The effects of single and repeated bouts of soccer-specific exercise on salivary IgA

Oral Health Status and Salivary Parameters in Stroke Patients at a Tertiary Hospital

Introduction: Dental caries and impaired salivary function are very common but undertreated. The aim of this study was to investigate the oral health status and salivary parameters of stroke patients. Methods: A cross-sectional study was carried out on 54 stroke and 54 non-stroke patients attending rehabilitation treatment at Hospital Universiti Sains Malaysia. Decay, Missing and Filled Teeth (DMFT) index and plaque scores were used to evaluate patients’ oral health. Salivary parameters such as salivary cortisol, salivary flow rate, pH and buffering capacity were measured. Salivary cortisol was analysed using Cobas E6000 automated immunoassay. Results: Among the 54 stroke patients, the majority were Malays 72.2% and 63.0% were male, with a mean age of 48.1 (14) years. There was a significant difference of dental caries between stroke patients, at 17.6 (4.26), compared to 15.7 (5.38) for non-stroke patients (p=0.042). Only 53.7% of stroke patients had good oral hygiene, compared to, 85.2% among non-stroke patients’ (p-value= 0.001). Salivary parameters showed no significant differences (p>0.05). However salivary cortisol levels were higher in stroke patients 5.2(5.1) nmol/L) than in non-stroke patients 4.0 (3.6) nmol/L). There was no significant correlation between salivary parameters and DMFT index (P>0.05). Conclusion: Stroke patients had more dental caries and poor oral hygiene compared to non-stroke patients. Salivary parameters showed no significant difference between stroke and non-stroke patients.

Biomarkers of post-match recovery in semi-professional and professional football (soccer)

High-level football (soccer) players face intense physical demands that result in acute and residual fatigue, impairing their physical performance in subsequent matches. Further, top-class players are frequently exposed to match-congested periods where sufficient recovery times are not achievable. To evaluate training and recovery strategies, the monitoring of players' recovery profiles is crucial. Along with performance and neuro-mechanical impairments, match-induced fatigue causes metabolic disturbances denoted by changes in chemical analytes that can be quantified in different body fluids such as blood, saliva, and urine, thus acting as biomarkers. The monitoring of these molecules might supplement performance, neuromuscular and cognitive measurements to guide coaches and trainers during the recovery period. The present narrative review aims to comprehensively review the scientific literature on biomarkers of post-match recovery in semi-professional and professional football players as well as provide an outlook on the role that metabolomic studies might play in this field of research. Overall, no single gold-standard biomarker of match-induced fatigue exists, and a range of metabolites are available to assess different aspects of post-match recovery. The use of biomarker panels might be suitable to simultaneously monitoring these broad physiological processes, yet further research on fluctuations of different analytes throughout post-match recovery is warranted. Although important efforts have been made to address the high interindividual heterogeneity of available markers, limitations inherent to these markers might compromise the information they provide to guide recovery protocols. Further research on metabolomics might benefit from evaluating the long-term recovery period from a high-level football match to shed light upon new biomarkers of post-match recovery.

Alternative and promising targets of biochemical analysis in sport (review of literature)

Current literature review provides an evaluation of advantages and limitations of biochemical control objects representing functional state of athletes as well as the outlook for using alternative targets regarding sports medicine. Traditionally, invasive procedures (venous blood collection, muscle biopsy) have been known as the gold standard for analyzing a wide range of biomarkers which could be employed as effective diagnostic tools to control the course of adaptation processes, monitor performance, overtraining and physical well-being of athletes, but these techniques are painful, time-consuming and place demands on storage and shipment. In this behalf finding an alternative objects for biochemical research that does not have disadvantages given above is the question of present interest. Saliva and dry blood spots (DBS) could serve as equally informative and promising targets for monitoring athletes' condition. The non-invasive nature of saliva collection allows to shorten sample collection time, reduce stress hormones levels and possible infection contamination. Moreover, collecting saliva process does not require special equipment and trained medical staff which is particularly important when athletes are at training camps. The DBS method has successfully proven itself with regard to neonatal screening and pharmacokinetics studies. Its key benefits are simplicity, small volume of bioliquid, enhanced stability of adsorbed biomarkers on the card surface, lack of special storage and transportation requirements and low costs for samples shipment to the laboratory. Taken together outlined advantages will provide the opportunity to increase the frequency of biomaterial collection to perform selective observation of training loads effects on various systems of athletes' body. The combination of DBS with immunochemical and mass-spectrometric approaches could serve as an efficient instrument to investigate the role of various biomarkers in monitoring the functional state of athletes. We searched for articles in MedLine database with the key words «dry blood spots», «saliva», «sports medicine», «sample collection», «sports biochemistry».

