DEEP-WATER RUNNING: A PRACTICAL REVIEW OF THE LITERATURE

Abstract

Deep-water running (DWR) is performed in the deep end of a swimming pool, normally with the aid of a flotation vest or a special suit with hydro buoyancy system. The method is used for preventing injuries, recovery from strenuous exercise or competition or as a form of complementary training for cardiovascular fitness. Responses to training programmes have confirmed the efficacy of deep-water running but proper DWR technique should mimic the patterns of land-based running. Taking into account that concept of training specificity should be further considered when prescribing DWR, we discuss biomechanical and physiological aspects in order to analyze the validity and applicability of individual implications examined in the literature.

Full text

Deep-water running: a practical review of the literature
1
Javier Vilamitjana, MSc;
2
Terrence Nelson, MT
1
CENARD (National Centre of High Performance Athletics), Bs As Argentina
2
Aqua Running HBS Ltd, Liverpool, England
Abstract
Deep-water running (DWR) is performed in the deep end of a swimming pool, normally with
the aid of a flotation vest or a special suit with hydro buoyancy system. The method is used
for preventing injuries, recovery from strenuous exercise or competition, and as a form of
complementary training for cardiovascular fitness. Responses to training programmes have
confirmed the efficacy of deep-water running but proper DWR technique should mimic the
patterns of land-based running. The concept of training specificity should be further
considered when prescribing DWR and using it as an enhancement tool or substitute for dry
land running. Although cardiorespiratory responses during DWR are well studied, further
investigations should concentrate on identifying how active specific muscles during DWR.
The method of running in deep water
The method of DWR is used for different purposes as preventing injury and promoting
recovery from strenuous exercise or as a form of complementary training for cardiovascular
fitness. A reduction in spinal loading constitutes a role for deep-water running in the
prevention of injury, while an alleviation of muscle soreness confirms its value in recovery
training (Reilly & Ekblom, 2005). Endurance running places repetitive stress on the lower
limbs and lower back. Compressive loading is inevitable during running as the feet impact
with the ground 600-1200 times per km (Valliant 1990), with each foot strike inducing ground
reaction forces equivalent to 2-4 times the body weight (Cavanagh, 1980). When the
compressive load exceeds the osmotic pressure of the discal tissues, fluid is expelled from
the intevertebral discs: The resultant loss in disc height is reflected in a loss of height which
has been referred to as spinal shrinkage (Reilly, 1984). One study supports the use of DWR
for reducing the compressive load on the spine in both injured and uninjured runners
(Dowzer, Reilly & Cable, 1998). The final conclusion was that running in deep water produced
significantly less spinal shrinkage than either the treadmill or shallow water conditions, no
difference being evident between the treadmill and shallow water running.
DWR is also used as an injury-rehabilitation technique (i.e limb stress fracture) (Liem,
Truswell & Harrast, 2013) and as conventional physical training in the days after competition
(Reilly & Ekblom, 2005). In a study of 30 previously untrained individuals, DWR proved to be
superior to other putative methods of reducing muscle soreness and restoring muscle
strength following ‘‘stretch – shortening regimen” (SSR) (Reilly, Cable, & Dowzer, 2002). This
kind of exercise employed to induce soreness consisted of drop jumps from a platform 50 cm
in height once every 7 s until voluntary exhaustion. Exercise on the three subsequent days
consisted of running for 30 min at 70 –80% of heart rate reserve. The methods of recovery
examined were: (1) rest on all days; (2) rest on day 1, DWR on remaining days; (3) rest on
day 1, treadmill running on later days; (4) treadmill run on all days; and (5) deep-water
running on all days. The most effective recovery was when DWR was incorporated in the
training programme for all 3 days following the SSR. DWR failed to prevent delayed-onset
muscle soreness but appeared to speed up the process of recovery for muscle strength
(determined using isokinetic dynamometry) and perceived soreness. CK concentrations
peaked 24 h earlier and at a lower value in the group employing deep-water running
compared with the other groups. Soreness was eliminated while participants were running in
deep water but returned post exercise, having allowed exercise to proceed pain free. The

