Triathlon Week Builder
Race distance, phase and key days in — a week that puts strength and S/B/R where the interference rules allow out.
| Day | Session |
|---|---|
| Mon | Rest |
| Tue | SwimThresholdThreshold swim set1 h |
| Wed | StrengthHeavyStrength · 3–4×5–8 @ 70–80% 1RM50 min |
| Thu | StrengthHeavyStrength · 3–4×5–8 @ 70–80% 1RM50 min |
| Fri | RunZ2Easy Z2 run45 min |
| Sat | BikeLongLong ride2h 30m |
| Sun | RunLongLong run1h 30m |
- Sat: Key long ride anchors the week.
- Sun: Key long run anchors the week.
- OLYMPIC · base phase · intermediate · 6 training days.
- Base: 2–3 heavy lifts, highest strength dose of the year.
- Carbs 1.0–1.2 g/kg/h for 2–4 h after a hard endurance session; 20–40 g leucine-rich protein within 1 h of a lift.
- Stick to the same core lifts 4–6 weeks — DOMS fades via the Repeated Bout Effect.
How this week is built
- Anchor the two long sessions — your long ride and long run go on the days you picked. If they collide, the long run slides one day.
- Protect the day before each long — no heavy lifting and no threshold session there. That single rule does most of the work in preventing blown long days.
- Stack strength safely — lifts land as far from the long-day anchors as possible. With two-a-days on, the paired PM slot is automatically a low-impact swim or Z2 ride — the 6–9 hour gap triathletes are famous for but rarely execute.
Why these placement rules?
Three results from the concurrent-training literature drive the builder's logic.
1. Two sessions per week is the dose. The Berryman et al. (2018) meta-analysis of 28 controlled studies found heavy, low-repetition lifting 2×/week produces moderate-to-large improvements in endurance performance (SMD 0.52), running economy (SMD 0.65) and maximal force (SMD 0.99) — with essentially no hypertrophy. One session preserves, three sessions usually drains. Two is the sweet spot, and the builder flags the schedule amber/red when you drift.
2. The 6–9 hour rule is molecular, not folk wisdom. Endurance work activates AMPK; heavy lifting activates mTOR. Within the same biological window AMPK actively suppresses mTOR, erasing the gym stimulus. Three hours is the minimum gap for AMPK to clear; 6–9 hours is clinically preferred (Hickson, 1980; Baar, 2014). When you toggle two-a-days on, every strength day in the generator pairs AM lift with PM Z2 — the only combination that passes the molecular test.
3. Strength load drops sharply in build and taper. Rønnestad's 13-week competition-period trials show a single weekly maintenance lift preserves strength gains once endurance volume climbs. The taper cuts it further: a priming session of 2×5 at 30–40% 1RM keeps muscles tonic without adding fatigue. Select taper in the builder and strength automatically collapses to one priming slot (or zero).
Need the full mechanism? Read the interference-effect deep-dive.
Reading the output
Each day card shows the discipline, an intensity chip (Long, Threshold, Z2, Heavy, Priming), a duration scaled from your distance and phase, and a short rationale when a pairing is non-obvious. Rest rows stay light-cream so true-rest days pop visually against training days — recovery is a session, not a gap.
The three summary pills at the top are the scorecard. Total hours tell you whether the week is feasible for your life (most working triathletes live in the 8–12 h/week band during build). Strength dose tints green when it matches the phase target, amber when it's off by one, red when it directly contradicts the phase rule. Interference risk is a 0–100 scalar — zero means every concurrent-training constraint was honoured; anything over 30 means the week needs more rest or a different long-day layout.
When to re-run the builder
Re-generate at the start of each phase transition: base → build six to ten weeks out, build → taper ten to fourteen days before the A-race. Not every week. Mid-phase, fix your week once and repeat it — the Repeated Bout Effect only kicks in when you stick to the same core lifts for 4–6 weeks.
Sources
- Berryman N, Mujika I, Arvisais D, Roubeix M, Binet C, Bosquet L. Strength training for middle- and long-distance performance: a meta-analysis. Int J Sports Physiol Perform, 2018.
- Rønnestad BR, Mujika I. Optimizing strength training for running and cycling endurance performance: a review. Scand J Med Sci Sports, 2014.
- Beattie K, Carson BP, Lyons M, Rossiter A, Kenny IC. The effect of strength training on performance indicators in distance runners. J Strength Cond Res, 2017.
- Hickson RC. Interference of strength development by simultaneously training for strength and endurance. Eur J Appl Physiol, 1980.
- Baar K. Using molecular biology to maximise concurrent training. Sports Medicine, 2014.
- Coffey VG, Hawley JA. Concurrent exercise training: do opposites distract? J Physiol, 2017.
Triathlon Week Builder FAQ
How does this week builder avoid the interference effect?
Strength sessions are never placed the day before a key long ride or long run, and — when two-a-days are enabled — strength is locked to the AM slot with a low-impact Z2 swim or easy spin in the PM, producing the 6–9 hour window that clears AMPK before the next mTOR signal. Same-day hard-endurance + lift stacks are flagged as interference risk (Hickson, 1980; Baar & Coffey reviews).
Why does the tool default to 2 strength sessions per week?
Two heavy sessions is the evidence-based minimum effective dose for endurance-athlete adaptations. The Berryman 2018 meta-analysis on middle- and long-distance athletes and Rønnestad's cycling / running trials both converge on 2×/week at ≥80% 1RM as the point where running economy and Type I fibre force meaningfully improve without bulk.
Why does strength drop during the taper?
Inside 10–14 days of an A-race the programmed stimulus becomes 0–1 priming session at 30–40% 1RM, 2 sets × 5 reps, under 20 minutes. Heavy lifting late in the taper produces residual fatigue without adding fitness. The builder automatically compresses long-session durations and caps strength at one priming slot when taper is selected.
Can I run this plan with 5 training days?
Yes. Pick 5, 6 or 7 days. At 5 days the tool inserts two full-rest days — typically the day after each key long session — and prioritises the long ride, long run, one threshold session and your chosen strength dose. The threshold bike or run drops first as you cut days.
What does the interference-risk score actually count?
It accumulates three kinds of risk: same-day hard-endurance before a lift (+15), same-day lift before a hard-endurance session (+25), and lift placed the day before a key long session (+15). Zero means every rule is honoured; 30+ means the schedule needs reshuffling.
Does this work for short-course and long-course together?
Emphasis switches the fill logic: run-first builds a sprint / Olympic week with an extra run session, bike-first builds a 70.3 / Ironman week with an additional easy bike. Long-session duration scales by distance (sprint 75-min ride → Ironman 300-min ride).
What if I can only train before work?
Leave the two-a-days toggle off. The builder then places one session per day and spaces strength away from the long ride / long run. You give up some flexibility on the 6–9 hour separation, so the builder also won't place a threshold session the day after a lift — the separation is enforced by the calendar instead.
How should I use the `regenerate` button?
The base layout is deterministic from your inputs. Regenerate re-seeds the shuffle of supporting sessions (which day gets the threshold swim, which gets the easy bike) while keeping your long-day anchors, strength dose and phase rules intact. Handy when the default ordering doesn't match your personal week.
Informational only — not a substitute for a qualified coach or medical professional. If you're returning from injury or managing a chronic condition, clear the plan with a clinician. See also the pillar article on strength training for triathletes.