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  • 1.
    Ahokas, E K
    et al.
    Unit of Biology of Physical Activity, University of Jyväskylä.
    Kyrolainen, H
    Unit of Biology of Physical Activity, University of Jyväskylä.
    Mero, AA
    Unit of Biology of Physical Activity, University of Jyväskylä.
    Walker, S
    Unit of Biology of Physical Activity, University of Jyväskylä.
    Hanstock, Helen
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Ihalainen, Johanna K.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Unit of Biology of Physical Activity, University of Jyväskylä.
    Minimal effect of water immersion on markers of inflammation and muscle damage after intensive exercise2019In: Proc Physiol Soc 44, 2019, article id C43Conference paper (Refereed)
    Abstract [en]

    Water immersion methods, such as cold water immersion and contrast water therapy are popular recovery interventions after athletic training and competition. Nevertheless, post-exercise cold water immersion may actually inhibit hypertrophic signalling pathways and muscle adaptation to training (1). It is has been commonly assumed that the mechanism of impaired training adaptation is mediated by blunted inflammatory responses to muscle-damaging exercise, although this assumption has been questioned by recent data (2). A weakness of previous studies is omission of active recovery in water immersion interventions, which would arguably be utilised in addition to water immersion by athletic populations. The aim of this study was to compare the influence of three water immersion methods, performed after active recovery, on inflammatory responses to muscle-damaging exercise. Nine male participants (age 20-35 y) performed an intensive exercise protocol, consisting of maximal jumps and sprinting, on four occasions. After each trial, participants completed one of four recovery protocols in a randomised, crossover design (ACT, active recovery only, 10 min cycling; heart rate 120-140 b/min; CWI, active recovery followed by 10 min cold water immersion, 10°C; TWI, active recovery followed by 10 min temperate water immersion, 24°C and CWT, active recovery followed by contrast water therapy, 10 min alternating 10°C and 38°C in 1 min cycles). The study was conducted in accordance with the Declaration of Helsinki and approved by the local ethical review board. Venous blood samples were collected pre-exercise and 5 min, 60 min, 24 h, 48 h and 96 h post-exercise, then analysed for myocyte chemoattractant protein 1 (MCP-1) and creatine kinase (CK) using ELISA and high-sensitivity C-reactive protein (hs-CRP) using a chemiluminescence assay. Two-way repeated measures ANOVA was used to compare biomarker concentrations between groups over time. There were no differences in biomarker concentrations during exercise and recovery between groups across the six time points, however main effects of time were present for all three markers (MCP-1: F(2.32, 18.56) = 23.1, p < 0.0001; CK: F(2.059, 16.47) = 8.74, p = 0.002; hs-CRP: F(1.07, 8.57 = 13.8, p = 0.005). Tukey’s post-hoc analysis of simple time effects revealed increases in MCP-1 at post-5 min versus pre in all groups except CWT. In TWI and CWI, MCP-1 was still elevated above pre at 60 min post-exercise. hs-CRP peaked at 24 h post-exercise in all groups. CK was elevated at post-60 versus pre in all groups and at post-24 except in CWT. Our findings suggest that use of cold or thermoneutral water immersion in combination with active recovery may slightly prolong the immediate post-exercise elevation in MCP-1 but have minimal overall effect on markers of inflammation and muscle damage.

  • 2.
    Diment, Bethany
    et al.
    Bangor University, UK.
    Fortes, Matthew B
    Bangor University, UK.
    Edwards, Jason P
    Bangor University, UK.
    Hanstock, Helen
    Bangor University, UK.
    Ward, Mark D
    Bangor University, UK.
    Dunstall, Huw M
    Bangor University, UK.
    Friedmann, Peter S
    University of Southampton, UK.
    Walsh, Neil P
    Bangor University, UK.
    Exercise Intensity and Duration Effects on In Vivo Immunity2015In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 7, p. 1390-1398Article in journal (Refereed)
    Abstract [en]

