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Underwater Treadmill Study:
The differences in
physiological adaptations between regular treadmills
and underwater treadmills. |
Principal Investigators:
 | Steve Crouse, Ph.D., FACSM - faculty
director of the project |
| Danny Kniffin, M.S. - Texas A&M rehabilitation
specialist |
Research Technicians:
| Nick Greene, M.S., project coordinator |
| John Green, Ed.D., Ph.D., FACSM - research design
and data analysis consultant |
| Karl Kapchinski - head athletic trainer, Texas A&M
University |
| Wade Womack, M.S. - research assistant |
| April Muller - research assistant and data
management |
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The
Huffines Institute for Sports Medicine and Human Performance
along with the Department of Health and
Kinesiology at Texas A&M, has received grant monies and approval to
begin research and testing on a new underwater treadmill
rehabilitation system.
| The giant pool /
treadmill system is designed to enhance the healing process
of numerous types of athletic injuries and reduce the time
an injured athlete is out of competition. The Huffines and
A&M research team will attempt to repeat earlier studies of
the device as well as determine it's effectiveness in the
rehabilitation of non-athletic type of injuries as well as
selected orthopedic procedures with an emphasis on older
persons. Installation of the device has been completed and
the research Has been underway for over a
year. A manuscript is in
preparation and study results have been presented at both
the
Regional and International Conferences of the American
College of Sports Medicine. Two
Abstracts of those presentations by Nicholas and Elizabeth
Green, primary workers on the project, appear in the table
below. |
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Prediction
of Oxygen Costs of Exercise on a Water Treadmill.
N.P. Greene, E.S.
Greene, G.S. Miller, A. Muller, B.E. Hansen, J.W. Womack, J.S.
Green, A.F. Carbuhn, T.H. Meade, S.F. Crouse. Department of
Health and Kinesiology, Texas A&M University, College Station,
TX (sponsor S.F. Crouse, FACSM) No known research has
been completed investigating the metabolic responses to exercise
on an underwater treadmill. PURPOSE: To derive
a means of predicting rate of oxygen consumption (VO2) during
exercise on an underwater treadmill. METHODS:
Twenty-one men and 20 women participated in this investigation.
The subjects’ mean age, height (Ht), weight (Wt), were 41.6 yr,
173.8 cm, and 90.9 kg, respectively. Exercise was performed on a
treadmill immersed in a pool with resistance jets in front of
the subject. Subjects performed one practice session and five
experimental sessions. Exercise sessions progressed from 2 to 7
mph, increasing 1 mph every 3 min, with jet pressures of 0, 25,
50, 75, and 100% of maximal resistance held constant and
randomly assigned to each session. Jets were pointed at the
subject’s umbilicus and water depth was set to the 4th
intercostal space. Metabolic responses were recorded using
indirect open circuit calorimetry, and measurements were taken
the final 15 s of each stage. Exercise sessions continued until
one of 3 termination criteria were met: heart rate above 85%max,
subject request, or completion of the protocol. Regression
equations were developed by multiple regression analysis using
the variables of height, weight, speed, and jet percentage to
predict VO2. RESULTS: All coefficients were
significant (P<0.001) for predicting both absolute and relative
VO2. Collinearity diagnostics revealed no variable correlation
problems. The equation for absolute VO2 was VO2 (LO2/min) =
(0.028) * Ht in centimeters + (0.002) * Wt in kilograms +
(0.308) * Speed in mph + (0.011) * Percent max jet – 5.333. The
equation for relative VO2 was VO2 (mlO2/kg/min) = (0.297) * Ht
in centimeters – (0.159) * Wt in kilograms + (3.594) * Speed in
mph + (0.131) * Percent max jet – 38.222. R-squared values were
0.735 and 0.743 for prediction of absolute and relative VO2,
respectively. CONCLUSIONS: These data provide a
reasonably reliable means of predicting oxygen consumption for
exercise on a water treadmill. This is of great importance in
providing accurate exercise prescriptions for this mode of
exercise. |
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Comparison of oxygen consumption and heart rate
response to exercise on land versus water treadmill.
E.S. Greene, N.P.
Greene, B.E. Hansen, G. Miller, A. Muller, J.W. Womack, J.S.
Green, A.F. Carbuhn, T. Meade, S.F. Crouse. Department of Health
and Kinesiology, Texas A&M University, College Station, TX
(sponsor S.F. Crouse, FACSM) Little research has been
performed measuring physiological responses to exercise on an
underwater treadmill. PURPOSE: To compare the
oxygen consumption (VO 2) and heart rate (HR) response to
exercise on a land and an underwater treadmill. METHODS:
Twenty-four men and 25 women participated in this investigation.
The subjects’ mean age, height, and weight were 40.5yr, 173.9cm,
and 88.3kg, respectively. The subjects performed one exercise
session on the land treadmill (LTM) at zero grade and one on the
underwater treadmill (WTM). Water depth was standardized to the
height of the fourth intercostal space of each subject. Subjects
performed one practice session on the WTM to become familiar
with this novel mode of exercise. The exercise sessions were
designed as a graded protocol such that each session began with
the treadmill at 2mph, with speed increasing 1mph every 3
minutes, up to 7mph. At the end of each stage, exercise HR was
recorded. Metabolic responses were recorded using indirect
open-circuit calorimetry. Measurements were taken from the final
15 seconds of each stage. Exercise sessions continued until one
of three termination criteria were met: HR exceeded 85% max,
subject request, or completion of the protocol. Oxygen
consumption and HR response to LTM and WTM were compared using a
paired Student’s t-test, with the comparison-wise error rate set
at a =0.05. RESULTS: See Table 1. Table 1. VO2
(LO2*min -1) and HR (bpm) responses to exercise on LTM vs WTM at
varying speeds
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Speed (mph)
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| Mode
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2 |
3 |
4 |
5 |
6 |
7 |
| VO 2
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| LTM
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0.84 ± 0.22
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1.09 ± 0.30
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1.61 ± 0.45
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2.33 ± 0.51
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2.69 ± 0.52
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2.99 ± 0.59
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| WTM
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0.71 ± 0.16*
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1.04 ± 0.31
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1.31 ± 0.39*
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1.68 ± 0.49*
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2.07 ± 0.56*
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2.41 ± 0.64*
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Heart Rate |
| LTM
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88.9 ± 12.2
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99.8 ± 14.7
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121.7 ± 20.2
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146.5 ± 18.0
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157.6 ± 18.9
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164.2 ± 15.2
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| WTM
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90.0 ± 11.9
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104.2 ± 13.9*
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115.2 ± 15.8*
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130.6 ± 19.5*
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142.9 ± 18.5*
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150.9 ±
15.4* |
| *P<0.05
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CONCLUSIONS:
These results show that VO2 and HR responses to
exercise are lower with WTM than with LTM at speeds of 4mph and
greater. |
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