Effect of acute exercise on the levels of salivary cortisol, tumor necrosis factor-alpha and nitric oxide

Perceived stress and salivary biomarkers in educators: comparison among three stress reduction activities

Background:

The teaching profession is a potentially stressful occupation with up to 30% of all novice teachers leaving the profession and annual teacher turnover is higher when compared with turnover of all other occupations. This study investigated the effects of a one-time stress reduction activity (meditation, yoga, or aerobic exercise) in university and K-12 educators who were part of one-day seminar on Stress Reduction.

Methods:

Participants (N = 26) self-selected their stress reduction activity, completed a demographic questionnaire, educator stress self-assessment tool, and visual analogue scales indicating current stress levels. Salivary cortisol and amylase levels were measured before, immediately after, and 30 minutes after completion of the stress reduction activity.

Results:

Three (time) by three (activity) mixed factorial ANOVAs were computed for salivary analytes. The ANOVA for cortisol revealed a significant interaction (F (4, 66) = 3.60, p = .01). Comparisons showed significant differences with the aerobic exercise group having significantly higher cortisol levels at the 30-minute post-activity level when compared to the meditation (p < .05, Cohen’s d = .74) and yoga groups (p < .05, Cohen’s d = .52).

Conclusion:

Overall, the one-time activity of meditation and yoga showed lowered salivary cortisol levels at 30-minutes post-activity when compared to aerobic exercise activity. Additional research to examine the effects of stress reduction on educators in the work setting is needed.

Salivary Diagnostic for Monitoring Strenuous Exercise-A Pilot Study in a Cohort of Male Ultramarathon Runners

Intense physical stress, such as that in ultramarathon running, affects the immune system. For monitoring in sports medicine, non-invasive methods, e.g., salivary analysis, are of interest. This pilot cohort study aimed to assess changes in salivary parameters in response to an ultramarathon. The results were compared to blood parameters. Male, healthy finishers (n = 9, mean age: 48 ± 8.8 years, mean height: 1.8 ± 0.1 m, mean weight: 72.5 ± 7.2 kg, mean BMI: 23.5 ± 1.9 kg/cm²) of a 160 km ultramarathon were included. Saliva and blood samples were collected at three time points: T1 (baseline), T2 (shortly after the ultramarathon) and T3 (after recovery). In saliva, cortisol, testosterone, IL-1β, IL-6, IL-8, IL-10, TNF-α, albumin, IgA, α-amylase, aMMP-8, and neopterin were assessed via ELISA. In blood, cortisol, testosterone, IL-1β, IL-6, IL-8, IL-10, TNF-α, blood cell counts, procalcitonin, CRP, osmolality, albumin, and α-amylase were analyzed. The statistical evaluation comprised longitudinal testing and cross-sectional testing between saliva and blood using ratios of T2 and T3 to baseline values. Various parameters in saliva and blood changed in response to the ultramarathon. Comparing blood and saliva, the longitudinal changes of testosterone (p = 0.02) and α-amylase (p = 0.03) differed significantly. Despite the limitations of the study, it underlines that saliva is an interesting option for comprehensive monitoring in sports medicine and necessitates further studies.

Salivary endocrine response following a maximal incremental cycling protocol with local vibration

The aim of this study was to compare the effects of vibration (Vib versus noVib) during a maximal graded cycling exercise on hormonal response, precisely on cortisol (C) and testosterone (T). Twelve active males (25 ± 5yrs; 181 ± 5cm; 80.7 ± 11.1kg) randomly performed two maximal incremental cycling tests on two separate days and at the same time of the day (09:00). The protocol consisted of incremental steps of 3 min duration performed on a PowerBIKE^TM that induces vibration cycling. The study was a repeated measures design and participants performed the test with and without vibration. Gas exchange and heart rate (HR) were continuously assessed and blood lactate (Bla) was recorded at the end of each incremental stage. Saliva samples were collected before and immediately after the test, and analysed for (C) and (T).

The results show that C and T increased in both cycling conditions; however, the C’s magnitude of change was significantly higher by 83% after Vib cycling in comparison to the no Vib (p = 0.014), whereas the T’s magnitude of change were not statistically different between trials (p = 0.715). Vibration induced a decrease of the T/C ratio (p = 0.046) but no significant changes were observed following noVib (p = 0.476). As a conclusion, the investigation suggests that adding mechanical vibration to cycling may potentiate a catabolic exercise-induced state, which could have potential clinical implications in rehabilitation and injury treatment. Sport experts should take this message home to carefully plan the recovery process and time during training and competitions.

