The Impact of Abbreviated Progressive Muscle Relaxation on Salivary Cortisol and Salivary Immunoglobulin A (sIgA)

This study examined the acute effects of relaxation training on salivary cortisol and salivary immunoglobulin A (sIgA). Members of age- and gender-matched undergraduate student pairs were randomly assigned to an experimental or control group. Forty-one experimental subjects were led through Abbreviated Progressive Relaxation Training (APRT) during a 1-h laboratory session; 14 control subjects merely sat quietly in the laboratory for an equal amount of time. All subjects provided pre- and post-intervention saliva samples and self-report data on state anxiety, perceived stress, and relaxation levels. Heart rate was also monitored immediately before and after APRT or quiet sitting. Results indicated that a brief relaxation exercise led to experimental subjects having significantly lower levels of post-intervention salivary cortisol (p = .036) and significantly higher levels of post-intervention sIgA concentration (p < .001) and secretion rate (p < .001) than control subjects. The data suggest that relaxation training may play a role in immunoenhancement.     

Measurements of Salivary Alpha Amylase and Salivary Cortisol in Hominoid Primates Reveal Within-Species Consistency and Between-Species Differences

Salivary alpha amylase (sAA) is the most abundant enzyme in saliva. Studies in humans found variation in enzymatic activity of sAA across populations that could be linked to the copy number of loci for salivary amylase (AMY1), which was seen as an adaptive response to the intake of dietary starch. In addition to diet dependent variation, differences in sAA activity have been related to social stress. In a previous study, we found evidence for stress-induced variation in sAA activity in the bonobos, a hominoid primate that is closely related to humans. In this study, we explored patterns of variation in sAA activity in bonobos and three other hominoid primates, chimpanzee, gorilla, and orangutan to (a) examine if within-species differences in sAA activity found in bonobos are characteristic for hominoids and (b) assess the extent of variation in sAA activity between different species. The results revealed species-differences in sAA activity with gorillas and orangutans having higher basal sAA activity when compared to Pan. To assess the impact of stress, sAA values were related to cortisol levels measured in the same saliva samples. Gorillas and orangutans had low salivary cortisol concentrations and the highest cortisol concentration was found in samples from male bonobos, the group that also showed the highest sAA activity. Considering published information, the differences in sAA activity correspond with differences in AMY1 copy numbers and match with general features of natural diet. Studies on sAA activity have the potential to complement molecular studies and may contribute to research on feeding ecology and nutrition.     

Salivary Composition Is Associated with Liking and Usual Nutrient Intake

Salivary flow and composition have an impact on flavor perception. However, very few studies have explored the relationship between saliva, individual liking and usual dietary intake. The aim of our study was to evaluate the association of salivary flow and composition with both a liking for fat, saltiness and sweetness and the usual nutrient intake in an adult French population. Liking for fat, saltiness, and sweetness were inferred from liking scores obtained during hedonic tests on 32 food products among 282 French adults participating in the Nutrinet-Santé Study. Before assessing liking, resting saliva was collected. Standard biochemical analyses were performed to assess specific component concentrations and enzymatic activities. Dietary data were collected using three web-based 24h records. Relationships between salivary flow and composition, sensory liking and nutrient intake were assessed using linear regression. Total antioxidant capacity was positively associated with simple carbohydrate intake (β = 31.3, 95% CI = 1.58; 60.99) and inversely related to complex carbohydrate consumption (β = -52.4, 95% CI = -87.51; -19.71). Amylolysis was positively associated with both total (β = 0.20, 95% CI = 0.01; 0.38) and simple carbohydrate intake (β = 0.21, 95% CI = 0.01; 0.39). Salivary flow was positively associated with liking for fat (β = 0.14, 95% CI = 0.03; 0.25). Proteolysis was positively associated with liking for saltiness and for fat (β = 0.31, 95% CI = 0.02; 0.59; β = 0.28, 95% CI = 0.01; 0.56, respectively). Amylolysis was inversely associated with liking for sweetness (β = -10.13, 95% CI = -19.51; -0.75). Carbonic anhydrase 6 was inversely associated with liking for saltiness (β = -46.77, 95% CI = -86.24; -7.30). Saliva does not substantially vary according to a usual diet, except for carbohydrate intake, whereas the specific association between salivary flow/composition and sensory liking suggests the influence of saliva characteristics in food acceptance.     

