Biomedical subjects

I L Kanstrup

Publications and source records attributed to I L Kanstrup.

57 records · Page 4Linked to original sources

PubMed1981

Reduced norepinephrine response to dynamic exercise in human subjects during O2 breathing.

The purpose of this investigation was to study the influence of hyperoxia on catecholamine response to dynamic exercise. While breathing either 21 or 100% O2 seven subjects performed submaximal bicycle exercise. Arterial blood pressure was similar in both exercise experiments. The CO2 output was not influenced by 100% O2 breathing, but increments in plasma lactate concentration were reduced. The increases in plasma norepinephrine and epinephrine concentrations and heart rate were significantly lower during 100% O2 than during 21% O2 breathing. The results suggest that O2 plays an important role in the regulation of sympathetic nervous activity during dynamic exercise in humans.

Adult↗

PubMed1978

Influence of age and physical activity on central hemodynamics and lung function in active adults.

Five female and seven male physically active adults were studied twice within a 13-yr interval. The individual state of physical activity was mainly unchanged. Maximal oxygen uptake (VO2 max) was reduced in all subjects except one female, in whom it remained unchanged. During maximal exercise, cardiac output (Q) in males was unchanged. In females, Q was significantly increased due to increased stroke volume (SV). In both sexes, the reduced VO2 max was explained by a smaller arteriovenous O2 difference (mixed venous O2 content (C-VO2) significantly increased). For a given submaximal VO2, Q was increased in both sexes and heart rate was unchanged. Thus, SV was increased and arteriovenous O2 difference was reduced due to increased C-VO2. Another four males were studied several times in various states of physical fitness during an 11-yr period. The reduced VO2 max from peak value was due to a reduced Qmax (SV smaller), whereas the arteriovenous O2 difference and C-VO2 were unchanged. Our results indicate that the observed changes in circulatory response to submaximal and maximal exercise in physically active adults may to a large extent be due to an effect of "detraining."

Adult↗

PubMed1976

Maximal oxygen uptake during exercise with various combinations of arm and leg work.

Oxygen uptake (VO2) was determined in 10 males during the following types of maximal exercise (work time: about 5 min): uphill running, bicycling, arm work (cranking), and combined arm work and bicycling (A + L). The A + L exercise was performed in four different ways, the arms doing 10%, 20%, 30%, or 40% of the same total rate of work; and also with the maximal bicycle work load plus either maximal or submaximal arm work. VO2 was the same in running as in all types of A + L exercise, except when the arm work load was 10% and 40% of the total rate of work, where VO2 was 2.5% (P less than 0.05) and 9.4% (P less than 0.001) lower, respectively. Bicycle VO2 was lower than VO2 in running but equal to A + L VO2 when arm work intensity was 40% of the total rate of work. It is concluded that VO2 during maximal exercise a) to a certain extent depends on the exercising muscle mass, b) is lower than the oxygen-consuming potential of the muscles involved in A + L exercise, and c) in A + L exercise is influenced by the ratio of arm work to total rate of work and the subject's fitness for arm work and bicycling.

Adult↗