Triathlon Plan

AI-built 70.3 triathlon plan (Half Ironman)

Q: How long does sprint triathlete need to prepare 70.3?

18 wk from completed Olympic triathlon. 20-22 wk from completed sprint (you need extra base). Never done triathlon? Do NOT start directly with 70.3 — do sprint or Olympic first (3-6 months).

Q: How long to complete 70.3 amateur?

Typical amateur time : 5-7 hours total. Sub-5 hours : top 30-40 % age group. Sub-4:30 : top 10-20 %. Sub-4 hours : amateur elite. Pro elite: 3:50-4:20.

Q: Do I need specific triathlon bike?

Not strictly — road bike with clip-on aerobars (€100-200) works perfectly for amateur 70.3. TT bike (Cervélo P-Series, BMC TimeMachine, Trek Speed Concept) saves ~10-30 min on 90 km bike, but €4000-12000 investment. Decide by budget + ambition.

Q: How do I train swim if I live in area without OWS?

Most plan in pool with sighting drills . OWS only for race day acclimation (1-2 OWS sessions pre-race instead of race). Goal distance allows warm water? Practice OWS before race in nearby lake/reservoir.

Q: Important 70.3 supplementation?

Carbohydrates during race : 80-100 g/h (gels + bars). Caffeine : 200-300 mg pre-race + 100 mg every 60-90 min during race. Electrolytes : SaltStick 1 capsule every 45-60 min. Beta-alanine 3-5 g/day : marginal but helps.

Q: How much rest post-70.3?

2-4 weeks minimum active recovery (very light Z2, no structure). 70.3 leaves you neurologically + muscularly exhausted. Returning to hard training immediately = injury + plateau. Next heavy block only after 1-month recovery.

Q: And after 70.3, do I move to full Ironman?

Yes, Ironman 140.6 (3.8/180/42) is natural next step. Ironman plan requires 24-32 wk, 15-20 h/wk peak, maximally structured life. Generally 1-2 70.3s before first Ironman is ideal.

16-20 weeks for your Half Ironman: 1.9 km swim + 90 km bike + 21 km run. EntrenAI structures 10-15 h/wk peak, brick sessions, T1/T2 transitions, fueling strategy and refined peaking. For triathlete with prior sprint or Olympic.

Updated September 14, 2026

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100+ athletes

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What is a 70.3 (Half Ironman) triathlon plan?

The 70.3 triathlon plan (also called Half Ironman) prepares for middle distance: 1.9 km swim + 90 km bike + 21 km run = ~113 km total. Typical amateur time: 5-6:30 hours (elite: 3:50-4:20).

Differences vs Olympic (1.5/40/10) and sprint (750/20/5):

Total training volume: 10-15 h/wk (vs 6-9 h Olympic, 4-6 h sprint)
Long bike dominant: 4-5 h Saturday ride (50-100 km Z2 with sweet spot)
Weekly long run: 1:45-2:30 run with target pace segments
Long swim extended OWS: 60-90 min OWS Saturday or Sunday alternating
Brick sessions critical (bike → immediate run): specific neuromuscular adaptation
Fueling strategy during 90 km bike + 21 km run: 80-100g carb/h, gels/bars/solid food on bike

Plan based on:

80/20 polarization Seiler adjusted for multidiscipline volume
Triathlon-specific: reduced interference between disciplines
Refined peaking 2-3 wk before event

Why 70.3 is the triathlon "sweet spot":

Challenging distance but recoverable in days, not weeks
Total time 5-6 h (manageable mentally and physically)
Compatible with work life vs full Ironman (excessive training)
Springboard to Ironman if you want to take next step

70.3 (1.9 km · 90 km · 21.1 km): how long each leg takes by level

The app estimates your total time from your real paces in each discipline and how long you take in transitions, and splits the plan's hours with it: the discipline where you lose most time is the one that trains most.