Relationships between Training Load,Salivary Cortisol Responses and Performance during Season Training in Middle and Long Distance Runners

Purpose

Monitoring training from a multifactorial point of view is of great importance in elite endurance athletes. This study aims to analyze the relationships between indicators of training load, hormonal status and neuromuscular performance, and to compare these values with competition performance, in elite middle and long-distance runners.

Method

Fifteen elite middle and long-distance runners (12 men, 3 women; age = 26.3±5.1 yrs) were measured for training volume, training zone and session rate of perceived exertion (RPE) (daily), countermovement jump (CMJ) and salivary free cortisol (weekly) for 39 weeks (i.e., the whole season). Competition performance was also observed throughout the study, registering the season best and worst competitions.

Results

Season average salivary free cortisol concentrations correlate significantly with CMJ (r = −0.777) and RPE (r = 0.551). Also, weekly averages of CMJ significantly correlates with RPE (r = −0.426), distance run (r = −0.593, p<0.001) and training zone (r = 0.437, p<0.05). Finally, it was found that the CMJ (+8.5%, g = 0.65) and the RPE (−17.6%, g = 0.94) measured the week before the best competition performance of the season were significantly different compared with the measurement conducted the week before the season’s worst competition performance.

Conclusions

Monitoring weekly measurements of CMJ and RPE could be recommended to control training process of such athletes in a non-invasive, field-based, systematic way.     

Green Tea Consumption after Intense Taekwondo Training Enhances Salivary Defense Factors and Antibacterial Capacity

The aim of this study was to investigate the short-term effects of green tea consumption on selected salivary defense proteins, antibacterial capacity and anti-oxidation activity in taekwondo (TKD) athletes, following intensive training. Twenty-two TKD athletes performed a 2-hr TKD training session. After training, participants ingested green tea (T, caffeine 6 mg/kg and catechins 22 mg/kg) or an equal volume of water (W). Saliva samples were collected at three time points: before training (BT-T; BT-W), immediately after training (AT-T; AT-W), and 30 min after drinking green tea or water (Rec-T; Rec-W). Salivary total protein, immunoglobulin A (SIgA), lactoferrin, α-amylase activity, free radical scavenger activity (FRSA) and antibacterial capacity were measured. Salivary total protein, lactoferrin, SIgA concentrations and α-amylase activity increased significantly immediately after intensive TKD training. After tea drinking and 30 min rest, α-amylase activity and the ratio of α-amylase to total protein were significantly higher than before and after training. In addition, salivary antibacterial capacity was not affected by intense training, but green tea consumption after training enhanced salivary antibacterial capacity. Additionally, we observed that salivary FRSA was markedly suppressed immediately after training and quickly returned to pre-exercise values, regardless of which fluid was consumed. Our results show that green tea consumption significantly enhances the activity of α-amylase and salivary antibacterial capacity.     

Human Salivary Micro-RNA in Patients with Parotid Salivary Gland Neoplasms

Background

Currently, clinical examination, ultrasound scanning (with or without fine needle aspiration cytology), preoperative CT-scan and MRI are available for the differential diagnosis of parotid gland swelling. A preliminary non-invasive salivary diagnostic tool may be helpful in the clinical decision making process. Altered salivary micro-RNA (miRNA) expression levels have been observed in saliva from patients with various cancers. Therefore, we investigated miRNA expression levels in saliva samples from patients with a parotid gland neoplasm using Human miRNA cards in comparison to controls.

Results

In the discovery phase, eight miRNAs were identified having different expression levels in patients compared to controls. In the validation phase, the differences in miRNA expression levels between patients and controls were confirmed for seven out of eight discovered miRNAs (p < 0.001). A combination of two miRNAs yielded a receiver-operator-characteristics curve with an AUC of 0.94 (95% CI: 0.87–1.00; sensitivity 91%; specificity 86%). Validation of discovered miRNAs in segregated collected parotid saliva revealed that expression of these miRNAs differ between whole saliva and parotid saliva.

Conclusions

A two miRNA combination can predict the presence of a parotid gland neoplasm. Furthermore, this study suggested that the identified, patient-specific, salivary miRNAs were not derived from the parotid gland itself.     

