Enhanced Strength and Sprint Levels, and Changes in Blood Parameters during a Complete Athletics Season in 800 m High-Level Athletes

Abstract

The purpose of this study was to analyze changes in sprint, strength, hematological, and hormonal parameters in high-level 800 m athletes during a complete athletics season. Thirteen male athletes of national and international level in 800 m (personal best ranging from 1:43 to 1:58 min:ss) participated in this study. A total of 5 tests were conducted during a complete athletics season. Athletes performed sprint tests (20 and 200 m), countermovement jump (CMJ), jump squat (JS), and full squat (SQ) tests. Blood samples (red and white blood profile) and hormones were collected in test 1 (T1), test 3 (T3), and test 5 (T5). A general increase in the performance of the strength and sprint parameters analyzed (CMJ, JS, SQ, 20 m, and 200 m) during the season was observed, with a significant time effect in CMJ (P < 0.01), SQ (P < 0.01), and 200 m (P < 0.05). This improvement was accompanied by a significant enhancement of the 800 m performance from T3 to T5 (P < 0.01). Significant changes in some hematological variables: hematocrit (Hct) (P < 0.01), mean corpuscular volume (MCV) (P < 0.001), mean corpuscular hemoglobin content (MCHC) (P < 0.001), white blood cells count (WBC) (P < 0.05), neutrophils (P < 0.05), monocytes (P < 0.05), and mean platelet volume (MPV) (P < 0.05) were observed throughout the season. The hormonal response and creatin kinase (CK) did not show significant variations during the season, except for insulin-like growth factor I (IGF-1) (P < 0.05). In conclusion, our results suggest the importance of strength levels in middle-distance athletes. On the other hand, variations in some hematological parameters and a depression of the immune system occurred during the season. Therefore, monitoring of the mechanical, hematological and hormonal response in athletes may help coaches and athletes to optimize the regulation of training contents and may be useful to diagnose states of overreaching or overtraining in athletes throughout the season.

Energy Constraint as a Novel Mechanism Linking Exercise and Health

“…Compromised immune function is a well-documented component of "overtraining syndrome" in elite athletes (30,75,87). Large workloads of high-intensity exercise are associated with reduced white blood cell count, including reduced neutrophils, monocytes, and lymphocytes (T cells) (6,51,75).…”

The effects of preparation period exercises on the hematological parameters of the taekwondo athletes

“…However, we determined that the values for the other sub-parameters taken before and after the preparation period were statistically nonsignificant. In a research study conducted on national and international level 13 male 800 m runners, comparing the summer and winter competition periods, it was determined that there were decreases for the RBC values and also statistically significant decreases for the HCT values [2]. It was reported that short term intensive basketball competition caused a statistically significant decrease for the HCT parameters of the athletes, while causing a statistically non-significant decrease for RBC and HGB parameters [3].…”

“…When we examined the thrombocyte and its subparameters, compared to the values obtained before the preparation period, we observed that there were decreases in all parameters of both male and female taekwondo athletes, except for the PLT value of the female taekwondo athletes. As far as the accessible literature findings, although there are many research studies [12,15,16,21,24,[26][27][28] reporting that both acute and chronic exercises cause increases in the values of thrombocyte and its sub-parameters, there are also studies [2,3,18] reporting that they cause a decrease. Increases obtained in the PLT levels are attributed to both exercise-contingent hemoconcentration and sympathetic nervous system activation, which is caused by stress-creating factors and the organism under pressure.…”

“…The effect of exercise on hematological parameters has been a research field for a long time. In many studies, the interrelation of factors determining the performance and physical / physiological characteristics of athletes of the elite level has been established [2][3][4][5].…”

“…In the accessible literature findings, we observed differences concerning the effects of exercise on hematological parameters. There are studies reporting that, in the athletes, who attend both acute [9] and chronic intense exercises [2], the hemoglobin [10] and hematocrit values decrease and this case is called as the athlete anemia [9]. Additionally, there are also research studies stating that, when the values before and after the acute sub-maximal exercise are compared, the acute submaximal exercise significantly increases erythrocyte, leukocyte [11], and thrombocyte count, hematocrit and hemoglobin levels [12]; and the researchers determined that these increases depended on plasma losses caused by this exercise [13].…”