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In a randomized double-blind study, subjects (n = 34) performed two workouts on a cycle ergometer to estimate their VO2 max. Workouts were preceded by intake of a 2% sucrose solution, one of which was an electrolyte-rich sport beverage (Outlast; Houston, TX) while the other was devoid of added electrolytes and served as a placebo. Heart rates (HR) were recorded before, at four times during, and after workouts. A rating of perceived exertion (RPE) was provided at the end of workouts. There were significant inter-time differences for HR. RPE and VO2 max each had inter-gender differences. Per dependent variable there were no inter-treatment differences. While little research exists on the ergogenic effects of formulations with the electrolyte and carbohydrate concentrations of Outlast, our results concur with prior study outcomes that noted a lack of inter-treatment differences. Our study's environmental conditions and the types of subjects examined may have also contributed to the lack of an ergogenic effect. [ABSTRACT FROM AUTHOR]

The influence of muscle fiber motion during exercise on diffuse correlation spectroscopy (DCS) measurements of skeletal muscle blood flow is explored. Isotonic (with muscle fiber motion) and isometric (without muscle fiber motion) plantar flexion exercises were performed at 30% of maximal force on a dynamometer, and muscle blood flow was continuously monitored on the medial gastrocnemius (calf) muscle of a healthy volunteer using DCS. During exercise, dynamometer recordings including footplate position, footplate angular velocity, and plantar flexion torque were obtained. Muscle fiber motions introduced artifacts into the DCS signals, causing an overestimation of blood flow changes. We show how proper co-registration of dynamometer recordings and DCS measurements enables separation of the true blood flow responses during exercise from those affected by the motion artifacts.

Abstract: Dolostones of the ∼1200 Ma Society Cliffs Formation within the hydrothermal zone surrounding the Nanisivik zinc deposits retain a stable characteristic remanent magnetization (ChRM) on alternating field and thermal step demagnetization. Based on the thermal data and saturation isothermal remanence analyses, the ChRM resides in pseudosingle domain magnetite and hematite. A paleomagnetic fold test favours a post-folding ChRM, and a paleomagnetic contact test, using a Franklin gabbro dike, indicates that the ChRM predates ∼720 Ma. The pole position calculated from the ChRM direction is at 168.2�E, 42.8�N (δp=4.9�, δm=6.8�), giving an age of 1095 � 10 Ma on the well-defined “Logan Loop” portion of the North American apparent polar wander path. This age is considered to date recrystallization of the dolostone host rocks in the halo around the hydrothermal sulfide deposits. No evidence is found for a postulated Cretaceous remagnetization event in the region.