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

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.

Changes in different salivary biomarkers related to physiologic stress in elite handball players: the case of females

This study evaluates pre- and post-match concentrations of salivary cortisol, alpha-amylase (AA) and immunoglobulin A (lgA) in a group of 21 elite female handball players in the Spanish national women's league. The players' mean age was 23.0 ± 5.4 years. The concentration of the biomarkers was determined using ELISA. Mean playing time was 25.2 min. The players' cortisol concentration increased significantly (p < 0.05) whereas the IgA concentration fell significantly (p < 0.01) at the end of the match. There were no significant changes in the concentrations of AA between pre and post-match timepoints. The changes observed in the study also depended on the position played; defenders exhibited the highest cortisol and lowest IgA concentrations after the match. Larger changes in cortisol and IgA were seen in those who played for more than 30 min. The present study shows that a competitive handball match increases physiologic stress in females, with activation of the hypothalamic-pituitary-adrenal axis and the adrenergic system, resulting in decreased immunocompetence.

Salivary and Plasmatic Antioxidant Profile following Continuous, Resistance, and High-Intensity Interval Exercise: Preliminary Study

The increase in antioxidant responses promoted by regular physical activity is strongly associated with the attenuation of chronic oxidative stress and physiological mechanisms related to exercise adaptation. The aim of this work was to evaluate and compare how different exercise protocols (HIIE: high-intensity interval exercise, CE: continuous exercise, and RE: resistance exercise) may alter salivary and plasmatic antioxidants and salivary markers of exercise intensity and nitric oxide. Thirteen healthy, trained male subjects were submitted to the three exercise protocols. Blood and saliva samples were collected at the points preexercise, postexercise, and 3 hours postexercise. Antioxidants (total antioxidant capacity, superoxide dismutase and catalase activities, and levels of reduced glutathione and uric acid), markers of exercise intensity (salivary total protein and amylase activity), and salivary nitric oxide were evaluated. As a result, all exercise protocols increased the markers of exercise intensity and nitric oxide. Antioxidant response was increased after exercise, and it was found that a single HIIE session exerts a similar pattern of antioxidant response compared to CE, in plasma and saliva samples, while RE presented minor alterations. We suggest that HIIE may lead to alterations in antioxidants and consequently to the physiological processes related to redox, similar to the CE, with the advantage of being performed in a shorter time. In addition, the antioxidant profile of saliva samples showed to be very similar to that of plasma, suggesting that saliva may be an alternative and noninvasive tool in sports medicine for the study of antioxidants in different physical exercise protocols.

Realising the Potential of Urine and Saliva as Diagnostic Tools in Sport and Exercise Medicine

Accurate monitoring of homeostatic perturbations following various psychophysiological stressors is essential in sports and exercise medicine. Various biomarkers are routinely used as monitoring tools in both clinical and elite sport settings. Blood collection and muscle biopsies, both invasive in nature, are considered the gold standard for the analysis of these biomarkers in exercise science. Exploring non-invasive methods of collecting and analysing biomarkers that are capable of providing accurate information regarding exercise-induced physiological and psychological stress is of obvious practical importance. This review describes the potential benefits, and the limitations, of using saliva and urine to ascertain biomarkers capable of identifying important stressors that are routinely encountered before, during, or after intense or unaccustomed exercise, competition, over-training, and inappropriate recovery. In particular, we focus on urinary and saliva biomarkers that have previously been used to monitor muscle damage, inflammation, cardiovascular stress, oxidative stress, hydration status, and brain distress. Evidence is provided from a range of empirical studies suggesting that urine and saliva are both capable of identifying various stressors. Although additional research regarding the efficacy of using urine and/or saliva to indicate the severity of exercise-induced psychophysiological stress is required, it is likely that these non-invasive biomarkers will represent "the future" in sports and exercise medicine.

