The behavior in plasma levels of insulin, glucose, free fatty acid, gycerol, norepinephrine and epinephrine in during swim training have been studied in humans. To assess the posible reguratory role of nutritional state in the control of these plasma fluctuations, the obese and lean women group were measured at intervals of 30, 60, 90, and 120 min in the swim training.
Continued swim training (60-120 min/day) and food restriction decreased body weight gain in both groups. Swim training plus food restriction in the obese women further depressed body weight gain such that it was similar to the gain of lean group in during swim training. Swiming periods in the 0-60 min range for glucose and insulin were consistently, however, progresive consumption to 60 min produced decreases in more irregularity and then were influenced in the plasma levels of free fatty acid, glycerol,and norepinephrine. These fluctuations were associated with changes in nutritional state. Plasma free fatty acid levels increased during the 60-120 min of swim training. It seems that it continued to rise for the exercise period and possible longer. The data presented that norepinephrine can elicit the mobilization of free fatty acid to the plasma in conscious swim training. The matabolites (free fatty acid and glycerol) are probably derived from adipose tissue (triglyceride). The data suggest an activation of the lipolytic enzyme system was stimulated by swim training (stimulation with norepinephrine).