Calculation of pcrccntage changes in volumes of blood, plasma, and red cells in dehydration. J. Appl. Physiol. 37(2): 247-248. 1974.-Observations on hematocrit (Hct) and hemoglobin (Hb) were Inade in six men before and after running long enough to cause a 4y0 decrease in body weight. Subscripts B and A were used to denote before dehydration and after dehydration, respectively. Relations were derived between BVn, BVA, Hbn, HbA, Hctg, and HctA with which one can calculate the percentage decreases in BV, CV, and PV, as well as the concentration of hemoglobin in red cells, g. 100 ml-l (MCHC). When subjects reach the same level of dehydration the water loss from the various body compartments may vary reflecting difference in salt losses in sweat. Changes in PV calculated from the increase in plasma protein concentration averaged-7.5(z compared with-12.2 y0 calculated from changes in Hb and Hct. The difference could be accounted for by a loss of 6v10 plasma protein from the circulation.

The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

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The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

The net oxygen cost of level and grade running was determined in three men-the author and two champion runners. The horizontal costs for the three were in agreement at the lower rates and for the two runners at high rates. A curve enables one to estimate the cost of horizontal walking and running and also of the horizontal component of grade walking and running. With this as a basis the cost of the vertical component in grade walking was found to be 1.53 ml/m·kg for the author and 1.31 ml/m·kg for one of the runners in both walking and running. This latter value and the curve relating the cost of the horizontal component to the rate of walking and running were used to estimate the cost of grade walking and running for seven other champion runners. The estimates checked closely with the observed cost in five. Marathoner DeMar was more efficient and the seventh runner was less efficient than predicted. champion athletes; work performance; work efficiency; oxygen cost of climbing Submitted on April 13, 1964

Altitude is a component of the physical environment to which animals show adjustments. Oxygen pressure and temperature decrease with increasing altitudes, and to both of these factors organisms respond in a variety of ways. As temperature varies with latitude and seasons as well as with altitude, oxygen pressure becomes the more specific factor in the study of effects of high altitudes.When man first climbs to high altitudes he has many of the sensations experienced in seasickness. He longs for his native habitat, wonders if he will survive the experience, and marvels at the ability of some of his fellows to enjoy food. I n due time, whether the environment is a rolling ship or a lofty mountain, acclimatization usually occurs. The mechanism of the adaptive process in the first case is not understood; in the second case many changes which take place during adaptation are familiar but their significance is not

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