Linking stress and immunity: Immunoglobulin A as a non-invasive physiological biomarker in animal welfare studies

As the animal welfare community strives to empirically assess how care and management practices can help maintain or even enhance welfare, the development of tools for non-invasively measuring physiological biomarkers is essential. Of the suite of physiological biomarkers, Immunoglobulin A (IgA), particularly the secretory form (Secretory IgA or SIgA), is at the forefront because of its crucial role in mucosal immunity and links to physical health, stress, and overall psychological well-being. While interpretation of changes in SIgA concentrations on short time scales is complex, long-term SIgA patterns are consistent: conditions that create chronic stress lead to suppression of SIgA. In contrast, when welfare is enhanced, SIgA is predicted to stabilize at higher concentrations. In this review, we examine how SIgA concentrations are reflective of both physiological stress and immune function. We then review the literature associating SIgA concentrations with various metrics of animal welfare and provide detailed methodological considerations for SIgA monitoring. Overall, our aim is to provide an in-depth discussion regarding the value of SIgA as physiological biomarker to studies aiming to understand the links between stress and immunity.

Intensified Training Period Increases Salivary IgA Responses But Does Not Affect the Severity of Upper Respiratory Tract Infection Symptoms in Prepuberal Rhythmic Gymnasts

This study examined the effect of a 4-week intensified training (IT) period, followed by a 2-week tapering period (TP), on salivary immunoglobulin A (SIgA), salivary cortisol, and the severity of upper respiratory tract infection symptoms in 23 rhythmic gymnasts [12.1 (2.6) y; 143.9 (13.7) cm; 37.2 (9.4) kg]. Saliva sampling was conducted at pre- and post-IT, and post-TP (analyzed using enzyme-linked immunosorbent assay). The Wisconsin Upper Respiratory Symptom Survey (WURSS-21) questionnaire was completed daily to analyze the severity of upper respiratory tract infection symptoms. The session rating of the perceived exertion was used to determine the internal training load and the acute:chronic workload ratio. A higher SIgA concentration [SIgA_abs (μg/mL); F = 7.6; P = .001] for post-IT [234 (104)] versus pre-IT [173 (91)], and post-TP [182 (70)], and a higher SIgA secretion rate [SIgA_rate (μg/min); F = 3.4; P = .04] for post-IT [69 (28)] versus pre-IT [55 (27)], and post-TP [58 (22)] were observed. No significant change was observed for cortisol (F = 0.81; P = .45) or for the severity of upper respiratory tract infection symptoms (χ² = 2.81; P = .24). Internal training load was higher during IT (vs TP; effect size = 2.37). The acute:chronic workload for the IT weeks varied from 1.2 (0.3) to 1.4 (0.3). These results suggest that a 4-week IT may temporarily augment the oral mucosal immunity, and an acute:chronic workload of 1.2-1.4 seems to be a safe approach to periodized training loads in youth rhythmic gymnasts.

Exercise intensity and its impact on relationships between salivary immunoglobulin A, saliva flow rate and plasma cortisol concentration

Introduction

Salivary secretory immunoglobulin A (sIgA), saliva flow rate and plasma cortisol concentrations have been shown to be influenced by exercise, particularly the intensity exercise is performed at, and circadian variation. The autonomic nervous system partly regulates salivary secretion, but it is not yet known whether cortisol also explains some variation in salivary parameters.

Methods

Twelve moderately trained male individuals (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_2}$$\end{document}V˙O2_{peak legs}: 46.2 ± 6.8 mL·kg⁻¹·min⁻¹) performed three 45-min constant load exercise trials in the morning: arm cranking exercise at 60%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_2}$$\end{document}V˙O2_{peak arms}; moderate cycling at 60%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_2}$$\end{document}V˙O2_{peak legs}; and easy cycling at 60%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot {V}{{\text{O}}_2}$$\end{document}V˙O2_{peak arms}. Timed saliva samples and blood samples for plasma cortisol concentration determination were obtained before, post, 2 h post, and 4 h post-exercise. Saliva was collected in an additional resting trial at the same time points.

Results

At each time point for each exercise trial, negative correlations between cortisol and saliva flow rate (explaining 25 ± 17% of the variance, R² = 0.002–0.46) and positive correlations between cortisol and sIgA concentration (explaining 8 ± 8% of the variance R² = 0.002–0.24) were found. Saliva flow rate increased over time, whereas sIgA concentration and cortisol decreased over time for all trials (P < 0.05), there was no effect of time for sIgA secretion rate (P = 0.16).

Conclusion

These results show a relationship between cortisol and saliva flow rate, which directly impacts on the concentration of salivary analytes. This study further confirms circadian variations in salivary parameters which must be acknowledged when standardising salivary data collection.

