Kevin Currell

..Furthermore, factors such as dehydration and ambient temperature can have a profound effect on the HR-VO(2) relationship...

..Nevertheless, some runners (~10-20%) experienced serious problems, and individualized feeding strategies might be required...

..Therefore, more research is needed in the years to come to give better advice to these young athletes...

..The vast majority of glucose disappearing from the plasma is oxidized and MCR increased markedly with glucose ingestion. Glucose carbon recycling was minimal suggesting that gluconeogenesis in these conditions is negligible...

..Carbohydrate feeding has been shown to be ergogenic, but recently substantial advances have been made in optimizing the guidelines for carbohydrate intake during prolonged exercise...

..It has become clear that the underlying mechanisms for the ergogenic effect during this type of activity are not metabolic but may reside in the central nervous system...

..Furthermore, this study found a very low coefficient of variation (1.1%) for a simulated 16 km time trial...

..Various supplements have been suggested to improve endurance performance, but most of these nutrition supplements lack the scientific support that would warrant the recommendation...

..In addition to these factors adaptation to training, in particular endurance training, will reduce the reliance on carbohydrate metabolism and increase fat oxidation, especially from intramuscular triacylglycerol stores...

....

..Most studies have not found any evidence for a beneficial effect of conjugated linoleic acid...

..abstract:..

..Hyponatraemia has occasionally been reported, especially among slow competitors in triathlons and probably arises due to loss of sodium in sweat coupled with very high intakes (8-10 L) of water or other low-sodium drinks...

..Future research should investigate the causes of the large inter-individual differences in fat metabolism between individuals and their links with various disease states...

..There was a greater loss in body weight with GLU corrected for fluid intake. These data suggest that ingestion of a combined GLU+FRU solution increases GE and "fluid delivery" compared with a glucose only solution...

..For many other supplements, although some show some promise, evidence is lacking. The list of supplements is industry-driven and is likely to grow at a rate that is not matched by a similar increase in scientific underpinning...

..These data suggest that the glycaemic response to ingestion of 75 g of CHO 45 min pre-exercise is similar during exercise of different intensities...

..Depending on the availability of time and financial resources cyclists have to make decisions about how to achieve their performance improvements. The data presented here may provide a guideline to help make such decisions...

..It is possible that when large amounts of glucose are ingested absorption is a limiting factor, and the liver will retain some glucose and thus act as a second limiting factor to exogenous CHO oxidation...

..Regulation of skeletal muscle fat metabolism is clearly multifactorial, and different mechanisms may dominate in different conditions...

..Here I provide a comprehensive overview of recent research findings and suggest several new guidelines for the endurance athlete on the basis of this. These guidelines are more detailed and allow a more individualized approach...

..Recently, several studies have tried to clarify this relationship. Here the effects of acute fat on metabolism and performance will be discussed, as well as the effects of short-term and long-term high-fat diets...

..It is therefore concluded that LPS does enter the circulation after ultra-endurance exercise and may, together with muscle damage, be responsible for the increased cytokine response and hence GI complaints in these athletes...

..There is considerable confusion regarding pre-exercise carbohydrate feeding with advice that ranges from 'consume carbohydrate in the hour before exercise' to 'avoid carbohydrate in the 60 min prior to exercise'...

..The ingestion of Glu+Fru increases CHO(Exo) compared with the ingestion of Glu alone, potentially through the oxidation of CHO(Exo) in the liver or through the conversion to, and oxidation of, lactate...

..Ingestion of GLU+FRUC during exercise in the heat resulted in higher exogenous CHO oxidation rates and fluid availability compared with ingestion of GLU and reduced endogenous CHO oxidation compared with ingestion of WAT...

..The aim of the present study was to investigate the effect of ingesting a glucose plus fructose drink compared with a glucose-only drink (both delivering carbohydrate at a rate of 1.8 g.min(-1)) and a water placebo on endurance performance...

..Therefore we can conclude that prior glycogen depletion does produce a reliable measure of performance with metabolic characteristics similar to ultraendurance exercise...

