Little is known about the strain and consequences of very prolonged and sustained exercise lasting multiple days. This thesis comprises two multi-day exercise field studies and a 24-h, controlled-trial field/laboratory study. The field studies were undertaken using international adventure races (2003 and 2004 Southern Traverses: 86-120 h) to profile exercise intensity and associated physiological and psychophysical strain, and physical and cognitive performance. The 2003 study showed that exercise intensity (from heart rate range) averaged 64% during the first 12 h, dropped to 41% by 24 h, and remained so thereafter. Body core temperature (gastrointestinal pills), throughout racing (n=8) was relatively stable (min 36.0�C and only briefly >39�C), despite widely varying endogenous and exogenous thermal stress. Blood samples obtained before (n=34), during (n=11) and after (n=34) racing revealed a large plasma volume expansion (24%), with stable [sodium]plasma (n=6). Acute (15-30 h) and chronic (96-120 h) elevation of neutrophil, monocyte and lymphocyte numbers were observed across the race. Standardised exercise tests (rest, 25 and 50% peak power output (PPO)) before and after racing (n=9) revealed an extreme shift toward fat utilisation, consistent with lowered fat mass (11%; n=44) and high [free fatty acids]plasma (up 370%; n=9) at race-finish, although [HAD]muscle was unchanged. Muscle glycogen was only 50% lower post-race (290 nmol�kg⁻�d.w.). Complex cognitive performance (Stroop test) impairment was attenuated during 50% PPO post-race. Perceived exertion uncoupled from HR at standardised workloads. Explosive power (jump test; n=24) and anaerobic power (30-s Wingate; n=27) were modestly (<10%) impacted. Strength reduction of arms (11%) and legs (17%) was equivalent (p=0.17). The 2004 study (n=4) involved dissimilar terrain, vegetation, and sequence of exercise modes, yet the profile of exercise intensity was similar: first 12 h 65%, then 45% by 24 h and thereafter. Thus, athletes reliably attain sustainable, low-to-moderate exercise intensity by 24 h. Plasma volume, neutrophil and monocyte responses were reliable across races, whereas lymphocytes were not. Plasma [IL-6] and [S100β] were elevated, substantially in some individuals (IL-6: 223 pg�mL⁻�; S100β: 113 pg�mL⁻�), during racing. A 24-h adventure race simulation (n=9) was then undertaken to investigate physiological and psychophysical factors influencing exercise intensity, autonomic function and orthostatic tolerance. Tests were at 0, ~7, ~15 and 24 h. The 24-h HR profile matched that observed during racing: first 12 h 58% (including 3-h testing), remainder 41%. The shift toward fat utilisation was almost complete within 7 h, and similar to that following 2003 race. The perceived exertion-to-HR uncoupling was also similar; being complete within 15 h. Plasma [noradrenaline] for rest and 12-km�h⁻� run was elevated post-simulation. Plasma [IL-6] peaked by 7 h, although not as high as field observations. The timeframe of metabolic change and perceived exertion uncoupling coincided with that of pace reduction, and may be important regulatory components of very prolonged exercise intensity. Orthostatic intolerance was evident during the simulation (n=6/9), as was cerebral hypo-perfusion (15 h & 24 h). Autonomic function (baroreflex sensitivity, sympathetic activation, parasympathetic withdrawal) was altered only at 7 h, whereas postural-induced hypotension (via impaired venous response) and hypocapnia were always present.

