Energy intake, hydration status, and sleep of world-class male archers during competition.

BACKGROUND: Nutritional intake and sleep, play an important role for recovery and performance in elite sport but little work has been undertaken in archery. The present study aimed to assess energy intake (EI), hydration status, and sleep parameters in world-class male archers over the course of a four-day competition. METHODS: Results, Conclusions Six male, elite-standard archers participated in the study and measurements of hydration status, EI, competition load, and sleep were recorded throughout each day of competition. RESULTS: Daily energy, carbohydrate, and protein intake ranged between 2,563 and 3,986 kcal, 4 and 7.1 g/kg BM, 2.2 and 3.6 g/kg BM per day, respectively. Thus, archers practiced elements of periodized nutrition such that energy and carbohydrate intake was greater on the high-volume competition days (i.e. days 1 and 3; more numbers of arrows, longer duration, and walking distance) in comparison to low-volume days (days 2 and 4) over the tournament (all p > 0.01). Additionally, urine specific gravity was higher after waking, compared to pre- and post-competition, and before bed (all p < 0.05). This indicates that archers were euhydrated pre- and post-competition and before bedtime, while they were slightly hypohydrated after waking up. Sleep data show that disturbances were kept to a minimum. CONCLUSIONS: Collectively, archers appear capable of periodizing their nutritional intake according to daily physical loading during a tournament whilst, staying euhydrated and maintaining sleep quality. In part, such data can help to explain why these archers experience a sustained level of success.

Plasma-Induced Changes in the Metabolome Following Vistula Tart Cherry Consumption.

Evidence suggests that tart cherry (TC) supplementation has beneficial effects on health indices and recovery following strenuous exercise. However, little is known about the mechanisms and how TC might modulate the human metabolome. The aim of this study was to evaluate the influence of an acute high- and low-dose of Vistula TC supplementation on the metabolomic profile in humans. In a randomised, double-blind, placebo controlled, cross-over design, 12 healthy participants (nine male and three female; mean ± SD age, stature, and mass were 29 ± 7 years old, 1.75 ± 0.1 m, and 77.3 ± 10.5 kg, respectively) visited the laboratory on three separate occasions (high dose; HI, low dose; LO, or placebo), separated by at least seven days. After an overnight fast, a baseline venous blood sample was taken, followed by consumption of a standardised breakfast and dose conditions (HI, LO, or placebo). Subsequent blood draws were taken 1, 2, 3, 5, and 8 h post consumption. Following sample preparation, an untargeted metabolomics approach was adopted, and the extracts analysed by LCMS/MS. When all time points were collated, a principal component analysis showed a significant difference between the conditions (p < 0.05), such that the placebo trial had homogeneity, and HI showed greater heterogeneity. In a sub-group analysis, cyanidine-3-O-glucoside (C3G), cyanidine-3-O-rutinoside (C3R), and vanillic acid (VA) were detected in plasma and showed significant differences (p < 0.05) following acute consumption of Vistula TC, compared to the placebo group. These results provide evidence that phenolics are bioavailable in plasma and induce shifts in the metabolome following acute Vistula TC consumption. These data could be used to inform future intervention studies where changes in physiological outcomes could be influenced by metabolomic shifts following acute supplementation.

Acute Beetroot Juice Supplementation Has No Effect on Upper- and Lower-Body Maximal Isokinetic Strength and Muscular Endurance in International-Level Male Gymnasts.

Nitrate (NO3-) has properties that can improve muscle function, leading to improvements in metabolic cost of exercise as well as enhance force production. Gymnastics is a whole-body sport, involving events that demand a high level of strength and fatigue resistance. However, the effect of NO3- supplementation on both upper- and lower-body function in gymnasts is unknown. This study examined the effect of acute beetroot juice (BRJ) supplementation on isokinetic strength and endurance of the upper- and lower-body in highly trained international-level male gymnasts. In a double-blind, randomized crossover design, 10 international-level male gymnasts completed two acute supplementation periods, consuming either 2 × 70 ml NO3--rich (∼12.8 mmol/L of NO3-) or NO3--depleted (PLA) BRJ. Maximal strength of the upper-leg and upper-arm at 60°/s, 120°/s, 180°/s, and 300°/s, and muscular endurance (50 repeated isokinetic contractions at 180°/s) were assessed. Plasma NO3- (BRJ: 663 ± 164 µM, PLA: 89 ± 48 µM) and nitrite (NO2-) concentrations (BRJ: 410 ± 137 nmol/L, PLA: 125 ± 36 nmol/L) were elevated following BRJ compared to PLA (both p < .001). Maximal strength of knee and elbow extensors and flexors did not differ between supplements (p > .05 for all velocities). Similarly, fatigue index of knee and elbow extension and flexion was not different between supplements (all p > .05). Acute BRJ supplementation, containing ∼12.8 mmol/L of NO3-, increased plasma NO3- and NO2- concentrations, but did not enhance isokinetic strength or fatigue resistance of either upper or lower extremities in international-level male gymnasts.