Salivary Immunoglobulin A Secretion Rate Is Negatively Associated with Cancer Mortality: The West of Scotland Twenty-07 Study

Immunoglobulins are essential for combating infectious disease although very high levels can indicate underlying pathology. The present study examined associations between secretory immunoglobulin A (sIgA) in saliva and mortality rates in the general population. Participants were 639 adults from the eldest cohort of the West of Scotland Twenty-07 Study aged 63 years at the time of saliva sampling in 1995. From unstimulated 2-minute saliva samples, saliva volume and S-IgA concentration were measured, and S-IgA secretion rate determined as their product. Mortality data were tracked for 19 years. Cox proportional hazard models were applied to compute hazard ratios (HR) for all-cause mortality from sIgA secretion rate. Associations were adjusted for gender, assay batch, household occupational group, smoking, medication usage, and self-reported health. There was a negative association between log sIgA secretion rate and all-cause mortality, HR = 0.81, 95%CI = 0.73–0.91, p < .001. Further analysis of specific causes of mortality revealed that the all-cause association was due to an underlying association with cancer mortality and in particular with cancers other than lung cancer. The HR for non-lung cancer was 0.68 (95%CI = 0.54 to 0.85) implying a 32% reduction in mortality risk per standard deviation rise in log sIgA secretion rate. Effects were stronger for men than women. For deaths from respiratory diseases, sIgA secretion had a non-linear relationship with mortality risk whereby only the very lowest levels of secretion were associated with elevated risk. SIgA concentration revealed a similar but weaker pattern of association. In the present study, higher secretion rates of sIgA were associated with a decreased risk of death from cancer, specifically non-lung cancer, as well as from respiratory disease. Thus, it appears that sIgA plays a protective role among older adults, and could serve as a marker of mortality risk, specifically cancer mortality.     

Salivary alpha amylase and salivary cortisol response to fluid consumption in exercising athletes

The objective of the study was to examine salivary biomarker response to fluid consumption in exercising athletes. Exercise induces stress on the body and salivary alpha amylase (sAA) and salivary cortisol are useful biomarkers for activity in the sympathoadrenal medullary system and the hypothalamic pituitary adrenal axis which are involved in the stress response. Fifteen college students were given 150 ml and 500 ml of water on different days and blinded to fluid condition. The exercise protocol was identical for both fluid conditions using absolute exercise intensities ranging from moderate to high. Saliva was collected prior to exercise, post moderate and post high intensities and analyzed by Salimetrics assays. Exercise was significant for sAA with values different between pre-exercise (85 ± 10 U · ml⁻¹) and high intensity (284 ± 30 U · ml⁻¹) as well as between moderate intensity (204 ± 32 U · ml⁻¹) and high intensity. There was no difference in sAA values between fluid conditions at either intensity. Exercise intensity and fluid condition were each significant for cortisol. Cortisol values were different between pre-exercise (0.30 ± 0.03 ug · dL⁻¹) and high intensity (0.45 ± 0.05 ug · dL⁻¹) as well as between moderate intensity (0.33 ± 0.04 ug · dL⁻¹) and high intensity. Moderate exercise intensity cortisol was lower in the 500 ml condition (0.33 ± 0.03 ug · dL⁻¹) compared with the 150 ml condition (0.38 ± 0.03 ug · dL⁻¹). This altered physiological response due to fluid consumption could influence sport performance and should be considered. In addition, future sport and exercise studies should control for fluid consumption.     

Health-Related Physical Fitness in Healthy Untrained Men: Effects on VO2max,Jump Performance and Flexibility of Soccer and Moderate-Intensity Continuous Running

