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Exercise
Kinds of Exercise Terms modified by Exercise Selected AbstractsEFFECTS OF ANTIOXIDANT SUPPLEMENTS COMBINED WITH RESISTANCE EXERCISE ON GAINS IN FAT-FREE MASS IN HEALTHY ELDERLY SUBJECTS: A PILOT STUDYJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2008Mélissa Labonté Dtp No abstract is available for this article. [source] OLDER PEOPLE INVOLVED IN PHYSICAL ACTIVITY BENEFIT FROM WATER EXERCISE, SHOWING LONGER TOTAL SLEEP TIMEJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2006Katia L. F. G. Alencar MSc No abstract is available for this article. [source] EFFECTS OF PHYSICAL EXERCISE ON PLASMA CONCENTRATIONS OF SEX HORMONES IN ELDERLY WOMEN WITH DEMENTIAJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2005Masahiro Akishita MD No abstract is available for this article. [source] LEARNING TO SOLVE PROBLEMS FROM EXERCISESCOMPUTATIONAL INTELLIGENCE, Issue 4 2008Prasad Tadepalli It is a common observation that learning easier skills makes it possible to learn the more difficult skills. This fact is routinely exploited by parents, teachers, textbook writers, and coaches. From driving, to music, to science, there hardly exists a complex skill that is not learned by gradations. Natarajan's model of "learning from exercises" captures this kind of learning of efficient problem solving skills using practice problems or exercises (Natarajan 1989). The exercises are intermediate subproblems that occur in solving the main problems and span all levels of difficulty. The learner iteratively bootstraps what is learned from simpler exercises to generalize techniques for solving more complex exercises. In this paper, we extend Natarajan's framework to the problem reduction setting where problems are solved by reducing them to simpler problems. We theoretically characterize the conditions under which efficient learning from exercises is possible. We demonstrate the generality of our framework with successful implementations in the Eight Puzzle, symbolic integration, and simulated robot planning domains illustrating three different representations of control knowledge, namely, macro-operators, control rules, and decision lists. The results show that the learning rates for the exercises framework are competitive with those for learning from problems solved by the teacher. [source] Blunted Hemodynamic Response and Reduced Oxygen Delivery With Exercise in Anemic Heart Failure Patients With Systolic DysfunctionCONGESTIVE HEART FAILURE, Issue 2 2007Jennifer Listerman MD Anemic heart failure patients with systolic dysfunction are known to have reduced exercise capacity. Whether this is related to poor hemodynamic adaptation to anemia is not known. Peak exercise oxygen consumption (VO2) and hemodynamics at rest and peak exercise were assessed among 209 patients and compared among those who were (n=90) and were not (n=119) anemic. Peak VO2 was significantly lower among anemic patients (11.7±3.3 mL/min/kg vs 13.4±3.1 mL/min/kg; P=.01). At rest, right atrial pressure was higher (10±5 mm Hg vs 8±4 mm Hg; P=.02) and venous oxygen saturation lower (62%±8% vs 58%±10%; P<.01) among anemic patients. At peak exercise, anemic patients had a higher wedge pressure (27±9 mm Hg vs 24±10 mm Hg; P=.04). No significant differences in stroke volume, cardiac index, systemic vascular resistance, or oxygen saturation were noted between the 2 groups. In conclusion, the relative hemodynamic response to exercise among anemic heart failure patients appears blunted and may contribute to worse exercise tolerance. [source] Protective effects of exercise preconditioning on hindlimb unloading-induced atrophy of rat soleus muscleACTA PHYSIOLOGICA, Issue 1 2009H. Fujino Abstract Aim:, A chronic decrease in the activation and loading levels of skeletal muscles as occurs with hindlimb unloading (HU) results in a number of detrimental changes. Several proteolytic pathways are involved with an increase in myofibrillar protein degradation associated with HU. Exercise can be used to counter this increase in proteolytic activity and, thus, may be able to protect against some of the detrimental changes associated with chronic decreased use. The purpose of the present study was to determine the potential of a single bout of preconditioning endurance exercise in attenuating the effects of 2 weeks of HU on the mass, phenotype and force-related properties of the soleus muscle in adult rats. Methods:, Male Wistar rats were subjected to HU for 2 weeks. One half of the rats performed a single bout of treadmill exercise for 25 min immediately prior to the 2 weeks of HU. Results:, Soleus mass, maximum tetanic tension, myofibrillar protein content, fatigue resistance and percentage of type I (slow) myosin heavy chain were decreased in HU rats. In addition, markers for the cathepsin, calpain, caspase and ATP-ubiquitin-proteasome proteolytic pathways were increased. The preconditioning endurance exercise bout attenuated all of the