A systematic review of the Trier Social Stress Test methodology: Issues in promoting study comparison and replicable research

Since its development in 1993, the Trier Social Stress Test (TSST) has been used widely as a psychosocial stress paradigm to activate the sympathetic nervous system and hypothalamic-pituitary-adrenal axis (HPAA) stress systems, stimulating physiological functions (e.g. heart rate) and cortisol secretion. Several methodological variations introduced over the years have led the scientific community to question replication between studies. In this systematic review, we used the Preferred Reporting Items of Systematic Reviews and Meta-Analysis (PRISMA) to synthesize procedure-related data available about the TSST protocol to highlight commonalities and differences across studies. We noted significant discrepancies across studies in how researchers applied the TSST protocol. In particular, we highlight variations in testing procedures (e.g., number of judges, initial number in the arithmetic task, time of the collected saliva samples for cortisol) and discuss possible misinterpretation in comparing findings from studies failing to control for variables or using a modified version from the original protocol. Further, we recommend that researchers use a standardized background questionnaire when using the TSST to identify factors that may influence physiological measurements in tandem with a summary of this review as a protocol guide. More systematic implementation and detailed reporting of TSST methodology will promote study replication, optimize comparison of findings, and foster an informed understanding of factors affecting responses to social stressors in healthy people and those with pathological conditions.

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.

The effects of isoflavone supplementation plus combined exercise on salivary markers of oxidative stress in postmenopausal women

This study tested the effect of isoflavone supplementation in addition to combined exercise training in salivary oxidative stress markers in non-obese postmenopausal women. Thirty-two postmenopausal women without hormone therapy were randomly assigned to exercise + placebo (n = 15) or exercise + isoflavone supplementation (n = 17) groups. They performed 30 sessions of combined exercises (aerobic plus resistance) over ten weeks and consumed 100 mg of isoflavone supplementation or placebo. Saliva samples were collected after an overnight fast. Superoxide dismutase, total antioxidant capacity, thiobarbituric acid reactive substances, catalase, total protein and nitrite were determined before and after ten weeks of the intervention. The ANOVA two-way analysis of variance was applied with α of 5%. Both groups increase (p<0.05) superoxide dismutase activity and decrease catalase levels. There was interaction (time × group) in both nitrite and thiobarbituric acid reactive substances results, with increase (p<0.05) in placebo group and decrease (p<0.05) in isoflavone group. No difference was found for total antioxidant capacity or total protein. The combination of isoflavone supplementation and exercise training can promote an antioxidant effect through reduction of lipid peroxidation and concentrations of salivary nitrite.

Influence of acute high-intensity exercise on salivary nitric oxide levels

This study, employing an exercise versus control crossover design, was conducted to investigate the influence of acute high-intensity exercise on salivary nitric oxide (NO) levels. Nine healthy males (aged 23.8 ± 1.4 years) performed ergometer exercise at 80%VO_2peak for 60 min, whereas controls sat at rest for 60 min. Saliva samples were collected before (Pre: 0800 h) and after (Post 0-h: 0900 h, Post 1-h: 1000 h, Post 2-h: 1100 h, Post 3-h: 1200 h) the interventions. Salivary NO levels were determined by colorimetric assay. It was found that the salivary NO levels in controls were decreased (P < 0.05) at Post 0-h (-94 ± 15), Post 1-h (-80 ± 20), Post 2-h (-92 ± 34) and Post 3-h (-145 ± 39) relative to the Pre values. Under exercise conditions, salivary NO levels did not change after high-intensity ergometer exercise relative to the Pre values. Thus, the response of salivary NO levels appeared to differ between high-intensity ergometer exercise and inactivity, that exercise-related stress induces the production of salivary NO.

Assessment of Salivary Nitric Oxide Levels in Elite University Athletes in Japan: Findings From a Cross Sectional Study Design

Background

High-intensity exercise affects the level of salivary nitric oxide (NO) with an impact on oxidative stress such as a reactive nitrogen-oxide species. However, in athletes with high-intensity training, the relationship between salivary NO levels and oxidative stress is yet to be clear. Additionally, the association of salivary NO levels and the common health disorders of athletes is unknown. Thus, the aim of this cross-sectional study was to clarify the relationship between salivary NO levels and oxidative stress, and the health/medical disorders existing in elite class university athletes.