The purpose of this study was to determine the effects of recreational soccer (SOC) compared to moderate-intensity continuous running (RUN) on all health-related physical fitness components in healthy untrained men. Sixty-nine participants were recruited and randomly assigned to one of three groups, of which sixty-four completed the study: a soccer training group (SOC; n = 20, 34±4 (means±SD) years, 78.1±8.3 kg, 179±4 cm); a running group (RUN; n = 21, 32±4 years, 78.0±5.5 kg, 179±7 cm); or a passive control group (CON; n = 23, 30±3 years, 76.6±12.0 kg, 178±8 cm). The training intervention lasted 12 weeks and consisted of three 60-min sessions per week. All participants were tested for each of the following physical fitness components: maximal aerobic power, minute ventilation, maximal heart rate, squat jump (SJ), countermovement jump with arm swing (CMJ), sit-and-reach flexibility, and body composition. Over the 12 weeks, VO₂max relative to body weight increased more (p<0.05) in SOC (24.2%, ES = 1.20) and RUN (21.5%, ES = 1.17) than in CON (-5.0%, ES = -0.24), partly due to large changes in body mass (-5.9, -5.7 and +2.6 kg, p<0.05 for SOC, RUN and CON, respectively). Over the 12 weeks, SJ and CMJ performance increased more (p<0.05) in SOC (14.8 and 12.1%, ES = 1.08 and 0.81) than in RUN (3.3 and 3.0%, ES = 0.23 and 0.19) and CON (0.3 and 0.2%), while flexibility also increased more (p<0.05) in SOC (94%, ES = 0.97) than in RUN and CON (0–2%). In conclusion, untrained men displayed marked improvements in maximal aerobic power after 12 weeks of soccer training and moderate-intensity running, partly due to large decreases in body mass. Additionally soccer training induced pronounced positive effects on jump performance and flexibility, making soccer an effective broad-spectrum fitness training intervention.     

Effects of 1 vs. 2 sessions per week of equal-volume sprint training on explosive,high-intensity and endurance-intensive performances in young soccer players

The study aimed to evaluate the effects of 1 vs. 2 sessions per week of equal-volume sprint training on explosive, high-intensity and endurance-intensive performances among young soccer players. Thirty-six young male soccer players were randomly divided into 2 experimental groups that performed either a single weekly sprint training session (ST1, n = 18, age: 17.2 ± 0.8 years) or two weekly sprint training sessions (ST2, n = 18; age: 17.1 ± 0.9 years) of equal weekly and total volume, in addition to their regular soccer training regimen. Linear sprinting (10 m, 20 m, 30 m, and flying 10 m), T-test agility, countermovement jump (CMJ) and maximal oxygen consumption were assessed one week before (T1), in the middle (T2) and immediately after the 10 weeks of training (T3). A large magnitude and statistically significant main effect for time was found in all the assessed variables after both training interventions (all p < 0.001; ES ≥ 0.80). No main effect was observed between the 2 groups at any time in linear sprinting, T-test or CMJ test (p > 0.05; ES < 0.20). A significant interaction effect (F = 4.05; p = 0.04, ES = 0.21) was found for maximal oxygen consumption with ST2 inducing better performance than ST1 (p = 0.001; ES = 1.11). Our findings suggested that the two sprint training frequencies were effective in enhancing explosive, high-intensity and endurance-intensive performances. However, it is recommended for coaches and fitness coaches to use a biweekly sprint training modality as it was found to be more effective in improving endurance-intensive performance.     

Evaluation of Serum & Salivary IgA in Patients with Type 1 Diabetes

Background

Diabetes mellitus is a common immune mediated disorder. The aim of the present study is to evaluate the level of serum and salivary IgA levels in patients with Type 1 diabetes.

Material and Method

In this case control study, serum and salivary IgA levels of patients with diabetes type 1 and similar non diabetes subjects were measured. Age, gender, duration of diabetes and the last HbA1c level of diabetic patients were also studied. Data was analyzed by SPSS software.

Results

Two hundred and fifty subjects (126 diabetics and 124 non diabetics) were enrolled in the study. The mean value of serum IgA in patients with Type 1 Diabetes and controls was 1.77± 1.55 g/lit and 2.39± 1.52 g/lit, respectively. The mean salivary IgA level in diabetics and controls was 276 ± 162.5 40 μg/ml and 129 ± 112.2 40 μg/ml, respectively. Selective IgA deficiency was detected in two (1.6%) and three(2.4%)cases of diabetic and control group; respectively (p=0.68). We found low salivary IgA level in 44.4% diabetic and 33.9% control (p=0.08). There was no significant correlation between serum and salivary IgA level. There was also significant association between serum IgA levels with age. Salivary IgA was significantly correlated with HbA1c level. But considering gender, duration of diabetes we didn’t find any association.

Conclusion

We didn''t find any significant difference in serum and salivary IgA level among diabetic and non diabetics and also, no association between serum and salivary IgA levels.     

Temporal Stability of the Salivary Microbiota in Oral Health

Objectives

Saliva is a biological fluid suitable for biomarker analysis, and differences in the salivary microbiota in oral health and disease have been reported. For such comparative analyses, time of sampling is critical since the bacterial composition may vary throughout the day, i.e., diurnal variation. The purpose of this study is to compare the salivary microbiome over time to determine the optimal time for sampling.