detrimental changes associated with HU, and increased HSP72 mRNA expression and protein levels. Conclusion:, These findings indicate that exercise preconditioning may be an effective countermeasure to the detrimental effects of chronic decreases in activation and loading levels on skeletal muscles and that an elevation in HSP72 may be one of the mechanisms associated with these responses. [source] Exercise is the primary factor associated with Hsp70 induction in muscle of treadmill running ratsACTA PHYSIOLOGICA, Issue 4 2006E. G. Noble Abstract Aim:, The cytoprotective, inducible stress protein, Hsp70, increases in muscles of rodents subjected to strenuous treadmill running. Most treadmill running protocols employ negative reinforcement to encourage animals to exercise. As these stimuli may themselves activate stress responses, the present investigation was conducted to determine their contribution to the exercise-induced expression of Hsp70. Methods:, Twenty-one male Sprague,Dawley rats were randomly divided into three equal groups including an exercise group (EX), which ran on a treadmill at 30 m min,1 for 60 min; a stimulation group (STIM), which was not allowed to run, but was stimulated with compressed air and mild electric shock concurrently with their exercising cohort; and a control group (CON), which was housed in the treadmill room during the exercise period. Animals were killed 24 h post-experiment and hearts (H), soleii (SOL) and white gastrocnemii (WG) were harvested and analysed for Hsp70 content (mean% ± SEM of standard). Results:, Significant increases in Hsp70 (as a % of standard) were noted in H and WG (H = 77.4 ± 8.5; WG = 93.9 ± 18.4) of EX but not in STIM (H = 32.5 ± 4.6; WG = 32.0 ± 3.4) or CON (H = 20.5 ± 3.7; WG = 32.4 ± 7.4). In SOL, Hsp70 expression in EX (126.7 ± 6.2) was different from STIM (98.3 ± 10.9) only. This occurred, despite the fact that all groups were exposed to a stressful environment and exhibited elevated (P < 0.001) temperatures (EX ,41.2 ± 0.1 °C > STIM ,40.5 ± 0.2 °C > CON ,39.0 ± 0.1 °C) indicative of a general stress response. Conclusions:, These data suggest that exercise per se, rather than environmental conditions or noxious stimuli, are responsible for the induction of Hsp70 in rat muscle during treadmill running. [source] The Animated Muse: An Interpretive Program for Creative ViewingCURATOR THE MUSEUM JOURNAL, Issue 3 2005Austin Clarkson ABSTRACT Explore a Painting in Depth, an experiment presented in the Canadian Collection of the Art Gallery of Ontario, consisted of a booth that offered seating for two visitors and, opposite them, The Beaver Dam, a 1919 landscape painting by the Canadian artist J. E. H. MacDonald. In a 12-minute audio-guided Exercise for Exploring, visitors were invited to engage in a creative process with the imagery of the painting. This paper sketches how the experiment evolved, presents the background of the Exercise for Exploring, and surveys the effects of the exhibit on a wide range of visitors. The question is raised: How can facilitating visitors' creative responses to artworks be part of the museum's educational mandate and its arsenal of interpretive resources? More broadly: Do strategies that foster and privilege visitor creativity, as well as honor the creativity of artists, affect the accessibility and relevance of the museum for the general public? [source] Acute exercise causes an enhancement of tissue renin,angiotensin system in the kidney in ratsACTA PHYSIOLOGICA, Issue 1 2005S. Maeda Abstract Aims:, Initially, the renin,angiotensin system (RAS) produced through the classical endocrine pathway was well known for its regulation of blood pressure. However, it was revealed that a local autocrine and/or paracrine RAS may exist in a number of tissues (such as kidney). Exercise causes a redistribution of tissue blood flow, by which the blood flow is greatly increased in active muscles, whereas it is decreased in the splanchnic circulation (such as in the kidney). We hypothesized that exercise causes an enhancement of tissue RAS in the kidney. Methods:, We studied whether exercise affects expression of angiotensinogen and angiotensin-converting enzyme (ACE) and tissue angiotensin II level in the kidney. The rats performed treadmill running for 30-min. Immediately after this exercise, kidney was quickly removed. Control rats remained at rest during this 30-min period. Results:, The expression of angiotensinogen mRNA in the kidney was markedly higher in the exercise rats than in the control rats. ACE mRNA in the kidney was significantly higher in the exercise rats than in the control rats. Western blot analysis confirmed significant upregulation of ACE protein in the kidney after exercise. Tissue angiotensin II level was also increased by exercise. Conclusion:, The present study suggests that the exercise-induced enhancement of tissue RAS in the kidney causes vasoconstriction and hence decreases blood flow in the kidney, which are helpful in increasing