DWR strategy also enabled participants to maintain range of motion at the hip joint while they
were experiencing soreness. These factors could be linked with the smaller decline in leg
strength that occurred when DWR was employed.
The physiology of DWR
DWR maximal heart rate and oxygen consumption values have been consistently shown to
be lower than those found during running on dry land (Dowzer, Reilly, Cable & Nevill, 1999;
Frangolias et.al. 1995; Mercer & Jensen 1997, 1998; Nakanishi, Kimura & Yokoo, 1999;
Reilly, Dowzer & Cable, 2003; Svedenhag & Seger, 1992;). However, recent evidence
reveals that DWR is a comparable form of submaximal intensity exercise as treadmill
regimenes in well-trained athletes (DeMaere & Ruby, 1997). Furthermore, when the subjects
were elderly women, these responses were higher during submaximal deep-water running
than during treadmill running (Broman et. al. 2006). Results showed an improvement of
submaximal work capacity (a reduction of 3% in HR), maximal aerobic power (an increase of
10% in VO2), and maximal ventilation (an increase of 14%) with the effects transferable to
land based activities (Broman et. al. 2006). Therefore, sedentary individuals benefit more
than athletes in improving maximal oxygen uptake (Reilly, Dowzer, Cable, 2003).
Responses to training programmes have confirmed the efficacy of deep-water running,
although positive responses are most evident when measured in a water-based test. Aerobic
performance is maintained with deep-water running for up to 6 weeks in trained endurance
athletes (Reilly, Dowzer & Cable, 2003). Otherwise, there is some limited evidence of
improvement in anaerobic measures and in upper body strength in individuals engaging in
deep-water running (Reilly & Ekblom, 2005).
One relevant consideration:
It is important for the physician or sports medicine practitioner to focus on the underlying
physics and biomechanics of running in water in order to better produce the desired
physiological metabolic, and psychological outcomes (Killgore, 2012).
DWR Technique
The concept of training specificity should be further considered when prescribing DWR and
using it as an enhancement tool or substitute for dry land running. (DeMaere & Ruby, 1997).
Authors as Azevedo et. al. (2010) conclude that adaptation to deep water running reduces the
difference in VO2max between the two modalities, possibly due to an increase in muscle
recruitment. DWR technique, psychological comfort, perception of work, muscular recruitment
patterns, and running kinematics are all affected by the physics (ie, temperature, buoyancy,
hydrostatic pressure, specific gravity, and drag) of running in water (Killgore, 2012).
Proper DWR technique should mimic the patterns of land-based running. The stride should
be very similar to that of sprinting in order to maximize the specificity of the movement to
running on land (Killgore, 2012). An upright posture with the trunk perpendicular to the
running surface is ideal running position, allowing mobility of the pelvis and lumbar spine
(Killgore, 2012). Some studies (Kaneda et. al. 2009) revealed forward inclinations of the trunk
were apparent for DWR with flotation vest: the pelvis was inclined forward in DWR. In
conclusion, the higher-level activities during DWR are affected by greater hip joint motion and
body inclinations with an unstable floating situation. DWR with the aid of extra buoyancy
system (i.e suit with buoyancy pads in legs, arms and trunk, front and back) allows the head
top to remain above the water and helps in maintenance of an upright position. The
positioning and different thickness of the core and back pads helps to hold a person in the
correct biomechanical body position. This is very important concept to maintain proper
ventilation, as the chest is already under increased strain during DWR because of the
hydrostatic pressure of the water on the thoracic cavity. This special device also adds
resistance to arm and leg work without risking injury: The water resistance imposed on the
body during aquatic locomotion is much greater than that on land, as water is about 800 times
more dense than air (DiPampero, 1998). Furthermore, the water generates an additional
resistance, with an increase in speed and surface area of the body (Shanebrook & Jaszczak,
1976).