Design

Stimulated saliva samples were collected from 5 orally healthy individuals in 4 h intervals for 24 h, and collection was repeated 7 days later (number of samples per person, n = 12, total number of samples, n = 60). Salivary microbiota was analyzed using the Human Oral Microbe Identification using Next Generation Sequencing (HOMINGS), and statistical analysis was performed using the Kruskal-Wallis test with Benjamini-Hochberg’s correction for multiple comparisons, cluster analysis, principal component analysis and correspondence analysis.

Results

From a total of 60 saliva samples, 477 probe targets were collectively identified with a mean number of probes per sample of 207 (range: 153–307). Little or no variation in microbial profiles within subjects was observed over time.

Conclusions

Although there was considerable variation between subjects, microbial profiles within subjects were stable throughout a 24 hour period and after 1 week. Since there is little or no evidence of diurnal variation of the salivary microbiome, time of sampling of saliva is not critical for perturbation or other microbial studies.     

Suppression of Radiation-Induced Salivary Gland Dysfunction by IGF-1

Background

Radiation is a primary or secondary therapeutic modality for treatment of head and neck cancer. A common side effect of irradiation to the neck and neck region is xerostomia caused by salivary gland dysfunction. Approximately 40,000 new cases of xerostomia result from radiation treatment in the United States each year. The ensuing salivary gland hypofunction results in significant morbidity and diminishes the effectiveness of anti-cancer therapies as well as the quality of life for these patients. Previous studies in a rat model have shown no correlation between induction of apoptosis in the salivary gland and either the immediate or chronic decrease in salivary function following γ-radiation treatment.

Methodology/Principal Finding

A significant level of apoptosis can be detected in the salivary glands of FVB mice following γ-radiation treatment of the head and neck and this apoptosis is suppressed in transgenic mice expressing an activated mutant of Akt (myr-Akt1). Importantly, this suppression of apoptosis in myr-Akt1 mice preserves salivary function, as measured by saliva output, three and thirty days after γ-radiation treatment. In order to translate these studies into a preclinal model we found that intravenous injection of IGF1 stimulated activation of endogenous Akt in the salivary glands in vivo. A single injection of IGF1 prior to exposure to γ-radiation diminishes salivary acinar cell apoptosis and completely preserves salivary gland function three and thirty days following irradiation.

Conclusions/Significance

These studies suggest that apoptosis of salivary acinar cells underlies salivary gland hypofunction occurring secondary to radiation of the head and neck region. Targeted delivery of IGF1 to the salivary gland of patients receiving head and neck irradiation may be useful in reducing or eliminating xerostomia and restoring quality of life to these patients.     

Salivary prions in sheep and deer

Scrapie of sheep and chronic wasting disease (CWD) of cervids are transmissible prion diseases. Milk and placenta have been identified as sources of scrapie prions but do not explain horizontal transmission. In contrast, CWD prions have been reported in saliva, urine and feces, which are thought to be responsible for horizontal transmission. While the titers of CWD prions have been measured in feces, levels in saliva or urine are unknown. Because sheep produce ∼17 L/day of saliva and scrapie prions are present in tongue and salivary glands of infected sheep, we asked if scrapie prions are shed in saliva. We inoculated transgenic (Tg) mice expressing ovine prion protein, Tg(OvPrP) mice, with saliva from seven Cheviot sheep with scrapie. Six of seven samples transmitted prions to Tg(OvPrP) mice with titers of −0.5 to 1.7 log ID₅₀ U/ml. Similarly, inoculation of saliva samples from two mule deer with CWD transmitted prions to Tg(ElkPrP) mice with titers of −1.1 to −0.4 log ID₅₀ U/ml. Assuming similar shedding kinetics for salivary prions as those for fecal prions of deer, we estimated the secreted salivary prion dose over a 10-mo period to be as high as 8.4 log ID₅₀ units for sheep and 7.0 log ID₅₀ units for deer. These estimates are similar to 7.9 log ID₅₀ units of fecal CWD prions for deer. Because saliva is mostly swallowed, salivary prions may reinfect tissues of the gastrointestinal tract and contribute to fecal prion shedding. Salivary prions shed into the environment provide an additional mechanism for horizontal prion transmission.Key words: scrapie, chronic wasting disease, saliva, horizontal transmission, titers     

