A training programme is a plan for distributing a limited amount of work across a season so that the athlete is at their best on the days that matter. Everything else in it follows from that sentence. The work is limited — by hours, by tolerance, by the rest of life — so the plan is fundamentally about allocation rather than accumulation.
The framework below is periodization: dividing the year into phases with different objectives, so that qualities are built in an order where each supports the next. It is not the only defensible way to organise training, but it is the one endurance sport has converged on, and its vocabulary is what most training plans are written in.
The year: a 52-week structure
The conventional annual plan divides into phases, each with a distinct objective. The traditional five-phase naming is descriptive and worth keeping because it says what each phase is for.
- Base preparation. The longest phase. General aerobic development at low intensity, technique work while fresh, and the gradual raising of volume. The objective is capacity, and the phase is dull by design.
- Base transition. Volume stabilises and moderate-intensity work is introduced. The athlete begins doing work that resembles racing without yet doing much of it.
- Race preparation. Specific intensity rises and total volume typically falls slightly. Sessions begin to look like the demands of the target event — the correct pace, the correct duration, the correct terrain.
- Peak transition. Volume drops substantially while intensity is maintained. This is the taper, and its purpose is to shed accumulated fatigue without shedding fitness.
- Restoration. Deliberate, planned reduction after the racing block. Not an absence of training but a phase with its own purpose, described in recovery and restoration.
Two structural points are worth stating explicitly. The plan is built backwards from the priority race, not forwards from today. And the phases have soft edges: nothing changes overnight, and a plan that switches character abruptly on a particular Monday is a plan that has not been thought about.
The microcycle: four weeks of flow
Within the phases, training is organised in microcycles — most commonly four-week blocks in which load rises for three weeks and drops in the fourth. The rising weeks provide the stimulus; the reduced week allows the adaptation to be expressed and gives an early warning if it is not.
The three-up-one-down shape is a convention rather than a law. Older athletes and those with heavy work or family loads often do better on two up and one down; a well-recovered athlete in a base phase can sometimes carry five. What matters is that reduced weeks are planned, because an athlete who only takes them when forced is taking them at the worst possible times.
The reason for the structure is the separation between stimulus and response. As the molecular bases of training adaptation describe, each session initiates a signalling cascade that plays out over the hours and days afterwards. Training continuously without a reduced week means every measurement is taken through a layer of fatigue, and the athlete cannot tell whether the plan is working.
Intensity distribution across the plan
How the year's hours divide between easy, moderate and hard work is the single most consequential decision in the plan, and it is the one most often made by accident. When elite endurance athletes are studied, the striking finding is how much of their training is genuinely easy — the analysis quantifying training intensity distribution in elite endurance athletes reports a large majority of sessions below the first ventilatory threshold, with a small proportion of clearly hard work and comparatively little in between.
The pattern most self-coached athletes fall into is the opposite: a middle-heavy distribution in which nearly everything is moderately hard. It feels productive and it is a trap, because moderate work carries much of the fatigue cost of hard work while providing much less of the stimulus, and it consumes the capacity to do the hard sessions properly.
Making the easy sessions genuinely easy is therefore the highest-yield change available to most athletes, and it requires being able to tell one intensity from another — the subject of judging training intensity.
Energy system contributions
An older way of expressing the same idea is to assign a percentage of each phase's volume to each energy system — predominantly aerobic work in base phases, a rising contribution from threshold and above as the season becomes specific. The numbers are a planning device rather than a physiological claim; energy systems are not switches and every session draws on all of them.
Used sensibly the device is genuinely useful, because it forces the plan to state its intent for each block before the sessions are written, rather than letting the intensity distribution emerge from whatever the athlete felt like doing.
Writing the sessions
Once phases and microcycles exist, individual sessions can be specified. A complete session specification names distance or duration, the intensity, the interval and rest structure where relevant, the technical focus, and the intended outcome. That last item is the one that gets skipped, and it is the one that makes the plan reviewable: a session whose purpose was never stated cannot be judged to have failed.
Training objectives are placed through the plan as measurable checkpoints — a repeatable test, a benchmark session, a controlled time trial — at intervals long enough for change to be real. They are the mechanism by which a plan is corrected mid-season rather than defended to the end of it.
The plan will be wrong
Every annual plan is a hypothesis about an athlete who does not exist yet. Illness, work, weather and injury will all intervene, and a plan that cannot absorb interruption is a plan that will be abandoned in March.
Two habits make plans survivable. Write the next four weeks in detail and the rest of the year in outline, since detail beyond a month is fiction. And when a week is lost, resume where the plan is rather than trying to make it up — the missed work is gone, and attempting to recover it is the most reliable way to turn a lost week into a lost month. The weekly execution of all this is covered in the weekly schedule, and the group-scale version in periodization for clubs and squads.