The contemporary model of preparing competitive swimmers in a given year is based on the following sequence of training and competition: preseason, early season, competitive season, taper, championship season, and recovery or off-season. For highly trained swimmers the competitive season usually takes the form of domestic competition or international competitions.
The championship season typically involves the national championships, often doubling as the national team selection trials, and then the major international competition for that particular year.
Once the competition schedule has been established, the training plan can be prepared with the goal of maximizing the performance of the swimmer for the competitive and championship seasons. For international swimmers, the entire season is typically 44-48 weeks in length with a short break permitted after completion of the championship season. The length of each of the different training phases will vary according to the individual circumstances of the swimmer, team, and coach. In recent years, the international swimming calendar has become more crowded and as a consequence the annual training plan has become more fragmented and complex.
Training by competitive swimmers typically consists of repeated bouts of shorter or longer intervals in a short-course or long-course pool. Intervals span a continuum from longer slower intervals (50-1600 m for developing aerobic or endurance fitness) to shorter faster intervals (15-200 m for developing anaerobic or race pace qualities). The basic prescription of interval training can be simplified to four primary variables: (i) the number of intervals or repeat efforts, (ii) the length/distance of the interval (15 m to continuous swimming), (iii) the intensity (i.e., pace or velocity) of the interval, and (iv) the rest period between intervals (variously formulated as the cycle time or rest period).
Preseason training commences from the low base of fitness maintained during the off-season. Swimmers typically start the preseason phase with a single session per day and gradually increase the number of sessions over the first few weeks. A graded increase sees the frequency of training increasing from one session per day, to three sessions over 2 days, and eventually to the traditional two sessions per day format followed by the majority of high-level swimmers.
The main features of the early-season phase are a modest training volume to start, small 5-10 km increases in volume per week, low initial training intensity, and dry-land conditioning including flexibility, circuits, weight training, and other games and activities, to improve the overall sport abilities of the swimmer. After several weeks there are further increases in training volume, a graduai introduction of higher intensity aerobic work to the level of the lactate threshold, and emphasis on skill and technique development before moving to the faster training speeds.
In simple terms, training volume elicits improvements in general endurance fitness while training intensity develops the specific fitness required for racing and competitive success. The later weeks of the early-season phase focus on continuing development of the lactate threshold (endurance fitness), maximal oxygen uptake (maximal aerobic) and race pace training capacities, ongoing manipulation of training volume and intensity to maintain improvement, an individualized approach to volume, intensity and recovery, and refinement of skills particularly at race speeds.