Relationship between Training Load Management and Immunoglobulin A to Avoid Immunosuppression after Soccer Training and Competition: A Theoretical Framework Based on COVID-19 for Athletes' Healthcare.

Markel Rico-González,José Pino-Ortega,Filipe Manuel Clemente,Naia Bustamante-Hernández

doi:10.3390/healthcare9070856

Abstract

Immunoglobulin A (IgA), which is the main effector against upper respiratory tract viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been related to training load management. The aim of this systematic review was to establish the relationship between training load and salivary IgA based on current evidence in order to avoid immunosuppression after exercise and players´ vulnerability to virus contagion. A systematic review of relevant articles was carried out using two electronic databases (PubMed and Web of Science) until 19 May 2021. From a total of 127 studies initially found, 23 were included in the qualitative synthesis. These studies were clustered depending on stress level. The salivary IgA was analysed considering soccer-specific treadmill exercise and repeated sprint drills (n = 5), matches (n = 7), and during certain periods during the season or pre-season (n = 11). Repeated sprint ability tests and treadmill exercises are suitable exercises for the first steps on return to play periods yet still maintain social distance. A rest or moderate training sessions (technical/tactical) are suggested after official matches to ensure 16–18 h to recover IgA levels, while periods with multiple matches per week with limited recovery time should be avoided. Weekly training load should assume a small increment (<10%) to ensure IgA immune responses, especially, during the post coronavirus disease 2019 (COVID-19) season.

Highlights

In soccer, the quantification of training load is crucial to ensure players’ optimal performance, and to reduce injury occurrences [1]
The findings suggest that monitoring of salivary IgA (sIgA)
Lessons learned and concluding remarks are six-fold: (1) the salivary immunoglobulin A (IgA) test is a valid metric to the control immune function of players, at least, during the initial stages of return to play after the COVID-19 confinement period

Summary

Introduction

The quantification of training load is crucial to ensure players’ optimal performance, and to reduce injury occurrences [1]. Its quantification may be carried out through electronic performance and tracking systems or inertial devices, with additional technologies such as heart-rate devices, or using other strategies such as blood analyses or salivary tests. Each reports different information about players’ performance, and some studies found a statistical relationship between them [2,3], it needs further research. With the aim to detect issues related to biomarkers, blood or salivary test are needed. Saliva samples, which make available hormone levels (e.g., testosterone and/or cortisol) and antibodies (e.g., immunoglobulin A), seem to be growing in popularity [4]. Antibodies are proteins that the immune system makes to fight attacks by bacteria, viruses, and toxins. The “first line of defense” of the mucosal immune system against pathogens is the production of secretory immunoglobulin A (IgA) [6]

Results

Discussion

Conclusion