Search Results
Results 651 - 700 of 816
< 7 8 9 10 11 12 13 14 15 16 17 >
Green H J - - 1987
To examine the significance of endogenous stores of glycogen in specific fiber types (I, IIa, IIb) of the costal region of the diaphragm, adult male Wistar rats performed continuous running (25 m/min, 8 degrees grade) exercise for either 30 min or until fatigue. At 30 min of exercise, glycogen loss, ...
Ahlborg G - - 1987
The effect on exercising muscle metabolism of prior ingestion of 200 g glucose was examined in six healthy subjects during 40 min leg exercise at 30% of maximal oxygen uptake. Leg glucose uptake during exercise was on average two- to three-fold higher after glucose (E + G) compared to exercise ...
Green H J - - 1987
Blood and muscle substrates and metabolites were investigated in six healthy males (ranging in age from 19 to 23 yr) during three consecutive days of supramaximal exercise training. Muscle biopsies from the vastus lateralis and arterialized blood samples from a hand vein were extracted before the exercise and at selected ...
Ianuzzo C D - - 1987
Some controversy exists in the literature as to whether or not diaphragmatic glycogen is utilized during exercise. In this study male Sprague-Dawley rats were used to determine whether prolonged treadmill exercise would result in a significant reduction of glycogen concentration in the respiratory muscles. Untrained rats were run to exhaustion ...
Ivey P A - - 1987
Male and female Wistar rats were run for 5 min at 1.7 mph at a 17% grade to determine whether a sex difference exists in the rate of glycogen resynthesis during recovery in fast-twitch red muscle, fast-twitch white muscle, and liver. Rats were killed at one of three time points: ...
Challiss R A - - 1987
A method is presented which allows simultaneous estimation of rates of glycogen synthesis and glycogenolysis in an isolated incubated skeletal muscle, thus allowing measurement of the glycogen/glucose-1-phosphate substrate cycling rate. In the absence of hormonal additions, the measured rates of glycogen synthesis and breakdown were similar [respectively, 0.54 +/- 0.12 ...
Hargreaves M - - 1987
Six men were studied to compare the effects of pre-exercise carbohydrate feedings on endurance performance and muscle glycogen utilization during prolonged exercise. Trials consisted of a cycling ride to exhaustion at 75% maximal oxygen uptake preceded by the ingestion of either 75 g of glucose in 350 ml of water ...
Plyley M J - - 1987
The effects of 64 h of sleep deprivation upon cardiorespiratory function was studied in 11 young men (VO2max = 55.5 ml kg-1 min-1, STPD). Six subjects engaged in normal sedentary activities, while the others walked on a treadmill at 28% VO2max for one hour in every three; eight weeks later, ...
Biasioli S - - 1987
In 21 uraemic subjects not yet requiring dialysis, the serum values of citrate, fumarate, oxalacetate and malate were significantly increased, so that the sum of the concentrations of the TCA-cycle intermediates were increased threefold compared to that of 18 control subjects. The replenishment of TCA intermediates could, in theory, occur ...
Nichols J F - - 1987
Senescent hamsters display a marked reduction in volume of voluntary running. The purpose of this study was to determine whether age differences exist in the pattern of fuel utilization during submaximal exercise, which may account for the reduction in voluntary running. Further, we determined the effects of age on muscle ...
Conlee R K - - 1987
In athletics, muscle and liver glycogen content is critical to endurance. This study compared the effectiveness of glucose and fructose feeding on restoring glycogen content after glycogen was decreased by exercise (90-min swim) or fasting (24 h). After 2 h of recovery from either exercise or fasting there was no ...
Lavoie J M - - 1987
The effects of supramaximal exercise on blood glucose, insulin, and catecholamine responses were examined in 7 healthy male physical education students (mean +/- SD: age = 21 +/- 1.2 years; VO2max = 54 +/- 6 ml X kg-1 X min-1) in response to the following three dietary conditions: a normal ...
Conlee R K - - 1987
The scientific revelations of 1967 regarding the relationship between glycogen and exercise endurance set in motion two decades of research mostly oriented toward the practical application of those early findings. It is surprising that, in spite of the considerable time that has elapsed between those initial studies and the wealth ...