Nutritional interventions in treating menopause-related sleep disturbances: a systematic review.

CONTEXT: Sleep disturbances are a core symptom of menopause, which refers to the permanent cessation of menstrual periods. Nutritional interventions may alleviate menopause-related sleep disturbances, as studies have shown that certain interventions (eg, tart cherry juice, or tryptophan-rich foods) can improve relevant aspects of sleep. OBJECTIVE: The aim of this systematic review was to examine the effect of nutritional interventions for menopause-related sleep disturbances, in order to inform the subsequent development of specific interventional trials and assess their potential as a treatment for menopause-related sleep disturbances. DATA SOURCES: Published studies in English were located by searching PubMed and PsycArticles databases (until September 15, 2022). DATA EXTRACTION: Following full-text review, a final total of 59 articles were included. The search protocol was performed in accordance with PRISMA guidelines. DATA ANALYSIS: A total of 37 studies reported that a nutritional intervention improved some aspect of sleep, and 22 studies observed no benefit. Most (n = 24) studies recruited postmenopausal women, 18 recruited menopausal women, 3 recruited perimenopausal women, and 14 recruited women from multiple groups. The majority of the studies were of low methodological quality. Due to the heterogeneity of the studies, a narrative synthesis without meta-analysis is reported. CONCLUSION: Despite the large heterogeneity in the studies and choice of intervention, the majority of the identified studies reported that a nutritional intervention did benefit sleep, and that it is mainly subjective sleep that is improved. More high-quality, adequately powered, randomized controlled trials of the identified nutritional interventions are necessary. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42021262367.

Behavioural sleep problems in children and adults with intellectual disabilities: An integrative literature review.

BACKGROUND: People with intellectual disabilities are more likely to experience sleep problems, which can affect quality of life, physical health, mental health and well-being. METHODS: An integrative literature review was conducted to investigate what is known about behavioural sleep disturbances in people with an intellectual disability. The search used the following databases: Scopus, PsycInfo and Cinahl, to find papers published since 2015. RESULTS: Within intellectual disability research, sleep appears as a common issue due to its high prevalence, negative relationships with an individual's physical and mental health, their quality of life, and impact of sleep problems on family or carers. The growing evidence base appears to support the use of behavioural, lifestyle and pharmacological interventions to improve sleep in people with an intellectual disability. CONCLUSION: A wide array of literature provides evidence that people with intellectual disabilities are affected by and need support with their sleep.

Impairments in glycaemic control do not increase linearly with repeated nights of sleep restriction in healthy adults: a randomised controlled trial.

Evidence suggests reduced glycaemic control following sleep restriction in healthy individuals. However, it remains unknown if impairments in glycaemic control increase with each additional night of sleep restriction in a linear manner. This randomised crossover study aimed to determine if the impairment in glycaemic control increases with each additional night of sleep restriction. Ten healthy individuals underwent 4 nights of control sleep (8 hours in bed) and 4 nights of sleep restriction (4 hours in bed) in a sleep laboratory. An oral glucose tolerance test was conducted each morning. Serum glucose and insulin were measured. Glucose and insulin area under the curve were higher overall in the sleep restriction trial compared with control (p < 0.001 and p = 0.033); however, no effect of day (p = 0.620 and p = 0.863) or interaction effect (p = 0.152 and p = 0.285) were observed. This supports previous literature showing a detrimental impact of sleep restriction on glucose regulation. The present findings, however, suggest the impairment in glycaemic control does not increase in a linear manner with an increasing number of nights of sleep restriction. This may have implications for the design of future studies examining sleep restriction and glycaemic control. Novelty: Four nights of sleep restriction impaired glycaemic control in healthy individuals, but did not do so in a linear manner. No effect of number of nights of restriction was found for glucose or insulin, which may have implications for future studies.

