Igor Mekjavic

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Extended exposure to microgravity leads to significant musculoskeletal adaptations. Contractile parameters of four skeletal muscles (biceps brachii–BB, vastus medialis–VM, biceps femoris–BF and gastrocnemius medialis–GM) were measured in ten healthy males (aged 22.3 ± 2.2 years) during 35 days of horizontal bed rest by a mechanomyography-based method termed(More)
The present study derives simple formulas for the prediction of optimal insertion length of an esophageal temperature-sensitive probe from the measurements of either standing or sitting height. The formulas assume that the optimal site for an esophageal temperature probe is in the region of the esophagus bounded by the left ventricle and aorta,(More)
An experimental protocol was designed to investigate whether human core temperature is regulated at a "set point" or whether there is a neutral zone between the core thresholds for shivering thermogenesis and sweating. Nine male subjects exercised on an underwater cycle ergometer at a work rate equivalent to 50% of their maximum work rate. Throughout an(More)
AIM The purpose was to examine whether graded ischaemia in the working muscles affects the rate of sweating and the control of exercise core temperature. METHODS Eight subjects performed cycle ergometry exercise in the supine position with (ischaemic exercise) and without (control exercise) restriction of blood flow in the contracting muscles,(More)
The aim of the present study was to investigate the changes in thickness, fascicle length (L f) and pennation angle (θ) of the antigravity gastrocnemius medialis (GM) and vastus lateralis (VL) muscles, and the non-antigravity tibialis anterior (TA) and biceps brachii (BB) muscles measured by ultrasonography in ten healthy males (aged 22.3 ± 2.2 years) in(More)
INTRODUCTION Little is known regarding local differences in foot sweat secretion. Since such information is important to our understanding of sweat gland control for thermoregulatory modeling and for the design of footwear we explored this topic. METHODS Local sweat rates were investigated across core temperatures from 37-39 degrees C, achieved using(More)
Body-to-body contact is often recommended for rewarming mildly hypothermic victims in the field. This procedure involves a euthermic individual donating heat to the recipient by direct contact in an insulated bag. However, this technique has not been critically evaluated and may not be beneficial because there is limited direct contact between recipient and(More)
The rate of body heat storage (S) is often used as an index of thermal stress. The traditional approach for determining S assumes that the specific heat (Cp) of all body tissues may be averaged to 0.83 kcal X kg-1 X degrees C-1, irrespective of the actual proportion of different tissues in the body. The present theoretical analysis primarily partitions the(More)
Cold-induced vasodilation (CIVD) is an acute increase in peripheral blood flow observed during cold exposures. It is hypothesized to protect against cold injuries, yet despite continuous research it remains an unexplained phenomenon. Contrary to the traditionally held view, we propose that CIVD is a thermoregulatory reflex mechanism contributing to heat(More)
Regional cutaneous sensitivity to cooling was assessed in males by separately immersing four discrete skin regions in cold water (15 degrees C) during head-out immersion. The response measured was gasping at the onset of immersion; the gasping response appears to be the result of a nonthermoregulatory neurogenic drive from cutaneous cold receptors. Subjects(More)