UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research.

Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a 'food first' philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.

Reliability of salivary cortisol and testosterone to a high-intensity cycling protocol to highlight overtraining.

Athletes physically overload to improve performance. Unbalanced stress/recovery may induce overtraining, which is difficult to diagnosis as no diagnostic marker exists. Hormonal responses to a 55/80 cycle (30-min of alternating blocks of 1-min at 55% and 4-min at 80% maximum work rate) may highlight early-stage overtraining (overreaching), as blunted cortisol and testosterone responses to 55/80 follows intensified training. However, the reliability of hormonal responses to 55/80 when not overreached is unknown. Therefore, reported blunted hormonal responses could be due to inconsistent cortisol and testosterone responses to 55/80. Participants (n = 23) completed three 55/80 bouts, >7 days apart, with no exercise 24 h pre-trials. Pre-exercise urine osmolality and stress questionnaire responses were measured. Pre, post, and 30-min post-exercise saliva samples were collected for cortisol and testosterone assessment. Salivary cortisol and testosterone responses, osmolality and well-being were not different between trials. Salivary cortisol and testosterone elevated from pre- to post-exercise [by 4.2 nmol.L-1 (cortisol) and 307 pmol.L-1 (testosterone)], and 30 min post-exercise [by 160 pmol.L-1 (testosterone) only]. Intraclass correlation coefficients for pre to peak post-exercise cortisol (0.89; good) and testosterone (0.53; moderate) were calculated. This demonstrates that 55/80 induces reliable elevations of salivary cortisol and testosterone when in a healthy state.

Hyperbaric oxygen therapy is well tolerated and effective for ulcerative colitis patients hospitalized for moderate-severe flares: a phase 2A pilot multi-center, randomized, double-blind, sham-controlled trial.

BACKGROUND: Hyperbaric oxygen therapy (HBOT) markedly increases tissue oxygen delivery. Case series suggest it may have a potential therapeutic benefit in ulcerative colitis (UC). We investigated the therapeutic potential of HBOT as an adjunct to steroids for UC flares requiring hospitalization. METHODS: The study was terminated early due to poor recruitment with 18 of the planned 70 patients enrolled. UC patients hospitalized for moderate-severe flares (Mayo score ≥6, endoscopic sub-score ≥2) were block randomized to steroids + daily HBOT (n = 10) or steroids + daily sham hyperbaric air (n = 8). Patients were blinded to study assignment, and assessments were performed by a blinded gastroenterologist. Primary outcome was the clinical remission rate at study day 5 (partial Mayo score ≤2 with no sub-score >1). Key secondary outcomes were: clinical response (reduction in partial Mayo score ≥2, rectal bleeding sub-score of 0-1) and progression to second-line therapy (colectomy or biologic therapy) during the hospitalization. RESULTS: A significantly higher proportion of HBOT-treated patients achieved clinical remission at study day 5 and 10 (50 vs. 0%, p = 0.04). HBOT-treated patients less often required progression to second-line therapy during the hospitalization (10 vs. 63%, p = 0.04). The proportion requiring in-hospital colectomy specifically as second-line therapy for medically refractory UC was lower in the HBOT group compared to sham (0 vs. 38%, p = 0.07). There were no serious adverse events. CONCLUSION: In this small, proof-of-concept, phase 2A trial, the use of HBOT as an adjunctive therapy to steroids for UC patients hospitalized for moderate-severe flares resulted in higher rates of clinical remission, and a reduction in rates of progression to second-line therapy during the hospitalization. Larger well-powered trials are needed, however, to provided definitive evidence of therapeutic benefit.

High power narrow linewidth discrete mode laser diode integrated with a curved semiconductor optical amplifier emitting at 2051 nm.

We report on a 2.051 µm InxGaAs/InP-based discrete mode laser diode monolithically integrated with a curved tapered semiconductor optical amplifier for CO2 sensing applications. At a heat-sink temperature of 0°C, the laser emits a record InP value of more than 35 mW continuous-wave output power in a single longitudinal mode.

Consensus Statement Immunonutrition and Exercise.

