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.
The tapering strategy used by many swimmers to optimize competition performance has been defined as "a progressive non-linear reduction of the training load during a variable period of time, in an attempt to reduce the physiological and psychological stress of daily training and optimize sports performance" (Mujika & Padilla 2000). The aim of the taper before the main competitions of the season is to elicit substantial improvements in performance. These performance gains have been variously attributed to increased levels of muscular force and power (Trappe et al. 2000), and improvements in neuromuscular, hematological, and hormonal function, and/or the psychological status of the swimmer (Mujika & Padilla 2000).
The main features of this phase are maintaining an active approach with at least three low- to moderateintensity aerobic swims completed each week, specialized programs to target weaknesses in individual fitness profiles, and dietary control to maintain body composition.
There are few studies that have directly addressed the issue of the most effective program for swimmers to follow during the off-season or in short breaks from training and competition.
There is, however, a significant body of literature that details the Lime course of training adaptations with training and loss of fitness during detraining (Counsilman & Counsilman 1991; Mujika & Padilla 2000). A typical strategy for the off-season involves a marked 50-70% reduction in the frequency, volume, and intensity of training.
The following is an example of the features of periodization that may encompass a typical 14-week swimming preparation fora national championships or major international meet.
As in most training programs the initial phase involves the development or reestablishment of endurance fitness. This serves as the basis for the subsequent development of aerobic and anaerobic capacities and the functional utilization of these capacities. Functional utilization refers to increased swimming speed at a given metabolic load. Apart from the underlying physiological adaptations, improved endurance will lead to an increased ability to cope with fatigue and more rapid recovery from the stresses of speed training and competition. In particular, the aim is to develop the capacity and efficiency of the cardiorespiratory system.
A creative approach to the planning of training sessions is essential to maintain an adequate adaptation stimulus. Once the various cycles are organized within the season or yearly plan, the detailing of individual training sessions can begin.
Some coaches make the mistake of not properly integrating speed and endurance in the training pro- gram. This is particularly evident in the endurance phase where too great an emphasis on the volume of training may impair speed. It is an oversimplification to think that only low to moderate intensity volume work is undertaken in an "endurance" week or phase, and that only speed work is done in a "speed" week. If insufficient speed work is undertaken during the endurance phase, a swimmer may pay the price later on when they are unable to reproduce race or competitive speeds. Conversely, swimmers may become overloaded and prone to fatigue, illness, and injury if they do too much speed work without the benefits of some complementary endurance training. Highly trained swimmers can use endurance training to recover from and prepare for speed training.
Over the pasl 10 years. the factors that contribute ta swimming successlully at top national and international competitions have been analyzed by leading sports scientists such as Dr Bruce Masan of Ihe Australien Instilule of Sport. Competilion analysis breaks down racing into its various components.