A hypoenergetic diet with decreased protein intake does not reduce lean body mass in trained females.

PURPOSE: Increasing protein intake during energy restriction (ER) attenuates lean body mass (LBM) loss in trained males. However, whether this relationship exists in trained females is unknown. This study examined the impact of higher compared to lower protein intakes (35% versus 15% of energy intake) on body composition in trained females during 2 weeks of severe ER. METHODS: Eighteen well-trained females completed a 1-week energy balanced diet (HD100), followed by a 2-week hypoenergetic (40% ER) diet (HD60). During HD60, participants consumed either a high protein (HP; 35% protein, 15% fat) or lower protein (CON; 15% protein, 35% fat) diet. Body composition, peak power, leg strength, sprint time, and anaerobic endurance were assessed at baseline, pre-HD60, and post-HD60. RESULTS: Absolute protein intake was reduced during HD60 in the CON group (from 1.6 to 0.9 g·d·kgBM-1) and maintained in the HP group (~ 1.7 g·d·kgBM-1). CON and HP groups decreased body mass equally during HD60 (- 1.0 ± 1.1 kg; p = 0.026 and - 1.1 ± 0.7 kg; p = 0.002, respectively) and maintained LBM. There were no interactions between time point and dietary condition on exercise performance. CONCLUSION: The preservation of LBM during HD60, irrespective of whether absolute protein intake is maintained or reduced, contrasts with findings in trained males. In trained females, the relationship between absolute protein intake and LBM change during ER warrants further investigation. Future recommendations for protein intake during ER should be expressed relative to body mass, not total energy intake, in trained females.

The Effect of Carbohydrate Mouth Rinsing on Multiple Choice Reaction Time During Amateur Boxing

PURPOSE: To examine whether the use of a carbohydrate mouth rinse (CMR) can improve multiple choice reaction time in amateur boxers during sparring. METHODS: A total of 8 male amateur boxers (age 22 [3] y, stature 1.78 [0.07] m, mass 73.6 [14.2] kg) with at least 18 months of experience in the sport volunteered to participate in the study. All participants attended a familiarization session, followed by an experimental (CMR; 6% dextrose) and placebo trials in a randomized order. Participants undertook 3 × 2 minutes of sparring against an ability- and size-matched (stature and mass) opponent. Multiple choice reaction time and perceived exertion were measured before round 1 and then after each round. The respective mouth rinse was administered in a 25-mL solution for 10 seconds before each round. Magnitude-based inferences were used to compare the results of each round (mean difference; ±90% confidence limits). RESULTS: The CMR was unlikely to have a beneficial effect on multiple choice reaction time compared with placebo (mean ± 90% confidence limits: 5 ± 9.5, 4 ± 3.4, -1 ± 8.5 lights for rounds 1 to 3, respectively) and had a possibly harmful effect on perceived exertion in round 1 (10 ± 20). There was an unlikely harmful effect on perceived exertion in rounds 2 (1 ± 12) and 3 (9 ± 23). CONCLUSION: There is no evidence to support the use of CMR during sparring in amateur boxers.

The effect of acute exercise on environmentally induced symptoms of dry eye.

The purpose of this study was to investigate the effects of acute exercise on environmentally induced symptoms of dry eye. Twelve participants without dry eye disease volunteered to complete three experimental visits in a randomized order; (1) control condition seated for 1 h at a relative humidity (RH) of 40% (CONT), (2) dry condition seated for 1 h at a RH of 20% (DRY), and (3) exercise condition seated for 40 min followed by 20 min of cycling exercise at a RH of 20% (EXER). Tear volume, tear matrix metalloproteinase 9 (MMP-9), perception of dry eye symptoms (frequency and severity), core temperature, and ocular surface temperature (OST) were measured at the end of each exposure. The perception of dry eye frequency and MMP-9 concentration were significantly higher in DRY compared to CONT (P < 0.012), with no differences in EXER compared to CONT. The results suggest that an acute bout of exercise may attenuate symptoms of environmentally induced dry eye, and warrant further research.