Differences in salivary hormones and perception of exertion in elite women and men volleyball players during tournament

BACKGROUND

Sports tournaments induce both psychological and physiological stress, which seems to be different between men and women. Competition induces anticipatory rises in testosterone and cortisol levels, which may affect performance and physical exertion during tournaments. The aim of this study was to compare the changes in salivary cortisol and testosterone concentrations between men and women during an official volleyball tournament and to test potential correlations between changes in these hormones and perceived exertion after match.

METHODS

Three matches of each team were assessed in the group stage of the Men and Women South American Volleyball Championship. Salivary cortisol and testosterone levels were measured in the fasting state, before and after each match. The rate of perceived exertion (RPE) was assessed after each match.

RESULTS

Fasting cortisol concentrations were higher in women than men (~25%, P<0.001) while fasting testosterone was higher in men than women (~46%, P<0.001). Cortisol concentration increased only after the second match in men (+53.7%, P<0.001). Testosterone concentration was low before and after the third match in men (P<0.001) while it was elevated after the third match in women (P=0.003). The rate of perceived exertion was correlated with the change in testosterone levels due to the matches in both women (r=0.33; P=0.04) and men (r=0.44; P=0.02), which was not observed for cortisol concentrations.

CONCLUSIONS

These results indicate that women have higher fasting cortisol, but lower fasting testosterone concentrations than men during a volleyball tournament. Thus, hormonal responses of women and men are different and related to their effort during the matches.

Cardiac Autonomic and Salivary Responses to a Repeated Training Bout in Elite Swimmers

This study examined the acute training responses of heart rate variability (HRV) and salivary biomarkers (immunoglobulin A and alpha-amylase) following a standardised training bout in Paralympic swimmers. Changes in HRV, sIgA and sAA were documented Monday morning, Monday afternoon and Tuesday morning over a 14-week monitoring period leading into international competition. Magnitude based inferences with effect sizes (ES) were used to assess the practical significance of changes each week. Normal training responses elicited increases in HR, α1, sAA and sIgA, accompanied by decreases in HF(nu), standard deviation of instantaneous RR variability (SD1) and the root mean square of successive differences (RMSSD) from Monday morning to Monday afternoon, and to Tuesday morning with similar week to week responses for most variables. Changes in RMSSD from Monday a.m. to p.m. were likely smaller (less negative) for Week 7 (78/18/3, ES = 0.40) following a competition weekend with similar changes observed from Monday a.m. to Tuesday a.m. (90/5/5, ES = 1.30). In contrast, the change in sAA from Monday a.m. to p.m. was very likely less (more negative) at Week 7 (0/0/99, ES = −2.46), with similar changes observed from Monday a.m. to Tuesday a.m. (0/0/99, ES = −4.69). During the taper period, there were also likely increases in parasympathetic modulations (RMSSD, Weeks 12–14) along with increased immune function (sIgA, Week 13) that demonstrated a favourable state of athlete preparedness. Used together, HRV and sAA provide coaches with valuable information regarding physiological changes in response to training and competition.

Salivary hormones and anxiety in winners and losers of an international judo competition

The purpose of this study was to investigate the responses of salivary hormones and salivary secretory immunoglobulin A (SIgA) and anxiety in winners and losers during an international judo competition. Twenty-three trained, male, national-level judo athletes provided three saliva samples during a competition day: morning, in anticipation of competition after an overnight fast, mid-competition, and post-competition within 15 min post-fight for determination of salivary cortisol, salivary testosterone, salivary testosterone/cortisol ratio, SIgA absolute concentrations, SIgA secretion rate and saliva flow rate. The competitive state anxiety inventory questionnaire was completed by the athletes (n = 12) after the first saliva collection for determination of somatic anxiety, cognitive anxiety and self-confidence. Winners were considered 1-3 ranking place (n = 12) and losers (n = 11) below third place in each weight category. Winners presented higher anticipatory salivary cortisol concentrations (p = 0.03) and a lower mid-competition salivary testosterone/cortisol ratio (p = 0.003) compared with losers with no differences for salivary testosterone. Winners tended to have higher SIgA secretion rates (p = 0.07) and higher saliva flow rates (p = 0.009) at mid-competition. Higher levels of cognitive anxiety (p = 0.02) were observed in the winners, without differences according to the outcome in somatic anxiety and self-confidence. The results suggest that winners experienced higher levels of physiological arousal and better psychological preparedness in the morning, and as the competition progressed, the winners were able to control their stress response better.