Methods

In 250 athletes (males, 151 and females, 99) from undergraduate levels of Japanese University, we investigated the relationship between levels of salivary NO and oxidative stress markers: derived reactive oxygen species (d-ROMs) and biological antioxidant potential (BAP), and also examined that whether salivary NO levels are associated with diseases.

Results

There were no significant association between the levels of salivary NO and oxidative stress markers (such as d-ROM and BAP). From the questionnaire, asthma was the most prevalent as evident from medical history of the athletes. Additionally, the salivary NO levels were higher (520 ± 43 µmol/L vs. 375 ± 13 µmol/L, P < 0.05) in the asthma group (n = 9) than in the non-asthma group (n = 241). We determined the optimal cut-off value (P = 0.019) of the salivary NO levels for asthma was 425 µmol/L, with a sensitivity of 88.9% and specificity of 61.8% (area under the curve (AUC), 0.73).

Conclusions

Our results suggest that the high levels of salivary NO in trained university athletes in Japan may potentially predict asthma. And this salivary NO level is not associated with markers of oxidative stress and existing diseases in athletes studied here.

Night work effects on salivary cytokines TNF, IL-1β and IL-6

Shift work is unavoidable in modern societies, but at the same time disrupts biological rhythms and contributes to social distress and disturbance of sleep, health and well-being of shift workers. Shift work has been associated with some chronic diseases in which a chronic inflammatory condition may play a role. However, few studies investigating the association of cytokine and other inflammation markers with shift workers have been published in recent years. In this study we evaluated the effects of permanent night work on the production of tumor necrosis factor (TNF), interleukin-1β (IL-1β), IL-6 and melatonin in saliva. Another aim was to demonstrate the benefit of the use of salivary cytokines for studies in chronobiology, since it is an easy and non-invasive method that allows for sampling at several times. Thirty-eight healthy male workers, being 21 day workers and 17 night workers, agreed to participate in this study. Sleep was evaluated by actigraphy and activity protocols. Saliva was collected during three workdays approximately at the middle of the work shift and at bed and wake times of the main sleep episode. Saliva samples were then analyzed by enzyme-linked immunosorbent assay to measure TNF, IL-1β, IL-6 and melatonin levels, and the results were submitted to non-parametric statistical analysis. The use of saliva instead of blood allowed for a greater number of samples from the same subjects, allowing identifying alterations in the daily production patterns of salivary cytokines TNF, IL-1β and IL-6 that probably are linked to night work. Salivary TNF and IL-1β levels were similar for day and night workers, with higher daily production after awakening, in the morning hours for day workers and in the afternoon for night workers. Both groups presented a significant daily variation pattern of these two cytokines. Day and night workers produced similar amounts of salivary IL-6. Nevertheless, the daily variation pattern observed among day workers, with a peak after awakening, was absent among night workers. Thus, in our study, night workers showed partially adjusted daily variation patterns for salivary TNF and IL-1β, not seen for salivary IL-6. Results for salivary IL-6 could be better explained as a consequence of circadian disruption due to permanent night work. Our results suggest that the whole circadian system, including clocks and pineal gland, is involved in regulating cytokine profile in shift workers and that a coordinated production of these cytokines, important for an adequate inflammatory response, could be disturbed by shift work. The distinct effects that shift work may have on different cytokines could give some cues about the mechanisms involved in this association.

Rationale and design of the Caloric Restriction and Exercise protection from Anthracycline Toxic Effects (CREATE) study: a 3-arm parallel group phase II randomized controlled trial in early breast cancer

Background

Anthracycline chemotherapy agents are commonly used to treat breast cancer, but also result in cardiac injury, and potentially detrimental effects to vascular and skeletal muscle. Preclinical evidence demonstrates that exercise and caloric restriction can independently reduce anthracycline-related injury to the heart as well as cancer progression, and may be promising short-term strategies prior to treatment administration. For women with breast cancer, a short-term strategy may be more feasible and appealing, as maintaining regular exercise training or a diet throughout chemotherapy can be challenging due to treatment symptoms and psychosocial distress.

