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This article discusses the relationship between creatine supplementation, anaerobic exercise, and fatigue. An analysis of participants' body weight, power output, and oxygen consumption measurements is presented

Research concerning exercise and mood finds that 10-30 minute bouts of moderate aerobic exercise is associated with reduced levels of fatigue, confusion, and overall negative mood. How his study impacts current exercise recommendations is addressed.

The effect of oxidative stress and acidosis on diaphragm contractile function was analyzed. Results of the experiments indicated that xanthine oxidase induced a reduction of low-frequency tension in the fatigued diaphragm. The process was mediated directly or indirectly through hydrogen peroxide. One-half relaxation period was prolonged only by the combination of acidosis and oxidative stress.

The diaphragms of young and adult Fischer 344 rats were analyzed during xanthine oxidase (XO)-induced oxidative damage to determine the detrimental effects of oxidant challenge on the contractility of the diaphragm. Analysis of rodent diaphragm during XO-induced oxidative challenge indicated the role of reactive oxygen species in damaging the contractile function of the skeletal muscle. Furthermore, aging rodent diaphragms were more susceptible to XO-induced depression in contractility due to greater airway resistance.

People intuitively walk at a speed that minimizes energy cost per meter. Therefore, the selective advantages of energetic efficiency are thought to drive individuals' preferred walking speed (PWS). This presumption disregards fuel partitioning, which may, in fact, be significant due to the disparate sizes of the carbohydrate (CHO) and fat reservoirs, coupled with the necessity of CHO for high intensity exercise. Potentially, PWS may reflect CHO conservation more than energetic efficiency per se. This study was designed to determine if PWS over a variety of conditions conforms to the CHO sparing hypothesis. Six subjects walked on a treadmill at five speeds: their PWS and speeds 0.45 and 0.22 m/s below and above PWS, under loads of 0, 10, and 20% of body weight, as well as at grades of -6.25, 0 and +6.25%. Oxygen consumption, carbon dioxide production and respiratory exchange ratio were measured over each 10 min bout to calculate total energy, CHO and fat usage. The subjects' mean (±SD) unloaded, level PWS was 1.32 ± 0.11 m/s. PWS was reduced by the 20% load and uphill grade, but not affected by the 10% load or downhill grade. Carbohydrate provided ≥50% of required energy in all conditions. The CHO oxidation rate was related to speed such that the gain was greater at speeds above than below the PWS; however, differences in CHO oxidation between conditions did not correspond to differences in PWS. We conclude that CHO sparing is not the primary determinant of PWS during externally loaded or grade walking. [ABSTRACT FROM AUTHOR]

This study examined the effects of drafting in swimming on heart rate and blood lactate in collegiate swimmers. Subjects consisted of two groups, one male and one female. Subjects swam eight 400m swims with the swimmers in a straight line. They swam in each position in the line (1,2,3,4) during swims where the subjects were separated by five or ten seconds (5-sec draft, and 10-sec draft, respectively). Heart rates were measured immediately post exercise. Lactate levels were measured two min post-exercise. Heart rates were significantly higher in position one in both the 5-sec and 10-sec draft conditions (p=0.015), but were not different between positions two through four. Lactate levels were significantly higher in position one than in position three or four in both drafting conditions (p=0.001), but positions two through four were not different. Results indicate that whether a person is swimming in a 5-sec or 10-sec interval draft the leader of a multi-person draft appears to expend more energy based on heart rate and lactate data. It can be concluded that there is a drafting effect in swimming, but little apparent change in energy expenditure the further back in the draft the person is swimming. These results may have implications for training swimmers when pool conditions dictate that numerous people swim in the same lane. [ABSTRACT FROM AUTHOR]