Salivary hormones and IgA in relation to physical performance in football

Salivary biomarkers have shown to be useful to assess physiological stress in football, but their relationship with physical performance is unknown. The aims of this study were to investigate the effect of a football match on salivary cortisol, testosterone and immunoglobulin A (IgA) concentrations in elite footballers, and to examine the relationship of physical performance during the match to these biomarkers. Nine elite football players were assessed before, during and after a friendly international match. Physical performance during the match was measured by time-motion analysis, whilst salivary cortisol, testosterone and IgA were measured before and 10 min post-match. The results showed that players covered an average of 9463 ± 458 m during the match. Salivary cortisol did not change post-match. Testosterone and IgA concentrations decreased by 30.6% and 74.5%, respectively. The testosterone/cortisol (T/C) ratio decreased by 64.2% after the match. Changes in testosterone concentrations correlated (r = 0.85) with distance covered. Pre- and post-match testosterone levels correlated with post-match IgA concentrations (r = 0.8 and 0.89, respectively). These results suggest that a football match induces catabolic stress as indicated by the decreased T/C ratio. It seems that footballers with smaller decreases in testosterone levels covered more distance and decreased their immune function less.

Stimulating whole saliva affects the response of antimicrobial proteins to exercise

This study investigated the salivary secretion rates of antimicrobial proteins in response to prolonged, exhaustive exercise in both stimulated (STIM) and unstimulated (UNSTIM) saliva flow sample methods. Twenty-four trained men cycled for 2.5 h at 60% V̇O₂max and then to exhaustion at 75% V̇O₂max. Timed collections of whole saliva were made before exercise, mid-exercise, at the end of the moderate exercise bout and post-exhaustive exercise. After each UNSTIM collection, a STIM sample was collected following chewing flavored gum for 1 min. Saliva was analysed for lysozyme, α-amylase and salivary immunoglobulin A (s-IgA), and secretion rates were calculated. Saliva flow was 156% higher in STIM compared with UNSTIM (P < 0.001) and decreased with exercise in STIM only (P < 0.001). Exercise increased lysozyme and α-amylase levels and secretion rates were 144% higher and 152% higher in STIM compared with UNSTIM for lysozyme and α-amylase, respectively (all P < 0.001). S-IgA concentration (P < 0.05) and secretion rate (P < 0.001) increased with exercise but were both lower in STIM compared with UNSTIM (P < 0.001). In conclusion, a STIM saliva flow collection during exercise by chewing flavored gum increased the quantity of saliva and the secretion of lysozyme and α-amylase, but had a limited impact on the secretion of s-IgA.

Resting salivary levels of IgA and cortisol are significantly affected during intensive resistance training periods in elite male weightlifters

The aim of this study was to investigate the cumulative effects of intensive resistance training on salivary immunoglobulin A (SIgA) and cortisol responses in elite male weightlifters. Eleven elite male Taiwanese weightlifters were trained through 3 training stages before a national weightlifting competition, and this was followed by a 2-week recovery stage. Resting saliva samples were collected once in each of the 4 stages. Salivary concentrations of total protein (TP), SIgA, lactoferrin, and cortisol were measured. The results showed that (a) salivary TP concentrations were not significantly affected; (b) resting levels of SIgA, the ratio of SIgA to TP (SIgA/TP), cortisol, and the ratio of cortisol to TP (cortisol/TP) were significantly higher in the training stages than in the recovery stage; (c) a positive correlation was revealed between the ratios of SIgA/TP and cortisol/TP; and (d) the resting salivary lactoferrin concentrations and the ratio of lactoferrin to TP (lactoferrin/TP) were significantly lower in stage 1 than in the recovery stage. The findings in this study suggest that prolonged, intensive resistance training exerts cumulative effects on SIgA and cortisol responses in elite weightlifters.

