| The
goals of our clinical research are
- to establish the most
effective exercise prescription in health and disease
- to understand the
mechanisms in which exercise/physical activity prevents and treats
modern chronic disease
The current diseases
of interest include hypertension, diabetes,
and obesity.
The measurement of endothelial
function is a new direction for our laboratory. We
are applying this measurement of artery health to the postprandial
period for the purpose of studying the effects of physical activity
on the postprandial endothelial dysfunction. |

Ryan
Harris (2007 Graduate) is measuring endothelial function in a subject |
|
RESEARCH
IN ENDOTHELIAL FUNCTION |
In 2005, our research
focus reached a new level with the incorporation of the measurement
of Brachial Artery Flow-Mediated Dilation (FMD). In the past, our
disease outcomes were classic risk factors for atherosclerotic cardiovascular
disease; i.e. cholesterol, blood pressure, and/or blood sugar. With
our new technology, we can now observe the nature of a single layer
of cells in the artery, the endothelium. The endothelium is the
site where atherosclerotic cardiovascular disease begins. The endothelium
is responsible for maintaining vascular functions that protect the
artery from disease. Life-style factors, such as diet or smoking,
insult the endothelium compromising its ability to protect the artery,
leading to heart disease, stroke, and peripheral vascular disease.
A simple illustration
of the measurement of endothelial function using the flow-mediated
dilation of the brachial artery is below. |
|
Although
the focus of our research is in the postprandial
endothelial function and exercise, our graduate students are
actively involved in supplemental endothelial function studies.
- Ryan
Harris
(2007 Graduate) published our first manuscript on the effects
of repetitive reactive hyperemia on flow-mediated dilation in
Vascular Medicine
last year. He found that repetitive measurements of flow-mediated
dilation did not affect the outcome. For us, this is good news.
The future of our work in endothelial function requires repetitive
measurements following exercise.
- Jaume
Padilla
(Doctoral Candidate) investigated
the technique to measure flow mediated dilation. He compared the
traditional reactive hyperemia technique to a hand-grip method
to cause hyperemia. He found that the two techniques did not produce
the same results; the traditional reactive hyperemic technique
was the more accurate and valid technique. He has published this
study in Clinical
Science

Active
(left) & Reactive (right) hyperemic techniques |
- Ryan
Harris
(2007 Graduate) established the reproducibility of brachial artery
FMD following exercise. He found FMD to be reproducible; quite
important for researchers working on exercise related studies.
This study has been published in Ultrasound,
Medicine and Biology.
- Both
Ryan and Jaume observed
the shear stress of blood flow during the recovery from exercise
and found shear stress not only to be intensity dependent, but
last for two hours post-exercise. This finding is important in
that the shear stress created by the blood flow may be one of
the mechanisms to improve arterial health with exercise. This
manuscript has been published in Vascular
Medicine.
- The
Team
wrote our first review article on the efficacy of measuring brachial
artery FMD in the acute exercise model. This article has been
published in Cardiovascular
Ultrasound.
|
Our most
recent work in endothelial function involves the interaction of diet
and exercise. It is well known that a high-fat meal compromises endothelial
function. We wanted to see if exercise could counteract the decrement
in endothelial function caused by the high-fat meal. |
Brachial artery
response to high-fat meal alone (square and dotted line), a low-fat
meal alone (square and dotted line) and high-fat meal combined with
physical activity (triangle and solid line). * Indicates significant
difference (P=0.005) from pre-meal; # Indicates significant difference
(P=0.001) from 4 h post-high-fat meal
|
In our first study,
eight young healthy adults, walked for 45 min at 60% of VO2max
two hours after eating a high-fat meal. The Figure to the right
illustrates these data. Subjects consumed the high fat meal at
8:00 am and exercised at 10:00 am. Brachial artery FMD was measured
at 7:30 am before the meal and at 12:00 pm, 4 hrs following the
meal.
|
The exercise significantly
counteracted the attenuation in brachial artery FMD associated with
the high-fat meal when the exercise was presented after the meal.