In this consensus statement on immunonutrition and exercise, a panel of knowledgeable contributors from across the globe provides a consensus of updated science, including the background, the aspects for which a consensus actually exists, the controversies and, when possible, suggested directions for future research.

Heightened Exercise-Induced Oxidative Stress at Simulated Moderate Level Altitude vs. Sea Level in Trained Cyclists.

Altitude exposure can exaggerate the transient increase in markers of oxidative stress observed following acute exercise. However, these responses have not been monitored in endurance-trained cyclists at altitudes typically experienced while training. Endurance trained males (n = 12; mean (± SD) age: 28 ± 4 years, V̇O2max 63.7 ± 5.3 ml/kg/min) undertook two 75-min exercise trials at 70% relative V̇O2max; once in normoxia and once in hypobaric hypoxia, equivalent to 2000m above sea level (hypoxia). Blood samples were collected before, immediately after and 2 h postexercise to assess plasma parameters of oxidative stress (protein carbonylation (PC), thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC) and catalase activity (CAT)). Participants cycled at 10.5% lower power output in hypoxia vs. normoxia, with no differences in heart rate, blood lactate or rating of perceived exertion observed. PC increased and decreased immediately after exercise in hypoxia and normoxia respectively (nmol/mg/protein: Normoxia-0.3 ± 0.1, Hypoxia + 0.4 ± 0.1; both p < .05). CAT increased immediately postexercise in both trials, with the magnitude of change greater in hypoxia (nmol/min/ml: Normoxia + 12.0 ± 5.0, Hypoxia + 27.7 ± 4.8; both p < .05). CAT was elevated above baseline values at 2 h postexercise in Hypoxia only (Normoxia + 0.2 ± 2.4, Hypoxia + 18.4 ± 5.2; p < .05). No differences were observed in the changes in TBARS and TAC between hypoxia and normoxia. Trained male cyclists demonstrated a differential pattern/ timecourse of changes in markers of oxidative stress following submaximal exercise under hypoxic vs. normoxic conditions.

Wisdom tooth extraction causing lingual nerve and styloglossus muscle damage: a mimic of multiple cranial nerve palsies.

The combination of tongue hemianaesthesia, dysgeusia, dysarthria and dysphagia suggests the involvement of multiple cranial nerves. We present a case with sudden onset of these symptoms immediately following wisdom tooth extraction and highlight the clinical features that allowed localisation of the lesion to a focal, iatrogenic injury of the lingual nerve and adjacent styloglossus muscle.

Immunological aspects of sport nutrition.

Prolonged bouts of exercise and heavy training regimens are associated with depression of immune system functions that can increase the risk of picking up opportunistic infections such as the common cold and influenza. Some common sport nutrition practices including high-carbohydrate diets and carbohydrate ingestion during exercise, training with low-glycogen stores, intentional dieting for weight loss, ingestion of high-dose antioxidant supplements and protein ingestion post exercise may influence immune system status in athletes. In order to maintain robust immunity, athletes need to consume a well-balanced diet that is sufficient to meet their requirements for energy, carbohydrate, protein and micronutrients. Dietary deficiencies of protein and specific micronutrients are well known to be potential causes of immune dysfunction and an adequate intake of some essential minerals including iron and zinc and the vitamins A, D, E, B6 and B12 are important to maintain a healthy immune function. Vitamin D may be a particular concern as recent studies have emphasised its importance in limiting infection episode incidence and duration in both the general population and in athletes and many individuals exhibit inadequate vitamin D status during the winter months. There is only limited evidence that individual amino acids, ß-glucans, herbal extracts and zinc are capable of boosting immunity or reducing infection risk in athletes. The ingestion of carbohydrate during exercise and daily consumption of probiotics, vitamin D3, bovine colostrum and plant polyphenol containing supplements or foodstuffs currently offer the best chance of success, particularly for those individuals who are prone to illness.

Is there an optimal vitamin D status for immunity in athletes and military personnel?

