SELECTED EXTRACTS FROM THE BOOK
Stroke rates …
For swimming purposes the frequency of contraction is largely determined by the stroke rating (SR), or speed of cyclical actions of the swimmer – the higher the SR the more often the fibres are required to contract. As the rate of stroking increases greater muscle tension is required to hold “good” water due to the higher hand speed resulting from the higher stroke rate. A greater frequency of contraction means energy is required at a higher rate and greater tension means a consequent rise in amounts of energy because more fibres need to be recruited.
Energy supply
Contrary to popular belief the CP system is used throughout the whole of all races, not just in 10m sprints or the first 15m of a race, and for any training efforts over approximately 130 bpm (below that there is no need to use it as other energy sources can be converted quickly enough). CP is converted to ATP very quickly, allowing …
Intensity zones
The various combinations of the three muscle fibre-types and three energy conversion mechanisms make it obvious there are six distinct training intensity zones to be identified. Sporting communities across the world give a variety of names to these zones but the lack of common terminology produces misunderstanding and confusion between sports and between coaches within a sport. A colour-coding method is common in North American swimming and serves as a useful short-hand when describing training sets, e.g. 6×300 ‘red’.
Anaerobic threshold
The fibre-type/zone diagram helps make clear the frequently misunderstood concept of ‘anaerobic threshold’; it is the ‘threshold’, or stepping off point, in the speed spectrum where significant amounts of anaerobic metabolism are about to be used. The word threshold originated in Old English and meant ‘doorsill’ or ‘point of entering’ (‘threshed’ corn laid against the wooden ‘holding’ bar at the house entrance) and that is exactly it’s meaning here – the point of entering significant anaerobic metabolism. Also clear from the diagram, and contrary to the understanding of many coaches, is the fact that swimming at anaerobic threshold speeds does not stress the aerobic metabolism to maximum – maximal aerobic stress only occurs towards the top end of zone 4 where the required speed already includes quite large contributions from anaerobic sources.
Zone 5
There are three distinct types of training described here but they can overlap to a great extent depending on the design of the training set. Stroke rate ranges are shown to illustrate the rise in intensity but, providing that intensity is within the zone 5 SR range (45-60), the effect of the set depends on design rather than intensity.
Heart rate
Pre-pubescent age-group swimmers have rather different heart-rate characteristics to post-pubescent swimmers because their anaerobic capabilities are not fully developed. This makes the relationship between SR and HR less ‘linear’ with the SR range of each zone significantly different to that of mature swimmers. Obviously this has training implications as, for example, a heart rate of 168 will target completely different zones and have a completely different training effect.
Capacity
Successful swimmers can store large amounts of energy and use it within the time-constraints of their race. This ability is vital as, although large amounts of energy are useful, there is no point having large amounts left over at the end of a race (capacity) when the speed could have been greater if it had been used during the race (power). Swimming speed is the particular factor in determining which mode is addressed; in order to move faster the expert swimmer increases the stroke rate and, therefore, the physiological cost increases. The higher stroke rate means the hands move faster through the water and this requires an increase in muscle tension (strength) to ‘hold’ good water. The consequence of the increased stroke rate, the increased number of fibres and the change in energy-conversion mechanisms means the “mode” of training also changes from capacity to power or from power to capacity.
Aerobic power
Development of AEROBIC POWER pushes the oxygen-dependent energy possibilities towards the race zone, moving the available energy from the left through the middle of the diagram towards zone 4 meaning swimmers can swim faster, easier. The effect of this is to make more total energy available during the race.
Power training with young swimmers
This energy is available, not because power development has been targeted, but because more base energy is available to use as power – a bigger performance footprint. This is a different training purpose to deliberately changing energy modes from capacity to power where existing aerobic energy is shifted right, higher up the speed spectrum, or existing anaerobic energy is shifted left, further along the distance spectrum and the muscle transformed to better use it. The analogy would be a bulge in the cone shape. The concept of moving aerobic energy towards the speedier areas of the cone and moving anaerobic energy towards the longer distance areas of the cone is the key to understanding power shifts.
Timing & sequencing training
The time spent on each phase will depend on the importance of each quality to the race performance, the individual condition of the swimmer in each particular area and the number of weeks available before the target competition. Different swimmers will exhibit different energy characteristics and combine them to produce identical race performances, e.g. a 100m swimmer and a 400m swimmer producing identical 200m times will ….