Impaired Insulin Profiles Following a Single Night of Sleep Restriction: The Impact of Acute Sprint Interval Exercise.

Experimental sleep restriction (SR) has demonstrated reduced insulin sensitivity in healthy individuals. Exercise is well-known to be beneficial for metabolic health. A single bout of exercise has the capacity to increase insulin sensitivity for up to 2 days. Therefore, the current study aimed to determine if sprint interval exercise could attenuate the impairment in insulin sensitivity after one night of SR in healthy males. Nineteen males were recruited for this randomized crossover study which consisted of four conditions-control, SR, control plus exercise, and sleep restriction plus exercise. Time in bed was 8 hr (2300-0700) in the control conditions and 4 hr (0300-0700) in the SR conditions. Conditions were separated by a 1-week entraining period. Participants slept at home, and compliance was assessed using wrist actigraphy. Following the night of experimental sleep, participants either conducted sprint interval exercise or rested for the equivalent duration. An oral glucose tolerance test was then conducted. Blood samples were obtained at regular intervals for measurement of glucose and insulin. Insulin concentrations were higher in SR than control (p = .022). Late-phase insulin area under the curve was significantly lower in sleep restriction plus exercise than SR (862 ± 589 and 1,267 ± 558; p = .004). Glucose area under the curve was not different between conditions (p = .207). These findings suggest that exercise improves the late postprandial response following a single night of SR.

Sleep Profiles of Elite Swimmers During Different Training Phases.

Walsh, JA, Sanders, D, Hamilton, DL, and Walshe, I. Sleep profiles of elite swimmers during different training phases. J Strength Cond Res 33(3): 811-818, 2019-This study aims to describe the sleeping patterns during different training phases in competitive swimmers. Twelve national- and international-level swimmers (3 females and 9 males) were monitored during 4 different phases, consisting of a preparation training phase, a taper phase, a competition phase, and a rest phase. Sleep parameters were assessed using wrist activity monitors and self-reported sleep diaries. There was a moderately higher (d = 0.70-1.00) sleep onset latency during the competition phase compared with taper, train, and rest phases. Trivial to small differences were observed for total sleep time between phases (d = 0.05-0.40). Sleep efficiency was moderately higher (d = 0.60-0.75) in the training and taper phases compared with competition and rest. Restfulness and fragmentation index (FI) were lowest in the rest with differences between phases being small (d = 0.43-0.51) for restfulness and small to moderate (d = 0.43-0.62) for FI. Time in and out of bed was very largely later (d = 1.96-2.34) in rest compared with the other phases. Total nap time was moderately lower in rest (d = 1.13-1.18) compared with the training and competition phases, whereas there was a small difference (d = 0.46) compared with taper. To conclude, while there were trivial to small differences in sleep quantity between phases, there are small to moderate differences in other sleep parameters. Specifically, sleep onset latency was higher during the competition phase. In addition, this study highlights the substantial between-individual variations in sleep responses during different training phases.

Long Sleep Duration and Social Jetlag Are Associated Inversely with a Healthy Dietary Pattern in Adults: Results from the UK National Diet and Nutrition Survey Rolling Programme Y1⁻4.

Limited observational studies have described the relationship between sleep duration and overall diet. The present study investigated the association between sleep duration on weekdays or social jetlag and empirically derived dietary patterns in a nationally representative sample of UK adults, aged 19⁻64 years old, participating in the 2008⁻2012 UK National Diet and Nutrition Survey Rolling Programme. Survey members completed between three to four days of dietary records. Sleep duration on weekdays was categorized into tertiles to reflect short, normal, and long sleep duration. Social jetlag was calculated as the difference between sleep duration on weekends and weekdays. The association between sleep duration/social jetlag and dietary patterns, derived by principal components analysis, was assessed by regressing diet on sleep, whilst accounting for the complex survey design and adjusting for relevant confounders. Survey members in the highest tertile of sleep duration had on average a 0.45 (95% Confidence Interval (CI) -0.78, -0.12) lower healthy dietary pattern score, compared to middle tertile (p = 0.007). There was an inverted u-shaped association between social jetlag and the healthy dietary pattern, such that when sleep on weekends exceeded weekday sleep by 1 h 45 min, scores for indicating a healthy dietary pattern declined (p = 0.005). In conclusion, long sleep duration on weekdays and an increased social jetlag are associated with a lower healthy dietary pattern score. Further research is required to address factors influencing dietary patterns in long sleepers.