blood flow in active muscles, thereby contributing to the redistribution of blood flow during exercise. [source] Mitogen-activated protein kinase signal transduction in skeletal muscle: effects of exercise and muscle contractionACTA PHYSIOLOGICA, Issue 3 2001U. Widegren Exercise has numerous growth and metabolic effects in skeletal muscle, including changes in glycogen metabolism, glucose and amino acid uptake, protein synthesis and gene transcription. However, the mechanism(s) by which exercise regulates intracellular signal transduction to the transcriptional machinery in the nucleus, thus modulating gene expression, is largely unknown. This review will provide insight on potential intracellular signalling mechanisms by which muscle contraction/exercise leads to changes in gene expression. Mitogen-activated protein kinase (MAPK) cascades are associated with increased transcriptional activity. The MAPK family members can be separated into distinct parallel pathways including the extracellular signal-regulated kinase (ERK) 1/2, the stress-activated protein kinase cascades (SAPK1/JNK and SAPK2/p38) and the extracellular signal-regulated kinase 5 (ERK5). Acute exercise elicits signal transduction via MAPK cascades in direct response to muscle contraction. Thus, MAPK pathways appear to be potential physiological mechanisms involved in the exercise-induced regulation of gene expression in skeletal muscle. [source] Aquatic exercise for children with cerebral palsyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 12 2005Michelle Kelly BScPT MSc Exercise for children with cerebral palsy (CP) is gaining popularity among pediatric physical therapists as an intervention choice. Exercise in water appeals to children with CP because of the unique quality of buoyancy of water that reduces joint loading and impact, and decreases the negative influences of poor balance and poor postural control. In this paper, research of land-based exercise and aquatic exercise for children with CP is reviewed. Clinically relevant considerations for aquatic exercise programming for children with CP are discussed. [source] Effects of insulin resistance on endothelial function: possible mechanisms and clinical implicationsDIABETES OBESITY & METABOLISM, Issue 10 2008D Tousoulis Insulin resistance (IR) is defined as a reduced responsiveness of peripheral tissues to the effects of the hormone, referring to abated ability of insulin in stimulating glucose uptake in peripheral tissues and in inhibiting hepatic glucose output. Insulin has both a vasodilatory effect, which is largely endothelium dependent through the release of nitric oxide, and a vasoconstrictory effect through the stimulation of the sympathetic nervous system and the release of endothelin-1. IR and endothelial dysfunction (ED) are not only linked by common pathogenetic mechanisms, involving deranged insulin signalling pathways, but also by other, indirect to the hormone's actions, mechanisms. Different treatment modalities have been proposed to affect positively both the metabolic effects of insulin and ED. Weight loss has been shown to improve sensitivity to insulin as a result of either altered diet or exercise. Exercise has favourable effects on endothelial function in normal states and in states of disease, in men and women, and throughout the age spectrum and, hence, in IR states. Metformin improves sensitivity to insulin and most likely affects positively ED. Studies have shown that inhibitors of the renin,angiotensin system alter IR favourably, while Angiotensin converting enzyme (ACE) inhibitors and Angiotensin receptor type II (ATII) inhibitors improve ED. Ongoing studies are expected to shed more light on the issue of whether treatment with the thiazolidinediones results in improvement of endothelial function, along with the accepted function of improving insulin sensitivity. Finally, improved endothelial function by such treatments is not in itself proof of reduced risk for atherosclerosis; this remains to be directly tested in clinical trials. [source] Self glucose monitoring and physical exercise in diabetesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue S1 2009G. Pugliese Abstract Cardiorespiratory fitness, which is determined mainly by the level of physical activity, is inversely related to mortality in the general population as well as in subjects with diabetes, the incidence of which is also increased by low exercise capacity. Exercise is capable of promoting glucose utilization in normal subjects as well as in insulin-deficient or insulin-resistant diabetic individuals. In diabetic subjects treated with insulin or insulin secretagogues, exercise may also result in complications, with too much insulin causing hypoglycaemia and not enough insulin leading to hyperglycaemia and possibly ketoacidosis; both complications may also occur several hours after exercise. Therefore, self-monitoring of blood glucose before, during (for exercise duration of more than 1 h) and after