    Purpose: To examine the effects of intensity and duration of exercise stress on induction of in vivo immunity in humans using experimental contact hypersensitivity (CHS) with the novel antigen diphenylcyclopropenone (DPCP).Methods: Sixty-four healthy males completed either 30 min running at 60% V˙O2peak (30MI), 30 min running at 80% V˙O2peak (30HI), 120 min running at 60% V˙O2peak (120MI), or seated rest (CON). Twenty min later, the subjects received a sensitizing dose of DPCP; and 4 wk later, the strength of immune reactivity was quantified by measuring the cutaneous responses to a low dose-series challenge with DPCP on the upper inner arm. Circulating epinephrine, norepinephrine and cortisol were measured before, after, and 1 h after exercise or CON. Next, to understand better whether the decrease in CHS response on 120MI was due to local inflammatory or T-cell-mediated processes, in a crossover design, 11 healthy males performed 120MI and CON, and cutaneous responses to a dose series of the irritant, croton oil (CO), were assessed on the upper inner arm.Results: Immune induction by DPCP was impaired by 120MI (skinfold thickness -67% vs CON; P < 0.05). However, immune induction was unaffected by 30MI and 30HI despite elevated circulating catecholamines (30HI vs pre: P < 0.01) and greater circulating cortisol post 30HI (vs CON; P < 0.01). There was no effect of 120MI on skin irritant responses to CO.Conclusions: Prolonged moderate-intensity exercise, but not short-lasting high- or short-lasting moderate-intensity exercise, decreases the induction of in vivo immunity. No effect of prolonged moderate-intensity exercise on the skin's response to irritant challenge points toward a suppression of cell-mediated immunity in the observed decrease in CHS. Diphenylcyclopropenone provides an attractive tool to assess the effect of exercise on in vivo immunity.

  • 3. Eklund, Linda
    et al.
    Schagatay, Filip
    Umeå Universitet.
    Sjöström, Rita
    Umeå Universitet.
    Söderström, Lars
    Östersunds Sjukhus.
    Hanstock, Helen
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Sandström, Thomas
    Norrlands Universitetssjukhus, Umeå.
    Stenfors, Nikolai
    Umeå Universitet.
    Symptoms of moderate exercise in subzero temeperatures: An experimental exposure study2018Conference paper (Other academic)
  • 4.
    Eriksson, Linda
    et al.
    Umeå universitet, Medicin.
    Schagatay, Filip
    Umeå universitet, Institutionen för folkhälsa och klinisk medicin.
    Sjöström, Rita
    Umeå universitet, Institutionen för samhällsmedicin och rehabilitering.
    Soderstrom, Lars
    Hanstock, Helen
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Sandström, Thomas
    Department of Medicine, Respiratory & allergy unit, Umeå university hospital, Umeå, Sweden.
    Stenfors, Nikolai
    Umeå universitet, Medicin.
    Symptoms of moderate exercise in subzero temperatures - An experimental exposure study2018In: European Respiratory Journal, ISSN 0903-1936, E-ISSN 1399-3003, Vol. 52Article in journal (Other academic)
    Abstract [en]

    Humans react to cold with various symptoms. Previous studies enquiring about symptoms during cold exposure have for the most part been population based studies using questionnaries and have focused on a narrow spectrum of symptoms. The purpose of this study was to study the effect of cold air and physical exercise on a wide range of symptoms in healthy individuals.

    A total of 31 healthy subjects were experimentally exposed to +10 °C and -10 °C in an environmental chamber for one hour, on two separate occasions. During each exposure, subjects performed an intermittent moderate-intensity running protocol between 62-78% of maximal oxygen consumption (VO2 max). At five timepoints, before, during and after the exposures, subjects were asked about 18 symptoms and their intensity. The Borg CR10 scale was used to rate the intensity from 0 to 11, where 0 meant "none" and 11 meant "maximal". The sum of all five Borg CR10-scores were added together to form a single score for each exposure. Paired Wilcoxon signed-rank test was used for analysis. Data are presented as medians.

    Symptoms of cough, eye irritation, physical discomfort, and cold extremities were present only at -10 °C. Compared to exercise in +10 °C, exercise in -10 °C induced significantly higher summed symptom scores for eye irritation 2.0 vs 0.5 (p=0.011), rhinitis 12.0 vs 8.0 (p=0.000), nasal irritation 3.5 vs 0.5 (p=0.001), cold face 7.0 vs 1.0 (p=0.000), physical discomfort 6.5 vs 0.0 (p=0.000), and cold extremities 10.0 vs 0.5 (p=0.000).

    In healthy subjects, moderate-intensity exercise in -10 °C can induce and enhance the intensity of a wide range of symptoms. Symptoms of the lower airways were infrequent and mild.