While the traditional dependent variables of motor skill learning are accuracy and consistency of movement outcome, there has been increasing interest in aspects of motor performance that are described as reflecting the ‘energetics’ of motor behaviour. One defining characteristic of skilled motor performance is the ability to complete the task with minimum energy expenditure (Sparrow & Newell, 1998). A further consideration is that movements also have costs in terms of cognitive ‘effort’ or ‘energy’. The present project extends previous work on energy expenditure and motor skill learning within a coordination dynamics framework. From the dynamic pattern perspective, a coordination pattern lowest on the 11KB model potential curve (Haken, Kelso & Bunz, 1985) is more stable and least energy is required to maintain pattern stability (Temprado, Zanone, Monno & Laurent, 1999). Two experiments investigated the learning of stable and unstable coordination patterns with high metabolic energy demand. An experimental task was devised by positioning two cycle ergometers side-by-side, placing one foot on each, with the pedals free to move independently at any metronome-paced relative phase, Experiment 1 investigated practice-related changes to oxygen consumption, heart rate, relative phase, reaction time and muscle activation (EMG) as participants practiced anti-phase, in-phase and 90°-phase cycling. Across six practice trials metabolic energy cost reduced and AE and VE of relative phase declined. The trend in the metabolic and reaction time data and percent co-contraction of muscles was for the in-phase cycling to demonstrate the highest values, anti-phase the lowest and 90°-phase cycling in-between. It was found that anti- and in-phase cycling were both kinematically stable but anti-phase coordination revealed significantly lower metabolic energy cost. It was, therefore, postulated that of two equally stable coordination patterns, that associated with lower metabolic energy expenditure would constitute a stronger attractor. Experiment 2 was designed to determine whether a lower or higher energy-demanding coordination pattern was a stronger attractor by scanning the attractor layout at thirty-degree intervals from 0° to 330°. The initial attractor layout revealed that in-phase was most stable and accurate, but the remaining coordination patterns were attracted to the low energy cost anti-phase cycling. In Experiment 2 only 90°- phase cycling was practiced with a post-test attractor layout scan revealing that 90°-phase and its symmetrical partner 270°-phase had become attractors of other coordination patterns. Consistent with Experiment 1, practicing 90°-phase cycling revealed a decline in AE and VE and a reduction in metabolic and cognitive cost. Practicing 90°-phase cycling did not, however, destabilise the in-phase or anti-phase coordination patterns either kinematically or energetically. In summary, the findings suggest that metabolic and mental energy can be considered different representations of a ‘global’ energy expenditure or ‘energetic’ phenomenon underlying human coordination. The hypothesis that preferred coordination patterns emerge as stable, low-energy solutions to the problem of inter-and intra-limb coordination is supported here in showing that the low-energy minimum of coordination dynamics is also an energetic minimum.

Uncoupling protein, UCP, present in the inner mitochondrial membrane of brown adipose tissue (BAT) contributes to adaptive thermogenesis. UCP functions as a proton pore and can dissipate the proton electrochemical gradient established by the respiratory chain during fuel oxidation, and thus generates heat without producing ATP. However, the brown adipose tissue thermogenesis is not likely to be a major mechanism in controlling energy expenditure for humans because adults have only residual amounts of the tissue. Two new members of the UCP family have been identified based on their high sequence homology to UCP in BAT and named UCP2 and UCP3. The original UCP was renamed UCP1. At the amino acid level, human UCP2 and UCP3 are 59% and 57% identical to UCP1, respectively. In contrast to UCP1, UCP2 is expressed in many tissues such as brown adipose tissue, white adipose tissue, muscle, spleen and macrophages. UCP3 is expressed preferentially in skeletal muscle in humans, and brown adipose tissue and skeletal muscle in rodents. Since their identification many functional studies, including transgenic animals and ectopic expression of UCP2 or UCP3 in yeast, showed uncoupling activity of UCP2 and UCP3. A number of studies have been done that show increased expression of UCP2 and UCP3 by fasting, high-fat diets and suckling of newborn mice. A common characteristic of these circumstances is an associated increase in plasma free fatty acid levels. This study aimed to investigate effects of fatty acids, peroxisome proliferator-activated receptors (PPARs) and other transcription factors on UCP2 and UCP3 gene expression and to explore the molecular mechanism of their regulation through analysis of the promoter of the UCP2 and UCP3 genes. The 3.1 kb and 3.2 kb 5�-flanking regions of the mouse UCP2 and UCP3 genes, respectively, were cloned and used to construct promoter reporter gene (firefly luciferase) plasmids. The cloned region of the UCP2 and UCP3 genes contained putative binding motifs for several transcription factors, including PPAR, myogenin, and MyoD. Luciferase assays of both constructs showed basal promoter activity with 20~190-fold induction for the UCP2 promoter and 1.3~23-fold induction for the UCP3 promoter in several transfected cell lines, including 3T3-L1, C2C12, L6, COS7 and HepG2. Oleic acid (0.3 mM) up-regulated endogenous UCP2 mRNA by 2.3-fold in 3T3-L1 preadipocytes but not in C2C12 myotubes, and UCP3 mRNA by 2.5-fold in C2C12 myotubes. Responsiveness of the cloned promoter to oleic acid reflected the tissue-specific responsiveness of their endogenous genes but with less fold induction, 1.4-fold for UCP2 promoter in 3T3-L1 preadipocytes and 1.5-fold for UCP3 promoter in C2C12 myotubes. Forced expression of PPAR isotypes (PPARα, PPAR[delta] and PPARγ) showed tissue and isotype-specific activation of the UCP2 promoter. UCP2 promoter activity was induced by 2-fold by PPARγ in 3T3-L1 and by 2.8-fold by PPAR[delta] in C2C12. Treatment of oleic acid (0.3 mM) brought about further induction of the UCP2 promoter activity only in 3T3-L1. In contrast, all three isotypes induced activation of the UCP3 promoter in 3T3-L1, C2C12 and HepG2 cells. Treatment with oleic acid (0.3 mM) or isotype-specific agonist (10 [mu]M) resulted in further increased activity of the UCP3 promoter in 3T3-L1 and HepG2 cells. In particular, rosiglitazone (10 [mu]M) induced a 41-fold increase in UCP3 promoter activity in PPARγ transfected HepG2 cells, and this induction returned to basal level by treatment with bisphenol A diglycidyl ether (BADGE) (50 [mu]M), an antagonist for PPARγ. In addition, UCP3 promoter activity increased up to 20-fold 4 days after induction of C2C12 myoblasts differentiation, whereas UCP2 promoter activity increased only up to 2-fold. Forced expression of myogenin and MyoD in C2C12 myoblasts to mimic differentiation, induced UCP3 promoter activity in an additive manner, consistent with UCP3 being regulated by muscle differentiation. In the present study, it has been shown that UCP2 and UCP3 genes are regulated differently by fatty acids. The tissue-type dependence in regulation of endogenous UCP2 and UCP3 paralleled the cell type-specific effect of oleic acid on the promoter-reporter constructs, suggesting that fatty acid effects are at the transcriptional level. UCP2 and UCP3 promoters showed differences in their response to PPARs. Mediation of the fatty acid effect through PPARs has been also demonstrated, but direct binding of PPARs and particular regulatory motifs on the cloned promoter region have not yet been investigated.