Braakhekke J P - - 1986
Three patients with McArdle's disease exercised for 2 h at 30% VO2max. During exercise two phases occurred. During the first 15 min they experienced progressive fatigue and weakness of exercised muscles, with a rapid and complete recovery (adaptation phase). Following this, all 3 patients were able to continue exercise without ...
Valberg S - - 1986
The glycogen depletion patterns in the gluteus muscle of Standardbred horses were studied under different trotting intensities. After racing significant glycogen depletion was found in all Type I and IIA fibres and in a varying percentage of Type IIB fibres, depending on the individual horse. When horses performed exercise over ...
Aoyama H - - 1986
Changes in the amount of hippurate synthesized and excreted in the urine after 1.5 gm benzoate loading (intravenous hippuric acid test [HAT]) in patients with liver disease before surgery were studied in relation to arterial blood ketone body ratio (acetoacetate/beta-hydroxybutyrate) (BKBR), reflecting energy status of the liver. In these patients, ...
Dohm G L - - 1986
Fasting before exercise increases fat utilization and lowers the rate of muscle glycogen depletion. Since a 24-h fast also depletes liver glycogen, we were interested in blood glucose homeostasis during exercise after fasting. An experiment was conducted with human subjects to determine the effect of fasting on blood metabolite concentrations ...
Marker J C - - 1986
To determine the role of epinephrine in glycogenolysis during high-intensity exercise, rats were adrenodemedullated (ADM) or sham operated (SHAM) and run for either 30 min at 38 m/min or for 5 min at 27, 38, or 48 m/min up a 15% grade. At the end of exercise the rats were ...
Guezennec C Y - - 1986
An investigation was made into the effects of physical exercise upon heart glycogen change in rats exposed to decreased barometric pressure in hypobaric chamber simulating the effects of 3,000 m and 5,000 m altitude. Blood and cardiac tissue samples were examined after 1 h and 5 h of treadmill running ...
Saitoh S - - 1986
The effects of fructose (F), a glycogen precursor, and arginine (A), a stimulator of insulin secretion, on glycogen stores in liver and skeletal muscle and lipolysis were studied in endurance exercising rats, in comparison with that of glucose (G) and A. The addition of citrate (C), which previously has been ...
Reverdin E C - - 1986
Measurements of the K activity (aiK) in ferret ventricle were made using either single- or double-barrelled K-sensitive micro-electrodes. aiK was also estimated from the Nernst equation by measuring the membrane potential when changing the external K concentration. Micro-electrodes filled with the Corning K sensor gave unreliable results most probably due ...
Coyle E F - - 1986
The purpose of this study was to determine whether the postponement of fatigue in subjects fed carbohydrate during prolonged strenuous exercise is associated with a slowing of muscle glycogen depletion. Seven endurance-trained cyclists exercised at 71 +/- 1% of maximal O2 consumption (VO2max), to fatigue, while ingesting a flavored water ...
Cheetham M E - - 1986
Biopsy samples were obtained from vastus lateralis of eight female subjects before and after a maximal 30-s sprint on a nonmotorized treadmill and were analyzed for glycogen, phosphagens, and glycolytic intermediates. Peak power output averaged 534.4 +/- 85.0 W and was decreased by 50 +/- 10% at the end of ...
Arnall D A - - 1986
To determine the possibility of a threshold concentration of plasma epinephrine that stimulates liver glycogenolysis during exercise, adrenodemedullated (ADM) and sham-operated (SHAM) rats were infused with saline or epinephrine at rates that produced plasma concentrations ranging between 0.01 ng/ml (0.06 nM) and 4.3 ng/ml (23.7 nM). During the infusion rats ...
Jansson E - - 1986
Epinephrine increases glycogenolysis in resting skeletal muscle, but less is known about the effects of epinephrine on exercising muscle. To study this, epinephrine was given intraarterially to one leg during two-legged cycle exercise in nine healthy males. The epinephrine-stimulated (EPI) and non-stimulated (C) legs were compared with regard to glycogen, ...