Adding Fish Oil to Whey Protein, Leucine, and Carbohydrate Over a Six-Week Supplementation Period Attenuates Muscle Soreness Following Eccentric Exercise in Competitive Soccer Players.

Soccer players often experience eccentric exercise-induced muscle damage given the physical demands of soccer match-play. Since long chain n-3 polyunsaturated fatty acids (n-3PUFA) enhance muscle sensitivity to protein supplementation, dietary supplementation with a combination of fish oil-derived n-3PUFA, protein, and carbohydrate may promote exercise recovery. This study examined the influence of adding n-3PUFA to a whey protein, leucine, and carbohydrate containing beverage over a six-week supplementation period on physiological markers of recovery measured over three days following eccentric exercise. Competitive soccer players were assigned to one of three conditions (2 × 200 mL): a fish oil supplement beverage (FO; n = 10) that contained n-3PUFA (1100 mg DHA/EPA-approximately 550 mg DHA, 550 mg EPA), whey protein (15 g), leucine (1.8 g), and carbohydrate (20 g); a protein supplement beverage (PRO; n = 10) that contained whey protein (15 g), leucine (1.8 g), and carbohydrate (20 g); and a carbohydrate supplement beverage (CHO; n = 10) that contained carbohydrate (24 g). Eccentric exercise consisted of unilateral knee extension/flexion contractions on both legs separately. Maximal force production was impaired by 22% during the 72-hour recovery period following eccentric exercise (p < 0.05). Muscle soreness, expressed as area under the curve (AUC) during 72-hour recovery, was less in FO (1948 ± 1091 mm × 72 h) than PRO (4640 ± 2654 mm × 72 h, p < 0.05) and CHO (4495 ± 1853 mm × 72 h, p = 0.10). Blood concentrations of creatine kinase, expressed as AUC, were ~60% lower in FO compared to CHO (p < 0.05) and tended to be lower (~39%, p = 0.07) than PRO. No differences in muscle function, soccer performance, or blood c-reactive protein concentrations were observed between groups. In conclusion, the addition of n-3PUFA to a beverage containing whey protein, leucine, and carbohydrate ameliorates the increase in muscle soreness and blood concentrations of creatine kinase following eccentric exercise in competitive soccer players.

Skeletal muscle insulin signaling and whole-body glucose metabolism following acute sleep restriction in healthy males.

Sleep restriction is associated with impaired glucose metabolism and insulin resistance, however, the underlying mechanisms leading to this impairment are unknown. This study aimed to assess whether the decrease in insulin sensitivity observed after sleep restriction is accompanied by changes in skeletal muscle PKB activity. Ten healthy young males participated in this randomized crossover study which included two conditions separated by a 3-week washout period. Participants underwent two nights of habitual sleep (CON) and two nights of sleep which was restricted to 50% of habitual sleep duration (SR) in the home environment. Whole-body glucose tolerance and insulin sensitivity were assessed by an oral glucose tolerance test after the second night of each condition. Skeletal muscle tissue samples were obtained from the vastus lateralis to determine PKB activity. Findings displayed no effect of trial on plasma glucose concentrations (P = 0.222). Plasma insulin area under the curve was higher after sleep restriction compared to the control (P = 0.013). Matsuda index was 18.6% lower in the sleep restriction (P = 0.010). Fold change in PKB activity from baseline tended to be lower in the sleep restriction condition at 30 min (P = 0.098) and 120 min (P = 0.087). In conclusion, we demonstrated decreased whole-body insulin sensitivity in healthy young males following two nights of sleep restriction. Skeletal muscle insulin signaling findings are inconclusive and require further study to examine any potential changes.

Signaling Responses After Varying Sequencing of Strength and Endurance Training in a Fed State.

