m on race day.

Endu runs its own plans through the plan check open to everyone: same public rules, same thresholds, same sources. The rules and their sources, and a check of your own plan.

Your plan, not a template athlete's

This plan is generated for an athlete at intermediate level with 4 days available per week. Yours will be calibrated on your MAS, your available days and your feedback after every session. 3 minutes. 14-day trial, cancel anytime.

Create my plan for 20K trail

Frequently asked questions

20K trail on 4 sessions a week: how many weeks of preparation?: For an athlete at intermediate level, Endu builds a 11-week preparation. If your race is closer, the plan compresses phases while keeping the taper; if it's further away, it lengthens the preparation, and when the gap is large the preparation starts right away, gently and at your current volume, before building up.
Is this plan well built?: Pass at Endu’s plan check, the same as for any plan: 14 of 14 checks passed. A 11-week build (recommended minimum: 8); a longest run never more than 10% above the previous month’s; volume rising at most 13% from one week to the next; 93% of the time at easy effort; a taper cutting volume by 51% in race week. The rules and their sources are public on endu.fr/en/controle-technique.
How many sessions per week?: This example has 4 sessions per week. You choose 3 to 7 training days and the exact days (e.g. Tue, Thu, Sat, Sun): the plan sticks to them.
Can I follow sessions on my watch?: Yes, on Garmin and COROS. On Garmin, the Endu app (Connect IQ Store) shows today’s session and starts it as a guided workout. On COROS, link your account from your profile: your running, trail and cycling sessions land in the watch calendar. Other brands are not supported yet.
How much does it cost?: 14-day free trial, then €7.99/month with no commitment or €59.88/year (€4.99/month). Unlimited objectives and sports.