Level	Swim	T1	Bike	T2	Run	Total
Finish2:30/100 m · 25 km/h · 6:00/km	47:30	3:00	3:36:00	2:00	2:16:44	6:45:14
Intermediate2:00/100 m · 30 km/h · 5:15/km	38:00	2:00	3:00:00	1:30	1:59:38	5:41:08
Fast1:40/100 m · 35 km/h · 4:30/km	31:40	1:30	2:34:17	1:00	1:42:33	4:51:00

Swim
Bike
Run
Transitions

How the plan works

Your AI-generated plan

1. Initial validation.

Olympic or sprint triathlon completed (recommended, not strict)
Base: 1500m swimmer + 60km comfortable cyclist + 10K runner
18+ months multidiscipline experience
No recurring injuries
Available time: 10-15 h/wk peak (must confirm before starting)
Complete cardiovascular health (medical check recommended)

2. Typical weekly structure (8 sessions, 12 h/wk peak):

Monday:

AM: Z2 Run (50-60 min)
PM: Rest

Tuesday:

AM: Bike sweet spot (75 min: 3×15 min @ 90 % FTP)
PM: Rest

Wednesday:

AM: Threshold swim (60 min: 4×400 m at threshold)
PM: Run intervals (60 min: 5×1000 m at 10K pace)

Thursday:

AM: Z2 bike (90 min)
PM: Rest

Friday:

Rest or recovery swim (45 min very gentle)

Saturday (LONG DAY):

Long bike + brick run (4-5 h Z2 bike with sweet spot segments + 20 min Z3 immediate run)

Sunday:

Long run (1:45-2:30 with target pace segments)

Total: 12 hours peak (4-5 bike + 1.5-2 run + 1.5-2 swim + brick + recovery)

3. 4-phase periodization (18 wk):

Base (5 wk):

Priority Z2 aerobic volume in 3 disciplines
1 quality session/discipline/wk (sweet spot bike, threshold swim, run intervals)
Long bike 2:30-3 h, long run 1:15, long swim 45 min OWS
Bike FTP test wk 5 + 1500m swim pace test

Build (6 wk):

Sustained aerobic volume
2 quality sessions/discipline/wk
Long bike 3-4 h with sweet spot segments, long run 1:45 with target pace, long swim 60 min OWS
Brick sessions introduced (40 km bike → 20 min immediate run)
Bike FTP test + 1500m swim pace wk 11

Specific (4 wk):

Maximum volume
Long bike 4-5 h with event gradient simulation, long run 2:00-2:30 with target pace segments
Longer brick: 60 km bike → 45 min immediate run (race-pace bricks)
Partial simulation: 30 km bike + 10 km run wk 14
Practice T1/T2 transitions

Tapering (2-3 wk):

Reduced volume (-30 %, then -50 %)
Maintain intensity (short fast intervals)
Long bike 2 h wk -2, 1 h wk -1
Long run 60 min wk -2, 30 min wk -1
Race day wk 18

4. Brick sessions (key 70.3):

Classic brick:

60-80 km Z2 bike with 2×20 min sweet spot
Immediate T2 → run: 30-45 min Z2 with last 15 min race pace
Neuromuscular adaptation from 'bike legs' to 'running legs'

Race-pace brick:

90 km Z2 bike + 1×30 min Z3 (race pace bike)
Immediate T2 → run: 30-45 min Z2 with last 20 min race pace
Specific race preparation

5. 70.3 fueling strategy:

Pre-race (3h before):

100g oats + banana + honey + coffee
Total carb: 130-150g

Swim (no fueling during 1.9 km, ~30-40 min):

Immediate hydration pre-swim

Bike (during 90 km, ~2.5-3 h):

80-100 g carb/h (gels, bars, bananas, peanut butter sandwich)
Hydration: 750 ml-1 L/h (water + electrolytes)
Pre-established fueling plan (exact timing every 20-30 min)

Run (during 21 km, ~1:45-2:30 h):

60-90 g carb/h (mainly gels, water/Coca-Cola at stations)
Hydration: 500 ml/h additional
Salt: 1 capsule (200-400 mg sodium) every 45-60 min if hot

The transition, drawn: what you practise every two weeks

A 3-minute T1 is 2 minutes given away. The plan includes a transition session every two weeks with the bike on a real rack; this is the order you rehearse.

