Central and regional circulatory effects of adding arm exercise to leg exercise.
7 young, healthy, male subjects performed exercise on bicycle ergometers in two 20 min periods with an interval of 1 h. The first 10 min of each 20 min period consisted of arm exercise (38--62% of Vo2 max for arm exercise) or leg exercise (58--78% of Vo2 max for leg exercise). During the last 10 min the subjects performed combined arm and leg exercise (71--83% of Vo2 max for this type of exercise). The following variables were measured during each type of exercise: oxygen uptake, heart rate, mean arterial blood pressure, cardiac output, leg blood flow (only during leg exercise and combined exercise), arterio-venous concentration differences for O2 and lactate at the levels of the axillary and the external iliac vessels. Superimposing a sufficiently strenuous arm exercise (oxygen uptake for arm exercise greater than 40% of oxygen uptake for combined exercise) on leg exercise caused a reduction in blood flow and oxygen uptake in the exercising legs with unchanged mean arterial blood pressure. Superimposing leg exercise on arm exercise caused a decrease in mean arterial blood pressure and an increased axillary arterio-venous oxygen difference. These findings indicate that the oxygen supply to one large group of exercising muscles may be limited by vasoconstriction or by a fall in arterial pressure, when another large group of muscles is exercising simultaneously.
D000328:Adult; D001132:Arm / Q000098:blood supply; D001794:Blood Pressure; D002302:Cardiac Output; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D007773:Lactates / Q000097:blood; D007866:Leg / Q000098:blood supply; D008297:Male; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D005082:Physical Exertion; D014655:Vascular Resistance
D007773:Lactates; D010100:Oxygen