دانلود رایگان مقاله انگلیسی تاثیر عوامل استرس زا وابسته به ورزش بر میزان ایمنی و بیماری در ورزشکاران تیم ورزشی - الزویر 2018

abstract

Objectives: Elite team-sport athletes are frequently exposed to stressors that have the potentialto depress immunity and increase infection risk. Therefore, the purpose of this review is to describe how team-sport stressors impact upon immune responses, along with exploring whether alterations in these markers have the potential to predict upper respiratory tract illness symptoms. Design: Narrative review. Methods: Salivary secretory immunoglobulin A (SIgA) and T-cell markers have been shown to predict infection risk in individual endurance athletes. Papers discussing the impact of team-sport stressors on SIgA and T-cells were discussed in the review, studies discussing other aspects of immunity were excluded. Journal articles were sourced from PubMed, Web of science and Scopus. Key search terms included team-sport athletes, stressors, immunity, T-cells, cytokines, SIgA and upper respiratory illness. Results: Most team-sport stressors appear to increase risk for illness. An association between reduced SIgA and increased illness incidence has been demonstrated. Intensive training and competition periods have been shown to reduce SIgA, however, itis less clear how additional stressors including extreme environmental conditions, travel, psychological stress, sleep disturbance and poor nutrition affect immune responses. Conclusions: Monitoring SIgA may provide an assessment of a team-sport athletes risk status for developing upper respiratory tract symptoms, however there is currently not enough evidence to suggest SIgA alone can predict illness. Team-sport stressors challenge immunity and it is possible that the combination of stressors could have a compounding effect on immunodepression and infection risk. Given that illness can disrupt training and performance, further research is required to better elucidate how stressors individually and collectively influence immunity and illness.

6. Conclusions

At present, our understanding on how stressors individually and collectively influence a team-sport athlete’s immune system is limited as much of the research has been conducted on endurance athletes. Immunodeprresion and increased illness risk have been shown with intensive training and competition periods. Monitoring SIgA may provide an assessment of a team-sport athletes risk status for developing URTS, however there is currently not enough evidence to suggest SIgA alone can predict URTS. Teamsport studies have predominately examined exercise stress, as such the influence of contributing stressors (travel, environmental conditions, psychological stress, sleep deprivation, poor nutrition and alcohol consumption) on immunity and illness risk is less clear. Furthermore, previous team-sport studies are somewhat limited in that they have tended to only examine SIgA or T-cell responses, whereas interactions between these immune markers normally occur. Future studies simultaneously evaluating the effect of teamsport stressors SIgAand T-cell responses are required to gain a more comprehensive insight. In addition, rather than investigating each stressor and immune marker in isolation, future longitudinal studies should be conducted to better elucidate how multiple stressors (training, competition, travel, environmental extremes and additional lifestyle factors) affect various immune functions and illness. If periods of increased risk are evident, strategies can be targeted to reduce a team-sport athletes risk for developing URTS.