Half Ironman on 5 sessions a week: how many weeks of preparation?

For an athlete at intermediate level, Endu builds a 21-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 5 sessions per week. You choose 5 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.

Half Ironman plan, 5 sessions a week

113 km · swim 1.9 · bike 90 · run 21.1

You have 5 slots a week. 21 weeks, 5 sessions a week, up to 9.8 h of training a week at the peak. Here is how Endu spreads a Half Ironman preparation over 5 sessions: the long run is protected, the quality session comes next, easy runs fill what is left.

Create my plan for Half Ironman

weeks: 21
sessions: 104
sessions / week: 5
peak week: 9.8 h

Plan structure

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

General preparation
Weeks 1–2 · 2 wk
Base
Weeks 3–8 · 6 wk
Build
Weeks 9–13 · 5 wk
Specific
Weeks 14–18 · 5 wk
Taper
Weeks 19–20 · 2 wk
Race week
Weeks 21–21 · 1 wk

Volume progression

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

Wk	Phase	Hours	km
1	General preparation	6.2 h	21
2	General preparation	6.4 h	21
3	Baserecovery	5 h	12
4	Base	7.1 h	16
5	Base	7.4 h	16
6	Base	7.6 h	17
7	Baserecovery	5.5 h	13
8	Base	8 h	18
9	Build	8.2 h	19
10	Build	8.3 h	19
11	Buildrecovery	5.8 h	15
12	Build	8.6 h	21
13	Build	8.9 h	21
14	Specific	9.1 h	22
15	Specificrecovery	6.5 h	17
16	Specific	9.2 h	22
17	Specific	9.6 h	24
18	Specific	9.8 h	24
19	Taper	6.7 h	21
20	Taper	5.6 h	18
21	Race week	2.9 h	7

Sample week — week 12 (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.

MondaySwimmingEasy
59 min continuous swim
59 min · 2.7 km
TuesdayBrickHard
1 h 30 bike + 45 min run
including 3 × 10 min at threshold on the bike · run at marathon pace
2 h 23
FridaySwimmingHard
10 × 200 m at threshold
20 s recovery
59 min · 2.8 km
SaturdayCyclingEasy
2 h 44 at endurance pace
2 h 44
SundayRunningEasy
Long run 1 h 33
1 h 33 · 15 km

Example generated for a intermediate-level profile (MAS 15 km/h, 5 days available per week). Your plan will depend on your level, availability and feedback.

This plan’s check-up

Pass with remarks

A 21-week build (recommended minimum: 12); a longest run never more than 6% above the previous month’s; 83% of the time at easy effort; the longest session 3 weeks before the race; a taper cutting volume by 70% in race week.

1 worth a look · 2 worth knowing · 21 checks passed

Remarks

Sessions per week — 5 sessions a week for a half or full Ironman.
Strength training — No strength session.
Fueling — Long sessions (up to 194 min in this plan) are where race fueling is rehearsed.

The 21 checks passed, in detail

Length of the build — 21 weeks: enough for this race (recommended minimum: 12).
Sessions per week — 5 sessions a week: the minimum for this race is met.
Volume progression — Running volume rises smoothly from week to week.
Long run increase — Each week, the longest run is at most 6% longer than the longest of the previous month (benchmark: 10%).
Lighter weeks — A lighter week comes back regularly (weeks 3, 7, 11, 15, 19).
Intensity distribution — About 83% of the time at easy effort: the most common distribution among trained endurance athletes.
Demanding sessions — No more than 3 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.
Timing of the longest session — The longest session falls 3 weeks before the race: the right time.
Bike-run bricks — 10 bike-run bricks over the last 12 weeks.
Taper — Volume drops 70% 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 (90%).
Swim / bike / run balance — Swim 22%, bike 50%, run 28%: within coaches’ benchmarks.
Frequency per discipline — Each discipline comes back at least 2 times a week.
Open water — 5 open-water session(s) before the race.
Longest ride — The longest ride lasts 194 min (benchmark: 180 to 270 min).
Longest run — The longest run lasts 110 min (benchmark: 90 to 135 min).
Swim distance — The longest swim covers 174% of the race distance.
Long ride increase — The long ride grows in small steps.

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 5 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 Half Ironman

Frequently asked questions

Half Ironman on 5 sessions a week: how many weeks of preparation?: For an athlete at intermediate level, Endu builds a 21-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 with remarks at Endu’s plan check, the same as for any plan: 21 of 22 checks passed. A 21-week build (recommended minimum: 12); a longest run never more than 6% above the previous month’s; 83% of the time at easy effort; the longest session 3 weeks before the race; a taper cutting volume by 70% in race week. The rules and their sources are public on endu.fr/en/controle-technique.
How many sessions per week?: This example has 5 sessions per week. You choose 5 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.