Leave the water walking fast, not running
Wetsuit down to the waist as you move
Helmet BEFORE touching the bike
Run with the bike by the saddle to the mount line

Dismount before the line, never on it
Rack the bike; helmet off ONLY afterwards
Elastic laces: no sitting down
The first 500 m slower than the body asks for

Who is this plan for?

Intermediate triathlete with completed Olympic or sprint wanting next level. 18-week build + race day plan.
Cardio athlete (marathon runner, gran fondo cyclist) wanting to add swim + multidiscipline. 20-week plan (4 extra wk to build swim if weak).
Amateur triathlete preparing first official Ironman 70.3. 18-week plan specific for WTC event.
Advanced triathlete seeking 70.3 PB (sub-5h amateur). 16-18-week plan with intensity focus + refined peaking.

Never done triathlon? Beginner triathlon plan (sprint first) or Olympic triathlon are previous steps. Looking for full Ironman? Specific Ironman plan (24-32 wk).

Hours per discipline across the 16 weeks

From 9 to 14 hours a week, a deload every fourth week and a taper at the end. Swim, bike and run are split according to their weight in the race and in your profile; "brick" marks the weeks with a bike + run session back to back.

Swim
Bike
Run

Sample plan

Your first weeks, in detail

Week 12

Specific — long bike with gradient simulation, consolidated race-pace brick

Day	Session type	Detail	Duration
Monday - Easy Z2 run	Aerobic recovery	- 5 min walk - 55 min easy Z2 (6:00-6:30/km pace) - Focus posture + natural cadence	60 min
Tuesday - Bike sweet spot 75 min	Z3 sweet spot	- 15 min warm-up Z1 → Z2 - 3×15 min @ 90 % FTP (sweet spot, ~230 W) with 5 min Z1 between - 15 min Z1 cool-down	75 min
Wednesday AM - Swim threshold 60 min	Z3 continuous swim	- 400 m progressive warm-up - Main set: 4×400 m at threshold with 30s rest - 200 m easy - Sprint set: 4×50 m at max with 60s rest - 200 m cool-down - Total: ~2400 m	60 min
Wednesday PM - Run intervals 60 min	Z4 VO2max + threshold	- 15 min Z2 warm-up - 5×1000 m at 10K pace (4:30/km pace) with 200 m jog recovery - 10 min Z1 cool-down	60 min
Thursday - Z2 medium bike	Bike aerobic base	- 90 min Z2 (~70 % FTP) - Varied cadence (85-95 RPM) - Focus on aerobic base + leg recovery	90 min
Friday - Rest or recovery swim	Recovery	Option A: 45 min Z1 easy swim (recovery + technique). Option B: full rest if accumulated fatigue.	0-45 min
Saturday - LONG BIKE + BRICK RUN	Long Z2 + sweet spot segments + brick run	Long bike 4 h: - First 1.5 h Z2 (70 % FTP) - Middle: 2×30 min @ 88-92 % FTP (sweet spot) with 15 min Z2 between - Last 1 h progressive Z2 - Fueling: 80-100 g carb/h (gels + bars + bananas) - Hydration: 1 L/h + electrolytes Immediate T2 transition (5 min): - Quick bike → run change - Practice efficient transition Brick run 30 min: - First 5 min Z1 (leg adaptation) - Last 25 min Z2 with last 15 min at target race pace - Apply nutrition during run (gel every 30 min)	275 min
Sunday - Long run with target pace segment	Z2 + Z3 segment	- First 30 min easy Z2 (6:00-6:30/km) - Middle: 30 min at 70.3 race pace (~5:00-5:15/km) — RPE 7 - Last 30 min easy Z2 - Total: 90 min, ~17 km - Hydration every 5 km + 1 gel at km 8	90 min

These examples are real extracts from the EntrenAI planning engine. Your personal plan adjusts to your level, equipment and availability.

Equipment needed

EntrenAI automatically substitutes any exercise if you don’t have the gear.

