[Plasma catecholamines, metabolic substrates, aerobic and anaerobic capacity during exercise in supine and sitting...

The influence of a graduated bicycle ergometric test in supine and sitting position on the work capacity, the plasma catecholamines, the carbohydrate (glucose and lactate) and lipid metabolism (free fatty acids and glycerol) and the heart rate and oxygen intake was examined in six healthy subjects. The work capacity is approx. 30% higher in sitting position. In supine position, adrenaline and nor-adrenaline are lower at rest, at all submaximum levels and during maximum ergometric exercise. Glucose, free fatty acids and glycerol show no differences dependent on the body position at the same submaximum levels, only the lactate level is approx. 30% higher (200 Watt) in supine position. During maximum graduated exercise in sitting position the glucose level is 10% higher than in supine position, the free fatty acids show no difference; the lactate level is approx. 37% higher, the glycerol level approx. 40% than in supine position. The heart rate and the oxygen intake don't show any position dependent differences at rest and at the same submaximum levels. During maximum ergometric exercise they are 15% (heart rate) and about 30% (oxygen intake) higher than in supine position, corresponding to a higher exercise level.