This study was published,
by Jaume Padilla in
the European Journal
of Applied Physiology.
|
| Next, we compared
the postprandial attenuation in brachial artery FMD associated with
the high-fat meal between physically active and inactive adults to
see if habitual physical activity has an effect on how your arteries
response to the high-fat meal. Jaume
Padilla is heading up this study. |
|
We matched
- 7 active
(3 men, 4 women; age= 26.1 ± 2.2 yrs; BMI=22.6 ±
0.6) and
- 7 sedentary
adults (3 men, 4 women; age= 25.3 ± 1.6 yrs; BMI=
23.0 ± 2.1) by age, sex, and BMI.
The figure
to the right illustrates that habitually active adults exhibited
no attenuation in brachial artery FMD (top panel)
following the high-fat meal whereas the sedentary adults exhibited
a significant 26% decrease in FMD (p=0.01). Higher
Superoxide Dismutase (SOD) activity (bottom panel) was found
in active adults (p=0.018). Furthermore, the active adults
exhibited an increase in SOD activity with the meal whereas
the sedentary adults did not. |

* Significant time difference
# Significant between group difference
|
|
When combining
both groups, a significant inverse relationship was found between
postprandial plasma SOD activity and the attenuation of FMD following
the high-fat meal (r= -0.674; p= 0.008).
We are currently
investigating the oxidative stress between the two groups. |
|
On those same
lines, we investigated the SOD activity response to a high-fat meal
in healthy active adults.
 |
Sixteen
adults (5 men and 11 women; age 27.8 ±1.5 yrs; BMI=
23.4±0.50 kg/m2) were fed a high-fat meal. SOD activity
was assessed at baseline (before the meal) and four hours
after the meal. We found a significant increase in SOD activity
following the high-fat meal (pre=8.16±0.19 to post=9.25±0.25
U/mL (p=0.044).
|
The applications
of these two studies support exercise and physical activity to protect
the artery from the detrimental effects of a high-fat meal. We believe
exercise and physical activity work through antioxidant mechanisms.
|
|
To apply our theories
on the antioxidant capacities of exercise and physical activity
in overweight and obesity, we have compared the brachial artery
FMD response to a single session of exercise in sedentary and active
overweight men. We
know that sedentary overweight men exhibit excessive oxidative stress
to a single session of exercise. We also know that physical activity
helps prevent cardiovascular disease in overweight men, despite
the excess weight. Again, we believe, it's the antioxidant defenses
that are increased in overweight active men that protect the artery.
So, we also observed
the inflammatory response to the single session of exercise and
it's effect on arterial health as measured by brachial artery FMD.
Subjects exercised at
intensities of 25%, 50%, and 75% on a treadmill. FMD and bloods
were measured before and one hour after exercise.
|
 |
|
Active
overweight men exhibited a significant increase
(p=0.034) in brachial artery FMD following physical activity,
whereas sedentary overweight adults exhibited a significant
decrease (p=0.010).
We definitely
have a found a significant difference in the arterial response
to exercise between sedentary and active overweight men. We
know we cannot attribute this difference to the inflammatory
response as we found no differences in IL-6 or TNF-alpha.
|
 |
We believe this difference
is due to oxidative stress and the antioxidant defense associated
with habitual exercise or physical activity. We are observing the
oxidative stress now.
This study has
been published in Obesity
Research.
|
Our
recent publications in endothelial function include:
- Padilla, J., R.A.
Harris, L.D. Rink, and J.P. Wallace. Characterization
of the brachial artery sheer stress following walking exercise.
Vascular Medicine, 13:105-111, 2008.
- Harris, R.A., J.
Padilla K.P. Hanlon, L.D. Rink, J.P. Wallace. Reproducibility
of the Flow-Mediated Dilation Response to Acute Exercise in Overweight
Men, Ultrasound and Medicine and Biology, 16:578–584,
2008.
- Harris, R.A., Padilla,
J., Hanlon, K.P., Rink, L.D., J.P Wallace. The
Flow-Mediated Dilation Response to Acute Exercise in Overweight
Active and Inactive Men, Obesity Research, 16:578–584,
2008.
- Padilla, J., R.A.
Harris, and J.P. Wallace. Can
the measurement of brachial artery flow-mediated dilation be applied
to the acute exercise model? Cardiovascular Ultrasound,
5:45-52, 2007.
- Padilla, J., R.A.
