Hormonal, immunological, and hematological responses to intensified training in elite swimmers

Abstract

The purpose of this study was to compare the responses of selected hormonal, immunological, and hematological variables in athletes showing symptoms of overreaching with these variables in well-trained athletes during intensified training. Training volume was progressively increased over 4 wk in 24 elite swimmers (8 male, 16 female); symptoms of overreaching were identified in eight swimmers based on decrements in swim performance, persistent high ratings of fatigue, and comments in log books indicating poor adaptation to the increased training. Urinary excretion of norepinephrine was significantly lower (P < 0.05, post hoc analysis) in overreached (OR) compared with well-trained (WT) swimmers throughout the 4 wk. There were no significant differences between OR and WT swimmers for other variables including: concentrations of plasma norepinephrine, cortisol, and testosterone, and the testosterone/cortisol ratio; peripheral blood leukocyte and differential counts, neutrophil/lymphocyte ratio, and CD4/CD8 cell ratio; serum ferritin and blood hemoglobin concentrations, erythrocyte number, hematocrit, and mean red cell volume (MCV). MCV increased significantly over the 4 wk in both groups, suggesting increased red blood cell turnover. These data show that, of the 16 hormonal, immunological, and hematological variables measured, urinary norepinephrine excretion appears to be the only one to distinguish OR from WT swimmers during short-term intensified training. Low urinary norepinephrine excretion was observed 2 to 4 wk before the appearance of symptoms of overreaching, suggesting the possibility that neuroendocrine changes may precede, and possibly contribute to, development of the overreaching/overtraining syndromes.

Changes in cell free DNA during a college soccer season

“…There were also no relationships found between T, C or T:C and CRP, CK or cf-DNA. These findings reiterate the results of previous research that found no consistent changes in T, C and T:C with changing training loads 31,32 and suggests that practitioners should use care when interpreting T:C.…”

“…For instance, testosterone, cortisol and T:C ratio in endurance athletes have not shown to respond consistently to increased or decreased training load or when overreached and overtrained. [31][32][33][34][35] There are also inconsistencies in resistance trained individuals. 36 The purpose of this study was to investigate changes in cf-DNA and other commonly used biochemical markers throughout a collegiate soccer season in order to examine the utility of cf-DNA as a potential variable to be included in a LTAMP for NCAA Division I collegiate soccer.…”

Compreendendo o overtraining no desporto: da definição ao tratamento

“…2) Parâmetros imunológicos a) Leucócitos: Normalmente, a quantidade de leucó-citos permanece dentro dos valores de referência, mesmo durante períodos de treinamento físico intenso e em atletas em OT [27,34,58]. Contudo, Lehmann et al [51] observaram em corredores uma diminuição da quantidade de leucócitos abaixo dos valores de referência, em resposta a um período de quatro semanas em que o volume, e não a intensidade de treinamento, foi dobrado.…”

“…Gorostiaga et al [28] sugerem que uma queda inferior a 45% da razão T/C nem sempre pode indicar OT. d) Catecolaminas: Mudanças na concentração plasmática e excreção urinária da noradrenalina têm sido associadas com o OT [58]. Aumento e diminuição da concentração plasmática em repouso e após exercício de alta intensidade, respectivamente, foram registrados em corredores de meio fundo após perío-dos de treinamento intenso [46,49,51,58].…”

“…d) Catecolaminas: Mudanças na concentração plasmática e excreção urinária da noradrenalina têm sido associadas com o OT [58]. Aumento e diminuição da concentração plasmática em repouso e após exercício de alta intensidade, respectivamente, foram registrados em corredores de meio fundo após perío-dos de treinamento intenso [46,49,51,58]. Hooper et al [33] também constataram menor concentração plasmática de noradrenalina em nadadores em OT.…”