Vitamin D is mainly obtained through sunlight ultraviolet-B (UVB) exposure of the skin, with a small amount typically coming from the diet.It is now clear that vitamin D has important roles beyond its well-known effects on calcium and bone homeostasis. Immune cells express the vitamin D receptor, including antigen presenting cells, T cells and B cells, and these cells are all capable of synthesizing the biologically active vitamin D metabolite, 1, 25 hydroxy vitamin D.There has been growing interest in the benefits of supplementing vitamin D as studies report vitamin D insufficiency (circulating 25(OH)D < 50 nmol/L) in more than half of all athletes and military personnel tested during the winter, when skin sunlight UVB is negligible. The overwhelming evidence supports avoiding vitamin D deficiency (25(OH)D< 30 nmol/L)to maintain immunity and prevent upper respiratory illness (URI) in athletes and military personnel.Recent evidence supports an optimal circulating 25(OH)D of 75 nmol/L to prevent URI and enhance innate immunity and mucosal immunity and bring about anti-inflammatory actions through the induction of regulatory T cells and the inhibition of pro-inflammatory cytokine production. We provide practical recommendations for how vitamin D sufficiency can be achieved in most individuals by safe sunlight exposure in the summer and daily 1, 000 IU vitamin D3 supplementation in the winter. Studies are required in athletes and military personnel to determine the impact of these recommendations on immunity and URI; and,to demonstrate the purported benefit of achieving 25(OH)D>75 nmol/L.

Salivary immunoglobulin free light chains: reference ranges and responses to exercise in young and older adults.

BACKGROUND: Free light chains (FLCs) have a range of biological functions and may act as a broad marker of immunesuppression and activation and inflammation. Measurement of salivary FLCs may provide practical advantages in a range of clinical populations. The aim of the present study was to develop normal reference ranges of FLCs in saliva and assess the effects of acute exercise on FLC levels in younger and older adults. METHODS: Saliva FLC concentrations and secretion rates were measuredin young (n = 88, aged 18-36) and older (n = 53, aged 60-80) adults. To assess FLC changes in response to acute exercise, young adults completed a constant work-rate cycling exercise trial at 60% VO2max (n = 18) or a 1 h cycling time trial (TT) (n = 10) and older adults completed an incremental submaximal treadmill walking exercise test to 75% HRmax (n = 53). Serum FLCs were measured at baseline and in response to exercise. RESULTS: Older adults demonstrated significantly higher levels of salivary FLC parameters compared with young adults. Median (5-95th percentile) concentrationswere 0.45 (0.004- 3.45) mg/L for kappa and 0.30 (0.08-1.54) mg/L for lambda in young adults; 3.91 (0.75-19.65) mg/L for kappa and 1.00 (0.02-4.50) mg/L for lambda in older ad ults. Overall median concentrations of salivary kappa and lambda FLCs were 10-fold and 20-fold lower than serum, respectively. Reductions in salivary FLC concentrations and secretion rates were observed immediately post- and at 1 h post exercise, but were only significant for the older cohort; FLCs began to recover between post and 1 h post-exercise. No changes in serum FLCs were observed in response to exercise.

Effects of Lactobacillus casei Shirota ingestion on common cold infection and herpes virus antibodies in endurance athletes: a placebo-controlled, randomized trial.

AIMS: To assess evidence of health and immune benefit by consumption of a Lactobacillus casei Shirota probiotic in highly physically active people. METHODS: Single-centre, population-based, randomized, double-blind, placebo-controlled trial. Daily ingestion of probiotic (PRO) or placebo (PLA) for 20 weeks for n = 243 (126 PRO, 117 PLA) university athletes and games players. Subjects completed validated questionnaires on upper respiratory tract infection symptoms (URS) on a daily basis and on physical activity status at weekly intervals during the intervention period. Blood samples were collected before and after 20 weeks of the intervention for determination of Epstein Barr virus (EBV) and cytomegalovirus (CMV) serostatus and antibody levels. RESULTS: URS episode incidence was unexpectedly low (mean 0.6 per individual) and was not significantly different on PRO compared with PLA. URS episode duration and severity were also not influenced by PRO. A significant time × group interaction effect was observed for plasma CMV antibody titres in CMV seropositive participants (p < 0.01) with antibody titre falling in the PRO group but remaining unchanged in the PLA group over time. A similar effect was found for plasma EBV antibody titres in EBV seropositive participants (p < 0.01) with antibody titre falling in the PRO group but increasing in the PLA group over time. CONCLUSIONS: In summary, regular ingestion of PRO did not reduce URS episode incidence which might be attributable to the low URS incidence in this study. Regular ingestion of PRO reduced plasma CMV and EBV antibody titres, an effect that can be interpreted as a benefit to overall immune status.