physical exercise is highly recommended, and also carbohydrate supplementation may be required. In the Italian Diabetes Exercise Study (IDES), measurement of blood glucose and systolic and diastolic blood pressure levels before and after supervised sessions of combined (aerobic + resistance) exercise in type 2 diabetic subjects with the metabolic syndrome showed significant reductions of these parameters, though no major hypoglycaemic or hypotensive episode was detected. The extent of reduction of blood glucose was related to baseline values but not to energy expenditure and was higher in subjects treated with insulin than in those on diet or oral hypoglycaemic agents (OHA). Thus, supervised exercise training associated with blood glucose monitoring is an effective and safe intervention to decrease blood glucose levels in type 2 diabetic subjects. Copyright © 2009 John Wiley & Sons, Ltd. [source] Evidence for a vicious cycle of exercise and hypoglycemia in type 1 diabetes mellitusDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2004A. C. Ertl Abstract Exercise is a cornerstone of diabetes management as it aids in glycemic control, weight management, reducing blood pressure, and improving the quality of life of patients. Unfortunately, owing to the complexity and difficulties of regulating exogenous insulin in a physiologic manner during exercise, physical activity often results in hypoglycemia in patients with type 1 diabetes mellitus (type 1 DM). When glucose levels fall below threshold glycemic levels, neuroendocrine, autonomic nervous system (ANS), and metabolic glucose counterregulatory mechanisms are activated. These hypoglycemic counterregulatory mechanisms in type 1 DM can be blunted irreversibly by disease duration or by acute episodes of prior stress. These reduced (or absent) counterregulatory responses result in a threefold increase in severe hypoglycemia when intensive glycemic control is implemented in type 1 DM 1. Much recent work has been focused on determining the in vivo mechanisms responsible for causing the increased incidence of severe hypoglycemia in type 1 DM. Studies from several laboratories have demonstrated the role played by episodes of antecedent hypoglycemia in producing blunted glucose counterregulatory responses during subsequent exposures of hypoglycemia. Until recently, the mechanisms responsible for exercise related hypoglycemia in type 1 DM have been attributed to relative or absolute increases of insulin levels or incomplete glycogen repletion after physical activity. Owing to the qualitative similarity of neuroendocrine, ANS, and metabolic responses to hypoglycemia and exercise, we have hypothesized that neuroendocrine and ANS counterregulatory dysfunction may also play an important role in the pathogenesis of exercise-related hypoglycemia in type 1 DM. Vicious cycles can be created in type 1 DM, where an episode of hypoglycemia or exercise can feed forward to downregulate neuroendocrine and ANS responses to a subsequent episode of either stress, thereby creating further hypoglycemia (Figure 1). This article will review the recent work that has studied the contribution of counterregulatory dysfunction to exercise-induced hypoglycemia in type 1 DM. Copyright © 2004 John Wiley & Sons, Ltd. 1. Reciprocal vicious cycles may be created in type 1 diabetes mellitus (type 1 DM), whereby an episode of hypoglycemia or exercise can feed forward to downregulate neuroendocrine and autonomic nervous system responses to a subsequent episode of either stress, thereby creating further hypoglycemia [source] Exercise, statins, and stroke prevention in Type 2 diabetesDIABETIC MEDICINE, Issue 3 2008L. Mascitelli No abstract is available for this article. [source] The influence of exercise on foot perfusion in diabetesDIABETIC MEDICINE, Issue 10 2007D. T. Williams Abstract Aims, Diabetic foot disease is associated with both macro- and microvascular disease. Exercise has both positive and negative effects on the perfusion of lower limbs with peripheral arterial occlusive disease (PAOD). We aimed to measure changes in foot perfusion following a brief period of lower-limb exercise in individuals with and without Type 2 diabetes and non-critical PAOD. Methods, Subjects were allocated to groups according to the presence or absence of diabetes, PAOD on colour duplex imaging and clinically detectable peripheral neuropaÍthy. Transcutaneous oxygen tension (TcPO2), transcutaneous carbon dioxide tension (TcPCO2), ankle-brachial pressure indices, toe pressures and toe-brachial pressure indices (TBI) were measured. Results, One hundred and sixteen limbs were studied in 61 subjects. Post-exercise, toe pressure and TBI increased in the non-diabetic group with arterial disease, but not in the groups with diabetes. Foot TcPO2 values increased in groups with diabetes and TcPCO2 decreased in all groups with arterial disease. Increased chest TcPO2 and decreased TcPCO2 were demonstrated in the groups with diabetes. Conclusions, Elevations