Abstract des Autors

12 non-specifically trained volunteers (26.5+-3.6 yrs) performed exhausting incremental exercise (ST) and 1-min anaerobic cycle ergometer exercise (AnT) at 2-h intervals in order to investigate beta-endorphin (b-E) behaviour dependent on exercise intensity and anaerobic metabolism. In order to determine <b-E>, adrenocorticotropic hormone <ACTH>, cortisol <C>, adrenaline <A> and noradrenaline <NA> concentrations, venous blood samples were collected prior and subsequent to exercise until the 20th min of recovery, as well as in ST before and after exceeding the individual anaerobic threshold (THan,i). Before, during and after ST, lactate concentration, heart rate and perceived exertion were also determined; after AnT maximum lactate concentration was measured. Both types of exercise led to significant increases in <b-E>, <ACTH>, <A> and <NA>, with levels of <b-E> and <ACTH> approximately twice as high after ST as after AnT. <C> increased significantly only after ST. During ST significant changes in <b-E> and <ACTH> were measured only after exceeding THan,i. At all measuring times before and after ST and AnT both hormones correlated positively. In AnT the increases of <b-E> and <A> demonstrated a correlation (r=0.65; P<0.05). Both in AnT and ST there was a relationship between the maximum concentrations of b-E and lactate (r=0.63 and 0.71; P<0.05). We conclude that exercise with increasing or mostly anaerobic components ledas to an increase in <b-E>, the extent correlating with the degree of lactate concentration.