Graduation date: 1992

While diet and sedentary lifestyle remain important factors in the development of obesity, recent findings have shown the possible involvement of environmental obesogens, chemicals that can disrupt homeostatic energy balance and increase adiposity. Bisphenol A (BPA) is a compound used in the manufacturing of plastics as a hardening agent and is ubiquitous in the environment due to its widespread use. BPA has been shown to be an endocrine disruptor through its ability to mimic estrogen, which is now known to play important roles in adipose tissue growth and metabolism. In fact, a small but compelling number of studies have shown that mice exposed to BPA in utero or postnatally are fatter as adults. We hypothesized that BPA exposure exerts effects on adipose tissue, promoting adipogenesis and inflammation, and altering energy homeostasis in a manner that promotes obesity. We tested our hypothesis using both in vitro and in vivo models. First, we found that low concentrations of BPA increased the expression of the inflammatory genes, Il-6 and Tnfa, approximately 1.5-3.0 fold in mouse adipose tissue explants. We also found a 3-fold increase in the expression of the lipogenic gene, Fasn. BPA also altered the adipose tissue metabolism, increasing the levels of a number of glycolytic and TCA cycle metabolites, suggesting that BPA may disrupt energy homeostasis. We also found that BPA exposure increased proliferation of mesenchymal stem cells approximately 1.2-fold, which are potential adipocyteprecursors. The study was expanded using two different strains of mice, C57BL/6 and DBA/2J, chronically exposing them to BPA through drinking water for six weeks. A moderate concentration of BPA increased the perigonadal fat pad mass in males. This increase in adiposity was associated with adipocyte hypertrophy and decreased serum adiponectin levels. There were also changes in the expression of some genes with BPA treatment, including a 1.4-fold increase in Leptin and decreases in some Cytochrome P450 genes; however the genes differentially expressed were different between the two strains. Our results suggest that childhood exposure to low doses of BPA, in lieu of any developmental exposure, may contribute to childhood obesity.

Several studies shows that dietary supplements do not have any proven effects on health, yet these supplements are increasing in sales. The study aims to find out what attitudes and knowledge people involved in physical activity have towards supplements and which factors influence them to buy supplements. How these factors differ between men and women was investigated. The study is based on answers from 100 collected questionnaires from people who are physically active at several gyms. Of those who participated in the study, 56 percent were men and 44 percent were women. The study showed that the influence of family and friends and to speed recovery after exercise, were the two most common reasons that affected men and women into buying dietary supplements. The study also showed that the majority of the participants found the supplements to be a good complement to their regular diet. Overall the study shows that the use of supplement is high among the respondents and women and men take supplements for different reasons.

名古屋大学博士学位論文 学位の種類 : 博士(医学)(論文) 学位授与年月日:平成5年9月14日 家田信人氏の博士論文として提出された

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 138-149).

Thesis (M.A.)--Central Connecticut State University, 2003. / Thesis advisor: Cheryl Watson. " ... in partial fulfillment of the requirements for the degree of Master of Arts in Department of Biological Sciences." Includes bibliographical references (leaves 45-50). Also available via the World Wide Web.