Constable S H - - 1986
Phosphorylase activation reverses during prolonged contractile activity. Our first experiment was designed to determine whether this loss of ability to activate phosphorylase by stimulation of muscle contraction persists following exercise. Phosphorylase activation by stimulation of muscle contraction was markedly inhibited in rats 25 min after exhausting exercise. To evaluate the ...
McCartney N - - 1986
Muscle power and the associated metabolic changes in muscle were investigated in eight male human subjects who performed four 30-s bouts of maximal isokinetic cycling at 100 rpm, with 4-min recovery intervals. In the first bout peak power and total work were (mean +/- SE) 1,626 +/- 102 W and ...
Fregosi R F - - 1986
We determined changes in rat plantaris, diaphragm, and intercostal muscle metabolites following exercise of various intensities and durations, in normoxia and hypoxia (FIO2 = 0.12). Marked alveolar hyperventilation occurred during all exercise conditions, suggesting that respiratory muscle motor activity was high. [ATP] was maintained at rest levels in all muscles ...
Goldfarb A H - - 1986
Glycogen, phosphorylase, and adenosine 3',5'-cyclic monophosphate (cAMP) were determined in rat heart following an acute exercise bout. Intensity and duration of exercise were varied to gain further insights into the mechanism regulating myocardial glycogenolysis during exercise. Groups of rats were run at either 15 or 30 m/min for 0, 5, ...
Devlin J T - - 1986
We studied the effects of ingesting either a snack food (S) (260 kcal) or placebo (P) 30 min before intermittent cycle exercise at 70% maximal O2 consumption on endurance performance and muscle glycogen depletion in eight healthy human males. Immediately before exercise there were significantly greater increases in plasma glucose ...
Ichiyama M - - 1986
The effects of bucumolol (BUC), nadolol (NAD) and nifenalol (NIF) on contractile forces and on action potentials (APs) were investigated in isolated guinea pig atrial and papillary muscles, respectively. Log 1/ED40 values for the negative inotropic effects of these drugs were 0.097, 10 and 0.74 mmol/l in this order. BUC ...
Roedde S - - 1986
The purpose of this study was to determine whether or not trained athletes have the same capacity for supercompensation of muscle glycogen as untrained subjects. Muscle glycogen was measured in 4 highly trained cyclists and 4 untrained controls over a 6 day period of exercise and dietary manipulation. During the ...
Tesch P A - - 1986
The objective of this study was to examine the muscle metabolic changes occurring during intense and prolonged, heavy-resistance exercise. Muscle biopsies were obtained from the vastus lateralis of 9 strength trained athletes before and 30 s after an exercise regimen comprising 5 sets each of front squats, back squats, leg ...
Hultman E H - - 1986
The glycogenolytic rates during maximum exercise with different durations have been calculated using own studies and reports from the literature. The initial glycogenolytic rates both in animal and in human muscle are close to the Vmax as determined in vitro. Already within the first seconds of electrical stimulation of human ...
Kayar S R - - 1986
Biopsies of vastus lateralis from seven well-trained males were studied 1 month before and 15-30 min after a 100-km race. The distribution of interfibrillar mitochondria was analyzed to determine whether a long bout of exercise induced a redistribution of mitochondria. Capillary densities and mean fiber areas were also estimated. Capillary ...
Blom P C - - 1986
Muscle glycogen concentration decreases continuously during prolonged severe exercise. The rate of depletion increases with increasing exercise intensity. During heavy exercise at 65-75% of VO2 max, time till exhaustion correlates with the pre-exercise muscle glycogen concentration and exhaustion coincides with empty glycogen stores. A substantial number of type I fibres ...
Zorzano A - - 1985
Concentrations of citrate, hexose phosphates and glycogen were measured in skeletal muscle and heart under conditions in which plasma non-esterified fatty acids and ketone bodies were physiologically increased. The aim was to determine under what conditions the glucose-fatty acid cycle might operative in skeletal muscle in vivo. In keeping with ...
Vøllestad N K - - 1985
Glycogen depletion of muscle fibre types I, IIA, IIAB and IIB was studied during bicycle exercise at 43% (n = 5), 61% (n = 7) and 91% (n = 5) of VO2max. Glycogen content in individual fibres from vastus lateralis muscles was quantified as optical density of periodic acid-Schiff (PAS) ...
