Syfte och frågeställningar Syftet med denna litteraturstudie är att undersöka om det finns stöd i nuvarande forskning för att en fettrik kost är mer effektiv som nutritionsstrategi vid uthållighetsprestationer jämfört med en kolhydratrik kost. Studiens frågeställningar är: Förbättras uthållighetsprestationen av en fettrik kost jämfört med en kolhydratrik kost? Hur påverkas kolhydrat- och fettmetabolismen av en högfett- och lågkolhydratkost? Metod Litteratursökningen genomfördes i databaserna Ebsco, Pubmed och Cinahl. Totalt inkluderades 16 artiklar, 11 artiklar från litteratursökningen i databaserna och 5 artiklar från valda referenslistor. Studierna kvalitetsgranskades med hjälp av SBU:s granskningsmall för randomiserade kontrollerade studier. Resultat I 3 av 16 studier förbättrades uthållighetprestationen vid intag av högfett- och lågkolhydratkost, i 4 av 16 studier försämrades prestationen och i resterande 9 studier sågs ingen signifikant skillnad i prestationen mellan kostinterventionerna. Majoriteten av studierna fick en förhöjd fettoxidation som resultat av en högfett- och lågkolhydratkost men ingen signifikant skillnad gällande blodglukos-, blodinsulin- eller blodlaktatvärde mellan kostinterventionerna. Slutsats Trots en förhöjd fettoxidation och välfyllda glykogenlager finns inte tillräcklig evidens för att påvisa en generell prestationshöjning vid uthållighetsprestationer av en högfettkost jämfört med en högkolhydratkost. Detta troligtvis på grund av nedsatt förmåga hos musklerna att använda glykogen. Resultaten från de studier som ingick i denna systematiska litteraturstudie visar konsekvent en försämrad prestation efter intag av högfett- och lågkolhydratkost vid arbetsintensiteter över 80% av VO2max. Vid arbetsintensiteter omkring 60-70% av VO2max kan prestationen eventuellt förbättras efter intag av högfettkost bestående av 60-70% fett och mindre än 15% kolhydrater. / Aim The purpose of this study is to investigate whether there is scientific evidence that a high fat diet is more effective as a nutrition strategy for endurance performance than a high carbohydrate diet is. The objectives of the study are: Does endurance performance improve by a high fat diet compared by a high carbohydrate diet? How is the metabolism of fat and carbohydrate affected by a high fat and low carbohydrate diet? Method The literature search was conducted in the databases Ebsco, Pubmed and Cinahl. A total of 16 studies was included, 11 studies from the literature search and 5 studies from selected reference lists. The studies quality was audited by SBU: s questionnaire for randomized controlled studies. Results Endurance performance was enhanced after ingesting a high fat- and low carbohydrate diet in 3 of 16 studies and was decreased in 4 of 16 studies. In the remaining 9 studies there was no significant difference in performance between the two trials. A high fat- and low carbohydrate diet resulted in an increased fat oxidation in the majority of the studies but there was no significant difference in bloodglucose-, blodinsulin- or blodlactatelevels between the two trials. Conclusions Despite increased fat oxidation and well-filled glycogen levels there is not sufficient evidence to prove that endurance performance will be enhanced by a high fat diet compared to a high carbohydrate diet. This is probably because of a lower ability of the muscles to use glycogen. The results from this systematic review consequently shows a decreased performance after a high fat- and low carbohydrate diet at work intensities over 80% of VO2max. At intensities around 60-70% of VO2max, the performance can possibly be enhanced after a high fat diet consisting 60-70% of fat and 15% or lower of carbohydrate.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2002. / Härtill 4 uppsatser.