Effect of exercise on the level of immunoglobulin a in saliva

The aim of this paper is to describe the structure, production and function of secretory immunoglobulin A (sIgA) as well as changes of its concentration caused by exercise of various intensity and duration. Immunoglobulin A is the main class of antibodies present in the body secreted fluids such as saliva, tears or mucus from the intestines. It is generally recognized that IgA, due to its dominance in the immune system of mucous membranes, is the first line of defence against harmful environmental factors. The secretion and composition of saliva depends on the activity of the sympathetic and parasympathetic nervous systems. Physical activity, stimulating the autonomous nervous system, may reduce the amount of saliva and/or inhibit its secretion. The relationship between physical activity and the suppression of the immune system is not fully understood, but it is known that moderate intensity exercise can improve immune defences, while extreme effort can reduce them by creating an increased risk of upper respiratory tract inflammation (URTI). In athletes, the lowest risk of upper tract infection was connected with the case of moderate intensity exercise. It is now believed that the relationship between exercise volume and the risk of URTI has the shape of the letter "J". This means that both too little and too much physical activity may increase the risk of upper respiratory tract infection. Training optimization and correct balance between exercise and rest periods may reduce the risk of adverse changes in the immune system and decrease the frequency of URTI.

Salivary immunoglobulin A and upper respiratory symptoms during 5 months of training in elite tetraplegic athletes

PURPOSE

Altered autonomic innervation in tetraplegic individuals has been shown to depress certain immune parameters at rest and alter exercise-related salivary immunoglobulin A (sIgA) responses. The purpose of this study was to examine resting sIgA responses as a function of training load and episodes of upper respiratory symptoms (URS) in elite tetraplegic athletes.

METHODS

Resting saliva samples were obtained from 14 tetraplegic athletes at 12 predefined time points over 5 months and analyzed for sIgA. Occurrence of self-reported URS and training load was recorded throughout the study's duration. Regression analyses were performed to investigate the relationship between sIgA responses and training load. Furthermore, the relationships between sIgA responses and URS occurrence were examined.

RESULTS

sIgA secretion rate was negatively correlated with training load (P=.04), which only accounted for 8% of the variance. No significant relationships were found between sIgA responses and subsequent URS occurrence. Finally, sIgA responses did not differ between athletes with and without recorded URS during the study period.

CONCLUSIONS

In line with findings in able-bodied athletes, negative relationships between sIgA secretion rate and training load were found in tetraplegic athletes. This may explain some of the higher infection risk in wheelchair athletes with a high training load, which has been previously observed in paraplegic athletes. However, the nonsignificant relationship between sIgA responses and URS occurrence brings into question the use of sIgA as a prognostic tool for the early detection of URS episodes in the studied population.

The ACTN3 genotype in soccer players in response to acute eccentric training

Genetic factors can interfere with sporting performance. The identification of genetic predisposition of soccer players brings important information to trainers and coaches for individual training loads adjustment. Different responses to eccentric training could be observed by the genotype referred to as α-actinin-3 (ACTN3) in biomarkers of muscle damage, hormones and inflammatory responses. The aim of this study was to compare acute inflammatory responses, muscle damage and hormonal variations according to the eccentric training in soccer professional athletes with different genetic profiles of ACTN3 (XX, RX and RR). 37 soccer professional athletes (9 XX, 13 RX, 15 RR) were randomly divided into five stations associated to eccentric muscle contraction and plyometrics. Blood samples were taken from athletes pre-eccentric training, immediately after (post), 2- and 4-h post-eccentric training to determine hormone responses (cortisol and testosterone), muscle damage (CK and α-actin), and inflammatory responses (IL-6). After eccentric training, athletes XX presented higher levels for CK (4-h post), α-actin (post and 2-h post) and cortisol (post) compared to RR and RX athletes. However, RR and RX athletes presented higher levels of testosterone (post) and IL-6 (2 h post and 4 h post) compared to athletes XX. The main conclusion of this study is that professional soccer athletes homozygous to ACTN3XX gene are more susceptible to eccentric damage and present a higher catabolic state, demonstrated by metabolic, hormonal and immune responses post an eccentric training, in comparison to ACTN3RR and ACTN3RX groups.

Effect of a kickboxing match on salivary cortisol and immunoglobulin A

The hypothesis that salivary cortisol would increase and salivary immunoglobulin A (IgA) decrease after a kickboxing match was tested among 20 male athletes. Saliva samples collected before and after the match were analyzed. Salivary cortisol and salivary IgA concentrations (absolute concentration, salivary IgAabs) and the secretion rate of IgA (salivary IgArate) were measured by enzyme-linked immunosorbent assay. A Wilcoxon test for paired samples showed significant increases in salivary cortisol from pre- to postmatch. No significant changes were observed in salivary IgAabs or secretory IgArate and saliva flow rate. This study indicates that a kickboxing match might increase salivary concentration and thereafter it could be considered a significant source of exercise-related stress. On the other hand, the effect of a kickboxing match on mucosal immunity seems not to be relevant.