Effect of acute exercise and hypoxia on markers of systemic and mucosal immunity.

PURPOSE: To determine how immune markers are affected by acute hypoxic exercise at the same relative intensity. METHODS: Twelve endurance-trained males (age: 28 ± 4 years, [Formula: see text]O2max: 63.7 ± 5.3 mL/kg/min) cycled for 75 min at 70 % of altitude-specific [Formula: see text]O2max, once in normoxia (N) and once in hypobaric hypoxia equivalent to 2000 m above sea-level (H). Blood and saliva samples were collected pre-, post- and 2 h post-exercise. RESULTS: Participants cycled at 10.5 % lower power output in H vs. N, with no significant differences in heart rate (P = 0.10) or rating of perceived exertion (P = 0.21). Post-exercise plasma cortisol was higher in H vs. N [683 (95 % CI 576-810) nmol/l vs. 549 (469-643) nmol/l, P = 0.017]. The exercise-induced decrease in CD4:CD8 ratio was greater in H vs. N (-0.5 ± 0.2 vs. -0.3 ± 0.2, P = 0.019). There were no significant between-trial differences for adrenocorticotropic hormone, plasma cytokines, antigen-stimulated cytokine production, salivary immunoglobulin-A or lactoferrin. However, there was a main trial effect for concentration [F(11) = 5.99, P < 0.032] and secretion [F(11) = 5.01, P < 0.047] of salivary lysozyme, with this being higher in N at every time-point. CONCLUSION: Whether the observed differences between H and N are of sufficient magnitude to clinically impair host defence is questionable, particularly as they are transient in nature and since other immune markers are unaffected. As such, acute hypoxic exercise likely does not pose a meaningful additional threat to immune function compared to exercise at sea level, provided that absolute workload is reduced in hypoxia so that relative exercise intensity is the same.

Impact of intensified training and carbohydrate supplementation on immunity and markers of overreaching in highly trained cyclists.

PURPOSE: To determine effects of intensified training (IT) and carbohydrate supplementation on overreaching and immunity. METHODS: In a randomized, double-blind, crossover design, 13 male cyclists (age 25 ± 6 years, VO2max 72 ± 5 ml/kg/min) completed two 8-day periods of IT. On one occasion, participants ingested 2 % carbohydrate (L-CHO) beverages before, during and after training sessions. On the second occasion, 6 % carbohydrate (H-CHO) solutions were ingested before, during and after training, with the addition of 20 g of protein in the post-exercise beverage. Blood samples were collected before and immediately after incremental exercise to fatigue on days 1 and 9. RESULTS: In both trials, IT resulted in decreased peak power (375 ± 37 vs. 391 ± 37 W, P < 0.001), maximal heart rate (179 ± 8 vs. 190 ± 10 bpm, P < 0.001) and haematocrit (39 ± 2 vs. 42 ± 2 %, P < 0.001), and increased plasma volume (P < 0.001). Resting plasma cortisol increased while plasma ACTH decreased following IT (P < 0.05), with no between-trial differences. Following IT, antigen-stimulated whole blood culture production of IL-1α was higher in L-CHO than H-CHO (0.70 (95 % CI 0.52-0.95) pg/ml versus 0.33 (0.24-0.45) pg/ml, P < 0.01), as was production of IL-1ß (9.3 (95 % CI 7-10.4) pg/ml versus 6.0 (5.0-7.8) pg/ml, P < 0.05). Circulating total leukocytes (P < 0.05) and neutrophils (P < 0.01) at rest increased following IT, as did neutrophil:lymphocyte ratio and percentage CD4+ lymphocytes (P < 0.05), with no between-trial differences. CONCLUSION: IT resulted in symptoms consistent with overreaching, although immunological changes were modest. Higher carbohydrate intake was not able to alleviate physiological/immunological disturbances.