PURPOSE: To compare anabolic signaling responses to differing sequences of concurrent strength and endurance training in a fed state. METHODS: Eighteen resistance-trained men were randomly assigned to the following experimental conditions: strength training (ST), strength followed by endurance training (ST-END), or endurance followed by strength training (END-ST). Muscle tissue samples were taken from the vastus lateralis before each exercise protocol, on cessation of exercise, and 1 h after cessation of strength training. Tissue was analyzed for total and phosphorylated (p-) signaling proteins linked to the mTOR and AMPK networks. RESULTS: Strength-training performance was similar between ST, ST-END, and END-ST. p-S6k1 was elevated from baseline 1 h posttraining in ST and ST-END (both P < .05). p-4E-BP1 was significantly lower than baseline post-ST (P = .01), whereas at 1 h postexercise in the ST-END condition p-4E-BP1 was significantly greater than postexercise (P = .04). p-ACC was elevated from baseline both postexercise and 1 h postexercise (both P < .05) in the END-ST condition. AMPK, mTOR, p38, PKB, and eEF2 responded similarly to ST, ST-END, and END-ST. Signaling responses to ST, ST-END, and END were largely similar. As such it cannot be ascertained which sequence of concurrent strength and endurance training is most favorable in promoting anabolic signaling. CONCLUSIONS: In the case of the current study an acute bout of concurrent training of differing sequences elicited similar responses of the AMPK and mTOR networks.

Recovery facilitation with Montmorency cherries following high-intensity, metabolically challenging exercise.

The impact of Montmorency tart cherry (Prunus cerasus L.) concentrate (MC) on physiological indices and functional performance was examined following a bout of high-intensity stochastic cycling. Trained cyclists (n = 16) were equally divided into 2 groups (MC or isoenergetic placebo (PLA)) and consumed 30 mL of supplement, twice per day for 8 consecutive days. On the fifth day of supplementation, participants completed a 109-min cycling trial designed to replicate road race demands. Functional performance (maximum voluntary isometric contraction (MVIC), cycling efficiency, 6-s peak cycling power) and delayed onset muscle soreness were assessed at baseline, 24, 48, and 72 h post-trial. Blood samples collected at baseline, immediately pre- and post-trial, and at 1, 3, 5, 24, 48, and 72 h post-trial were analysed for indices of inflammation (interleukin (IL)-1ß, IL-6, IL-8, tumor necrosis factor alpha, high-sensitivity C-reactive protein (hsCRP)), oxidative stress (lipid hydroperoxides), and muscle damage (creatine kinase). MVIC (P < 0.05) did not decline in the MC group (vs. PLA) across the 72-h post-trial period and economy (P < 0.05) was improved in the MC group at 24 h. IL-6 (P < 0.001) and hsCRP (P < 0.05) responses to the trial were attenuated with MC (vs. PLA). No other blood markers were significantly different between MC and PLA groups. The results of the study suggest that Montmorency cherry concentrate can be an efficacious functional food for accelerating recovery and reducing exercise-induced inflammation following strenuous cycling exercise.

Influence of compression garments on recovery after marathon running.

Strenuous physical activity can result in exercise-induced muscle damage. The purpose of this study was to investigate the efficacy of a lower limb compression garment in accelerating recovery from a marathon run. Twenty four subjects (female, n = 7; male, n = 17) completed a marathon run before being assigned to a treatment group or a sham treatment group. The treatment group wore lower limb compression tights for 72 hours after the marathon run, the sham treatment group received a single treatment of 15 minutes of sham ultrasound after the marathon run. Perceived muscle soreness, maximal voluntary isometric contraction (MVIC), and serum markers of creatine kinase (CK) and C-reactive protein (C-RP) were assessed before, immediately after, and 24, 48, and 72 hours after the marathon run. Perceived muscle soreness was significantly lower (p ≤ 0.05) in the compression group at 24 hours after marathon when compared with the sham group. There were no significant group effects for MVIC, CK, and C-RP (p > 0.05). The use of a lower limb compression garment improved subjective perceptions of recovery; however, there was neither a significant improvement in muscular strength nor a significant attenuation in markers of exercise-induced muscle damage and inflammation.

Montmorency cherries reduce the oxidative stress and inflammatory responses to repeated days high-intensity stochastic cycling.