..075). The present results demonstrate that, when fructose and glucose are ingested simultaneously at high rates during cycling exercise, exogenous carbohydrate oxidation rates can reach peak values of approximately 1.3 g/min...

..Green tea consumption is reportedly associated with various health-promoting properties. For example, it has been shown to promote fat oxidation in humans at rest and to prevent obesity and improve insulin sensitivity in mice...

..5 g.min, and this is markedly higher than oxidation rates from ingesting maltodextrin alone...

..A lower CHO delivery and a small difference in plasma insulin may have resulted in higher endogenous CHO use and higher fat oxidation during the ISO trial than during the SUC trial...

..Hypoglycaemia was observed in some subjects during the first 10 min but this did not affect performance...

..087 and P = 0.082, respectively). These results demonstrate that the oxidation rate of ingested CHO is reduced and muscle glycogen utilization is increased during exercise in the heat compared with a cool environment...

..CONCLUSION: The finding was that 2.5 mg.kg(-1) bw pseudoephedrine ingested 90 min preexercise improves 1500-m running performance...

..In conclusion, exogenous carbohydrate, independent of sweetness, improves exercise capacity in the heat compared to water alone...

..12 +/- 0.37 g/min for Wat). In conclusion, compared with glucose alone, 5 mg x kg(-1) x h(-1) of caffeine coingested with glucose increases exogenous CHO oxidation, possibly as a result of an enhanced intestinal absorption...

..The results demonstrate that when a mixture of glucose and fructose is ingested at high rates (2.4 g/min) during 150 min of cycling exercise, exogenous CHO oxidation rates reach peak values of approximately 1.75 g/min...

..Maximal fat oxidation was 28% higher when walking compared with cycling, but the intensity, which elicits maximal fat oxidation, is not different between these 2 exercise modes...

..Combined ingestion of protein and carbohydrate improves net protein balance at rest as well as during exercise and postexercise recovery...

..05) when CHO was ingested compared with placebo. In conclusion, the protocol is a reliable test of soccer performance, and ingesting CHO leads to an improvement in soccer performance...

....

..To evaluate the efficacy of using combined glucose and fructose (GF) ingestion as a means to stimulate short-term (4 h) postexercise muscle glycogen synthesis compared to glucose only (G)...

..8 g.kg.h) substantially augments insulin secretion, but does not affect plasma glucose disposal during the first 3.5 h of postexercise recovery in trained athletes...

..These results demonstrate that, when a mixture of glucose and sucrose is ingested at high rates (1.8 g/min) during cycling exercise, exogenous CHO oxidation rates reach peak values of approximately 1.25 g/min...

..In contrast, the real effect of CHO intake was a 10.6% improvement in TT cycling performance...

..CONCLUSION: The results demonstrate that glucose infusion had no effect on 1-h cycle time-trial performance, despite an increased availability of plasma glucose for oxidation and evidence of increased glucose uptake into the tissues...

....

..Furthermore, when a mixture of glucose and sucrose was ingested at high rates (2.4 g/min), exogenous CHO oxidation rates reached peak values of approximately 1.20 g/min...

..These data suggest that a 12.5% carbohydrate beverage containing glucose and fructose results in more rapid fluid delivery in the first 75 min than a beverage containing glucose alone...

..05). In conclusion, the ingestion of 75 g of carbohydrate 45 min before the onset of exercise decreased Fatmax by 14%, while the maximal rate of fat oxidation decreased by 28%...

..Fat oxidation rates are high over a large range of intensities; however, at exercise intensities above Fat(max), fat oxidation rates drop markedly...

..We will also discuss some of the potential mechanisms that are thought to link obesity and physical inactivity with the major pathophysiological precursor of T2DM, insulin resistance...

..Furthermore, we examined the effects of coingesting protein with CHO during exercise on postexercise markers of sarcolemmal disruption and the recovery of muscle function...

..Beta-alanine and bicarbonate may be useful as buffering agents in longer sprints. Creatine may be efficacious for increasing muscle mass and strength and perhaps increasing intensity of repeat sprint performance during training...

