Shindo The problem is not the training, it is the bookkeeping#
Single-sport athletes have an easy time comparing weeks. Sixty kilometres of running is more than fifty kilometres of running, and both are easy to feel.
Triathlon breaks that. A 3,000 m swim, a three-hour ride and a 90-minute run are three different kinds of work landing on one cardiovascular system, one set of tendons and one recovery budget. Ask most self-coached triathletes whether last week was harder than the week before and they will hesitate — not because they are careless, but because they have no common unit.
Almost every failure mode in self-coached multisport starts there. You cannot cap what you cannot count, and you cannot tell a hard week from a heavy one if the three disciplines are tallied in three separate notebooks.
One currency, three sports#
The fix is old and boring: convert every session to a training stress score — a single number that expresses intensity relative to your threshold in that sport, multiplied by duration. An hour at threshold is about 100 points, whatever the sport. That is the whole idea.
It only works if the threshold used for each sport is genuinely yours:
- Bike — critical power, and W′, the finite work available above it.
- Run — critical speed, and D′, its running equivalent.
- Swim — critical swim speed, usually expressed in seconds per 100 m.
Three thresholds, one per sport, each estimated from your own recent efforts. With those in place a swim, a ride and a run become comparable, weekly load becomes a number, and fitness, fatigue and form can be tracked across the whole athlete rather than per discipline.
Without them you are back to notebooks. This is the reason a triathlon week is worth computing rather than eyeballing, and it is the same reason the first few weeks with any system are the least useful — the thresholds have not settled yet.
What a self-coached week actually looks like#
For an athlete training six to ten hours a week with no team and no coach, a workable skeleton:
| Day | Session | Why it is there |
|---|---|---|
| Mon | Rest, or an easy swim | Swimming is the lowest-impact way to move on a tired day |
| Tue | Run — the hard one | Fresh legs, and running is where intensity costs the most |
| Wed | Swim — technique and short intervals | Skill work needs a non-exhausted nervous system |
| Thu | Bike — the second hard session | Cycling absorbs intensity with the least structural cost |
| Fri | Easy run, or off | Genuinely easy, or genuinely nothing |
| Sat | Long ride, optionally into a short run | The week’s endurance anchor |
| Sun | Long run, easy | Long, not fast |
Two rules matter more than the layout itself. Keep the hard sessions to two or three, and keep everything else genuinely easy — the 80/20 distribution is if anything more important in triathlon than in single-sport training, because three disciplines give you three separate opportunities to drift into the moderate zone. And cap the week-over-week growth, on total load rather than per sport; it is trivially easy to hold each discipline flat and still add 20% overall by adding a session.
Where the intensity should go#
Not evenly. Running produces the most fatigue and the most structural stress per unit of load, cycling the least. A week with hard efforts in all three sports is usually a week with too much intensity. The common allocation is hard bike, hard run, and swimming used mostly for volume and technique — with the exception of athletes whose limiter is genuinely the swim, who should invert that and accept less running intensity in exchange.
When the swim falls through#
The swim is the session that disappears. The pool closes, the lane is full, the session is at a fixed hour you cannot move, and you are back at your desk. This is not a discipline problem; it is a logistics problem, and it happens to everybody.
What should happen next is the actual test of a training system.
The missed load should not carry forward. Load is not a debt. The physiological effect of a swim you did not do is that it did not happen — adding it to next week produces exactly the spike a ramp cap exists to prevent.
A substitution should count as what it was, not as a failure. If you rode instead of swam, that is a real session with real load in a real sport. It is not the swim, and a sensible system should say so — the aerobic stimulus transfers, the specific skill and the shoulder conditioning do not — but it is emphatically not a zero.
A partial should count partially. Forty minutes of a planned seventy is 40 minutes of work, not a failure and not a success.
The rest of the week should re-flow, not restack. If the week has lost a session, the remaining days should be reconsidered against what is actually left, not shuffled forward one slot each.
And the week should not turn red. A week rendered as four green ticks and three red crosses is telling you something false — that adherence is the goal. The goal is adaptation, and the honest summary of that week is a load number and a form trajectory, not a compliance percentage.
What one iPhone can do#
More than most people expect. Every device that writes to Apple Health — watches, chest straps, bike computers via their own apps — puts workouts, sleep, heart-rate variability and resting heart rate into the same store. From that you can compute per-sport thresholds, weekly load, fitness, fatigue, form and a daily readiness estimate, and build a week that respects all of it. That is genuinely most of what a coaching platform reads, and none of it needs a subscription to a particular brand’s ecosystem. The same argument for a single sport is worth reading alongside this one.
What one iPhone cannot do — the honest list#
This is the part worth reading twice, because a phone-only setup has real edges.
- Structured workouts do not go back out to your watch. Apple Health is a data store, not a delivery mechanism. You read tomorrow’s session on the phone and execute it yourself — from memory, from a screenshot, or by building it in your watch’s own app.
- There is no direct connection to third-party training services. Not to device vendors’ cloud platforms, not to activity networks, not to coaching platforms. Data arrives because your device wrote it into Apple Health, and that is the only route.
- If your whole workflow already lives inside one vendor’s ecosystem, this is friction, not a feature. An athlete who plans in a device maker’s web platform, pushes sessions to the watch, and reviews them in the same account is being asked to give up the part they like most. That athlete is better served by staying where they are.
- Data quality is whatever your device recorded. Wrist optical heart rate during a swim is unreliable, open-water GPS wanders, and nothing downstream repairs either.
- Pool swims often arrive thin. Many devices log distance and duration without a usable heart-rate series, which makes swim load an estimate rather than a measurement.
None of these are fixable by software on the phone. They are properties of the arrangement, and a guide that did not name them would be selling you something.
The one thing to take away#
Get the three thresholds right, express every session in one currency, cap the growth of the total rather than the parts, and treat a missed session as information rather than debt. Everything else in a triathlon week is scheduling.
Shindo runs on an iPhone 11 or newer. It reads swim, bike and run sessions from Apple Health, estimates critical power and W′, critical speed and D′, and critical swim speed from your own history, and expresses all three sports in one load currency. Swaps, partials and shifted sessions are matched against the plan and counted for what they were. It does not record workouts, does not push sessions to a watch, and has no direct connection to any third-party service. The methodology documents the matching rules.
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