Plasma catecholamine responses to four resistance exercise tests in men and women

The plasma adrenaline ([A]) and noradrenaline ([NA]) concentration response s of nine men and eight women were investigated in four resistance exercise tests (E80, E60, E40 and E20), in which the subjects had to perform a maxi mal number of bilateral knee extension-flexion movements at a given cycle p ace of 0.5 Hz, but at different load levels (80%, 60%, 40% and 20% of 1 rep etition maximum, respectively). The four test sessions were separated by a minimal interval of 3 rest days. The number of repetitions (Rep(max)), the total work (W-tot) done normalized for the lean body mass and the heart rat e (HR) responses were similar in the two groups in each test. In addition, no differences were found between the two groups in [A] and [NA] either bef ore or after the exercise tests. The postexercise [NA], both in the men [10 .8 (SD 7.0) nmol . l(-1)] and in the women [11.7 (SD 7.4) nmol . l(-1)], wa s clearly the highest in E20, where also the Rep(max), W-tot, the total amo unt of integrated electromyograph activity in the agonist muscles and the p eak postexercise blood lactate concentration [men 8.3 (SD 1.6) vs women 7.3 (SD 0.9) mmol . l(-1), ns] were significantly higher than in the other tes ts. Although the postexercise [A] in E20 both in the men [7.1 (SD 6.0) nmol . l(-1)] and in the women [5.2 (SD 2.0) nmol . l(-1)] were higher than in E80 [men 3.1 (SD 4.2), women 2.1 (SD 2.0) nmol . l(-1)] (P < 0.05), they we re not significantly different from E60 [men 3.6 (SD 1.9), women 4.0 (SD 3. 3) nmol . l(-1)] and E40 [men 3.8 (SD 4.1), women 5.8 (SD 4.0) nmol . l(-1) ] in either group. The present study did not indicate any sex differences i n performance and in plasma catecholamine responses in different exhausting resistance exercise tests performed with the knee extensor muscles. In bot h groups the plasma [NA] response was clearly the largest in the longest ex ercise with the greatest amount of muscle activity and work done, and with the largest blood lactate response. The differences in the plasma [A] respo nses between the exercises tended to be somewhat smaller.