in foot TcPO2 and reductions in TcPCO2 indicate improved cutaneous perfusion response to local heating post-exercise. Elevated toe pressures in the non-diabetes group suggest that improved perfusion may be associated with enhanced lower limb macrovascular haemodynamics. However, improvements in TcPO2 and TcPCO2 at foot and chest sites in diabetes imply a global change in cutaneous perfusion. The results suggest that brief exercise results in an improvement in cutaneous perfusion in non-critical PAOD, particularly in individuals with diabetes. [source] CLINICAL PRACTICE QUESTION Exercise in Type 1 diabetesDIABETIC MEDICINE, Issue 2003I. Gallen First page of article [source] Exercise of royal power in early medieval Europe: the case of Otto the Great 936,73EARLY MEDIEVAL EUROPE, Issue 4 2009David Bachrach Current scholarly orthodoxy holds that the German kingdom under the Ottonians (c.919,1024) did not possess an administration, much less an administrative system that relied heavily upon the ,written word'. It is the contention of this essay that the exercise of royal power under Otto the Great (936,73) relied intrinsically on a substantial royal administrative system that made very considerable use of documents, particularly for the storage of crucial information about royal resources. The focus of this study is on Otto I's use of this written information to exercise royal power in the context of confiscating and requisitioning property from both laymen and ecclesiastical institutions. [source] Ten-Year Echo/Doppler Determination of the Benefits of Aerobic Exercise after the Age of 65 YearsECHOCARDIOGRAPHY, Issue 1 2010Alexander J. Muster M.D. As the human lifespan becomes progressively extended, potential health-related effects of intense aerobic exercise after age 65 need evaluation. This study evaluates the cardiovascular (CV), pulmonary, and metabolic effects of competitive distance running on age-related deterioration in men between 69 (±3) and 77 (±2) years (mean ± SD). Twelve elderly competitive distance runners (ER) underwent oxygen consumption and echo/Doppler treadmill stress testing (Balke protocol) for up to 10 years. Twelve age-matched sedentary controls (SC) with no history of CV disease were similarly tested and the results compared for the initial three series of the study. CV data clearly separated the ER from SC. At entry, resting and maximal heart rate, systolic/diastolic blood pressure, peak oxygen consumption (VO2max), and E/A ratio of mitral inflow were better in the ER (P < 0.05 vs. SC). With aging, ER had a less deterioration of multiple health parameters. Exceptions were VO2max and left ventricular diastolic function (E/A, AFF, IVRT) that decreased (P < 0.05, Year 10 vs. Year 1). Health advantages of high-level aerobic exercise were demonstrated in the ER when compared to SC. Importantly, data collected in ER over 10 years confirm the benefit of intensive exercise for slowing several negative effects of aging. However, the normative drop of exercise capacity in the seventh and eighth decades reduces the potential athleticism plays in prevention of CV events. (Echocardiography 2010;27:5-10) [source] Mortgage Terminations, Heterogeneity and the Exercise of Mortgage OptionsECONOMETRICA, Issue 2 2000Yongheng Deng As applied to the behavior of homeowners with mortgages, option theory predicts that mortgage prepayment or default will be exercised if the call or put option is ,in the money' by some specific amount. Our analysis: tests the extent to which the option approach can explain default and prepayment behavior; evaluates the practical importance of modeling both options simultaneously; and models the unobserved heterogeneity of borrowers in the home mortgage market. The paper presents a unified model of the competing risks of mortgage termination by prepayment and default, considering the two hazards as dependent competing risks that are estimated jointly. It also accounts for the unobserved heterogeneity among borrowers, and estimates the unobserved heterogeneity simultaneously with the parameters and baseline hazards associated with prepayment and default functions. Our results show that the option model, in its most straightforward version, does a good job of explaining default and prepayment, but it is not enough by itself. The simultaneity of the options is very important empirically in explaining behavior. The results also show that there exists significant heterogeneity among mortgage borrowers. Ignoring this heterogeneity results in serious errors in estimating the prepayment behavior of homeowners. [source] The effects of acute exercise on attentional bias towards smoking-related stimuli during temporary abstinence from smokingADDICTION, Issue 11 2009Kate Janse Van Rensburg ABSTRACT Rationale Attentional bias towards smoking-related cues is increased during abstinence and can predict relapse after quitting. Exercise has been found to reduce cigarette cravings and desire to smoke during