Cardiac Fibrosis Alleviated by Exercise Training Is AMPK-Dependent

Regular exercise can protect the heart against external stimuli, but the mechanism is not well understood. We determined the role of adenosine monophosphate-activated protein kinase (AMPK) in regulating swimming exercise-mediated cardiac protection against β-adrenergic receptor overstimulation with isoproterenol (ISO) in mice. Ten-week-old AMPKα2^+/+ and AMPKα2-knockout (AMPKα2^-/-) littermates were subjected to 4 weeks of swimming training (50 min daily, 6 days a week) or housed under sedentary conditions. The mice received daily subcutaneous injection of ISO (5 mg/kg/d), a nonselective β-adrenergic receptor agonist, during the last 2 weeks of swimming training. Swimming training alleviated ISO-induced cardiac fibrosis in AMPKα2^+/+ mice but not AMPKα2^-/- mice. Swimming training activated cardiac AMPK in AMPKα2^+/+ mice. Furthermore, swimming training attenuated ISO-induced production of reactive oxygen species (ROS) and expression of NADPH oxidase and promoted the expression of antioxidant enzymes in AMPKα2^+/+ mice but not AMPKα2^-/- mice. In conclusion, swimming training attenuates ISO-induced cardiac fibrosis by inhibiting the NADPH oxidase–ROS pathway mediated by AMPK activation. Our findings provide a new mechanism for the cardioprotective effects of exercise.     

SALIVARY IL-21 AND IGA RESPONSES TO A COMPETITIVE MATCH IN ELITE BASKETBALL PLAYERS

Athletes engaged in strenuous training might experience transient immune suppression that could lead to greater incidence of upper respiratory tract infections (URTI). Since interleukin 21 (IL-21) stimulates immunoglobulin A (IgA) secreting cells and a low level of this immunoglobulin is associated with increased incidence of URTI, the aim of the present study was to investigate the effect of a basketball match on salivary cortisol (sC), salivary IL-21 (sIL-21) and salivary IgA (sIgA) levels. Twenty male basketball players participated in an official game in two teams (10 players in each team). The saliva samples were collected before the warm-up and approximately 10-15 min after the end of the match and were analysed by ELISA methods. sC concentration increased significantly after the match while sIL-21 level was reduced (p < 0.05). In opposition to the study''s hypothesis, sIgA level did not change in response to the match. The present findings suggest that a basketball match is sufficiently stressful to elevate sC concentration and attenuates the sIL-21 output without compromising the sIgA level. It is reasonable to speculate that the stability of sIgA acute responses to the match, despite the decrement in sIL-21, indicates that other mechanisms rather than IL-21 stimulating B cell proliferation/differentiation might modulate IgA concentration and secretion rate.     

Markers for Routine Assessment of Fatigue and Recovery in Male and Female Team Sport Athletes during High-Intensity Interval Training

Aim

Our study aimed to investigate changes of different markers for routine assessment of fatigue and recovery in response to high-intensity interval training (HIIT).

Methods

22 well-trained male and female team sport athletes (age, 23.0 ± 2.7 years; V̇O_2max, 57.6 ± 8.6 mL·min·kg⁻¹) participated in a six-day running-based HIIT-microcycle with a total of eleven HIIT sessions. Repeated sprint ability (RSA; criterion measure of fatigue and recovery), countermovement jump (CMJ) height, jump efficiency in a multiple rebound jump test (MRJ), 20-m sprint performance, muscle contractile properties, serum concentrations of creatinkinase (CK), c-reactive protein (CRP) and urea as well as perceived muscle soreness (DOMS) were measured pre and post the training program as well as after 72 h of recovery.

Results

Following the microcycle significant changes (p < 0.05) in RSA as well as in CMJ and MRJ performance could be observed, showing a decline (%Δ ± 90% confidence limits, ES = effect size; RSA: -3.8 ± 1.0, ES = -1.51; CMJ: 8.4 ± 2.9, ES = -1.35; MRJ: 17.4 ± 4.5, ES = -1.60) and a return to baseline level (RSA: 2.8 ± 2.6, ES = 0.53; CMJ: 4.1 ± 2.9, ES = 0.68; MRJ: 6.5 ± 4.5, ES = 0.63) after 72 h of recovery. Athletes also demonstrated significant changes (p < 0.05) in muscle contractile properties, CK, and DOMS following the training program and after the recovery period. In contrast, CRP and urea remained unchanged throughout the study. Further analysis revealed that the accuracy of markers for assessment of fatigue and recovery in comparison to RSA derived from a contingency table was insufficient. Multiple regression analysis also showed no correlations between changes in RSA and any of the markers.

