The week is the unit in which endurance training is actually lived. Seasons are planned in months and adaptations occur over weeks, but what an athlete has to solve every seven days is a scheduling problem: which sessions, on which days, in which order, around a life that has its own fixed points.
A good week is not the one containing the most training. It is the one in which the hard sessions were done properly, the easy sessions were genuinely easy, and the athlete arrives at the following Monday able to do it again.
Start from the fixed points
Most athletes do not have a blank week. Pool lane hours, a track that is available on one evening, a group ride that leaves at a particular time on a particular morning, and the days work makes impossible are all decided before any training consideration.
The practical method is therefore to place the immovable items first, then the key sessions of the week in the best remaining slots, then everything else around them. Building an ideal week and then trying to force facility hours into it produces a plan that is abandoned by February.
Fixed group sessions have a second effect worth planning for: they set an intensity the athlete does not choose. A club track session on a Tuesday and a hard group ride on a Wednesday makes a two-day hard block whether or not anyone intended one.
Hard days and easy days
The most durable principle in endurance scheduling is that hard days should be genuinely hard and easy days genuinely easy, with enough separation between the hard ones for each to be performed rather than merely survived.
For most athletes that means two, at most three, genuinely hard sessions in a week, separated by at least forty-eight hours, with everything else clearly easy. The number is lower than most athletes expect and the difficulty is not doing the hard sessions but resisting the drift of the easy ones upward.
That drift is the near-universal failure. It happens because easy running feels embarrassingly slow, because a group's easy pace is set by its strongest member, and because a session that felt fine at the time is only recognisable as too hard two days later. Data on training intensity distribution in middle- and long-distance runners shows the distribution successful athletes actually achieve, and it contains far more easy work than intuition suggests. How to tell the intensities apart is the subject of judging training intensity.
A recognisable weekly shape
Endurance weeks converge on a similar skeleton regardless of sport, because the constraints are similar. A typical multisport week contains:
- One long aerobic session, usually a ride, on the day with most available time.
- One long run, placed at least a day away from the long ride unless a bike-to-run transition is being rehearsed deliberately.
- Two or three swims, spread through the week rather than clustered, because swimming rewards frequency.
- One or two quality sessions — an interval swim, a track session, or a threshold ride — separated from each other.
- One or two short strength sessions, placed after a hard session rather than before one.
- One genuinely easy or off day.
An older convention that still works well is to anchor the week with two group sessions on fixed evenings — a technique-focused swim on one, a track session on another, with an optional trail, hill or technique alternative offered alongside the track for athletes for whom the interval session is inappropriate that week. The alternative is what makes a fixed group session survivable inside an individual plan.
Ordering two sessions in one day
When two sessions share a day, three rules cover most cases. Technical work goes first, because skill degrades with fatigue. High-intensity work goes before long steady work, because the reverse produces a poor-quality interval session and no particular benefit. And strength work goes after endurance work rather than before it, unless the strength session is the day's priority.
A meaningful gap between the two — several hours where possible, with food in between — makes the second session substantially better than one squeezed in immediately afterwards. The discipline-specific version of this reasoning is in multisport session ordering.
Camps, clinics and the weeks around them
Weeks containing a camp, a clinic or a race are not normal weeks and should not be planned as though a normal week could also fit around them. A full-day camp is the week's long session, its quality session and often its long run all at once; the days on either side should be adjusted before the camp rather than after it.
Recording what actually happened
A plan is a hypothesis; the log is the data. Recording what was actually done — duration, perceived effort, and one line on how it felt — takes under a minute and is the only way to find out, six weeks later, why a block did or did not work.
The most useful single field is subjective effort, because it captures what heart rate and pace miss: the session that was much harder than its numbers suggest is the early warning that the week's distribution has drifted. How that fits into the longer plan is covered in building a training program. Structured session material for adult swimmers is published by U.S. Masters Swimming.