By David Pyne Ph.D.
Sports Physiologist Australian Institute of Sport
The middle distance (400m) and distance (800m and 1500m) events require a highly developed level of endurance fitness. Historically. Australia has produced many champion distance swimmers. This trend continues with our successes in the Mens 1500m Freestyle and the Womens 800m Freestyle events at the international level in the last few years. Despite the great work of our leading swimmers, there is some concern about the next generation of distance swimmers coming through. After the top two or three male and female distance swimmers, the standard drops away fairly quickly. The depth in these events appears to be considerably lower than in some of the form stroke and sprint events where the number of competitors in contention is comparatively much greater.
Inspection of the current world rankings shows that Australia is in good shape in the distance events. In the mens events we have swimmers ranked at:
(1) Daniel Kowalski 7:50.28,
(2) Kieren Perkins 7:50.80,
(3) Glen Housman 7:54.66 and
(21) Daniel Bates 8:12.10 for the 800m FS,
(1) Kieren Perkins 14:58.92,
(2) Daniel Kowalski 15:02.20,
(9) Glen Housman 15:20.32 and
(34) David Bates 15:35.91 for the 1500m FS.
For the women we have swimmers ranked at:
(1) Hayley Lewis 8:28.78,
(19) Stacey Gartrell 8:42.05,
(26) Chloe Flutter 8:45.95 and
(48) Christina Thorpe 8:49.56 in 800m FS and (1) Hayley Lewis 16: 14.71,
(8) Stacey Gartrell 16:28.89,
(12) Simone Cotter 16:41.17,
(13) Christina Thorpe 16:41.69, and
(20) Chloe Flutter 16:50.98 in the 1500m FS.
On face value, this is a good situation, however we must not rest on our laurels. Success will not be a formality without a substantial and ongoing individual and team effort around Australia. It can take a whole generation of swimmers to regain quality and depth in particular events: witness the mens sprint freestyle and backstroke over the last few years.
Around the world there has been a move away from distance to shorter sprint-oriented events in the last few years. The times for female swimmers [400-1500m FS], in particular, have plateaued over the last few years. We (and the rest of the world) have not progressed forward from days of Tracey Wickham and Michelle Ford (Janet Evans being the exception) and this is over 15 years ago These events must surely be ripe for some young women to come in and take them to a new level in the same manner that Kieren Perkins has done in the mens events. Our history, current successes and work-oriented training programs have stood us in good stead, however we must be careful that we do not let our hard-earned competitive edge slip away. Endurance work is the corner stone of the training program for the 800/1500m swimmer, and as has been discussed in previous articles, an important aspect of the preparation of all swimmers even the sprinters. I often think of the words of Forbes Carlile… “speed through endurance.”
In simple terms, endurance fitness can be divided, depending on your terminology, into two categories: general endurance and specific endurance. General endurance refers to the capacity to perform submaximal physical activity like swimming, running, walking, or manual tasks, over an extended period of time. This type of fitness is necessary for the efficient development of specific endurance, fitness and then higher quality anaerobic and speed capacities. Specific endurance refers to the capacity to perform higher quality muscular work within the specific time frame of competitive events. For middle-distance and distance swimmers this means a maximal effort over 4-16 minutes for 400m to 1500m events.
The training of endurance fitness is based on two related principles: an understanding of the energy systems that underpin the various training sets, and utilization of some system to classify different sessions that you use in your program. These two principles must be addressed correctly for effective endurance training and a higher level of competitive performance. All coaches should have a basic understanding of the continuum of energy sources that contribute to different swimming events;these aspects are covered in the Level 2 Coaching Accreditation Course. In terms of endurance swimming (and any endurance activity for that matter) the energy requirements (read training zones) can be divided into three areas: 1) low-intensity aerobic endurance, 2) aerobic/anaerobic endurance (the so-called ‘anaerobic threshold’ or ‘threshold’) and 3) anaerobic endurance. At various times, each area will need to be addressed in the training program.
To develop low-intensity aerobic endurance, a swimmer’s training speed must exceed the so-called ‘aerobic threshold’ (heart rate around 120 – 140 bpm or 60 to 80 beats below maximum HR) but not the ‘anaerobic threshold’ (HR around 160 – 170 bpm or 30 to 40 beats below maximum HR). All swimming should be conducted with ‘good’ technique and one often see’s low-intensity aerobic work (recovery swimming and warm downs) being undertaken with ‘poor technique’. This type of work will improve the ability to utilize fat as an energy substrate and limit the excessive use of carbohydrate. Don’t neglect the technique of your swimmer. Gennadi Tourestki often says that the slowest speed one should swim is the pace where a swimmer can still hold good technique: any slower would see a mechanically inefficient technique.
