Ketosis, the metabolic response to energy crisis, is a mechanism to sustain life by altering oxidative fuel selection. Often overlooked for its metabolic potential, ketosis is poorly understood outside of starvation or diabetic crisis. Thus, we studied the biochemical advantages of ketosis in humans using a ketone ester-based form of nutrition without the unwanted milieu of endogenous ketone body production by caloric or carbohydrate restriction. In five separate studies of 39 high-performance athletes, we show how this unique metabolic state improves physical endurance by altering fuel competition for oxidative respiration. Ketosis decreased muscle glycolysis and plasma lactate concentrations, while providing an alternative substrate for oxidative phosphorylation. Ketosis increased intramuscular triacylglycerol oxidation during exercise, even in the presence of normal muscle glycogen, co-ingested carbohydrate and elevated insulin. These findings may hold clues to greater human potential and a better understanding of fuel metabolism in health and disease.

Accounts of prison life consistently describe a culture of mutual mistrust, fear, aggression and barely submerged violence. Often too, they explain how prisoners adapt to this environment—in men’s prisons, at least—by putting on emotional ‘masks’ or ‘fronts’ of masculine bravado which hide their vulnerabilities and deter the aggression of their peers. This article does not contest the truth of such descriptions, but argues that they provide a partial account of the prison’s emotional world. Most importantly, for current purposes, they fail to describe the way in which prisons have a distinctive kind of emotional geography, with zones in which certain kinds of emotional feelings and displays are more or less acceptable. In this article, we argue that these ‘emotion zones’, which cannot be characterized either as ‘frontstage’ or ‘backstage’ domains, enable the display of a wider range of feelings than elsewhere in the prison. Their existence represents a challenge to depictions of prisons as environments that are unwaveringly sterile, unfailingly aggressive or emotionally undifferentiated

Acute ingestion of dietary nitrate may not represent an effective strategy for reducing the oxygen cost of submaximal exercise or for enhancing endurance exercise performance in highly trained cross-country skiers.

It is recognized that exercise produces abnormally large increases in pulmonary artery pressure in patients with pulmonary vascular disease as a consequence of a variety of disorders, but the relationship between pressure and cardiopulmonary exercise performance is poorly understood. This lack of understanding is due (in part) to difficulty making measurements of pulmonary haemodynamics using conventional fluid filled catheters. This article seeks to improve understanding by comparing variables measured during formal exercise testing with simultaneous measurements of pulmonary artery pressure using a micro-manometer tipped catheter.Ten patients with suspected pulmonary hypertension were studied using a micromanometer tipped pulmonary artery catheter, during cardiopulmonary exercise testing.Ventilatory equivalents for oxygen and carbon dioxide correlated with the pulmonary artery pressure measured on exercise, but oxygen pulse and oxygen uptake did not. Ventilatory equivalents, noninvasively measured during exercise, may merit further study as potential surrogates of pulmonary artery pressure and hence be useful in identifying individuals at risk of developing pulmonary hypertension. Eur Respir J 2000; 16: 282±287.