Sonne B - - 1985
Carbohydrate metabolism in exercise, including regulation of glucose production, was studied by isotope-dilution methods, and these were evaluated. Chronically catheterized rats were examined before, during, and after 45 min of running at either low (LIE) or moderate (MIE) intensity. Glucose production (Ra) and disappearance (Rd), as well as muscular glycogen ...
Coyle E F - - 1985
The effect of a high-carbohydrate meal 4 h before 105 min of exercise at 70% of maximal O2 uptake was determined in seven endurance-trained cyclists and compared with exercise following a 16-h fast. The preexercise meal produced a transient elevation of plasma insulin and blood glucose, which returned to fasting ...
Mineo I - - 1985
To investigate purine catabolism in exercising muscles of patients with muscle glycogen storage disease, we performed ischemic forearm exercise tests and quantitated metabolites appearing in cubital venous blood. Two patients with glycogen storage disease type V and three with glycogen storage disease type VII participated in this study. Basal lactate ...
Ivy J L - - 1985
The effects of an exercise-induced muscle glycogen reduction and an elevated muscle glycogen concentration on glucose tolerance and the insulin response to an oral glucose tolerance test (GTT) were examined. GTTs were administered to seven male subjects after 3 days on a mixed diet (C), after exhaustive exercise and 1 ...
Hargreaves M - - 1985
Eight healthy males were studied to compare the effects of preexercise fructose and glucose ingestion on muscle glycogen usage during exercise. Subjects performed three randomly assigned trials, each involving 30 min of cycling exercise at 75% VO2max. Forty-five min prior to commencing each trial, subjects ingested either 50 g of ...
Evans W J - - 1985
Antecedent diet can greatly influence both substrate utilization during exercise and exercise performance itself. A number of studies have convincingly demonstrated that short-term (three to seven days) adaptation to a low carbohydrate diet results in greatly reduced liver and muscle glycogen stores. While carbohydrate utilization after such a diet is ...
Bonen A - - 1985
Bicycle ergometric exercise was used to deplete glycogen by either 80 or 35% in the vastus lateralis of both legs. Thereafter, subjects from each group rested or maintained single-leg exercise [20% of maximal O2 consumption (Vo2max) for 4 h. All subjects ingested glucose (1.5 g/kg wt; 20% solution) at min ...
Hodgson D R - - 1985
Muscle biopsy samples were collected from the left middle gluteal muscle of the horses participating in day 2 (speed and endurance test) of a three day event. Six Thoroughbred horses were biopsied the day before and within 30 minutes of completion of the speed and endurance test. Serial muscle sections ...
Costill D L - - 1985
The role of dietary carbohydrates (CHO) in the resynthesis of muscle and liver glycogen after prolonged, exhaustive exercise has been clearly demonstrated. The mechanisms responsible for optimal glycogen storage are linked to the activation of glycogen synthetase by depletion of glycogen and the subsequent intake of CHO. Although diets rich ...
Haller R G - - 1985
We studied oxidative metabolism during bicycle exercise in 4 patients with myophosphorylase deficiency. Maximal oxygen uptake (VO2max) was low (14.0 +/- 1.4 ml X kg-1 X min-1, mean +/- SE) compared with that in normal subjects (37.7 +/- 1.9; n = 12) and patients with myalgia (24.9 +/- 1.8; n ...
Jacobs I - - 1985
This study compared glycogen depletion in active skeletal muscle after light and moderate exercise in both cold and comfortable ambient conditions. Twelve male subjects (Ss) were divided into two groups equally matched for the submaximal exercise intensity corresponding to a blood lactate concentration of 4 mM (W4) during cycle exercise. ...
Neary P J - - 1985
To determine if blood lactate (LA) is the stimulus responsible for 'breakaway' ventilation (VE), the lactate (LT) and ventilation (VT) thresholds were monitored during one-legged cycling exercise. Ten healthy volunteer male subjects (Mean 2-legged VO2max = 4.27 l X min-1) performed prior exercise (PE) to reduce muscle glycogen stores by ...
< 7 8 9 10 11 12 13 14 15 16 17 >