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22
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Introduction
Additional affiliations
August 2007 - June 2012
Education
January 2009 - June 2012
August 2007 - December 2008
August 2005 - May 2007
Publications
Publications (22)
We addressed a practical question that remains largely unanswered after more than a century of active investigation: can equations developed in the laboratory accurately predict the energy expended under free-walking conditions in the field? Seven subjects walked a field course of 6415 meters that varied in gradient (-3.0 to +5.0%) and terrain (asp...
The metabolic energy human walking requires can vary by more than 10-fold depending on the speed, surface gradient and load carried. Although the mechanical factors determining economy are generally considered to be numerous and complex, we tested a minimum-mechanics hypothesis that only three variables are needed for broad, accurate prediction: sp...
New Findings
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A positive association between telomere length and exercise training has been shown in cardiac tissue of mice. It is currently unknown how each bout of exercise influences telomere‐length‐regulating proteins. We sought to determine how a bout of exercise altered the expression of telomere‐len...
Accurate prediction of the metabolic energy walking requires can inform numerous health, bodily status and fitness outcomes. Here, we adopted a two-step approach to identifying a concise, generalized equation for predicting level human walking metabolism. Using literature-aggregated values, we compared: 1) the predictive accuracy of three literatur...
We formulated a "one-size-fits-all" model that predicts the energy requirements of level human walking from height, weight and walking speed. Our three-component model theorizes that the energy expended per kg•stride-1 is independent of stature at mechanically equivalent walking speeds. We measured steady-state rates of oxygen uptake of 78 subjects...
Reductions in estrogen function lead to adiposity and peripheral insulin resistance. Significant metabolic changes have been found in adipocytes and skeletal muscle with disruptions in the estrogen-signaling axis function; however it is unclear if inter-cellular communication exists between these tissues. The purpose of this study was to examine th...
Aging is associated with a tissue degeneration phenotype marked by a loss of tissue regenerative capacity. Regenerative capacity is dictated by environmental and genetic factors that govern the balance between damage and repair. The age-associated changes in the ability of tissues to replace lost or damaged cells is partly the cause of many age-rel...
Disruptions of ovarian function in women are associated with increased risk of metabolic disease due to dysregulation of peripheral glucose homeostasis in skeletal muscle. Our previous evidence suggests that alterations in skeletal muscle lipid metabolism coupled with altered mitochondrial function may also develop. The objective of this study was...
SPANGENBURG, E. E., L. M. WOHLERS, and A. P. VALENCIA. Metabolic dysfunction under reduced estrogen levels: looking to exercise for prevention. Exerc. Sport Sci. Rev., Vol. 40, No. 4, pp. 195-203, 2012. Loss of estrogen function leads to the development of metabolic dysfunction that spans numerous tissues. In this review, we explore the concept tha...
Impaired ovarian function alters lipid metabolism, ultimately resulting in increased visceral fat mass. Currently, we have a poor understanding of alterations in signaling events regulating lipolysis after ovarian function declines. The purpose of this study was to determine if cellular mechanisms regulating lipolysis are altered in mice after ovar...
Decreases in female sex steroids enhance the accumulation of visceral fat mass, leading to a predisposition to developing metabolic diseases. The purpose of this study was to determine whether loss of ovarian function alters the amount and (or) the fatty acid (FA) composition of triacylglycerol (TAG) levels in the liver of ovary-intact (SHAM) or ov...
Triglyceride storage is altered across various chronic health conditions necessitating various techniques to visualize and quantify lipid droplets (LDs). Here, we describe the utilization of the BODIPY (493/503) dye in skeletal muscle as a means to analyze LDs. We found that the dye was a convenient and simple approach to visualize LDs in both sect...
Adipocytes from post-menopausal females have higher basal lipolytic rates than pre-menopausal females, which contributes to increased risk of developing dyslipidemia following menopause. The purpose of this study was to delineate cellular mechanisms affecting adipose tissue function in the ovariectomized (OVX) mouse and also determine if physical a...
Post‐menopausal females are at risk for dyslipidemia, thus we sought to discover if surgical‐induced menopause (OVX) altered mechanisms that regulate lipid metabolism and to determine if voluntary wheel running (Ex) or 17β‐estradiol (E2) attenuated these changes. C57BL/6 mice were placed into the following groups for 8 wks: SHAM, OVX, OVX‐Ex, or OV...
Recent evidence suggests that ovarian hormones contribute to altered function of skeletal muscle, however the signaling processes thought to regulate muscle function remain undefined in females. Thus, the purpose of this investigation is to determine if ovarian hormone status is critical for contraction-induced activation of AMPK or MAPK in skeleta...