RELATIONSHIPS BETWEEN BODY COMPOSITION, PLASMA GROWTH HORMONE LEVELS AND ENDURANCE TRAINING OF UNİVERSITY STUDENTS

The study sample comprised 18 women (10 for training, 8 for control) and 17 men (9 for training, 8 for control), totally 35 voluntary students studying at Selçuk University, School of Physical Education and Sports, aged between 18-24, non-smokers and who did not exercise regularly. Body compositions were measured at the beginning and end of the study, and growth hormone (GH) was determined in the blood samples taken at 8.00am-11.00 am and 14.00 pm. at the end of the 4th and 8th weeks. No special nutrition program was applied to the subjects, and the training groups were asked to perform cycling exercise for 60 minutes 4 days a week, at the intensity of 50- 70% of their pre-determined target heart rates for 8 weeks. The control groups were asked not to do any specific sportive activity except for their applied classes. Plasma GH levels were measured by Enzyme Immuno Assay (EIA) method.At the beginning of the training and at the end of the 8th week, it was detected that gender had a significant effect on body weight, body fat percentages (BFP) and maximal aerobic capacity (VO2_max) of female and male students in the control and training groups (P 0,001). The exercise increased VO2max level significantly in female and male training groups (P 0,001). At the beginning of the study, plasma GH levels of female and male control groups were found higher than those of training groups (P 0,001), and it was concluded that exercise had no significant effect on GH levels. The negative relationship observed between GH and BFP in female control groups before the training (P 0,05) was not observed at the end of the training, and a relationship was detected between GH and body weight in female training group (P 0,05). It was observed that the significant relationship between GH level and body weight in male control groups (P 0,05) had no significance after the training. In conclusion, it was determined that the endurance training applied to women and men had no effect on body weight, BFP and BMI in all groups of the study; however, VO2_max levels of all subjects in the training group showed a significant increase with the aerobic endurance exercise, and gender had a significant effect on body weight, BFP and VO2_max. It was concluded that GH levels were not affected from the aerobic endurance exercise.