Running-induced alterations in growth hormone, prolactin, triiodothyronine, and thyroxine concentrations in trained and untrained men and women.
This study examined whether gender and/or training were related to the exercise-induced changes in plasma concentrations of growth hormone (GH), prolactin (PRL), triiodothyronine (T3), and thyroxine (T4). Twenty subjects (male and female 10-km runners; untrained males and females) ran on a treadmill for 30 min at 80% of previously determined maximum heart rate. Blood samples were taken through an indwelling catheter from an antecubital vein at -30, 0, +15, +30 min of the test and 30 min of recovery. Rectal temperature rose significantly (p < .01) at +15 and +30 min with concomitant rise in GH concentration, but PRL, T3, and T4 were not affected by the exercise. We concluded that a 30-min run at 80% of maximum heart rate is associated with higher concentrations of GH but not of PRL, T3, and T4. Neither training state nor gender affected the aforementioned results.
Kraemer
R R
RR
Department of Health, Physical Education, and Dance, Southeastern Louisiana University.
Blair
M S
MS
McCaferty
R
R
Castracane
V D
VD
D000328:Adult; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010806:Physical Education and Training; D011388:Prolactin / Q000097:blood*; D012420:Running / Q000502:physiology*; D012737:Sex Factors; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*
D014284:Triiodothyronine; D011388:Prolactin; D013006:Growth Hormone; D013974:Thyroxine