Effects of continuous and interval running training on serum growth and cortisol hormones in junior male basketball players.

Effects of two different eight-week aerobic training programs consisting of continuous (CR) or extensive interval running (IR) on serum growth (GH) and cortisol hormones in 33 male basketball players aged 15-16 were assessed. The CR group ran 4.8 km and the IR group ran 4 x 1.2 km, using equal work-to-rest ratio, three times per week. Aerobic power scores of all subjects and anaerobic power marks of the training subjects increased (p<0.01). Upon exertion, though serum GH levels increased in both exercise groups (p<0.01) prior to and following training; cortisol levels increased only in the IR group prior to training, and in both exercise groups following training (p<0.05). Following the eight week period, resting cortisol levels rose in the training (p<0.05) and control (p<0.01) groups. To conclude, an 8-week training program consisting of continuous or extensive interval running has been effective on acute GH and cortisol secretion in 15-16 year-old male athletes.

Evaluation of iron metabolism indices and their relation with physical work capacity in athletes.

OBJECTIVE: To evaluate the relation between iron status and physical working capacity, and to assess the effect of oral iron treatment on these variables, in athletes with borderline iron status. METHODS: Blood haemoglobin (Hb), packed cell volume (PCV), red blood cell count (RBC), serum iron, total iron binding capacity (TIBC), and ferritin determinations were compared in 71 male and 18 female athletes participating in various sports and in matched male (n = 11) and female (n = 8) controls. The first aim was to assess the relations between these variables and performance in a physical work capacity test (PWC170). Oral iron treatment (175-350 mg ferrous fumarate daily) was provided for three weeks to six male and five female athletes with borderline Hb concentrations, to determine the effects of such treatment on both iron status and performance. RESULTS: Among females, handball players had the lowest serum ferritin concentrations (P < 0.05), the highest TIBC values, and lowest PWC170 scores (P < 0.01); runners had the highest ferritin concentrations and PWC170 scores (P < 0.01). There were significant correlations (P < 0.01) between PWC170 and PCV, serum ferritin, and transferrin saturation of female athletes. Hb, serum iron, serum ferritin, and transferrin saturation increased with iron treatment in both males (P < 0.01) and females (P < 0.05). CONCLUSIONS: Serum ferritin determination may prove a valuable addition to the screening of athletes and may indicate the need for iron treatment, even though a causal effect on improvement of work capacity may not be present.

Changes in serum creatine kinase, lactate dehydrogenase and aldolase activities following supramaximal exercise in athletes.

While it is well known that prolonged intense exercise raises serum enzyme activities, the effects of short duration intense exercise on enzyme activity changes have not been clearly described. Three successive standard 30 s Wingate anaerobic cycle ergometer tests separated by 6-8 min rest intervals were performed by competitive male middle- and long-distance runners or cyclists (no. = 33), and matched healthy control subjects (no. = 30). Immediately before and 6 h after the tests, blood samples were before and 6 h after the tests, blood samples were taken to assess the effects of exercise on serum creatine kinase (CK), lactate dehydrogenase (LD) and aldolase (ALS) enzyme activities. Serum CK activities were found to be significantly higher in athletes than in the controls, both before and 6 hours after the test (p < 0.001), as were ALS activities (p < 0.01 before and p < 0.05 after the test), whereas LD activities were significantly higher (p < 0.05) in the athletes only after the test. Following the test, increases in LD activities (p < 0.01) were observed in athletes and rises in CK activities (p < 0.05) were seen in the controls. Significant correlations between pre- and post-exercise serum enzyme activities were established for both groups. In conclusion, following a supramaximal exercise test, increases in serum LD activities of athletes and in CK activities of controls appear to be more pronounced, and increases in serum CK, LD and ALS activities seem to depend more on the duration of exercise than on its intensity.