Although soluble carbohydrates and carbohydrate solubility may sound synonymous, they, in fact, are not when one considers their influence upon the fermentat ion in the rumen. The former refers to a restricted class of carbohydrates of specified solubility whereas the latter portrays a characteristic of any carbohydrate or group of carbohydrates that often can be modified by pH and concentratio...

Background Evidence suggests that women oxidize more fat for fuel at rest than males. Potential sex differences in fuel utilization during exercise remain unclear. Alterations in diet may influence substrate utilization by altering substrate availability and metabolic enzyme activity. Reduced carbohydrate (CHO) intake has been shown to lower respiratory exchange ratio (RER) over time, which may...

Growth parameters and biochemical composition of the green microalga Chlorella vulgaris cultivated under different mixotrophic conditions were determined and compared to those obtained from a photoautotrophic control culture. Mixotrophic microalgae showed higher specific growth rate, final biomass concentration and productivities of lipids, starch and proteins than microalgae cultivated under p...

In a randomized, balanced, crossover study each of six fit, adult horses ran on a treadmill at 50% of maximal rate of oxygen consumption for 60 min after being denied access to food for 18 h and then 1) fed corn (51.4 kJ/kg digestible energy), or 2) fed an isocaloric amount of alfalfa 2-3 h before exercise, or 3) not fed before exercise. Feeding corn, compared with fasting, resulted in higher p...

The genome of the Xanthomonas campestris pathovar campestris (Xcc) strain 8004 encodes three uncharacterized proteins, XC1166, XC1223 and XC1976, annotated as glucose kinase (Glk) by bioinformatic studies. Here we have investigated the biochemical characteristics and physiological roles of these proteins with particular reference to the synthesis of extracellular polysaccharide (EPS). XC1166, X...

Eight trained men cycled at 70% peak oxygen uptake for 120 min followed by a 30-min performance cycle after ingesting either a high-glycemic index (HGI), low-glycemic index (LGI), or placebo (Con) meal 30 min before exercise. Ingestion of HGI resulted in an elevated (P<0.01) blood glucose concentration compared with LGI and Con. At the onset of exercise, blood glucose fell (P<0.05) such that it...

By employing serial enrichment, a derivative of Clostridium acetobutylicum ATCC 824 was obtained which grew at concentrations of butanol that prevented growth of the wild-type strain. The parent strain demonstrated a negative growth rate at 15 g of butanol/liter, whereas the SA-1 mutant was still able to grow at a rate which was 66% of the uninhibited control. SA-1 produced consistently higher ...

The purpose of this experiment was to study endurance performance and substrate storage and utilization in fat- or carbohydrate-fed rats. Ninety-nine rats were randomly divided into three groups and over 4 wk were fed either a carbohydrate-rich [CHO; 10% total energy content in the diet (E%) fat, 20 E% protein, 70 E% carbohydrate] diet or one of two fat-rich diets (65 E% fat, 20 E% protein, 15 ...

When people walk at low intensity after fasting, the energy needed is provided mostly by oxidation of plasma fatty acids. As exercise intensity increases (eg, to moderate running), plasma fatty acid turnover does not increase and the additional energy is obtained by utilization of muscle glycogen, blood glucose, and intramuscular triglyceride. Further increases in exercise intensity are fueled ...