Harris, A.D. Fly, L.D. Rink, and J.P. Wallace. The
effect of acute exercise on endothelial function following a high-fat
meal, European Journal of Applied Physiology, 98:256-262,
2006.
- Padilla, J., R.A.
Harris, A.D. Fly, L.D. Rink, and J.P. Wallace, A
comparison between active and reactive hyperemia-induced brachial
artery vasodilation, Clinical Science, 110:387-392,
2006.
- Harris, R.A., J.
Padilla, and J.P. Wallace. Variability
of flow-mediated dilation measurements with repetitive reactive
hyperemia, Vascular
Medicine, 11:1-6, 2006.
- Harris, RA, J Padilla,
JP Wallace, The Effect of Repetitive Reactive
Hyperemia on Brachial Artery Flow Mediated Dilation Measurements,
Medicine & Science in Sports & Exercise,
37(5) Supplement:S221-S222, 2005
- Padilla, J., R. Harris,
JP Wallace, The Variation of Flow Mediated
Dilation During Morning Hours, Medicine & Science
in Sports & Exercise, 37(5) Supplement:S221, 2005.
|
| Blair
Johnson,
a first year doctoral student is extending our interest in oxidative
stress and exercise with a dose response study. His work will help
us determine the optimal exercise prescription to improve antioxidant
defense. |
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| |
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Our most recent
efforts in hypertension have been to compare exercise to physical
activity in the nonpharmalogical treatment of hypertension.
Using ambulatory
blood pressure monitoring (pictured to the right), we are able to
measure blood pressure for 24 hours. We obtain a total of 100 blood
pressures, measuring it every 15 min during the day and every 30
min during sleep.
|
 |
|

Illustrated
above is a typical blood pressure pattern of an adult with hypertension.
The systolic blood pressure is illustrated in red; the diastolic
in yellow; and the normal pressures in green. Normal blood pressure
should be below 140/90 mm Hg during the waking hours and below120/80
mm Hg during the sleeping hours.
With this technology
we have observed the value of the time of day to exercise on the
blood pressure reduction. We have also identified adults with nocturnal
high blood pressure. The tracing above is an adult with normal nocturnal
blood pressure.
|
| Saejong
Park
(2006 doctoral graduate)
found that four 10 min sessions of physical activity was more effective
in reducing blood pressure in prehypertension than one 40 min continuous
session of physical activity. These results are original and provocative.
Saejong incorporated Holter monitoring with the ambulatory blood pressures
to investigate the heart rate variability. She found that the changes
in blood pressure were related to changes in sympathetic tone. Her
work has been published in Journal of Hypertension
(article 1
and article
2). |
 |
|
 |
Jaume
Padilla,
as a masters student from the University
of Leuven, completed a study in which he measured the ambulatory
blood pressures during life-style physical activity. His subjects
wore the ambulatory monitor while doing yard work and house work.
We found that simple life-style activities such as mowing the lawn,
etc. lowered blood pressure quite effectively in both prehypertension
and hypertension. His work was published in Medicine
and Science in Sports and Exercise. |
Our most recent articles
in exercise and hypertension are:
- Park,
S., L.D. Rink, and J.P. Wallace. Accumulation
of physical activity: blood pressure reduction between 10-min
walking sessions. Journal of Human Hypertension,
22:475-482, 2008.
- Wallace, J.P. and
A. Fly. Lifestyle: Sound Medicine for high blood pressure. ACSM’s
Health & Fitness Journal, 12(2):8-15, 2008.
- Park,
S. D.L. Rink and J.P. Wallace. The
accumulation of physical activity leads to a greater blood pressure
reduction than a single continuous session in prehypertension,
Journal of Hypertension 24:1761-1770, 2006.
- Lehmkuhl,
L.A.A., S. Park, D. Zakutansky, D. Tanner, J. Stager, C.A. Jastremski
and J.P. Wallace, Reproducibility
of postexercise ambulatory blood pressure in Stage I hypertension.
Journal of Human Hypertension 19:589-595, 2005.
- Wallace,
J.P., S. Park, D.W. Zakutansky, L.A.A. Lehmkuhl, and C.A. Jastremski,
Time of day
to monitor ambulatory blood pressure affects the outcome.