To develop the anaerobic threshold, a certain proportion of training must be undertaken at or close to anaerobic threshold speed (determined by the 5 x 200m step test, the 2000m test, or by the assessment of the coach). The term ‘anaerobic endurance’ is a slight misnomer in that swimming at this speed is dependent on the maximal capacity of aerobic pathways (i.e. the VO2 max) and the capacity of aerobic and anaerobic pathways to tolerate fatigue under conditions of insufficient oxygen supply and/or accelerating glycolytic flux. The key is to develop simultaneously the underlying physiological capacity (i.e. aerobic threshold (A1), anaerobic threshold (AT), maximal oxygen uptake (VO2 max) and the respective swimming velocity (time (seconds) per 100m) in each of these areas. It is the latter aspect, the swimming speed at each physiological capacity (i.e. functional utilization) that is correlated most highly with performance. The following example illustrates this point: three female distance swimmers may have maximal oxygen uptakes of 3.2, 3.8 and 4.4 litres per minute. However the determining factor is the speed at V02 max, and a swimmer with a V02 max of 3.8 litres per min who can hold 64.0 seconds per 100m (for a predicted 400m time of 4 x 64 seconds = 4:16.0 400m time) should beat her counterpart with a higher V02 max of 4.4 1 min but who can only hold 65.0 seconds per 100m at this level (predicted time 4 x 65 seconds = 4:20.0 400m time).
In the last year or so at the AIS we have refined our classification system of training. We have rationalized the old 7 point system into an easier to use 5 point system:
- Maximal Oxygen Uptake
- Lactate Tolerance
Using the 5-point system, it follows that levels  and  are used predominantly for continuous swimming or longer slower intervals with short to very short rest periods e.g. 3 x 1000m on 14:00, 8 x 400m on 5:00, or 15 x 200m with a 10 seconds rest interval. The higher intensity levels ,  and  involve interval training with the combination of number, distance, intensity, type and rest periods being manipulated as required. This issue has been addressed in detail in a previous issue of Australian Swim Coach.
The development of endurance fitness should continue over the entire season or preparation. There is, of course, a particular emphasis on endurance during the initial conditioning phase in the first few weeks. However, endurance training should be maintained and continued right through the preparation up to the major competition. This applies to all swimmers and is, obviously, essential for middle-distance and distance swimmers. All three levels ,  and  should be trained through the middle and final parts of the preparation. Physiological principles of recovery should be considered during high volume and intensity phases. Whilst ATP-PC energy stores can be replenished within a few minutes, and excess lactate removed within half an hour, it may take up to 48 hours to replace glycogen within the fast-twitch muscle fibers. This aspect of glycogen replacement and swimming training was dealt with by Dr. Bob Treffene in his recent article .
One point that should be made is that the specificity of energy supply and consumption during a particular swimming event doesn’t necessarily determine that training programs follow the same percentage breakdown. Whilst most experienced coaches are intuitively aware of this point, it is worthwhile for everyone involved in swimming, coaches, swimmers, parents, officials and sports scientists, to consider and evaluate their position on this issue. Simple inspection of most elite programs would reveal that more than 80% of swimming training is conducted at levels [1-3] and only a small percentage is performed at the higher intensities [4, 5]. This is even more pronounced for distance swimmers who must undertake larger volumes in total, and larger volumes of specific aerobic work, in their programs.
The total weekly training volume (km) is the most common means of quantifying the training load.
Simple analysis shows that elite swimmers average somewhere around 40-50 km of swimming per week through the training year. Endurance swimmers average about 20-50% more and weekly volumes may peak at 90-100 km. However this is after a long buildup and such volumes should not be sustained for any extended period of time. It is far better to reduce the volume to around 60-80 km per week and do it with good technique and speed. This is particularly important for younger swimmers who should concentrate on developing good technique in all the strokes within a balanced program of endurance and speed. There are too many young swimmers who have to endure programs of excessive volume and intensity. Many coaches acknowledge that over-training is a problem, but apparently not in their program. Another important point is that volume should be increased gradually: one rule of thumb is to increase the load by 5-15% per week for both younger (5-10 km/week) and older (10-15 km/week) swimmers.
In one sense, training for endurance events is relatively simple compared to the complex demands of sprint and middle-distance events. The former simply requires building endurance (and associated speed) over a period of time, while the latter necessitates the integration of endurance, power and maximal speed. The notion that endurance swimmers just need loads of work is not far from the truth, but the secret of the best distance coaches is to do this with a high degree of technical precision and the lowest degree of undue stress. The best distance swimmers are the thoroughbreds of the pool, but if you don’t manage them carefully you could end up with a stable of draught horses.
- Pyne, D.B. (1995). A model 14 day taper: the transition from training to racing. Aust. Swim Coach 11(11):28-30
- Treffene, R.J. (1995). Glycogen replacement rate and its use in program design. Aust. Swim Coach 11(10): 28-31.