N. Maassen

Training induced effects on blood volume, erythrocyte turnover and haemoglobin oxygen binding properties

SummaryThe effect of three weeks ergometer training (Tr) 5 times a week for 45 min at 70%

Changes in plasma volume and red cell formation after a marathon competition.

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Exercise versus immersion: antagonistic effects on water and electrolyte metabolism during swimming.

by 6 subjects on erythrocyte turnover and haemoglobin O2 affinity has been studied. Increased reticulocytosis could be observed from the second day after beginning Tr until a few days after its end, probably caused by increased erythropoietin release by the kidney. Erythrocyte destruction was most pronounced in the first and markedly reduced in the third week of Tr. Elevated glutamate oxalacetate transaminase activity and creatine as well as lowered mean corpuscular haemoglobin indicate a younger erythrocyte population in the first week of recovery. Total blood volume increased during the course of Tr by 700 ml, mainly caused by a raised plasma volume (74%). Red cell volume increased later with maximal values one week after Tr (+280 ml). In this week the standard oxygen dissociation curve was most shifted to the right (P50 increased from 3.77±0.05 kPa to 3.99±0.07 kPa) and the Bohr coefficients had their lowest values. Both effects are completely explainable by the haemoglobin O2 binding properties of young erythrocytes.After training, all parameters of physical performance (

Lung diffusion capacity, oxygen uptake, cardiac output and oxygen transport during exercise before and after an Himalayan expedition

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Carbon dioxide storage and nonbicarbonate buffering in the human body before and after an Himalayan expedition

, maximal workload, heart rate during rest and exercise) were markedly improved, indicating fast adaptation mechanisms. The increased erythrocyte turnover, including higher erythropoiesis, seems to be one important part of these effects.

Hemoglobin oxygen affinity in patients suffering from arterial occlusive disease of the legs.

SummaryThe influence of low and high carbohydrate diets on the relationship between blood lactate concentration ([Lac]) and work load (WL) in incremental exercise tests (cycle ergometer) and endurance tests was evaluated in trained subjects. The relationship between relative work load (WLrel) and [Lac] in arterialized blood was compared in untrained subjects (UT) and trained male athletes (TR) after 2 days without training while consuming a high carbohydrate diet (HCD). In both groups [Lac] of 2 mmol·l−1 was reached at about 60% [(mean±SD) UT 57.7%±6%, TR 62.7%±3.8%] and 4 mmol·l−1 at about 75% (UT 75.2%±3.6%, TR 77.8±2.2) of the maximal work load (WLmax). In eight cyclists the relationship between [Lac] and WL was not influenced by a 13-day training camp; however, heart rate was lower after the training camp. During their normal training programme, trained subjects had high relative work loads at their [Lac] thresholds, but after an HCD combined with an interruption of the training of 3 days, the relationship between [Lac] and WLrel was the same as in UT. In six TR a low carbohydrate diet (LCD) combined with training led to high absolute (WLabs) and WLrel at [Lac] of 2 and 4 mmol·l−1; an HCD combined with 3 days without training led to low WLabs and WLrel at the same [Lac] and to higher WLmax. In spite of the apparently lower endurance capacities TR were able to work significantly longer after HCD than after LCD (23±10.5 min and 49±16.2 min, respectively) at 65% of their WLmax. The variability of the relationship between [Lac] and WL following the dietary regimes leads to the conclusion that the “typical” [Lac] versus WL curve of endurance TR may result from a permanent glycogen deficiency.