Blood Pressure Monitoring 10:43-50, 2005
- Park,
S., C.A. Jastremski, and J.P. Wallace, Time
of day for exercise on blood pressure reduction in dipping and
nondipping hypertension, Journal of Human Hypertension
19:597-605, 2005.
- Padilla,
J., J.P. Wallace, and S. Park, Accumulation
of physical activity reduces blood pressure in pre- and hypertension,
Medicine and Science in Sports and Exercise, 37:1264-1275,
2005.
- Wallace,
J.P., Exercise
in Hypertension: A Clinical Review. Sports Medicine,
33(8):585-598, 2003.
- Wallace,
J.P., P.G. Bogle, B.A. King, J.B.
Krasnoff, and C.A. Jastremski, The magnitude
and duration of ambulatory blood pressure reduction following
acute exercise. Journal of Human Hypertension,13:361-366,
1999.
|
|
Our experience with
exercising adults with diabetes led us to investigate the efficacy
of exercise in treating diabetic neuropathy.
Diabetic neuropathy is
a complication of diabetes where the nerve becomes deficient in
conducting impulses. Neuropathy affects both the sympathetic and
peripheral nerves. Neuropathy of the peripheral nerves compromises
sensation (such as touch) and motor control (such as gait). Neuropathy
of the sympathetic nerves affects anything having to do with autonomic
control. In terms of exercise, autonomic neuropathy affects the
heart rate, blood pressure, blood flow distribution response to
exercise. It also affects the ability to sense angina and hypoglycemia. |
| Several adults with
diabetes who exercised in our programs reported they
could feel their feet again and wanted
to go dancing. Apparently there
was something about the exercise that was changing their neuropathy.
We believed it was the improvement in blood flow associated with
exercise. So, we set out to do a series of studies to investigate
the influence of exercise on blood flow and nerve function.

Franz
Jones
(Master's student 2006) and Don Zakutansky
(doctoral graduate 2006) conducted an experiment which altered blood
flow of the calf and observed the nerve function during the different
levels of blood flow.
The conditions of blood
flow variability are:
- ischemia
- reactive hyperemia
- exercise
|
Our most recent publications
are:
- Zakutansky,
D.W., K Kitano, J.P. Wallace, and D.M. Koceja, H-Reflex
and motor responses to acute ischemia in apparently healthy individuals,
Journal of Clinical Neurophysiology 22:210-215, 2005
- Zakutansky,
DW, Kitano, K, Park,SJ, Koceja, DM, Wallace, JP. Sensory
and Motor Responses to Acute Ischemia in Healthy Individuals,
Medicine and Science in Sport and Exercise 36(5) Supplement:S165,
May 2004
- Zakutansky,
D.W. and J.P. Wallace, Relationships among
physical activity, limb blood flow, and autonomic neuropathy tests
in adults with diabetes, Medicine and Science in Sports
and Exercise, 33:S21, 2001
- King, B.A.,
J.P. Wallace, and R.A. Kaplan. The relationship
between VO2max and autonomic neuropathy. Medicine and
Science in Sport and Exercise 29 (Suppl 5): S90, 1997.
|
|
Our obesity research
began in 1992 when Dr.
Wayne Miller joined our research team. Dr. Miller created
the Non-Diet Diet and integrated it into our Weight Loss Clinic,
administered through the Adult Fitness Program.
One of our current research
directions in obesity is directed at the influences of diet and
exercise on endothelial health.
In addition,
we are also working through a behavioral approach to healthy diet
and exercise with Drs. Susan
Middlestadt and Alyce
Fly in Applied Health Sciences. Dr. Middlestadt, a
social behaviorists, is leading the team to find out the success
factors to healthy eating and exercise/physical activity.
Publications from
our obesity research:
- Wallace, J.P., Obesity,
in American College of Sports Medicine: Exercise Management
for Persons with Chronic Diseases and Disabilities, Human
Kinetics Publishers, Champaign, 2002.
- Miller, W.C., T. Swenson,
and J.P. Wallace, Derivation of prediction
equations for residual volume in overweight men and women.
Medicine and Science in Sport and Exercise, 30:322-327,
1998.
- Miller, W.C., M.G.
Niederpruem, J.P. Wallace, and A.K. Lindeman, Dietary
fat, sugar, and fiber predict body fat content. Journal
of the American Dietetic Association 94:612-615, 1994.