Training-related and competition-related risk factors for respiratory tract and gastrointestinal infections in elite cross-country skiers.

AIM: To examine symptoms indicative of respiratory tract and gastrointestinal infections and determine risk factors for such symptoms in elite cross-country skiers. METHODS: Self-reported training and symptom data for 37 elite cross-country skiers from 2007 to 2015 were analysed using multilevel logistic regression equations with symptom incidence and duration as outcome variables, and sex, performance level, season, competition, air travel, altitude exposure and training characteristics as independent variables. RESULTS: Data for 7016 person-weeks were analysed, including 464 self-reported infection events and 110 959 h of training. Athletes reported median (range) 3 (1-7) respiratory tract and/or gastrointestinal events per year, with symptoms lasting 5 (1-24) days. During the winter, symptoms occurred more frequently (OR 2.09, p<0.001) and lasted longer (b=0.043, p<0.001) compared with summer. Competition and air travel increased the risk of symptoms, with ORs of 2.93 (95% CI 2.24 to 3.83) and 4.94 (95% CI 3.74 to 6.53), respectively (p<0.001). Athletes with higher training monotony had lower risk of symptoms (OR 0.87 (95% CI 0.73 to 0.99), p<0.05). Other training variables were not associated with symptoms. Athletes who had won an Olympic/World Championship medal reported shorter symptom duration compared with less successful athletes (b=-0.019, p<0.05) resulting in significantly fewer symptomatic days/year (14 (6-29) vs 22 (8-43) days/year). CONCLUSIONS: Air travel and competition are major risk factors for acute respiratory tract and gastrointestinal symptoms in this population. Athletes who have large fluctuations in training load experience such symptoms more frequently. Shorter duration of symptoms appears to be associated with success in cross-country skiing.

How much is too much? (Part 2) International Olympic Committee consensus statement on load in sport and risk of illness.

The modern-day athlete participating in elite sports is exposed to high training loads and increasingly saturated competition calendar. Emerging evidence indicates that inappropriate load management is a significant risk factor for acute illness and the overtraining syndrome. The IOC convened an expert group to review the scientific evidence for the relationship of load-including rapid changes in training and competition load, competition calendar congestion, psychological load and travel-and health outcomes in sport. This paper summarises the results linking load to risk of illness and overtraining in athletes, and provides athletes, coaches and support staff with practical guidelines for appropriate load management to reduce the risk of illness and overtraining in sport. These include guidelines for prescription of training and competition load, as well as for monitoring of training, competition and psychological load, athlete well-being and illness. In the process, urgent research priorities were identified.

How much is too much? (Part 1) International Olympic Committee consensus statement on load in sport and risk of injury.

Athletes participating in elite sports are exposed to high training loads and increasingly saturated competition calendars. Emerging evidence indicates that poor load management is a major risk factor for injury. The International Olympic Committee convened an expert group to review the scientific evidence for the relationship of load (defined broadly to include rapid changes in training and competition load, competition calendar congestion, psychological load and travel) and health outcomes in sport. We summarise the results linking load to risk of injury in athletes, and provide athletes, coaches and support staff with practical guidelines to manage load in sport. This consensus statement includes guidelines for (1) prescription of training and competition load, as well as for (2) monitoring of training, competition and psychological load, athlete well-being and injury. In the process, we identified research priorities.

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.

The effect of 14 weeks of vitamin D3 supplementation on antimicrobial peptides and proteins in athletes.

Heavy training is associated with increased respiratory infection risk and antimicrobial proteins are important in defence against oral and respiratory tract infections. We examined the effect of 14 weeks of vitamin D3 supplementation (5000 IU/day) on the resting plasma cathelicidin concentration and the salivary secretion rates of secretory immunoglobulin A (SIgA), cathelicidin, lactoferrin and lysozyme in athletes during a winter training period. Blood and saliva were obtained at the start of the study from 39 healthy men who were randomly allocated to vitamin D3 supplement or placebo. Blood samples were also collected at the end of the study; saliva samples were collected after 7 and 14 weeks. Plasma total 25(OH)D concentration increased by 130% in the vitamin D3 group and decreased by 43% in the placebo group (both P = 0.001). The percentage change of plasma cathelicidin concentration in the vitamin D3 group was higher than in the placebo group (P = 0.025). Only in the vitamin D3 group, the saliva SIgA and cathelicidin secretion rates increased over time (both P = 0.03). A daily 5000 IU vitamin D3 supplement has a beneficial effect in up-regulating the expression of SIgA and cathelicidin in athletes during a winter training period, which could improve resistance to respiratory infections.

