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 4×1.2 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

The relationship between ACTN3 R577X gene polymorphism and physical performance in amateur soccer players and sedentary individuals

WOS: 000452861300002PubMed ID: 30899134The aim of this study was to determine the distribution of ACTN3 R577X gene polymorphism in soccer players and sedentary individuals, and to investigate the relationship of this distribution with performance tests. A total of 100 soccer players and 101 sedentary individuals were enrolled in the study. Standing long jump and countermovement jump (with arm swing, without arm swing and repeated) scores were recorded, using a jump meter. Maximum VO2 levels were measured using a treadmill-connected cardiopulmonary exercise device, Masterscreen CPX. ACTN3 R577X polymorphism was evaluated by real-time PCR. ACTN3 R577X genotype distribution was found to be similar in soccer players and controls (p>0.05). The only statistically significant finding was a shorter countermovement jump with arm swing scores in the RR-genotyped soccer players, compared with their RX genotyped counterparts (p<0.05). In the soccer player group, RX-genotyped subjects were observed to have lower respiratory threshold values compared with RR-genotyped subjects (p<0.05). No significant correlation was detected between this distribution and performance test results. ACTN3 R577X genotype distribution was found to have no effect on sprint and endurance characteristics in amateur soccer players. The ACTN3 R577X polymorphism may not be a specific enough genetic marker to determine athletic performance in soccer

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

Acute oxidative stress and antioxidant status responses following an American football match

WOS: 000297828600022PubMed ID: 21904294Aim. Intense physical activity is known to induce oxidative stress. Though regular physical training enhances the antioxidant defence system, the effects of diminished training periods are unclear. American football is one of the recently popular sports in Turkiye and is defined as a mixed activity. The aim of the research was to examine some markers of oxidative stress and antioxidant status in occasionally competitive American football players following a match, and relations with aerobic power and playing position. Methods. Twenty two male players volunteered for the study. To determine oxidative stress and antioxidant status from blood samples collected before and immediately following a match, plasma malondialdehyde (MDA) and nitric oxide (NO) levels, erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, and total antioxidant status (TAS) were assessed, using spectrophotometric methods. Wilcoxon's signed rank test was used to determine the match effect, and Mann-Whitney U test was used to compare playing position and VO(2)max effects. Results. Plasma MDA (P<0.001) and NO (P<0.05) levels increased significantly following the match. Antioxidant parameters were unchanged. following the match when compared with the resting level, except for a VO2max related effect (P<0.05) on TAS. Conclusion. Collected data revealed that an American football match caused excessive production of free radicals and oxidative stress. The training loads players underwent were not high enough to cause positive effects on the antioxidant status. To enhance training-induced antioxidant status adaptation, higher amounts of physical activity may be required

Are there differences in performance, metabolism, and quadriceps muscle activity in black African and Caucasian athletes during brief intermittent and intense exercise?

The purpose of the present study was to determine whether there are any differences in power output (PO) and/or quadriceps muscle (Quad) activity between black African and Caucasian football players during a force-velocity (fv) exercise test, which consisted of performing maximal 6-s sprints against an increasing load. Each subject started the test with a load of 2 kg and then recovered for 5 min before repeating the same test with a load increased by 2 kg. When the pedal frequency did not exceed 130 rev·min–1, the load was increased by only 1 kg. Each subject attained the load corresponding to his maximal power if an additional increase in load (+1 kg) induced a power decrease. Nine black Africans (mean age 24.2 ± 3.3 years) and nine Caucasians (24.7 ± 4.2 years) (matched for stature and aerobic fitness) participated in the fv exercise test. During the test, PO, blood lactate, and the quadriceps electromyography (EMG) root mean square (Quad RMS) were assessed. Higher blood lactate was observed in Caucasians than in black Africans for POs over the load range from 4 kg up to the maximal power. However, PO and Quad RMS values were similar in Caucasians and black Africans. They also had similar lean leg volume (LLV) and consequently produced similar PO/LLV and Quad RMS/LLV values. Overall, our results suggest that Caucasians and black Africans matched for stature, max, and training background have similar PO and Quad RMS values, but different blood lactate concentrations during brief, intermittent, intense exercise performed on a cycloergometer