Conclusions

Mean changes in measures of neuromuscular function, CK and DOMS are related to HIIT induced fatigue and subsequent recovery. However, low accuracy of a single or combined use of these markers requires the verification of their applicability on an individual basis.     

Repeated Oronasal Exposure to Lipopolysaccharide Induced Mucosal IgA Responses in Periparturient Dairy Cows

This study investigated the effects of repeated oronasal treatment with lipopolysaccharide (LPS) on the humoral immune responses in saliva, vaginal mucus, and the plasma markers of the acute phase response in periparturient dairy cows. One hundred pregnant Holstein cows were administered either 3 increasing doses of LPS (n = 50) as follows: 1) 0.01 µg/kg body weight (BW) on d −28, 2) 0.05 µg/kg BW on d −25, and −21, and 3) 0.1 µg/kg BW on d −18, and −14, or sterile saline solution (controls; n = 50) oronasally for 3 consecutive wk starting at 28 d before parturition. Intensive sampling was conducted on thirty cows (n = 15/group). Multiple saliva, vaginal mucus and blood samples were collected around parturition and analyzed for total immunoglobulin-(Ig)A, plasma serum amyloid A (SAA), lipopolysaccharide-binding protein (LBP), anti-LPS IgA, IgG, IgM, tumour necrosis factor(TNF)-α, and interleukin(IL)-1. Results regarding total secretory IgA (sIgA) antibodies showed greater concentrations in the saliva and an overall tendency for higher total sIgA in the vaginal mucus of the LPS-treated cows. Treatment had no effect on plasma sIgA, IgG, IgM anti-LPS antibodies, haptoglobin, SAA, LBP, TNF-α, and IL-1. Treatments by time interactions were observed for SAA and IL-1 with lowered concentrations of both variables in the plasma of LPS-treated cows after parturition. Overall, repeated oronasal LPS treatment clearly enhanced total sIgA antibodies in the saliva, stimulated their production in vaginal mucus shortly before calving, and lowered plasma IL-1 around parturition, but showed limited effects on markers of the acute phase response in the plasma in dairy cows around parturition.     

Resisted sprint training with partner towing improves explosive force and sprint performance in young soccer players – a pilot study

The purpose of this study was to examine the effects of non-resisted (NRS) and partner-towing resisted (RS) sprint training on legs explosive force, sprint performance and sprint kinematic parameters. Sixteen young elite soccer players (age 16.6 ± 0.2 years, height 175.6 ± 5.7 cm, and body mass 67.6 ± 8.2 kg) were randomly allocated to two training groups: resisted sprint RS (n = 7) and non-resisted sprint NRS (n = 9). The RS group followed a six-week sprint training programme consisting of two “sprint training sessions” per week in addition to their usual soccer training. The NRS group followed a similar sprint training programme, replicating the distances of sprints but without any added resistance. All players were assessed before and after training: vertical and horizontal jumping (countermovement jump (CMJ), squat jump (SJ), and 5-jump test (5JT)), 30 m sprint performance (5, 10, and 20 m split times), and running kinematics (stride length and frequency). In the RS group significant (p < 0.05) changes were: decreased sprint time for 0–5 m, 0–10 m and 0–30 m (-6.31, -5.73 and -2.00%; effect size (ES) = 0.70, 1.00 and 0.41, respectively); higher peak jumping height (4.23% and 3.59%; ES = 0.35 and 0.37, for SJ and CMJ respectively); and 5JT (3.10%; ES = 0.44); and increased stride frequency (3.96%; ES = 0.76). In the NRS group, significant (p < 0.05) changes were: decreased sprint time at 0–30 m (-1.34%, ES = 0.33) and increased stride length (1.21%; ES = 0.17). RS training (partner towing) for six weeks in young soccer players showed more effective performances in sprint, stride frequency and lower-limb explosive force, while NRS training improved sprint performance at 0–30 m and stride length. Consequently, coaches and physical trainers should consider including RS training as part of their sprint training to ensure optimal sprint performance.