Methods

The Caloric Restriction and Exercise protection from Anthracycline Toxic Effects (CREATE) study will determine whether acute application of these interventions shortly prior to receipt of each treatment can reduce anthracycline-related toxicity to the heart, aorta, and skeletal muscle. Fifty-six women with early stage breast cancer scheduled to receive anthracycline treatment will be randomly assigned to one of three groups who will: 1) perform a single, 30-min, vigorous-intensity, aerobic exercise session 24 h prior to each anthracycline treatment; 2) consume a prepared diet reduced to 50% of caloric needs for 48 h prior to each anthracycline treatment; or 3) receive usual cancer care. The primary outcome is magnetic resonance imaging (MRI) derived left ventricular ejection fraction reserve (peak exercise LVEF – resting LVEF) at the end of anthracycline treatment. Secondary outcomes include MRI-derived measures of cardiac, aortic and skeletal muscle structure and function, circulating NT-proBNP, cardiorespiratory fitness and treatment symptoms. Exploratory outcomes include quality of life, fatigue, tumor size (only in neoadjuvant patients), oxidative stress and antioxidants, as well as clinical cardiac or cancer outcomes. MRI, exercise tests, and questionnaires will be administered before, 2–3 weeks after the last anthracycline treatment, and one-year follow-up.

Discussion

The proposed lifestyle interventions are accessible, low cost, drug-free potential methods for mitigating anthracycline-related toxicity. Reduced toxic effects on the heart, aorta and muscle are very likely to translate to short and long-term cardiovascular health benefits, including enhanced resilience to the effects of subsequent cancer treatment (e.g., radiation, trastuzumab) aging, and infection.

Trial registration

ClinicalTrials.gov NCT03131024; 4/21/18.

Effects of Carbohydrate and Glutamine Supplementation on Oral Mucosa Immunity after Strenuous Exercise at High Altitude: A Double-Blind Randomized Trial

This study analyzed the effects of carbohydrate and glutamine supplementation on salivary immunity after exercise at a simulated altitude of 4500 m. Fifteen volunteers performed exercise of 70% of VO_2peak until exhaustion and were divided into three groups: hypoxia placebo, hypoxia 8% maltodextrin (200 mL/20 min), and hypoxia after six days glutamine (20 g/day) and 8% maltodextrin (200 mL/20 min). All procedures were randomized and double-blind. Saliva was collected at rest (basal), before exercise (pre-exercise), immediately after exercise (post-exercise), and two hours after exercise. Analysis of Variance (ANOVA) for repeated measures and Tukey post hoc test were performed. Statistical significance was set at p < 0.05. SaO₂% reduced when comparing baseline vs. pre-exercise, post-exercise, and after recovery for all three groups. There was also a reduction of SaO₂% in pre-exercise vs. post-exercise for the hypoxia group and an increase was observed in pre-exercise vs. recovery for both supplementation groups, and between post-exercise and for the three groups studied. There was an increase of salivary flow in post-exercise vs. recovery in Hypoxia + Carbohydrate group. Immunoglobulin A (IgA) decreased from baseline vs. post-exercise for Hypoxia + Glutamine group. Interleukin 10 (IL-10) increased from post-exercise vs. after recovery in Hypoxia + Carbohydrate group. Reduction of tumor necrosis factor alpha (TNF-α) was observed from baseline vs. post-exercise and after recovery for the Hypoxia + Carbohydrate group; a lower concentration was observed in pre-exercise vs. post-exercise and recovery. TNF-α had a reduction from baseline vs. post-exercise for both supplementation groups, and a lower secretion between baseline vs. recovery, and pre-exercise vs. post-exercise for Hypoxia + Carbohydrate group. Five hours of hypoxia and exercise did not change IgA. Carbohydrates, with greater efficiency than glutamine, induced anti-inflammatory responses.

Excess Blood Flow Response to Acute Resistance Exercise in Individuals Who are Obese or Nonobese

