The maximal metabolic steady state: redefining the ‘gold standard’

The maximal lactate steady state (MLSS) and the critical power (CP) are two widely used indices of the highest oxidative metabolic rate that can be sustained during continuous exercise and are often considered to be synonymous. However, while perhaps having similarities in principle, methodological differences in the assessment of these parameters typically result in MLSS occurring at a somewhat lower power output or running speed and exercise at CP being sustainable for no more than approximately 20–30 min. This has led to the view that CP overestimates the ‘actual’ maximal metabolic steady state and that MLSS should be considered the ‘gold standard’ metric for the evaluation of endurance exercise capacity. In this article we will present evidence consistent with the contrary conclusion: i.e., that (1) as presently defined, MLSS naturally underestimates the actual maximal metabolic steady state; and (2) CP alone represents the boundary between discrete exercise intensity domains within which the dynamic cardiorespiratory and muscle metabolic responses to exercise differ profoundly. While both MLSS and CP may have relevance for athletic training and performance, we urge that the distinction between the two concepts/metrics be better appreciated and that comparisons between MLSS and CP, undertaken in the mistaken belief that they are theoretically synonymous, is discontinued. CP represents the genuine boundary separating exercise in which physiological homeostasis can be maintained from exercise in which it cannot, and should be considered the gold standard when the goal is to determine the maximal metabolic steady state

Critical Power: An Important Fatigue Threshold in Exercise Physiology

The hyperbolic form of the power-duration relationship is rigorous and highly conserved across species, forms of exercise and individual muscles/muscle groups. For modalities such as cycling, the relationship resolves to two parameters, the asymptote for power (critical power, CP) and the so-called W' (work doable above CP), which together predict the tolerable duration of exercise above CP. Crucially, the CP concept integrates sentinel physiological profiles - respiratory, metabolic and contractile - within a coherent framework that has great scientific and practical utility. Rather than calibrating equivalent exercise intensities relative to metabolically distant parameters such as the lactate threshold or V[spacing dot above]O2 max, setting the exercise intensity relative to CP unifies the profile of systemic and intramuscular responses and, if greater than CP, predicts the tolerable duration of exercise until W' is expended, V[spacing dot above]O2 max is attained, and intolerance is manifested. CP may be regarded as a 'fatigue threshold' in the sense that it separates exercise intensity domains within which the physiological responses to exercise can (CP) be stabilized. The CP concept therefore enables important insights into 1) the principal loci of fatigue development (central vs. peripheral) at different intensities of exercise, and 2) mechanisms of cardiovascular and metabolic control and their modulation by factors such as O2 delivery. Practically, the CP concept has great potential application in optimizing athletic training programs and performance as well as improving the life quality for individuals enduring chronic disease

‘‘Beet-ing’’ the Mountain: A Review of the Physiological and Performance Effects of Dietary Nitrate Supplementation at Simulated and Terrestrial Altitude

Exposure to altitude results in multiple physiological consequences. These include, but are not limited to, a reduced maximal oxygen consumption, drop in arterial oxygen saturation, and increase in muscle metabolic perturbations at a fixed sub-maximal work rate. Exercise capacity during fixed work rate or incremental exercise and time-trial performance are also impaired at altitude relative to sea-level. Recently, dietary nitrate (NO3-) supplementation has attracted considerable interest as a nutritional aid during altitude exposure. In this review, we summarise and critically evaluate the physiological and performance effects of dietary NO3- supplementation during exposure to simulated and terrestrial altitude. Previous investigations at simulated altitude indicate that NO3- supplementation may reduce the oxygen cost of exercise, elevate arterial and tissue oxygen saturation, improve muscle metabolic function, and enhance exercise capacity/ performance. Conversely, current evidence suggests that NO3- supplementation does not augment the training response at simulated altitude. Few studies have evaluated the effects of NO3- at terrestrial altitude. Current evidence indicates potential improvements in endothelial function at terrestrial altitude following NO3- supplementation. No effects of NO3- supplementation have been observed on oxygen consumption or arterial oxygen saturation at terrestrial altitude, although further research is warranted. Limitations of the present body of literature are discussed, and directions for future research are provided

A multi-criteria decision analysis assessment of waste paper management options

The use of Multi-criteria Decision Analysis (MCDA) was investigated in an exercise using a panel of local residents and stakeholders to assess the options for managing waste paper on the Isle of Wight. Seven recycling, recovery and disposal options were considered by the panel who evaluated each option against seven environmental, financial and social criteria. The panel preferred options where the waste was managed on the island with gasification and recycling achieving the highest scores. Exporting the waste to the English mainland for incineration or landfill proved to be the least preferred options. This research has demonstrated that MCDA is an effective way of involving community groups in waste management decision making

The history of the english language : a source book

About the BookThis second edition of The History of the English Language- A Sourcebook provides a comprehensive and accessible guide to the origins and development of the English language. First published in 1992, the book contains over fifty illustrative passages, drawn from the oldest English to the twentieth century. The passages are contextualised by individual introductions and grouped into the traditional periods of Old English, Early Middle English, Later Middle English, Early Modern English and Modern English. These periods are connected by brief essays explaining the major linguistic developments associated with each period, to produce a continuous outline history.For this new edition Professor Burnley has expanded the outline of linguistic features at each of the main chronological divisions and included more selections and illustrations. A new section has also been included to illustrate the language of advertising from the 18th century to the present. The book will be of general interest to all those interested in the origins and development of the English language, and in particular to students and teachers of the history of the English language at A-level and university. For more information:https://goo.gl/GF0WzBxxii, 418 p.; 24 c

The Auchinleck Manuscript

The Auchinleck Manuscript (NLS Adv MS 19.2.1) is one of the National Library of Scotland’s greatest treasures. Produced in London in the 1330s, it provides a unique insight into the English language and literature that Chaucer and his generation grew up with and were influenced by. It acquired its name from its first known owner, Lord Auchinleck, who discovered the manuscript in 1740 and donated it to the precursor of the National Library in 1744. Among the features offered by this site are: - A full transcription of the manuscript with sophisticated search facilities. - A digital facsimile of the entire manuscript. - Background information on the origins and importance of the manuscript. This edition was co-edited by Professor David Burnley and Dr Alison Wiggins