This investigation examined the impact of Montmorency tart cherry concentrate (MC) on physiological indices of oxidative stress, inflammation and muscle damage across 3 days simulated road cycle racing. Trained cyclists (n = 16) were divided into equal groups and consumed 30 mL of MC or placebo (PLA), twice per day for seven consecutive days. A simulated, high-intensity, stochastic road cycling trial, lasting 109 min, was completed on days 5, 6 and 7. Oxidative stress and inflammation were measured from blood samples collected at baseline and immediately pre- and post-trial on days 5, 6 and 7. Analyses for lipid hydroperoxides (LOOH), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interleukin-8 (IL-8), interleukin-1-beta (IL-1-ß), high-sensitivity C-reactive protein (hsCRP) and creatine kinase (CK) were conducted. LOOH (p < 0.01), IL-6 (p < 0.05) and hsCRP (p < 0.05) responses to trials were lower in the MC group versus PLA. No group or interaction effects were found for the other markers. The attenuated oxidative and inflammatory responses suggest MC may be efficacious in combating post-exercise oxidative and inflammatory cascades that can contribute to cellular disruption. Additionally, we demonstrate direct application for MC in repeated days cycling and conceivably other sporting scenario's where back-to-back performances are required.

Prevalence of allergy and upper respiratory tract symptoms in runners of the London marathon.

BACKGROUND: The prevalence of self-reported upper respiratory tract (URT) symptoms in athletes has been traditionally associated with opportunistic infection during the temporal suppression of immune function after prolonged exercise. There is little evidence for this, and a competing noninfectious hypothesis has been proposed, whereby the exercise-induced immune system modulations favor the development of atopy and allergic disease, which manifests as URT symptoms. The aim of this study was to examine the association between allergy and URT symptoms in runners after an endurance running event. METHODS: Two hundred eight runners from the 2010 London Marathon completed the validated Allergy Questionnaire for Athletes (AQUA) and had serum analyzed for total and specific immunoglobulin E response to common inhalant allergens. Participants who completed the marathon and nonrunning controls who lived in the same household were asked to complete a diary on URT symptoms. RESULTS: Forty percent of runners had allergy as defined by both a positive AQUA and elevated specific immunoglobulin E. Forty-seven percent of runners experienced URT symptoms after the marathon. A positive AQUA was a significant predictor of postmarathon URT symptoms in runners. Only 19% of nonrunning controls reported symptoms. CONCLUSIONS: The prevalence of allergy in recreational marathon runners was similar to that in elite athletes and higher than that in the general population. There was a strong association between a positive AQUA and URT symptoms. The low proportion of households in which both runners and nonrunners were symptomatic suggests that the nature of symptoms may be allergic or inflammatory based rather than infectious. Allergy is a treatable condition, and its potential effect on performance and health may be avoided by accurate clinical diagnosis and management. Both athletes' and coaches' awareness of the potential implications of poorly managed allergy needs to be raised.

The effect of carbohydrate ingestion on plasma interleukin-6, hepcidin and iron concentrations following prolonged exercise.

The aim of our study was twofold, firstly to examine the relationship between plasma concentrations of IL-6, hepcidin and iron following prolonged exercise and secondly, to assess the effect of carbohydrate ingestion on circulating hepcidin concentration post-exercise. The study was a randomised double-blind cross-over design, with participants consuming either a carbohydrate (CHO) or an isovolumetric placebo drink throughout the trial. Nine healthy, trained males completed a treadmill run at 60% vVO(2max) for 120 min followed by a 5 km time trial. Plasma concentrations of both IL-6 and hepcidin significantly increased post-exercise following both trials (p<.05) and returned to baseline by 24 h post (p>.05). A positive correlation between hepcidin and IL-6 was demonstrated immediately following exercise during PLA while there was a trend for a moderate correlation during CHO (PLA trial rho=0.81, p<0.001; CHO trial rho=0.36, p=0.07). Plasma iron was unaffected immediately post-exercise but significantly reduced by 24 h post-exercise compared to baseline. CHO ingestion significantly reduced post-exercise IL-6 (p<.05) but this had no effect on plasma hepcidin or iron concentration. Our data demonstrate CHO supplementation does not alter the rapid hepcidin response associated with exercise and does not prevent a subsequent fall in plasma iron concentration. This finding adds further support to the theory that an exercise-induced, up-regulation of hepcidin activity is a mechanism causing iron deficiency in endurance athletes.