Can the Alexander Technique improve balance and mobility in older adults with visual impairments? A randomized controlled trial.

OBJECTIVE: To investigate the impact of Alexander Technique lessons on balance and mobility in older adults with visual impairments. DESIGN: Randomized assessor blinded controlled trial with intervention and usual care control groups. SETTING: Participants' homes. SUBJECTS: A total of 120 community-dwellers aged 50+ with visual impairments. INTERVENTION: Twelve weeks of Alexander lessons and usual care. MAIN OUTCOME MEASURES: Short Physical Performance Battery items were primary outcomes at 3 months and secondary outcomes at 12 months. Additional secondary outcomes were postural sway, maximal balance range and falls over 12 months. RESULTS: Between-group differences in primary outcomes were not significant. The intervention group reduced postural sway on a firm surface with eyes open at 3 months after adjusting for baseline values (-29.59 mm, 95%CI -49.52 to -9.67, P < 0.01). Planned sub-group analyses indicated a greater intervention effect among past multiple-fallers (2+) than non-multiple fallers for gait speed (P = 0.02) and step length (P < 0.01) at 3 months and chair stand at 12 months (P < 0.01). There was a non-significant reduction in falls rate (IRR = 0.64, 95%CI 0.34 to 1.15, P = 0.13) and injurious falls (IRR = 0.61, 95% CI 0.28 to 1.30, P = 0.20) in the intervention group compared to the control group. CONCLUSION: The intervention did not have a significant impact on the primary outcomes but benefits for the intervention group in postural sway, trends towards fewer falls and injurious falls and improved mobility among past multiple-fallers suggest further investigation of the Alexander Technique is warranted.

The influence of hydration status during prolonged endurance exercise on salivary antimicrobial proteins.

PURPOSE: Antimicrobial proteins (AMPs) in saliva including secretory immunoglobulin A (SIgA), lactoferrin (SLac) and lysozyme (SLys) are important in host defence against oral and respiratory infections. This study investigated the effects of hydration status on saliva AMP responses to endurance exercise. METHODS: Using a randomized design, 10 healthy male participants (age 23 ± 4 years, [Formula: see text] 56.8 ± 6.5 ml/kg/min) completed 2 h cycling at 60 % [Formula: see text] in states of euhydration (EH) or dehydration (DH) induced by 24 h fluid restriction. Unstimulated saliva samples were collected before, during, immediately post-exercise and each hour for 3 h recovery. RESULTS: Fluid restriction resulted in a 1.5 ± 0.5 % loss of body mass from baseline and a 4.3 ± 0.7 % loss immediately post-exercise. Pre-exercise urine osmolality was higher in DH than EH and overall, saliva flow rate was reduced in DH compared with EH (p < 0.05). Baseline SIgA secretion rates were not different between conditions; however, exercise induced a significant increase in SIgA concentration in DH (161 ± 134 to 309 ± 271 mg/L) which remained elevated throughout 3 h recovery. SLac secretion rates increased from pre- to post-exercise in both conditions which remained elevated in DH only. Overall, SLac concentrations were higher in DH than EH. Pre-exercise SLys concentrations were lower in DH compared with EH (1.6 ± 2.0 vs. 5.5 ± 6.7 mg/L). Post-exercise SLys concentrations remained elevated in DH but returned to pre-exercise levels by 1 h post-exercise in EH. CONCLUSIONS: Exercise in DH caused a reduction in saliva flow rate yet induced greater secretion rates of SLac and higher concentrations of SIgA and SLys. Thus, DH does not impair saliva AMP responses to endurance exercise.