| Abstract: |
We evaluated the relationship between nutritional status and maximal aerobic capacity in hospitalized normal subjects receiving intravenous nutritional support. In addition, the impact of a daily submaximal exercise regimen on maximal oxygen consumption (VO2 Max) during weight-stable intravenous feeding (IVF) was quantified. Six normal male volunteers were studied serially in the post-absorptive state following 3 days of standard enteral feeding, after 10 days of starvation, and after 10 days of intravenous nutritional repletion (group A). Another group of 11 normal subjects were studied post-absorptively after 3 days of enteral feeding and again after 10 days of weight-stable IVF (group B). Five of the 11 subjects in group B were randomized to perform 1 hour of daily bicycle exercise at 75 watts during IVF whereas the remaining 6 subjects received IVF without daily exercise. In group A subjects, VO2 Max (ml min-1 kg-1 ±SE) was 36.2±1.5 after enteral feeding and fell to 32.4±2.6 after 10 days of starvation. VO2 Max remained significantly (p<0.05) less than the enteral study even after 10 days of repletion IVF (28.4±2.9). Group B subjects demonstrated a VO2 Max of 34.1±3.0 at admission and, despite 10 days of weight-stable IVF, the nonexercised subjects experienced a decrease in VO2 Max to 26.4±2.4 (p<0.05). In contrast, those subjects who received daily exercise during IVF demonstrated a nonsignificant decrease in VO2 Max (31.4±4.6) after 10 days of weight-stable IVF compared to their admission enteral study. The data suggest that loss of cardiovascular functional aerobic capacity as determined by maximal oxygen consumption occurs independently of nutritional status and reflects the relative immobilization of hospital confinement. Moreover, 1 hour of bicycle exercise at 40-50 % of admission VO2 Max during IVF diminishes, but does not totally inhibit, the hospital-acquired loss of aerobic functional capacity. © 1988 Société Internationale de Chirurgie. |