  • 5.
    Eriksson, Linda
    et al.
    Enheten för medicin, Institutionen för folkhälsa och klinisk medicin, Umeå Universitet.
    Schagatay, Filip
    Institutionen för folkhälsa och klinisk medicin, Umeå Universitet.
    Sjöström, Rita
    Institutionen för samhällsmedicin och rehabilitering, Umeå Universitet.
    Söderström, Lars
    Enheten för förskning, utveckling och utbildning, Östersunds sjukhus.
    Hanstock, Helen
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Sandström, Thomas
    Medicincentrum, Lung- och allergisektionen, Norrlands Universitetssjukhus, Umeå.
    Stenfors, Nikolai
    Enheten för medicine, Institutionen för folkhälsa och klinisk medicin, Umeå Univeristet.
    Symptom av måttlig träning i minusgrader: En experimentell exponeringsstudie2018Conference paper (Other academic)
    Abstract [sv]

    Bakgrund: Exponering för kyla leder till ökad sjuklighet och dödlighet i befolkningen. Tidigare studier av symptom i samband med köldexponering har mestadels varit befolkningsbaserade enkätstudier fokuserade på ett smalt symptomspektrum. Syftet meddenna studie var att undersöka effekten av kyla och fysisk aktivitet på ett brett spektrumav symptom hos friska individer.Material och metod: Trettioen friska försökspersoner exponerades i en köldkammare för +10 °C och -10 °C under en timme, vid två separata tillfällen. Under varje exponeringsprang försökspersonerna intermittent på 62-78% av maximal syreupptagningsförmåga. Vid fem tillfällen, före, under och efter exponeringarna, frågades försökspersonerna om 18 symptom och dessas intensitet. Borgs CR10 skala användes för att skatta intensitetenfrån 0 till 11, där 0 betydde ”inget alls” och 11 betydde ”maximalt”. Maximalt Borg-värdeför varje symptom under exponeringarna jämfördes med värdena innan exponeringarna. Summan av alla fem Borg CR10-värdena jämfördes mellan de två exponeringarna. PairedWilcoxon signed-rank test användes för analyser. Data presenteras som medianvärden.Resultat: En signifikant stegring av symptomen hosta, ögonirritation, fysiskt obehag ochkalla extremiteter förekom endast vid -10 °C. I jämförelse med fysisk aktivitet i +10 °C, gav fysisk aktivitet i -10 °C upphov till signifikant högre summerade värden för ögonirritation 2,0 jfr 0,5 (p=0,011), rinit 12,0 jfr 8,0 (p=0,000), irritation i näsan 3,5 jfr 0,5 (p=0,001), kyla i ansiktet 7,0 jfr 1,0 (p=0,000), fysiskt obehag 6,5 jfr 0,0 (p=0,000), och kalla extremiteter 10,0 jfr 0,5 (p=0,000).Slutsats: Hos friska individer kan fysisk aktivitet på måttlig intensitet i -10 °C ge upphovtill och öka intensiteten av ett brett spektrum av symptom. Symptom från de nedre luftvägarna var milda och inte frekventa vid de aktuella exponeringarna.

  • 6.
    Hanstock, Helen
    Bangor University.
    Tear Secretory IgA: A Noninvasive Biomarker of Mucosal Immune Competence2016Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Since early studies investigated the influence of exercise on salivary secretory IgA(SIgA) in the 1980s, there has been demand for non-invasive biomarkers capableof monitoring the immune response to exercise, training and stress, and provideinsight into whether such stressors may influence susceptibility to URTI. In spiteof >30 years of research and ~200 original articles investigating a multitude ofcandidate markers, this tool remains elusive. Transmission of URTIs has beendemonstrated via the nasal and ocular mucosae, so maintainence of a strong‘first line of defence’ at mucosal surfaces is likely important for host defence. Tearfluid has been recently highlighted as a non-invasive medium for assessment ofhydration status (through determination of tear osmolarity) and blood glucoseconcentrations (via glucose-sensing contact lenses). Prompted by the searchfor viable non-invasive immune biomarkers, this thesis set out to explore thepotential of tear SIgA to assess immune status. First, in a prospective monitoringstudy, we demonstrated that tear SIgA secretion falls ~50% during the weekbefore experiencing upper respiratory symptoms (URS), with a 30% reductionin tear SIgA secretion conferring a six-fold increased chance of experiencing URSin the following week. Next, we undertook three studies to explore the influenceof everyday stressors on tear SIgA secretion. Both a two-hour bout of moderateintensityexercise and two-minutes of acute psychological stress caused animmediate ~50% decrease in tear SIgA concentration. The observations fromthe first study suggest that these reductions are of sufficient magnitude totemporarily compromise host defence, in line with the ‘open window’ theory.Dehydration, on the other hand, did not influence tear SIgA secretion. Thesestudies provide the first experimental evidence that tear SIgA has potentialas a non-invasive marker of mucosal immune competence that is sensitive toeveryday stressors and has utility to assess common cold risk.