temporary abstinence and attenuate increased cravings in response to smoking cues. Objective To assess the acute effects of exercise on attentional bias to smoking-related cues during temporary abstinence from smoking. Method In a randomized cross-over design, on separate days regular smokers (n = 20) undertook 15 minutes of exercise (moderate intensity stationary cycling) or passive seating following 15 hours of nicotine abstinence. Attentional bias was measured at baseline and post-treatment. The percentage of dwell time and direction of initial fixation was assessed during the passive viewing of a series of paired smoking and neutral images using an Eyelink II eye-tracking system. Self-reported desire to smoke was recorded at baseline, mid- and post-treatment and post-eye-tracking task. Results There was a significant condition × time interaction for desire to smoke, F(1,18) = 10.67, P = 0.004, eta2 = 0.36, with significantly lower desire to smoke at mid- and post-treatment following the exercise condition. The percentage of dwell time and direction of initial fixations towards smoking images were also reduced significantly following the exercise condition compared with the passive control. Conclusion Findings support previous research that acute exercise reduces desire to smoke. This is the first study to show that exercise appears to also influence the salience and attentional biases towards cigarettes. [source] Haematological and respiratory gas changes in horses and mules exercised at altitude (3800 m)EQUINE VETERINARY JOURNAL, Issue S36 2006H. M. GREENE Summary Reason for performing study: Despite the common use of equids as visitors to high altitude mountainous environments, there are a paucity of carefully orchestrated scientific approaches. Further, again as a function of a common perceived advantage of mules over horses in these similar environments there are needs for controlled comparisons between these 2 equids. Objective: To measure haematological and respiratory function in horses and mules at low altitude (225 m), at rest and post exercise. In addition the rate and magnitude of these changes were followed over a 13 day period at high altitude (3800 m) to contrast acclimatisation. Methods: Resting and exercise venous blood samples (1 min post exercise) were obtained from 6 horses and 5 mules housed at 225 m (LA) and then transported to 3800 m (HA) for 13 days. The standardised exercise tests at both LA and HA consisted of trotting (3.0 m/sec) up an incline (6%) for 2 km. Data were analysed with repeated measures ANOVA (comparison of altitude acclimatisation and species) for changes in haematological and respiratory gases. Results: At low altitude, no group differences were found with both resting (P=0.69) and exercising (P=0.74) heart rates. Resting PCV was 8% lower in the mules (P=0.02) and 20% lower during exercise (P=0.02). Horses had significantly higher 2,3-diphosphoglycerate (2,3-DPG)/g Hb at both rest (P=0.003) and exercise (P=0.03). Exercise at HA increased PCV (P=0.03) in both groups, but the increase was attenuated in the mules compared to horses. The increase with 2,3-DPG/g Hb was expressed at HA in both groups (P=0.001) and was also attenuated in mules (P=0.03). Both groups were alkalotic compared to LA (P=0.001), and there were no group differences (P = 0.95). Conclusion: Of the variables measured, the most notable distinction between species was identified for only PCV and 2,3-DPG with both higher in horses, at both LA and HA. While the attenuated response of PCV in mules for the same exercise might argue for an improved adaptation to altitude, the lower 2,3-DPG might not. Other variables during the exercise bout were not different between species. [source] Exercise training in late middle-aged male Fischer 344 × Brown Norway F1-hybrid rats improves skeletal muscle aerobic functionEXPERIMENTAL PHYSIOLOGY, Issue 7 2008Andrew C. Betik The Fischer 344 × Brown Norway F1-hybrid (F344BN) rat has become an increasingly popular and useful strain for studying age-related declines in skeletal muscle function because this strain lives long enough to experience significant declines in muscle mass. Since exercise is often considered a mechanism to combat age-related declines in muscle function, determining the utility of this strain of rat for studying the effects of exercise on the ageing process is necessary. The purpose of this study was to evaluate the plasticity of skeletal muscle aerobic function in late middle-aged male rats following 7 weeks of treadmill exercise training. Training consisted of 60 min per day, 5 days per week with velocity gradually increasing over the training period according to the capabilities of individual rats. The final 3 weeks involved 2 min high-intensity intervals to increase the training stimulus. We used in situ skeletal muscle aerobic metabolic responses and in vitro assessment of muscle mitochondrial oxidative capacity to describe the adaptations of aerobic function from the