Lipford, GF, Evans, RK, Acevedo, EO, Wolfe, LG, and Franco, RL. Excess blood flow response to acute resistance exercise in individuals who are obese or nonobese. J Strength Cond Res 31(11): 3120-3127, 2017-Resistance exercise (RE) is a commonly recommended treatment option for obese individuals. However, little is known regarding alterations in vasodilatory responses to RE, which could impair exercise tolerance. No studies to date have compared microvascular vasodilatory capacity, assessed by excess blood flow (EBF), responses in individuals who are obese or nonobese following acute RE. The purpose of the study was to evaluate EBF before and up to 24-hour after a single RE bout in obese (n = 18, 38.1 ± 7.64% body fat) and nonobese (n = 10, 23.6 ± 4.03% body fat) individuals who volunteered to participate. Each subject completed a leg flexion and knee extension one repetition maximum (1RM) test, and subsequently completed 4 sets of 8 repetitions at 85% of 1RM. Excess blood flow, adiponectin, and tumor necrosis factor α (TNF-α) were evaluated at baseline (PRE-RE), immediately after (POST-RE), and 1 (POST-1) and 24 (POST-24) hours after exercise. A repeated-measures analysis of variance revealed a significant interaction for EBF between the 2 groups (p = 0.029). The estimated marginal means plot suggested that obese individuals had a significant increase in POST-RE EBF in comparison with PRE-RE EBF (428.54 ± 261.59 vs. 547.00 ± 311.15 ml/100 ml/min·s; p = 0.046). In addition, EBF significantly decreased at POST-24 in comparison with POST-RE in the obese individuals (547.00 ± 311.15 vs. 389.33 ± 252.32 ml/100 ml/min·s; p = 0.011). Changes in EBF were not related to adiponectin or TNF-α. An acute bout of RE resulted in an opposite EBF response between nonobese and obese individuals immediately after RE. Furthermore, only the obese individuals displayed a significant increase in EBF immediately after RE, which was significantly reduced 24 hours after the RE bout. Microvascular vasodilatory capacity may alter the adaptive exercise response associated with RE, requiring alterations to frequency, intensity, and/or duration that are specific to populations of various body composition profiles.

Effects of acute exercise on salivary free insulin-like growth factor 1 and interleukin 10 in sportsmen

BACKGROUND

Saliva analysis is rapidly developing as a tool for the assessment of biomarkers of sports training. It remains poorly understood whether a short bout of sport training can alter some salivary immune biomarkers.

AIM

To investigate the effect of acute exercise using football training session on salivary flow rate, salivary free Insulin-like Growth Factor-1 (IGF-1) and Interleukin 10 (IL-10).

METHODS

Saliva samples were collected before and immediately after a football session. Salivary flow rates, salivary levels of free IGF-1 and IL-10 (using ELISA) were determined. Data was analyzed and compared using Related Samples Wilcoxon Signed Rank test (non-parametric test). Relationships between salivary flow rate and levels of free IGF-1 and IL-10 were determined using Spearman correlation test.

RESULTS

There were 22 male footballers with a mean age of 20.46 years. Salivary flow rate reduced significantly (p = 0.01) after the training session while salivary levels of free IGF-1 and IL-10 did not show any significant change. Also, there were no correlations between salivary flow rates and salivary levels of free IGF-1 and IL-10 before and after exercise.

CONCLUSION

These findings suggest that acute exercise caused significant reduction in salivary flow rate but no change in the levels of salivary free IGF-1 and IL-10.

The effects of four weeks aerobic training on saliva cortisol and testosterone in young healthy persons

[Purpose] The purpose of this study was to evaluate the effect of 4 weeks moderate aerobic exercise on outcome measures of saliva stress hormones and lactate levels in healthy adult volunteers. [Subjects and Methods] Sixteen healthy students with an age range of 15-25 years participated in this study. The participants performed an exercise test of moderate intensity for 4 weeks, three times per week. The exercise was treadmill walking. Saliva concentrations of cortisol, testosterone and lactate dehydrogenase (LDH) were measured before and after the 4 weeks of moderate aerobic training using immunoassay techniques. [Results] After 4 weeks of exercise, there were significant increases in cortisol, free testosterone levels, and LDH activity along with a significant decrease in the ratios between testosterone and cortisol levels. No significant correlations were found among the studied parameters in the resting stage, a result which supports the positive effect of exercise on stress hormones following 4 weeks of training. [Conclusion] The results suggest that four weeks exercise of moderate intensity significantly affects the salivary stress hormones of young healthy volunteers. The data support the importance of salivary stress hormones as potential biological markers especially for older ages. However, more research is required to validate these biological markers which determine the host response to physical activity.