Studies conducted for this dissertation utilized a rodent model exposed to single or multiple short duration heat loads in an effort to: 1) elucidate the changes in energy metabolism occurring at the tissue and whole-body level in response to hyperthermia, 2) characterize specific aspects of glucose utilization and hepatic glucose production following a heat load and 3) determine if aspects of mitochondrial function and/or dysfunction might play a role in the metabolic changes that occur in response to heat stress. Study 1 was conducted to determine if rodents exposed to heat stress shared similarities using a bovine heat stress model. Specifically, we were interested in identifying changes in blood metabolites and hormones, as well as gene expression and protein abundance of enzymes associated with energy metabolism in skeletal muscle (type I and type II), liver and adipose tissue. Previous bovine data indicates glucose may be preferentially utilized during heat stress, suggesting alterations in energy metabolism. This study provided evidence that tissue-specific changes occur in response to a heat load and that full glucose oxidation might be reduced, specifically in skeletal muscle where abundance of PDK4 mRNA was increased. Within skeletal muscle, glucose transporters (GLUTs 1 and 4) also tended to be increased in rats exposed to a heat load. Increases in skeletal muscle AMPK-α and PGC-1α as well as increased expression of energy substrate transporters suggests heat stress may impose a cellular energy deficit and/or increased energy demands which subsequently leads to changes in energy metabolism. Few changes were noted in either hepatic or adipose tissue in response to acute heat stress in this pilot study. Study aim of Chapter 3 was to further characterize the effects of heat stress on energy metabolism at the tissue and whole-body level in rats exposed to either 1 or 2 bouts of heat. Rats exposed to a 6 h heat load tended to have higher plasma glucose but reduced insulin levels, compared to thermal neutral controls, suggesting decreased glucose uptake or increased hepatic glucose output. Additionally, although heat stress likely increases whole-body energy demand, plasma NEFA levels were blunted in the early hours following onset of heat, suggesting increased adipocyte insulin sensitivity. Gene expression of enzymes associated with oxidative energy metabolism were increased in the TA (which is comprised primarily of glycolytic muscle fibers) following 2 bouts and in liver following a single bout of heat, while expression of oxidative enzymes were decreased within the soleus (a primarily oxidative muscle type). AMPK mRNA was increased following a single bout of heat in hepatic tissue and after 2 bouts of heat in type I skeletal muscle. AMPK mRNA abundance remained the same following 1 bout but was reduced following 2 bouts of heat within type II skeletal muscle. In the TA, phosphorylated AMPK protein abundance was reduced by HS. Abundance of PGC-1α mRNA was increased in types I and II skeletal muscle but was only numerically increased in liver following heat exposure. These data suggest differences at the transcription level in how heat effects energy metabolism within types I and II skeletal muscle as well as between muscle and hepatic tissue and also suggests a cellular attempt to increase energy production (by all mechanisms) in response to heat exposure. Study 3 (Chapter 4) focused on the effect of a heat load on glucose utilization in skeletal muscle and hepatic glucose production capacity. Similar to study 1, PDK4 expression was increased in types I and II skeletal muscle, while PDK2 expression was increased in hepatic tissue. Within skeletal muscle, increases in PDK expression paralled the increased protein abundance of PDHE1α following heat exposure, implying a decrease in oxidative glucose metabolism. Within the liver, protein abundance of PDH-E1α was reduced following a single heat load, but returned to TN levels after a 2nd heat exposure, suggesting that glucose oxidative metabolism is increased above normal levels after an initial heat exposure, but reduced following multiple heat bouts. Hepatic mRNA abundance for gluconeogenic enzymes were increased, implying an increase in hepatic glucose output capacity. The purpose of Study 4 (Chapter 5) was to determine if heat stress elicits changes on mitochondrial function/dysfunction (i.e. oxidative stress), that may account for changes observed in energy metabolism. Expression of genes associated with antioxidant defense were increased by heat stress, but differed between types I and II skeletal muscle as well as between muscle, hepatic tissue and WBCs. The abundance of mRNA for antioxidant enzymes was increased the greatest, and expression of DNA repair enzymes were also upregulated the most within hepatic tissue due to heat exposure, suggesting either increased damage at the level of hepatocytes or greater defensive capacity following an environmental insult. Taken together, this data provides evidence that heat alters energy metabolism, but these changes are tissue-specific and may be reflective of where damage is occurring, or which tissues are able to adapt and/or compensate for increased energy demands imposed by an environmental insult.