training. Training increased running endurance from 11.3 ± 0.6 to 15.5 ± 0.8 min, an improvement of ,60%. Similarly, distal hindlimb muscles from trained rats exhibited a higher maximal oxygen consumption in situ (23.2 ± 1.3 versus 19.7 ± 0.8 ,mol min,1 for trained versus sedentary rats, respectively) and greater citrate synthase and complex IV enzyme activities in gastrocnemius (29 and 19%, respectively) and plantaris muscles (24 and 28%, respectively) compared with age-matched sedentary control animals. Our results demonstrate that skeletal muscles from late middle-aged rats adapt to treadmill exercise by improving skeletal muscle aerobic function and mitochondrial enzyme activities. This rat strain seems suitable for further investigations using exercise as an intervention to combat ageing-related declines of skeletal muscle aerobic function. [source] Exercise Heat Stress does not Reduce Central Activation to non-exercised Human Skeletal MuscleEXPERIMENTAL PHYSIOLOGY, Issue 6 2003Julian Saboisky In this study we measured the central activation ratio (CAR) of the leg extensors and the elbow flexor muscles before and after exhaustive exercise in the heat to determine whether exercise-induced hyperthermia affects the CNS drive to exercised (leg extensors) and/or non-exercised (forearm flexors) muscle groups. Thirteen subjects exercised at fixed intensities representative of a percentage of peak power output (PPO) for 10 min periods (50%, 40%, 60%, 50%) and then at 75% PPO until exhaustion in ambient conditions of 39.3 ± 0.8 °C and 60.0 ± 0.8% relative humidity. Before and immediately following exercise subjects performed a series of maximal voluntary contractions (MVCs) with the leg extensors (exercised muscles) and forearm flexors (non-exercised muscles). The degree of voluntary activation during the sustained MVCs was assessed by superimposing electrical stimulation to the femoral nerve and the biceps brachii. Exercise to exhaustion increased the rectal temperature from 37.2 ± 0.2 to 38.8 ± 0.2 °C (P < 0.0001). The mean heart rate at the end of exercise to exhaustion was 192 ± 3 beats min,1. Leg extensor voluntary force was significantly reduced from 595 ± 143 to 509 ± 105 N following exercise-induced hyperthermia but forearm flexor force was similar before and after exercise. The CAR of the leg extensors decreased from 94.2 ± 1.3% before exercise to 91.7 ± 1.5% (P < 0.02) following exercise-induced hyperthermia. However, the CAR for the forearm flexors remained at similar levels before and after exercise. The data suggest that the central nervous system selectively reduces central activation to specific skeletal muscles as a consequence of exercise-induced hyperthermia. [source] Cerebral Metabolism is Influenced by Muscle Ischaemia During Exercise in HumansEXPERIMENTAL PHYSIOLOGY, Issue 2 2003Mads K. Dalsgaard Maximal exercise reduces the cerebral metabolic ratio (O2/(glucose + 1/2lactate)) to < 4 from a resting value close to 6, and only part of this decrease is explained by the ,intent' to exercise. This study evaluated whether sensory stimulation of brain by muscle ischaemia would reduce the cerebral metabolic ratio. In 10 healthy human subjects the cerebral arterial-venous differences (a-v differences) for O2, glucose and lactate were assessed before, during and after three bouts of 10 min cycling with equal workload: (1) control exercise at light intensity, (2) exercise that elicited a high rating of perceived exertion due to a 100 mmHg thigh cuff, and (3) exercise followed by 5 min of post-exercise muscle ischaemia that increased blood pressure by , 20%. Control exercise did not significantly affect the a-v differences. However, during the recovery from exercise with thigh cuffs the cerebral metabolic ratio decreased from a resting value of 5.4 ± 0.2 to 4.0 ± 0.4 (mean ±s.e.m.. P < 0.05) as a discrete lactate efflux from the brain at rest shifted to a slight uptake. Also, following post-exercise muscle ischaemia, the cerebral metabolic ratio decreased to 4.5 ± 0.3 (P < 0.05). The results support the hypothesis that during exercise, cerebral metabolism is influenced both by the mental effort to exercise and by sensory input from skeletal muscles. [source] EMG and Oxygen Uptake Responses During Slow and Fast Ramp Exercise in HumansEXPERIMENTAL PHYSIOLOGY, Issue 1 2002Barry W. Scheuermann This study examined the relationship between muscle recruitment patterns using surface electromyography (EMG) and the excess O2 uptake (ExV,O2) that accompanies slow (SR, 8 W min,1) but not fast (FR, 64 W min,1) ramp increases in work rate (WR) during exercise on a cycle ergometer. Nine subjects (2 females) participated in this study (25 ± 2 years, ± S.E.M.). EMG was obtained from the vastus lateralis and medialis and analysed in the time (root mean square, RMS) and frequency (median power frequency, MDPF) domain. Results for each muscle were averaged to provide an overall response and expressed relative to a maximal voluntary contraction (%MVC). ,V,O2/,WR was calculated for exercise below (S1) and above (S2) the lactate threshold (LT) using linear regression. The increase in RMS relative to the increase in WR for exercise below the LT (,RMS/,WR-S1) was determined using linear regression. Due to non-linearities in RMS above the LT, ,RMS/,WR-S2 is reported as the difference in RMS (,RMS) and the difference in WR (,WR) at end-exercise and the LT. SR was associated with a higher (P < 0.05) ,V,O2/,WR (S1, 9.3 ± 0.3 ml min,1 W,1; S2, 12.5 ± 0.6 ml min,1 W,1) than FR (S1, 8.5 ± 0.4 ml min,1 W,1; S2, 7.9 ± 0.4 ml min,1 W,1) but a similar ,RMS/,WR-S1 (SR, 0.11 ± 0.01% W,1; FR, 0.10 ± 0.01% W,1). ExV,O2 was greater (P < 0.05) in SR (3.6 ± 0.7 l) than FR (-0.7 ± 0.4 l) but was not associated with a difference in either ,RMS/,WR-S2 (SR, 0.14 ± 0.01% W,1; FR, 15 ± 0.02% W,1) or MDPF (SR, 2.6 ± 5.9%; FR, -15.4 ± 4.5%). The close matching between power output and RMS during SR and FR suggests that the ExV,O2 of heavy exercise is not associated with the recruitment of additional motor units since ExV,O2 was observed during SR only. Compared to the progressive decrease in MDPF observed during FR, the MDPF remained relatively constant during SR suggesting that either (i) there was no appreciable recruitment of the less efficient type II muscle fibres, at least in addition to those recruited initially at the onset of exercise, or (ii) the decrease in MDPF associated with fatigue was offset by the addition of a higher frequency of type II fibres recruited to replace the fatigued motor units. [source] Homoeopathy for Sports, Exercise and DanceFOCUS ON ALTERNATIVE AND COMPLEMENTARY THERAPIES AN EVIDENCE-BASED APPROACH, Issue 3 2000C Stevinson [source] The Invisible (Inaudible) Woman: Nursing in the English AcademyGENDER, WORK & ORGANISATION, Issue 2 2005Liz Meerabeau Nursing is numerically a far larger academic discipline than medicine, and is situated in many more higher education institutions in England (over 50), whereas there are 21 medical schools. Like the rest of ,non medical education and training' it is purchased through a quasi-market. Despite the size of this market, however, nursing education has until recently been largely invisible in policy documents and the ambitions of nursing academics to develop their subject are seen as inappropriate. This article explores this invisibility and inaudibility, with particular reference to the 1997 Richards Report, Clinical Academic Careers and the 2001 Nuffield Trust report, A New Framework for NHS/University Relations. It draws on the work of Davies on the ,professional predicament' of nursing, to argue that, although the move of nursing education into higher education had the aim of improving its status, nursing has difficulty finding its voice within academia. As a result, issues which are salient for nursing (as for many of the health professions), such as a poor (or relatively poor) showing in the Research Assessment Exercise and the complexities of balancing research, teaching and maintaining clinical competence, are raised as high-profile issues only in medicine. [source] Sexual Harassment as an Exercise of PowerGENDER, WORK & ORGANISATION, Issue 1 2001Fiona Wilson This article argues that the key to the explanation as to why sexual harassment is a feature of organizational life lies in the issue of power. Yet there has been little attempt to link sexual harassment with theories or explanatory models of power. This article first takes Lukes's (1986) three-dimensional model as a framework to explore how harassment may be understood as an exercise of power at different levels then shows how radical feminist and post-structuralist analyses overlap with and are distinct from Lukes's third dimension of power. [source] The Impact of Research and Teaching Quality Inputs on the Employment Outcomes of PostgraduatesHIGHER EDUCATION QUARTERLY, Issue 4 2005Peter Urwin In this paper we analyse the extent to which the quality of teaching and research inputs, as measured by Quality Assurance Agency (QAA) and Research Assessment Exercise (RAE) scores, can account for variations in the employability of taught postgraduates. Pooling data from the 1997, 1998 and 1999 First Destinations Surveys we estimate regression equations for male and female UK postgraduates. Our results suggest that the lack of direct financial rewards associated with a higher QAA score may have persuaded many institutions to adopt a ,threshold' approach to Subject Review. However, the impact of RAE score suggests that students in institutions with a stronger research culture do have enhanced levels of employability. This is in line with the strong emphasis on active research input mandated by many professional bodies at the postgraduate level. When considered alongside recent policy pronouncements, this suggests that many institutions choosing to become teaching-only, may ultimately risk becoming undergraduate-only. [source] | ||||||||||||||||||||||||||||||||||||||||||||||