Road or triathlon bike with gears + power meter
Aerodynamic helmet optional but useful
Cleats + cycling shoes
OWS wetsuit (Orca, BlueSeventy)
Competition swimsuit + training swimsuit
Swim goggles + OWS mirror goggles
Multisport GPS watch (Garmin Forerunner 955, COROS Vertix, Suunto)
Chest HR strap (Polar H10)
Training running shoes + lighter race shoes
Hydration: bike bottles + running soft flasks + belt
Energy gels + bars (1 unit every 30-45 min)
Electrolyte tablets (SaltStick)
Triathlon transition backpack
Strava + Garmin Connect (log + analysis)

Common mistakes

What most people get wrong (and how to avoid it)

1
Not respecting 80/20 polarization
Amateur 70.3 tends to do too much Z3 (medium pace). 80 % Z2 + 20 % Z3-Z5 is optimal. More Z3 = accumulated fatigue + plateau + injury. Trust power meter/HR data.
2
Skipping brick sessions
Brick (bike → immediate run) is UNIQUE to triathlon. Skipping = first race, bike legs are NOT ADAPTED to running transition. Result: race run pace 30-50 % slower than expected. 1 brick/wk from wk 8 MANDATORY.
3
Skipping long swim OWS due to cold water
Race in May-October? Water will be 18-22°C. Long swim must be similar conditions. Skipping OWS due to cold water → first race OWS = panic + slow pace. Adapt gradually from wk 6.
4
Not practiced fueling
Don't practice 80-100 g carb/h during long bikes? Race day GI distress guaranteed. Digestive system NEEDS adaptation to that carb amount under load. Practice from wk 6 minimum.
5
Forgetting T1/T2 transitions
Efficient transitions save 1-3 min in race. Without practicing (transition area setup, quick change), you lose minutes. Practice T1 (swim → bike) and T2 (bike → run) during brick sessions.
6
Volume rising >10 % per week
70.3 plan has high volume (10-15 h/wk peak). Rise >10 %/wk = overload injury (fasciitis, IT band, periostitis). Ideal rise: 8-10 % per week, deload every 4 wk.
7
Skip swim because 'it's just 1.9 km'
1.9 km swim = 30-40 min in water. Deficient technique? You can lose 5-10 min vs someone with good technique. Swim is 30 min of race, not 4 hours — but those 30 min impact position + residual energy for bike.
8
Eating in caloric deficit during plan
12-15 h/wk training demands maintenance or slight surplus (+200-400 kcal). Deficit = injury + insufficient recovery + accumulated fatigue. Want to lose weight? **Olympic triathlon** moderate deficit plan, NOT 70.3.

Other Triathlon plan variants

Back to the general Triathlon plan

Frequently asked questions

18 wk from completed Olympic triathlon. 20-22 wk from completed sprint (you need extra base). Never done triathlon? Do NOT start directly with 70.3 — do sprint or Olympic first (3-6 months).

Typical amateur time: 5-7 hours total. Sub-5 hours: top 30-40 % age group. Sub-4:30: top 10-20 %. Sub-4 hours: amateur elite. Pro elite: 3:50-4:20.

Not strictly — road bike with clip-on aerobars (€100-200) works perfectly for amateur 70.3. TT bike (Cervélo P-Series, BMC TimeMachine, Trek Speed Concept) saves ~10-30 min on 90 km bike, but €4000-12000 investment. Decide by budget + ambition.

Most plan in pool with sighting drills. OWS only for race day acclimation (1-2 OWS sessions pre-race instead of race). Goal distance allows warm water? Practice OWS before race in nearby lake/reservoir.

Carbohydrates during race: 80-100 g/h (gels + bars). Caffeine: 200-300 mg pre-race + 100 mg every 60-90 min during race. Electrolytes: SaltStick 1 capsule every 45-60 min. Beta-alanine 3-5 g/day: marginal but helps.

2-4 weeks minimum active recovery (very light Z2, no structure). 70.3 leaves you neurologically + muscularly exhausted. Returning to hard training immediately = injury + plateau. Next heavy block only after 1-month recovery.

Yes, Ironman 140.6 (3.8/180/42) is natural next step. Ironman plan requires 24-32 wk, 15-20 h/wk peak, maximally structured life. Generally 1-2 70.3s before first Ironman is ideal.

Mild injury (1-discipline discomfort): pivot volume to other 2 (injured running → more bike + swim). Moderate injury (2 disciplines): pause plan 2-4 wk + recovery focus. Serious injury: race possibly lost — better to abort well than finish injured worse.