Table 2.
Change from baseline data for metabolic, ventilatory, and hemodynamic variables and perceptual responses during prolonged exercise with saline and dopamine intravenous infusions
| n | 25% |
50% |
75% |
100% |
|||||
|---|---|---|---|---|---|---|---|---|---|
| Saline | Dopamine | Saline | Dopamine | Saline | Dopamine | Saline | Dopamine | ||
| Insulin, µU/ml | 10 | −3.6 ± 0.9 | −4.1 ± 0.8 | −4.5 ± 1.0 | −5.0 ± 0.7 | −5.3 ± 1.0 | −5.9 ± 0.8 | −6.0 ± 1.0 | −6.4 ± 0.8 |
| Free glycerol, mg/dl | 10 | 16.0 ± 1.9 | 14.8 ± 2.0 | 25.9 ± 2.8 | 26.0 ± 3.4 | 34.5 ± 2.8 | 34.5 ± 3.4 | 43.3 ± 2.4 | 42.7 ± 3.8 |
| Lactate, mmol/l | 12 | 0.8 ± 0.2 | 0.8 ± 0.1 | 0.9 ± 0.2 | 0.8 ± 0.1 | 1.0 ± 0.4 | 1.0 ± 0.2 | 1.4 ± 0.5 | 1.5 ± 0.2 |
| Respiratory exchange ratio† | 11 | 0.04 ± 0.03 | 0.13 ± 0.04 | 0.02 ± 0.03 | 0.11 ± 0.04 | 0.02 ± 0.03 | 0.10 ± 0.04 | 0.02 ± 0.03 | 0.10 ± 0.04 |
| Ventilation, l/min | 11 | 49 ± 2 | 52 ± 4 | 51 ± 3 | 56 ± 5 | 54 ± 3 | 60 ± 7 | 58 ± 4 | 65 ± 8 |
| V̇e/V̇co2 | 11 | −9.1 ± 1.1 | −9.1 ± 0.9 | −7.9 ± 1.2 | −6.5 ± 0.9 | −6.2 ± 1.1 | −4.5 ± 1.8 | −4.5 ± 1.8 | −1.8 ± 3.0 |
| Oxygen consumption, %peak | 11 | 63.7 ± 1.1 | 63.6 ± 1.5 | 64.7 ± 1.1 | 64.2 ± 1.8 | 64.8 ± 1.1 | 64.4 ± 1.6 | 65.5 ± 1.1 | 64.2 ± 1.8 |
| , mmHg | 11 | 3 ± 1 | 4 ± 1 | 1 ± 1 | 1 ± 1 | 0 ± 1 | −1 ± 1 | −1 ± 1 | −3 ± 1* |
| Intestinal temperature, °C | 7 | 1.2 ± 0.2 | 1.0 ± 0.1 | 1.5 ± 0.2 | 1.4 ± 0.2 | 1.6 ± 0.2 | 1.4 ± 0.2 | 1.6 ± 0.2 | 1.4 ± 0.2 |
| Heart rate, beats/min | 12 | 76 ± 4 | 78 ± 3 | 81 ± 4 | 83 ± 3 | 84 ± 4 | 85 ± 3 | 89 ± 4 | 89 ± 3 |
| Mean arterial pressure, mmHg | 12 | 0 ± 2 | 5 ± 3 | −3 ± 2 | 2 ± 4 | −1 ± 2 | 1 ± 4 | −1 ± 3 | 3 ± 4 |
| RPE | 12 | 11 ± 1 | 11 ± 1 | 13 ± 1 | 13 ± 1 | 14 ± 1 | 14 ± 1 | 15 ± 1 | 16 ± 1 |
Values are means ± SE; n, no. of experiments. Data are for 25, 50, 75, and 100% of total exercise time. RPE, rating of perceived exertion. All values are change from baseline except oxygen consumption and RPE.
*
P < 0.05 vs. saline.
†
Condition main effect, P < 0.05.