En combinant l’expertise du Cermav dans la conception de films minces de très haute résolution obtenus par auto-assemblage de glycopolymères biosourcés et le savoir-faire du LETI sur les procédés de lithographie innovante, l’objectif de ce projet de thèse est d’évaluer ces nouveaux copolymères biosourcés -associant des oligosaccharides- comme solution alternative pour la nano lithographie de demain. En effet, ces dernières années l’équipe de « Physico-chimie des glycopolymères » du Cermav dirigée par R. Borsali a développé une nouvelle classe de glycopolymères (type PS-Maltoheptaose, PCL-Maltoheptaose, Xyloglycan-PSSI) pouvant s’auto-organisér avec une résolution de 5nm, dépassant ainsi largement la résolution atteinte aujourd’hui par les seuls copolymères à blocs issus du pétrole type PS-PMMA (20nm). En parallèle, durant les deux dernières années, le Cea/Leti a validé le potentiel des procédés basés sur l’auto assemblage des copolymères à bloc type PS-b-PMMA (résolution 20nm) comme solution alternative aux techniques de lithographie actuelles. Ces résultats positionnent le Cea/Leti dans l’état de l’art international et constituent une bonne base pour intégrer, dans le domaine de la nano-electronique, de nouveau systèmes à plus forte résolution (<10nm), tels que ceux développés par le Cermav. Le travail de thèse proposé se déroulera en trois temps : – Dans un premier temps le candidat adressera la synthèse et la caractérisation de nouveaux copolymères à blocks hybrides associant des oligosaccharides. – Ensuite il va d’intéressé à l’élaboration de glycofilms nano-organisés ainsi que à l’identification des facteurs importants jouant sur la nano-organisation. – Et finalement le contrôle de l’organisation à l’échelle nanométrique par grapho-épitaxie pour des applications lithographiques sera adressé. Deux applications seront visées : le contact et la ligne (phases cylindriques et lamellaires). La compatibilité du procès avec les contraintes de la micro-électronique sera également détaillée. / Combining the Cermav expertise in the thin films design with very high resolution obtained by self-assembly of glycopolymers biobased and the know-how of LETI on innovative lithography processes, the objective of this thesis is to evaluate these new bio-based copolymers, combining-oligosaccharides as an alternative for nano lithography tomorrow. Indeed, in recent years the team of "Physical Chemistry of glycopolymers" of Cermav directed by R. Borsali has developed a new class of glycopolymers (PS-maltoheptaose, PCL-maltoheptaose, Xyloglycan-PSSI) can self-organize with a resolution of 5 nm, far surpassing the resolution reached today only by block copolymers from Oil PS-PMMA (20 nm). In parallel, during the last two years, Cea / Leti has validated the potential methods based on self-assembly of block copolymers PS-b-PMMA (20 nm resolution) as an alternative to the current lithography techniques. These results position the Cea / Leti in the international state of the art and provide a good basis for integration in the field of nano-electronics, new systems with higher resolution (<10 nm) as those developed by the Cermav. The proposed thesis work will take place in three stages: - First time candidate address the synthesis and characterization of new copolymers blocks combining hybrid oligosaccharides. - Then he's going to be interested in the development of nano-glycofilms organized as well as to identify important factors playing on the nano-organization. - And finally the control of the organization at the nanoscale by grapho-epitaxy for lithographic applications will be addressed. Two applications are described: the contact line (cylindrical and lamellar phases). Compatibility constraints trial microelectronics will also be detailed.

Research data indicates a persistence of elevated muscle glycogen concentration 3 days post-supercompensation in resting athletes. This study expands our earlier findings by determining whether muscle glycogen remains elevated 3, 5, or 7 days post-supercompensation. Seventeen trained male cyclists underwent one bout of exhaustive exercise to deplete muscle glycogen. This was followed by a 3-day consumption of a high carbohydrate/low protein/low fat diet (85:08:07%). Three post-loading phases followed with subjects randomly assigned to either a 3-day, 5-day, or 7-day post-loading maintenance diet of 60% carbohydrate and limited physical activity. Biopsies (50-150 mg) of the vastus lateralis were obtained pre-load (BASELINE), at peak-load (PEAK), and either at 3-day, 5-day, or 7-day post-load (POST). On average, PEAK to POST muscle glycogen concentrations decreased 34, 20 and 46% respectively for the 3-, 5-, and 7-day POST groups. Only the 7-day post-load group's PEAK to POST mean muscle glycogen concentration decreased significantly. In addition, multi-regression analysis indicated that the PEAK glycogen level was the main determinant of the number of days that glycogen levels remained significantly greater than BASELINE. Thus, trained athletes-supercompensated glycogen levels can remain higher than normal for up to 5 days post-loading. The amount of carbohydrate consumed, the level of physical activity, and the magnitude of the glycogen supercompensation determine the interval for which the glycogen levels are elevated.

