Transcript The Physiology of Deep Water Running

The Physiology of Deep Water Running
Dr. Moran
EXS 558
November 16, 2005
Lecture Outline
 Introduction
 What is the purpose? USES
 Research Interest  9,470 hits in Google Scholar for deep-water
running
 Cardiorespiratory Responses to Water Immersion
 Blood Compartments
 Cardiovascular
 Lung Function
 Physiological Response
 Maximal exercise
 Sub-maximal exercise
 Longitudinal Studies
“The Physiology of Deep Water Running”
Journal of Sport Sciences
Reilly et al. (2003)
Uses
 Why deep-water running?
 Injury prevention
– Decreased compressive forces on
spine (Dowzer et al., 1998)
– Decreased lower back injuries
within a running population
– Reduced musculoskeletal loading
as compared to over-ground
running
– Rudzki & Cunningham (1999): with
the introduction of deep-water
running a total reduction of injury
of 46.6% in military recruits
Uses
 Recovery
 Recommended for accelerating the recovery rate in
between soccer games
(Cable, 2000)
 This has not been scientifically proven
 Reilly et al. (2001)
 Examined the role that deep-water running had on
preventing delayed-onset-muscle-soreness (DOMS)
 Deep-water running (DWR) failed to prevent DOMS but
appeared to speed the process of recovery for leg
strength and perceived soreness
 Leg strength was reduced 20% 48hr post-activity w/o
DWR but 7% with DWR
Uses (con’t)
 Health-Related Exercises
 Recommended for people with
orthopedic injuries
 Cardiovascular Training
– Overweight People
– Takeshima et al. (2002)
 Women aged 60-75 had
improvements in:
1.) Knee extension strength
2.) Chest Press
3.) VO2 Max
4.) Vertical Jump
5.) Shoulder Press
Uses (con’t)
 Ancillary Training
 Endurance athletes attempting to increase training volume without
the associated pounding on musculoskeletal system
 Summary of Uses
Population
Purpose
Benefit
Injured
Rehabilitation
Prevents detraining
Accelerates Rehab
Soccer Players
Recovery from DOMS
Accelerates Recovery
Pain-free exercise
Runners
Ancillary training
Avoid overtraining
NM training
Untrained
Aerobic/Strength Training
Avoids injuries associated
with over-land exercise
Promotes muscular strength
Physically Disabled
Allows movement
Freedom from risk of falling
Overweight
Aerobic Training
Reduced load-bearing on
joints (prevent injury)
Cardiorespiratory Response
Water Immersion
 Blood Compartments
 Hydrostatic Vascular Gradient
– Contributes to increased central blood volume because of
adjusted intrathoracic pressure relative to surrounding water
– Pressure imbalance
 Between thoracic cavity and alveolar spaces
 Creates a 700ml redistribution of blood volume to the
central circulation with the heart accepting about 200ml
of that
(Arborelius et al. 1972)
The effect of graded immersion on heart volume, central
venous pressure, pulmonary blood distribution, and heart
rate in man. Risch et al. (1977)
Cardiovascular Response
 Cardiac Output
 ↑ 30-35% when an individual at rest is immersed in water
 Obviously creates an improved end-diastolic volume (EDV)
 Peripheral Vascular Volume (PVV)
 Hydrostatic pressure of tissues causes transcapillary fluid
shift leading to a ↓ in PVV
 Thus, an ↑ with thoracic blood volume  stretch of heart
walls
 Christie et al. (1990)
 left-ventricular end-systolic (30% ↑ ) and end-daistolic
pressure greater in water than on land
Cardiovascular Response (con’t)
 Stroke volume higher for any exercise intensity
while submerged as opposed to on ground
 Possible reasons:
 Displacement of peripheral blood volume to central core area
 Does this affect O2 delivery?
 Left ventricular EDV is close to maximum at rest eliminating the
chance for it increase with more intense exercise
 Cardiac filling time is reduced
 Cause of increased stroke volume
 Enhanced pre-load (Frank-Starling mechanism)
 NOT b/c of enhanced ventricle emptying
Alterations of Lung Function

Reduce action of inspiratory muscles
–

Because of hydrostatic pressure
compressing the diaphragm
Reduced lung capacity and vital capacity
(def: the volume change of the lung between a full
inspiration and a maximal expiration)
 3-9%

(Hong et al., 1967)
The level of immersion will affect the
amount of reduced pulmonary action
–
Functional residual capacity declines only
slightly in immersion up to the hip, but
400ml when immersed to the xiphoid and
another 400ml when immersed to the
neck
(Farhi et al., 1977)
Physiological Response to DWR
 VO2 max
 Consistently reduced when DWR is compared to running on a
treadmill
 Questionable methods


Short duration of DWR protocols
Rely on participants to increase exercise based on RPE

Failure to reach true maximum?
 Dowzer et al. (1999)
– Peak Oxygen Uptake
 Shallow Water Running (SWR)  83.7% VO2 Max
 DWR  75.3% VO2 Max
– Peak Heart Rates
 SWR  94.1% of max HR
 DWR  87.2% of max HR
Muscle Recruitment Changes?
 Michaud et al. (1995a)
 a greater % of work in water performed by upper
extremity
 Upper arm action may be needed to aid in buoyancy
 This could explain the reduced VO2 max found from
DWR
Reduced HR During DWR
 No clear consensus on what causes a
reduced HR while DWR
 Possible Mechanisms
– Baroreflex-mediated decline in HR during rest in water temp
below thermoneutrality
– Enhanced venuous return and cardiac pre-load
 Cardiac Output = HR x SV
– Reduced sympathetic neural outflow from an altered
baroreceptor activation
Respiratory Exchange Ratio
 RER = (volume of CO2)/(volume of O2)
 DeMaere and Ruby (1997)
 DWR induced a higher RER ration indicating an
increased reliance of carbohydrate oxidation and
decreased lipid (fat) utilization
Summary of DWR
Reilly et al. (2003)
Longitudinal Studies