Deep water running for injury rehab

Everyone knows that swimming can be a good cross-training strategy for building fitness, or maintaining it when injury strikes. But according to Colin Brow and David Murrie, a more effective training protocol during high- intensity, competitive periods of the season or as part of an injury rehabilitation programme is deep water running

Deep water running (DWR) consists of stimulated running in the deep end of a pool aided by a flotation belt. The form of running in water follows as closely as possible the running pattern used on land. During deep water running (DWR), you can run without travelling through the water or by actually running through the water. Because no contact is made with the bottom of the pool during deep water running (DWR), there’s no impact and a number of studies have demonstrated the benefits of this type of training activity ^(1,2,3).

The most obvious advantage for deep water running (DWR) participants is that there’s very little stress placed on the lower extremities while training ⁽⁴⁾. Using a flotation aid like that illustrated opposite, deep water running (DWR) has been shown to be an equally effective training alternative to land based running, and therefore helps the maintenance of aerobic performance ^(2,5).

For example, professional soccer players (like runners and other games players) are susceptible to running injuries such as shin splints, stress fractures, muscle strains, pelvic, groin, knee and ankle disorders ^(6,7). Incorporating deep water running (DWR) (which can be considered as a low-impact aerobic activity) into a training programme could reduce the risk of these types of injuries.

DWR is also an effective method of increasing the endurance capacity of muscular contractions involved in the running action because of the physical properties of water itself – ie its greater density than air. This extra density results in increased resistance during the sprinting action for both the upper and lower extremities of the body when performed in water. Combined with an increase in frequency of strides, this can lead to an increase in sprint performance ^(3,8,9).

Consequently, deep water running (DWR) has the potential to provide professional games players with a training protocol that can help increase sprinting endurance and provide the appropriate training intensity necessary to achieve and maintain the cardiovascular levels required for their sport.

There’s certainly evidence for the benefits of deep water running (DWR) training programmes that are designed to reproduce the work an athlete would perform on land and which incorporate longer runs, as well as interval and speed training. For example, a study examined aerobic, anaerobic and muscular changes in nine male subjects following an eight-week interval training programme (three days per week, 20-45 minutes per session), involving running in shallow water ⁽¹⁰⁾. Compared to the controls, the deep water runners showed significant increases in VO2max and anaerobic power. These were also accompanied by reductions in the maximal heart rate and in the heart rate at submaximal workloads.

Meanwhile, a six-week study analysed the performance of 32 recreational runners who used a progressive deep water running (DWR) training protocol ⁽¹¹⁾. Initially, participants trained up to 70% of their maximum heart rates (MHR), and then progressed to 80% MHR in sessions lasting 25-30 minutes. The scientists concluded that ‘deep water running (DWR) was an effective method of training to maintain VO2max and two-mile running time. However, caution is needed as the participants’ heart rates were self- monitored by each participant locating their own pulse and then calculating their own heart rates – a procedure that is prone to error.

Interestingly, it has been documented that during DWR, the vertical position in water combined with the hydrostatic water pressure promotes blood flow back to the heart ^(9,12-15). This is thought to (partly) explain why lower heart rates are recorded during deep water running (DWR) than the equivalent intensity exercise on land. Another explanation is that the amount of active muscle mass is lower during deep water running (DWR) than running on land due to the lack of need to counteract gravity. However, this hypothesis has not been tested and further research is needed to determine if differing muscle activity levels can fully explain the different physiological responses between deep water running (DWR) and land running.

Deep water running flotation belt

[caption id=" align="alignnone" width="616"] Illustration by Viv Mullett[/caption]

Deep water running action – a study of young footballers

Given that there’s plenty of positive evidence in the literature for deep water running (DWR), how should a programme of deep water running (DWR) be implemented? The following describes an actual programme with six participants who were all full-time professional soccer players aged 16 or 17 (see panel right). The key behind the deep water running (DWR) training programme was to attempt to mimic the ‘stop-start’ sprinting endurance required by professional football players.

The deep water running training programme sessions were held twice weekly for four weeks and lasted approximately 30-40 minutes per session. Before getting underway, the young footballers were given a supervised familiarisation session, during which they mechanically reproduced their dry land running pattern within the water environment. This enabled them to become familiar with running in the water using the floatation belt and using heart rate monitors.

Training heart rates

The programme above was designed so that the average intensity of the heart rates recorded by the participants during the deep water running (DWR) training closely reflected the actual average heart rates recorded during professional football matches. The mean heart rate for the six participants averaged over the eight training sessions for the initial 10-second pyramid sprint was 143; for the 60-second pyramid sprint it was 176; for the final 10-second pyramid sprint it was 146. The mean heart rate for the final 10-metre relay sprint was 182.

Results

The benefits of this training programme were assessed by sprinting endurance. Sprinting endurance times were recorded electronically prior to the deep water running (DWR) training programme over the distance of 92.8 metres (length of the training pitch) and 52.8 metres (width of the training pitch). A control group who did not take part in the DWR were also timed and recorded over both distances.

Although the results indicated that there were no statistical differences between the sprint endurance times of both the groups over the two distances, all of the participants who participated in the deep water running (DWR) training programme improved on their sprinting endurance performance. The lack of statistical significance was probably due to the very small sample size (which means that very large differences would have been required to produce statistical significance), rather than the lack of efficacy of the programme itself. Indeed, both the participants and the manager reported significant subsequent improvements in ‘dry land’ performance.

In conclusion

Deep water running is useful for low-impact fitness maintenance and the development of speed and multi-sprint endurance. Moreover, the elimination of weight bearing during Ddeep water running (DWR)WR also makes this an ideal environment for the rehabilitation and conditioning of injured athletes, particularly with lower limb injuries where load bearing running on land is contraindicated or restricted. Deep water running provides a biomechanical specific method of maintaining and, potentially, improving cardiovascular conditioning during recovery, and indeed has recently been endorsed by the English Football Association as an alternative training protocol to help prevent and minimise pre-season overuse injuries among professional soccer players.

Colin Brow MCSP is a chartered physiotherapist who has previously worked full time in professional football and is currently employed at the University of Paisley as a lecturer in sports injuries and rehabilitation

David Murrie is a senior lecturer in sport at the University of Paisley and is also a highly experienced coach in games sports, athletics and skiing

References

1. Med Sci Sports, Vol 29, pp 649-699, 1997
2. Med Sci Sports, Vol 28, No 8, pp1056- 1062, 1996
3. Sports Med, Vol 16, No6, pp374- 380, 1993
4. Br J Sports Med, Vol32, pp44-48, 1998
5. J Sports Sci, Vol 21, No 12, pp 959- 972, 2003
6. Br J Sports Med, Vol 34, 2000
7. Med Sci Sports, Vol 16, No1, pp1-7, 1984
8. Isokintics and Exercise Science, Vol 3, No 4, pp207-215, 1993
9. McArdle WD, Katch F, Katch VL (1996) Exercise Physiology (fourth edition)
10. Aus J Sci Med Sport, Vol 23, No 1, pp13- 22, 1990
11. Am J Sports Med, Vol 21, No1, 1993
12. J Appl Physiol, Vol 69, pp657- 664, 1990
13. Med Sci Sports, Vol 27, pp1007-1013, 1995
14. Health and Fitness Journal, Vol 8, No 5, pp 5-8, 2004
15. Res Quart Ex and Sport, Vol 65, No4, pp386-389, 1994