Director: Richard J. Bloomer
Trint Gunnels (Graduate Research Assistant)
JohnHenry Schriefer (Graduate Research Assistant)
Courtney Countess (Graduate Research Assistant)
Research Focus: Within the Cardiorespiratory/Metabolic Laboratory, we have three specific areas of
investigation. Our work involves human subjects and has the central focus on improving
metabolic and cardiovascular health, as well as physical performance. Specifically,
our research is focused on the following:
- The study of isolated nutraceuticals and dietary supplements to improve biomarkers
of health and performance.
- The study of acute stress (both feeding-induced and exercise-induced) related to the
production of reactive oxygen and nitrogen species and associated biomarkers.
- The study of nutrient interventions (often involving dietary restriction) to improve
risk factors for metabolic and cardiovascular disease.
- In relation to focal point 3, we are actively engaged in work related to the Biblically-based
Daniel Fast, a dietary restriction model that has yielded impressive results in our
initial investigations. For more information pertaining to the Daniel Fast, please
Although the above areas of investigations are somewhat distinct, most studies are
centered on our interest in "oxidative stress." Oxidative stress is a condition in
which an imbalance exists between prooxidant and antioxidant levels in such a way
that prooxidant production overwhelms antioxidant defenses, often leading to oxidative modification of lipids, proteins, DNA,
and other molecules in ways that impair cellular function. The generation of these
"reactive oxygen and nitrogen species" (often referred to as "free radicals") occurs
in part as a consequence of normal cellular metabolism. Under ordinary physiologic
conditions, the body's endogenous antioxidant defense system, in conjunction with
exogenous antioxidants consumed through dietary sources, act to protect small and
large molecules from modification and destruction via oxidants.
In addition to normal cellular metabolism, radicals can be generated through exposure
to a wide variety of environmental and physiological challenges. Two such challenges
are the consumption of high saturated fat meals and the performance of strenuous physical
exercise. Specifically, oxidative stress may be mediated by an increased activity
of radical generating enzymes (e.g., xanthine oxidase), activation of phagocytes,
phospholipases, cyclooxygenases, and lipoxygenases, release of heme proteins via destruction
of iron containing proteins, through disruption of the electron transport system leading
to increased leakage of superoxide radicals, and via decreased antioxidant protection.
In these situations when radical production is increased, the use of supplemental
antioxidants may prove beneficial.
Although reactive oxygen and nitrogen species are constantly generated in cells and
increase with exposure to certain stressors, their production does not necessarily
lead to cellular modification and degradation. This is because there exist numerous
defenses aimed to minimize their formation, or to neutralize their damaging effects
once formed. These are categorized as antioxidant enzymes, antioxidant scavengers
and miscellaneous antioxidant compounds, and metal-binding proteins. It should be
noted that routine exposure to radicals may lead to an adaptation to improve antioxidant
defense within the body (via a process known as hormesis). Such an adaptation may
reduce the need for antioxidant consumption in the form of dietary supplements.
Considering the above, the central focus of our lab is to study oxidative stress in
response to acute stressors such as feeding and exercise, and to determine the degree
of attenuation of oxidative stress following varying interventions. In particular,
investigations routinely include the use of nutrient, exercise, and antioxidant treatments
in an attempt to minimize oxidative tissue damage in both healthy and diseased individuals.
Due to the fact that oxidative stress has a strong association with most known human
diseases, as well as the aging process, a variety of outcome variables related to
both metabolic and cardiovascular health are routinely included within our investigations.