- Wallace, J.P., P.K.
Bogle, K. Murray and C.A. Jastremski, Variation
in anthropometric dimensions for estimating upper and lower body
obesity. American Journal of Human Biology 6:699-709,
1994.
- Miller, W.C., J.P.
Wallace, and K. E. Eggert, Predicting max
HR and HR-V02 relationship for exercise prescription in obesity.
Medicine and Science in Sport and Exercise 25:1077-1081,
1993.
- Miller, W.C., J.P.
Wallace, A.K. Lindeman and C. Jastremski, Successful
weight loss in a self-taught, self-administered program.
International Journal of Sports Medicine 14:401-405,
1993.
- Miller, W.C., J.P.
Wallace, K.E. Eggert and A.K. Lindeman, Cardiovascular
risk reduction in self-taught, self-administered weight-loss program
called the Non-Diet Diet. Medicine, Exercise, Nutrition,
and Health 2:218-223, 1993.
- Miller, W.C., A.K.
Lindeman, J.P. Wallace, and M. Niederpruem, Diet
composition, caloric intake, and exercise in relation to body
fatness, American Journal of Clinical Nutrition
52:426 430, 1990.
|
MEET
OUR GRADS |
 |
Greg
Dwyer, Ph.D. FACSM
1986 - 1992
Thesis: Glycosylated hemoglobin and the oxygen
kinetics in individuals with type II diabetes
Current Employment: Associate
Professor, Clinical Exercise Physiology, East Stroudsburg
University, East Stroudsburg, PA
|
|
Galit
Inbar, Ph.D.
1985-1992
Thesis: Hemodynamic determinants of postexercise
hypotension in borderline hypertensive women
Employment: Clinical Exercise Specialist
and Instructor, Wingate Institute, Israel
|
 |
 |
Darcy
Sun, Ph.D.
1985-1993
Thesis: Orocecal transit during prolonged
caloric restriction and refeeding
Employment: Director of Cardiac Rehabilitation
and Nutrition Services, Hospital, Macon Georgia
|
|
Mitch
Whaley, Ph.D. FACSM
1988- 1993
Thesis: Maximal aerobic power as a predictor
of cardiac morbidity in adult men and women during long term
follow-up
Employment: Dean College of Applied Sciences
and Technology, Ball
State University.
|
 |
 |
Phil
Bogle, Ph.D.
1990-2001
Thesis: Hemodynamic determinants of post
exercise hypotension: An ambulatory study
Employment: Captain Phil Bogle, Ph.D.
Assistant Professor
Health, Exercise, & Sport Science
The Citadel
|
|
Lee
Hwa Chen, P.E.D
1993 -2003
Thesis:
Physical activity patterns and its relationship to cardiovascular
risk factors in an adult Taiwanese population
Employment: Assistant Professor, National
College of Physical Education and Sports, Taoyuan, Tiawan.
|
 |
 |
Saejong
Park, Ph.D.
2000-2006
Thesis:
The role of physical activity in the treatment of prehypertension:
accumulation vs. continuous exercise.
Employment:
Research Scientist
Korea Institute
of Sport Science
Seoul, Korea
|
| Don
Zakutansky, Ph.D.
2000
- 2006
Thesis:
The effects of blood flow on peripheral nerve function in
adults with type 2 diabetes mellitus
Employment:
Lecturer, Gateway College, Wisconsin
|
 |
Joanne
Krasnoff, Ph.D.
2002 - 2007
Thesis:
The relationships among health-related fitness measures, physical
activity, and nonalcoholic fatty liver disease
Employment:
Assistant Professor and Associate Director of the Exercise
Physiology and Physical Function Lab for the Division of Endocrinology,
Boston University School of Medicine |
 |
 |
Ryan
Harris, Ph.D.
2003-2007
Thesis:
The Interaction of TNF-alpha, Interleukin-6, and
acute exercise on endothelial Function
Employment:
Post-Doc with Russell
Richardson, School
of Medicine, University of California, San Diego |
|
OUR
CURRENT DOCTORAL CANDIDATES ENGAGING IN THEIR DISSERTATIONS |
Jaume
Padilla, M. S.
2004-present
Thesis: |
 |
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