Muscle activity during DWR
Although cardiorespiratory responses during DWR are well understood, there has been little
research on identifying how active specific muscles are during DWR. This work is important to
better understand the salient features of DWR that allow it to be a suitable alternative to
running on dry land.
Masumoto et. al. (2009) evaluated 7 healthy subjects who performed DWR and treadmill
running (TMR) at rate perceived exertion (RPE) values of 11 (fairly light), 13 (somewhat
hard), and 15 (hard). Surface EMG was used to evaluate muscle activity of the rectus femoris
(RF), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius (GA) with average EMG
calculated across a 30-s window. It was concluded that the muscle activity levels of the TA
and GA were lower during DWR than during TMR when exercise intensity was matched on
RPE. In contrast, the muscle activity levels of the BF and RF were either not different or
tended to be lower during DWR than TMR at matched RPE. Most importantly, it seems that
higher levels of RPE are needed during DWR to achieve muscle activity levels and patterns
that are more similar to TMR lower intensity exercise. In another study from Masumoto et. al.
(2013), the authors compared different styles of DWR (high-knee style, HK and cross-country
style, CC) with treadmill running on dry land, as well as to investigate effect of stride
frequency (SF) on muscle activity. From all tested muscles during both styles, muscle activity
levels increased with increasing SF. These observations indicated that muscle activity is
influenced not only by running in the water but also by the two styles of DWR tested.
Conclusions
DWR is used by a variety of populations either as a mode of exercise during rehabilitation or
as a supplement to an exercise program because it is thought that this exercise is less likely
to cause injury than dry land running. DWR is also promoted as light recovery sessions
immediately after or the day following competitive games. DWR with the aid of extra
buoyancy system allows a correct biomechanical body position. Although cardiorespiratory
responses during DWR are well studied, further investigations should concentrate on
identifying how active specific muscles during DWR.
References
!" Azevedo L, Lambert M, Zogaib P, Barros Neto T. Maximal and submaximal physiological
responses to adaptation to deep water running. J Sports Sci. 2010 Feb;28(4):407-14.
!" Broman G, Quintana M, Engardt M, Gullstrand L, Jansson E, Kaijser L. Older women's
cardiovascular responses to deep-water running. J Aging Phys Act. 2006 Jan;14(1):29-40.
!" Broman G, Quintana M, Lindberg T, Jansson E, Kaijser L. High intensity deep water training
can improve aerobic power in elderly women. Eur J Appl Physiol. 2006 Sep;98(2):117-23.
!" DeMaere J, Ruby B. Effects of deep water and treadmill running on oxygen uptake and
energy expenditure in seasonally trained cross country runners. J Sports Med Phys Fitness.
1997 Sep;37(3):175-81.
- Di Pampero, P. The energy cost of human locomotion on land and in water. Int J Sports
Med 1986;7:55–72.
!"Dowzer C, Reilly T, Cable N, Nevill A. Maximal physiological responses to deep and shallow
water running. Ergonomics. 1999 Feb;42(2):275-81.
- Dowzer, C, Reilly, T, Cable, N. Effects of deep and shallow water running on spinal
shrinkage. British Journal of Sports Medicine, 1998, 32, 44 – 48.
- Frangolias D, Rhodes C. Maximal and ventilatory threshold responses to treadmill and water
immersion running. Med Sci Sports Exerc. 1995;27(7):1007–13.
!" Kaneda K, Sato D, Wakabayashi H, Nomura T. EMG activity of hip and trunk muscles
during deep-water running. J Electromyogr Kinesiol. 2009 Dec;19(6):1064-70.
- Killgore G. Deep-water running: a practical review of the literature with an emphasis on
biomechanics. Phys Sportsmed. 2012 Feb;40(1):116-26.
!" Liem B, Truswell H, Harrast M. Rehabilitation and return to running after lower limb stress
fractures. Curr Sports Med Rep. 2013 May-Jun;12(3):200-7.

!" Masumoto K, Applequist B, Mercer J. Muscle activity during different styles of deep water
running and comparison to treadmill running at matched stride frequency. Gait Posture. 2013
Apr;37(4):558-63.
!" Masumoto K, Delion D, Mercer J. Insight into muscle activity during deep water running.
Med Sci Sports Exerc. 2009 Oct;41(10):1958-64.
- Mercer J, Jensen R. Heart rates at equivalent submaximal levels of VO2 do not differ
between deep water running and treadmill running. J Strength Cond Res. 1998;12:161–5.
- Mercer J, Jensen R. Reliability and validity of a deep water running graded exercise test.
Meas Phys Educ Exerc Sci. 1997;1:213–22.
- Nakanishi Y, Kimura T, Yokoo Y. Maximal physiological responses to deep water running at
thermoneutral temperature. Appl Human Sci. 1999;18:31–5.
!" Reilly T, Dowzer C, Cable N. The physiology of deep-water running. J Sports Sci. 2003
Dec;21(12):959-72.
- Reilly T, Tyrrell A, Troup J. Circadian variation in human stature. Chronobiol Int. 1984;
1:121-6.
- Reilly, T, Ekblom, B. The use of recovery methods post-exercise. J Sports Sci. 2005
Jun;23(6):619-27.
- Reilly, T, Cable, N, Dowzer, C. The efficacy of deep-water running. In P. T. McCabe (Ed.),
Contemporary ergonomics 2002 (pp.162 – 166). London: Taylor & Francis.
- Shanebrook J, Jaszczak R. Aerodynamic drag analysis of runners. Med Sci Sports
1976;8:43–5.
!" Svedenhag J, Seger J. Running on land and in water: comparative exercise physiology.
Med Sci Sports Exerc. 1992 Oct;24(10):1155-60.
- Valiant, G Transmission and attenuation of heel strike accelerations. In Cavanagh PR.
Biomechanics of distance running. Champaign, IL: Human Kinetics Publishers, 1990;225-48.
"