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Digitized by Kansas Correctional Industries

Physical inactivity is a major risk factor for chronic disease; yet the majority of the population does not meet physical activity recommendations, with fatigue being a primary underlying reason. Common nutritional supplements such as caffeine (CAF) and carbohydrate (CHO) are frequently taken prior to and during exercise and can delay fatigue, particularly in trained athletes; but, whether these same reductions in fatigue translate to habitually sedentary individuals is less clear. The main goal of this research was to investigate the influence of nutritional aids: CAF, low-calorie CHO, and their combination CAF+CHO to delay physical and mental fatigue in healthy but sedentary men and women compared to endurance-trained counterparts. The minimum amount of CHO that could elicit a benefit without eliciting a metabolic response when ingested remains unclear. Thus, our first aim was to evaluate glycemic response after ingestion of CHO drinks ranging from 0-6% CHO; and, to determine effects of two methods of CHO administration (ingest and oral rinse without ingestion) on sustained attention during a mentally fatiguing cognitive task. In agreement with evidence that “low calorie beverages” do not appear to alter blood glucose, a 0.4% CHO solution (<2 g CHO) elicited the most similar response to artificially sweetened placebo and was evaluated further. Compared to oral rinse of a small amount (<2 g) of CHO or control (0 g CHO), ingestion of an equivalent “dose” (<2 g CHO) in the 0.4% CHO solution maintained sustained attention, providing evidence that ingesting a low-CHO drink may be more effective than simply rinsing, in a fasted state. Oral rinse of CHO did not, however, provide any benefit compared to rinsing a control solution. Our second aim was to evaluate the efficacy of ingesting a moderate dose of CAF (3 mg/kg), low-CHO, and the combination of CAF+CHO on exercise capacity in trained (ET) versus sedentary (SED) groups. As expected, CAF reduced perceived effort during exercise and increased endurance capacity (longer total time to volitional fatigue and longer duration before rating vigorous intensity exercise as “very hard”), for ET and SED. However, addition of <2 g CHO did not provide further improvement with CAF; or any benefit when ingested alone, compared to placebo. CAF and CHO did not influence blood glucose but CAF resulted in higher blood lactate compared to no-CAF. As expected, ET had higher fat oxidation than SED; and, CAF increased CHO oxidation but not fat oxidation. CAF tended to maintain maximal voluntary contractile (MVC) strength in the quadriceps after exercise; but, CAF did not influence voluntary muscle activation or appear to have a direct effect on skeletal muscle since electrically evoked strength was not altered with CAF. Since acute exercise also benefits cognition independent of CAF or CHO, our third aim was to determine: (1) the effect of moderate intensity exercise (MOD-EX) on sustained attention in comparison to seated rest; and 2) whether CAF provides additional benefit to sustained attention and perceptual measures when combined with exercise. As expected, compared to an equivalent duration of rest, MOD-EX improved sustained attention following mental fatigue in both groups; and, when coupled with CAF, provided greater benefit to sustained attention and perceived mental energy. Although CAF’s beneficial effect on sustained attention persisted after exercise to volitional fatigue, it did not improve perceptual measures of reduced mental energy and increased mental fatigue at the point of physical fatigue. Our research investigated nutritional aids that are not only beneficial for athletes, but also widely consumed by the general population despite their lack of regular physical activity. In response to public health recommendations for reducing sugar intake, low-sugar/low-calorie drinks have been heavily marketed to the population despite much research to support their efficacy. Our findings suggest that low-CHO can be ergogenic during a sedentary mental task in a fasted state, perhaps through central mechanisms. Although CHO mouth rinse is evidenced to be efficacious for exercise performance without ingestion, we did not find that ingestion of low-CHO provides any significant benefit during moderate to vigorous exercise following a small meal. However, a moderate dose of CAF was ergogenic for both ET and SED. Future work should not only investigate additional exercise interventions; but also different CHO and CAF doses and administration protocols, and their relative metabolic implications.