Imunoglobulina A salivar (IgA-s) e exercício: relevância do controle em atletas e implicações metodológicas

O objetivo do presente estudo é realizar uma análise e discussão dos principais achados envolvendo o comportamento da imunoglobulina A salivar (IgA-s) em relação ao estímulo do exercício e evidenciar a importância de seu controle em atletas. O exercício físico é um importante modulador das características do sistema imune, sobretudo do comportamento da IgA-s, componente fundamental na proteção de infecções do trato respiratório superior (ITRS). No entanto, a relação direta entre baixas concentrações de IgA-s e ITRS precisa de mais evidências para ser confirmada. As concentrações de IgA-s durante e logo após um exercício intenso diminuem, deixando o indivíduo mais suscetível à infecção, porém, atletas envolvidos em atividades extenuantes não são clinicamente imunodeficientes, comparados com indivíduos sedentários. Essas modificações são transitórias, com retorno aos valores normais após aproximadamente 48 horas de repouso. A razão dessas alterações não é clara, mas se apresenta multifatorial: elevação de hormônios estressores; fatores nutricionais; ação de espécies reativas de oxigênio; e estresse psicológico. Apesar do efeito transitório das alterações provocadas nos elementos do sistema imune frente ao exercício, observa-se diferença na variabilidade da IgA-s em populações com diferentes níveis de condicionamento. Diferenças metodológicas - como o protocolo de exercício, o método de coleta, armazenamento e manipulação da saliva, a forma de expressão da IgA-s, o nível de hidratação, o controle da dieta, a sazonalidade do período de competição, a aclimatação entre outros fatores - devem ser levadas em consideração para comparação entre os estudos. Além disso, ajudam a explicar, em parte, os resultados adversos envolvendo exercício moderado e os intermitentes, em que se encontram aumento, redução e até ausência de alteração nos níveis de IgA-s. Investigações de elementos inovadores, como os toll-like receptors, e o avanço tecnológico podem colaborar para aumentar as evidências sobre o tema.

The impact of physical exercise on the gastrointestinal tract

PURPOSE OF REVIEW

Physical exercise can be both beneficial and harmful for the gastrointestinal tract in a dose-effect relationship between its intensity and health. Mild-to-moderate intensity exercises play a protective role against colon cancer, diverticular disease, cholelithiasis and constipation, whereas acute strenuous exercise may provoke heartburn, nausea, vomiting, abdominal pain, diarrhea and even gastrointestinal bleeding. This review focuses on mechanisms involved in those symptoms and their associations with type of exercises in humans.

RECENT FINDINGS

One quarter to one half of elite athletes are hampered by the gastrointestinal symptoms that may deter them from participation in training and competitive events. Vigorous exercise-induced gastrointestinal symptoms are often attributed to altered motility, mechanical factor or altered neuroimmunoendocrine secretions. Training, lifestyle modifications, meal composition, adequate hydration and avoidance of excessive use of some medications are the recommendations.

SUMMARY

Strenuous exercise and dehydrated states would be the causes of gastrointestinal symptoms referred by 70% of the athletes. Gut ischemia would be the main cause of nausea, vomiting, abdominal pain and (bloody) diarrhea. The frequency is almost twice as high during running than during other endurance sports as cycling or swimming and 1.5-3.0 times higher in the elite athletes than the recreational exercisers.

Muscle fatigue during football match-play

One of the consequences of sustaining exercise for 90 minutes of football match-play is that the capability of muscle to generate force declines. This impairment is reflected in the decline of work-rate towards the late part of the game. Causes of this phenomenon, which is known as fatigue, and some of its consequences are considered in this article. The stores of muscle glycogen may be considerably reduced by the end of the game, especially if there has not been a tapering of the training load. Thermoregulatory strain may also be encountered, resulting in a fall in physical performance, or there may be a reduced central drive from the nervous system. The decline in muscle strength may increase the predisposition to injury in the lower limbs. Central fatigue may also occur with implications for muscle performance. Strategies to offset fatigue include astute use of substitutions, appropriate nutritional preparation and balancing pre-cooling and warm-up procedures. There is also a role for endurance training and for a pacing strategy that optimizes the expenditure of energy during match-play.