  • 7.
    Hanstock, Helen
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Understanding ”ski asthma”: risk factors and management strategies.2017Conference paper (Other academic)
    Abstract [en]

    Asthma and exercise-induced bronchoconstriction (EIB) are common in high-level athletes and especially prevalent in cross-country ski athletes. In a recent online questionnaire distributed to high level Swedish cross-country skiers, 29% of adolescent athletes (age 15-19) and 35% of senior athletes self-reported physician-diagnosed asthma. Cross-country skiing has been identified as an independent risk factor for development of EIB and it has been hypothesized that a combination of the cold and dry climate, high ventilation rates, training frequency and duration may contribute to airway inflammation and trigger bronchoconstriction during or shortly after exercise. Alongside pharmacological management, there may be strategies that athletes and coaches can utilise to manage asthma or EIB. Several studies suggest that warm up routines containing short bouts of high-intensity exercise may offer protection against subsequent EIB, termed a ‘refractory period’. In cross-country skiers, refractoriness was observed in around a third of athletes in a small cohort. Other athletes may display a gradual, progressive EIB; whether these athletes also respond to high-intensity warm-up warrants further investigation. Heat-exchanger masks have been shown to reduce the severity of EIB substantially in athletes with mild to severe EIB in cold conditions (-15°C to -25°C). It is recommended that athletes with asthma/EIB explore the efficacy of high-intensity warm-up regimes on airway responses and utilise heat exchanger masks, especially on the coldest days.

  • 8.
    Hanstock, Helen
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor, UK.
    Edwards, Jason P
    Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor, UK.
    Walsh, Neil P
    Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor, UK.
    Potential of tear fluid antimicrobial proteins to evaluate risk of upper respiratory illness2017In: 13th ISEI Symposium: Training our immune system for health and performance, 2017Conference paper (Other academic)
    Abstract [en]

    Transmission of upper respiratory tract infections (URTI) has been demonstrated at the ocular surface (Bischoff et al., 2011). Thus, the immunological profile of the tear fluid likely plays an important role in host defence against URTI, and moreover provides a non-invasive medium for assessment of immune status. We recently demonstrated that tear secretory IgA (SIgA) has potential as a biomarker of URTI risk (Hanstock et al., 2016). It is likely that several other antimicrobial proteins abundant in tears such as lactoferrin (Lf) and lysozyme (Lys) contribute to host defence at the ocular surface (McDermott, 2013).

     PURPOSE: To explore the potential of tear Lf and Lys to evaluate risk of subsequent URTI independently and in combination with tear SIgA data from the same subjects presented in Hanstock et al., (2016).

     METHODS: Forty healthy, physically active subjects were recruited during the common-cold season. Subjects reported upper respiratory symptoms (URS) daily and provided weekly tear samples for 4 weeks. If URS were reported for ≥ 48h, subjects provided a nasopharyngeal swab for identification of common-cold pathogens using RT-PCR and a tear sample. Following an episode of URS, subjects reported daily URS until they had been symptom-free for 4 weeks at which time a ‘Recovery’ tear sample was collected. Tear Lf and Lys concentration was determined using ELISA.

     RESULTS: Eleven students reported episodes of URS; nine returned positive virology tests for human rhinovirus (URTI). Twenty-two students remained symptom-free during the monitoring period (Healthy) and seven were excluded due to non-compliance. Tear Lys concentration (Lys-C) and secretion rate (Lys-SR) were lower in URTI vs. Healthy (p<0.01 and p<0.05 respectively) but there was no difference in Lf-C and Lf-SR. The potential of Lf and Lys to assess URS risk was determined by comparing Lf and Lys the week before URS with Recovery samples. Tear Lf-C, Lf-SR and Lys-C were not altered before URS, whereas Lys-SR tended to be reduced in the week before URS (p<0.1). A binary logistic regression incorporating tear flow rate, Lys-C, Lf-C and SIgA-C as predictors was able to correctly identify subjects at risk of URS in the next week with 70% accuracy (95% CI: 54 – 85%) but only 27% sensitivity.