....

..In the absence of a clear metabolic explanation, a central effect involving an increased tolerance of rising deep body temperature merits further investigation...

....

..Fat oxidation rates have been shown to decrease after ingestion of high-fat diets, partly as a result of decreased glycogen stores and partly because of adaptations at the muscle level...

..7+/-0.4 vs. 3.8 +/- 0.5, respectively). The present results suggest that insulin sensitivity does not play an important role in the occurrence of rebound hypoglycemia...

..70 +/- 0.08 and 0.65 +/- 0.06 g/min, respectively). The present investigation suggests that the metabolic response to CHO ingestion during exercise is largely similar in men and women...

....

..Physical activity, Vo(2 max), and gender explained only 12% of the interindividual variation in MFO during exercise, whereas body fatness was not a predictor. The interindividual variation in fat oxidation remains largely unexplained...

..A quantitative value of sensitivity may be accomplished through the signal : noise ratio, where the signal is the percentage improvement in performance and the noise is the CV...

..Furthermore, intestinal glucose absorption may also be a rate-limiting factor for muscle glycogen synthesis when large quantities (>1 g/min) of glucose are ingested following exercise...

..Carbohydrate mouth rinsing does not improve time-trial performance when exercise is performed in a practical, postprandial setting...

..4 g x min(-1)) during cycling exercise, exogenous CHO oxidation rates can reach peak values of approximately 1.7 g x min(-1) and estimated endogenous CHO oxidation is reduced compared with the ingestion of an isocaloric amount of glucose...

..Finally, although an exercise-induced increase in the plasma IL-6 concentration was observed, this effect was independent of pre-exercise CHO ingestion...

..The purpose of the present study was to determine whether combined ingestion of moderate amounts of glucose plus fructose would result in higher rates of exogenous CHO oxidation compared with an isocaloric amount of glucose alone...

..Use of CE solutions formulated to minimize erosion during exercise may provide significant dental benefits...

..05). This study provides further evidence that the postprandial fall in ghrelin might be due, at least partially, to the rise in insulin and that high-frequency feeding may disrupt this relationship...

..8 +/- 0.1 vs. 4.7 +/- 0.1 vs. 4.7 +/- 0.1, respectively). These results demonstrate that there are no acute and short-term effects of VS administration on insulin sensitivity in healthy humans...

..These findings indicate that a state of overreaching can already be induced after 7 days of intensified training with limited recovery...

..Given the prevalence of stage racing in professional cycling, more research into the influence of nutrition on repeated bouts of exercise performance and training is required...

..The purpose of this study was to examine the role of branched-chain amino acid (BCAA) supplementation during recovery from intense eccentric exercise...

..The nature and role of putative CHO receptors in the mouth warrants further investigation...

..The available scientific and anecdotal evidence supports the existence of the overtraining syndrome; however, more research is required to state with certainty that the syndrome exists...

....

..To compare the effects of high (HMW) versus low molecular weight (LMW) glucose polymer solutions on the pattern of substrate oxidation during exercise...

..Whereas NaHCO3 ingestion increased fat oxidation, a similar response did not occur following NaAc ingestion despite the fact both sodium salts induced a similar increase in energy expenditure and shift in acid-base balance...

..Decreased endocrine responsiveness to exercise may be implicated in the decreased performance and increased mood disturbance characteristic of overreaching...

....

..The effect of different quantities of carbohydrate (CHO) intake on CHO metabolism during prolonged exercise was examined in endurance-trained females...

..These results suggest a possible mechanism for the increased incidence of infection reported during chronic exercise training via modulation of type 1/type 2 T lymphocyte distribution...

..These results demonstrate that TLR function is subject to modulation under physiological conditions in vivo and provide evidence for the role of immunomodulatory hormones in the regulation of TLR function...

..8-45.8%). The exercise study showed the Oxycon Pro and Oxycon Alpha to be both valid and reliable on-line systems for the measurement of parameters of respiration, at least at workloads up to 150 W...