Training
Swim, Bike, Run — How Much of Each
Why training time is not split the way race time is, how the balance shifts with distance, and what to cut first when training time is short.
Swim, Bike, Run — How Much of Each
The obvious answer would be to split training time the way race time splits. At Olympic distance roughly 15 percent of race time goes to the swim, 50 percent to the bike and 35 percent to the run — so train accordingly?
That is wrong, for three reasons that each pull in a different direction.
Why race proportions do not work
Swimming is technical, not conditional. In the water, drag decides your speed, and drag depends on your position and the way you move. Someone who swims badly barely gets faster from more endurance — they just get more tired. Technique comes from frequency, not volume: three times 40 minutes beats one session of two hours.
Running is the most expensive in recovery terms. It is the only one of the three with full impact loading. An hour of running costs more recovery than an hour on the bike and carries the highest injury risk. That is why running volume is progressed more cautiously than cycling volume.
Cycling carries the aerobic base. It is joint-friendly, easy to dose and sustainable for long durations. Most of your volume is built here — and because the bike is the largest share of race time, it pays off directly.
Guideline shares of training time
As a starting point for someone without a pronounced weakness, measured in training time:
Sprint and Olympic distance:
- Swim around 25 to 30 percent
- Bike around 40 to 45 percent
- Run around 30 percent
Middle and long distance:
- Swim around 15 to 20 percent
- Bike around 50 to 55 percent
- Run around 30 percent
The shift with distance has a simple cause: the longer the race, the smaller the swim's share of total time and the larger the advantage you can gain or lose on the bike. Over a long distance a minute in the water matters little; twenty minutes on the bike matter a great deal.
Frequency beats volume
Regardless of percentages, one floor applies: each discipline at least twice a week.
Swimming once a week does not maintain your feel for the water, it only slows its decline. Running once a week does not prepare tendons for the load. If time forces you down to one session per discipline, you are better off dropping one discipline entirely for a few weeks and keeping the others at two — or accepting that this phase is about maintenance, not progress.
Your own weakness
The split above applies to someone without a pronounced weakness. Those are rare. Most people come from one discipline and carry a clear deficit in another.
Two considerations help with weighting:
- Time is easier to find where you are bad. Someone swimming 2:20 per 100 metres can take several minutes off with a few months of technique work. Someone swimming 1:25 is fighting for seconds.
- But only up to a point. Over long distance the swim is so short that a large improvement there is worth less than a small one on the bike. Past a serviceable level, working on your strength pays better than further work on your weakness.
In practice: work on the weakness until it is no longer a race-killer, then invest where the race actually spends its time.
The brick session
One session falls outside the scheme because it joins two disciplines: running straight off the bike. The first minutes feel as if your legs belong to someone else — that settles after ten to fifteen minutes.
Once a week is enough, and it does not need to be long: 20 minutes of running after a normal bike session is plenty to rehearse the switch. Do it a few times before your first race.