Emotions, immunity and sport: Winner and loser athlete's profile of fighting sport

Several studies have focused on the relationship between hormonal changes and affective states in sporting contexts relating to an agonistic outcome. More recently, pro-inflammatory cytokines have also been successfully associated with affective state modulation. The aim of this study was to investigate whether athletes who won or lost show different levels of steroid hormones (testosterone and cortisol), pro-inflammatory cytokine IL-1β, or expressions of anger and anxiety during six training fights in seasonal competitions down to the main seasonal competition. In 25 male kick-boxing athletes (age±SD, 28.68±5.34), anger states (RS score) and anxiety states (AS score) were assessed by STAXI-2 and STAI-Y, respectively. Cortisol (C), testosterone (T) and IL-1β salivary levels were measured by the ELISA method. The saliva samples were taken in the afternoon, 30min prior to the start and 30min from the end of both simulated and official competitions. The results showed that the RS score, T, T/C ratio salivary levels increased during the season, whereas the AS score, C and IL-1β suggested an opposite trend. Close to an official competition, the RS score, T, T/C ratio and IL-1β salivary concentrations were significantly higher, and then decreased during competition. By contrast, the AS score and C levels significantly increased throughout the official competition. In addition, significant differences were found for hormones and IL-1β concentrations as well as psychometric assessment close to the outcome of an official match. Athletes who lost showed an higher AS score and C level, while those who won were characterized by an higher level during the pre-competition RS score, T, T/C ratio, and IL-1β. Note that these factors were positively and significantly correlated at the pre-official competition time, while in a linear regression analysis, IL-1β, T and T/C ratio concentrations explained 43% of the variance in the RS score observed at the same time (adjusted R(2)=0.43, ANOVA P<.05). Our data suggest that the beginning of an agonistic event could trigger emotional responses which correspond to different biological processes instead that of a simulated fight. In particular, IL-1β could be a potential new biological marker of anger and the combined measurement of these factors may be a useful way of understanding athletes' change in relation to their performance.

Effect of orally administered soy milk fermented with Lactobacillus plantarum LAB12 and physical exercise on murine immune responses

Probiotics are live microorganisms that confer health benefits through the gastrointestinal microbiota. This nutritional supplement may benefit athletes who undergo rigorous training by maintaining their gastrointestinal functions and overall health. In this study the influence of moderate physical exercise using a graded treadmill exercise, alone or in combination with the consumption of a soy product fermented with Lactobacillus plantarum LAB12 (LAB12), on tumour necrosis factor alpha (TNF-α) responses was investigated in a murine model. Male BALB/c mice were randomly divided into four groups of six mice each (control, exercise alone, LAB12 and LAB12 + exercise). Mice treated with the potential probiotic LAB12 were orally gavaged for 42 days. At autopsy, blood and spleen from the animals were collected. The splenocytes were cultured in the presence of a mitogen, concanavalin A (Con A). The amount of TNF-α produced by the Con A-stimulated splenocytes was quantified using ELISA, while their proliferation was determined using the [(3)H]-thymidine incorporation method. This study shows that LAB12-supplemented and exercise-induced mice showed marked increase (P<0.05) in cell proliferation compared to the control animals. TNF-α production was suppressed (P<0.05) in the LAB12 group compared to the untreated mice. These results demonstrate that supplementation with LAB12 has immunomodulatory effects, under conditions of moderate physical exercise, which may have implications for human athletes. Further investigation in human trials is warranted to confirm and extrapolate these findings.

Salivary surrogates of plasma nitrite and catecholamines during a 21-week training season in swimmers

The collection of samples of saliva is noninvasive and straightforward, which turns saliva into an ideal fluid for monitoring the adaptive response to training. Here, we investigated the response of the salivary proteins alpha-amylase (sAA), chromogranin A (sCgA), and the concentration of total protein (sTP) as well as salivary nitrite (sNO2) in relation to plasma catecholamines and plasma nitrite (pNO2), respectively. The variation in these markers was compared to the intensity and load of training during a 21-week training season in 12 elite swimmers. Overall, the salivary proteins tracked the concentration of plasma adrenaline and were inversely correlated with the training outcomes. No correlations were observed between sNO2 and pNO2. However, sNO2 correlated positively with the intensity and load of training. We argue that the decrease in sympathetic activity is responsible for the decrease in the concentration of proteins throughout the training season. Furthermore, the increase in nitrite is likely to reflect changes in hemodynamics and regulation of vascular tone. The association of the salivary markers with the training outcomes underlines their potential as noninvasive markers of training status in professional athletes.