     CONCLUSION: Although tear Lys was decreased during URTI, the new model including tear Lys and Lf was not able to improve upon the utility of tear SIgA alone to assess URS risk in this small cohort. Larger datasets will be required to evaluate and optimise model performance for models based on tear SIgA, possibly in combination with other biomarkers, to predict URTI.

  • 9.
    Hanstock, Helen
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Bangor University, Gwynedd, UK.
    Edwards, Jason
    Bangor University, Gwynedd, UK.
    Roberts, Ross
    Bangor University, Gwynedd, UK.
    Walsh, Neil
    Bangor University, Gwynedd, UK.
    High heart rate reactors display greater decreases in tear SIgA concentration following a novel acute stressor2018In: Biological Psychology, ISSN 0301-0511, E-ISSN 1873-6246, Vol. 133, p. 85-88Article in journal (Refereed)
    Abstract [en]

    Tear secretory immunoglobulin-A (SIgA) is a putative biomarker of common-cold risk with potential utility in non-invasive diagnostics. As SIgA secretion at the ocular surface is under strong autonomic control, we investigated the relationship between HR reactivity and tear SIgA responses to novel experiential stress. Thirty-two healthy participants undertook a 60-second zip-line ride to evoke acute stress and a seated-rest control trial in a randomised-crossover design. We recorded heart rate (HR) continuously and collected unstimulated tear samples 5-min-pre-, 2-min-post- and 20-min-post-stress/control. Stress increased HR and state anxiety whereas tear SIgA concentration decreased 44% post-stress vs. control. Higher peak HR values during stress uniquely explained 21% of the variance in tear SIgA reactivity to stress (p < .01); high HR reactors displayed greater decreases in tear SIgA concentration. We conclude that physiological arousal increases immune reactivity to acute stress and highlight tear SIgA as a minimally-invasive, physiologically relevant biomarker of immune reactivity.

  • 10.
    Hanstock, Helen
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Bangor University, Bangor, Gwynedd, Wales.
    Edwards, Jason
    Bangor University, Bangor, Gwynedd, Wales.
    Walsh, Neil
    Bangor University, Bangor, Gwynedd, Wales.
    Tear Lactoferrin and Lysozyme as Clinically Relevant Biomarkers of Mucosal Immune Competence2019In: Frontiers in Immunology, ISSN 1664-3224, E-ISSN 1664-3224, Vol. 10, article id 1178Article in journal (Refereed)
    Abstract [en]

    Tears have attracted interest as a minimally-invasive biological fluid from which to assess biomarkers. Lactoferrin (Lf) and lysozyme (Lys) are abundant in the tear fluid and have antimicrobial properties. Since the eye is a portal for infection transmission, assessment of immune status at the ocular surface may be clinically relevant. Therefore, the aim of this series of studies was to investigate the tear fluid antimicrobial proteins (AMPs) Lf and Lys as biomarkers of mucosal immune status. To be considered biomarkers of interest, we would expect tear AMPs to respond to stressors known to perturb immunity but be robust to confounding variables, and to be lower in participants with heightened risk or incidence of illness. We investigated the relationship between tear AMPs and upper respiratory tract infection (URTI; study 1) as well as the response of tear AMPs to prolonged treadmill exercise (study 2) and dehydration (study 3). Study 1 was a prospective cohort study conducted during the common cold season whereas studies 2 and 3 used repeated-measures crossover designs. In study 1, tear Lys concentration (C) as well as tear AMP secretion rates (SRs) were lower in individuals who reported pathogen-confirmed URTI (n = 9) throughout the observation period than in healthy, pathogen-free controls (n = 17; Lys-C, P = 0.002, d = 0.85; Lys-SR, P < 0.001, d = 1.00; Lf-SR, P = 0.018, d = 0.66). Tear AMP secretion rates were also lower in contact lens wearers. In study 2, tear AMP SRs were 42–49% lower at 30 min−1 h post-exercise vs. pre-exercise (P < 0.001, d = 0.80–0.93). Finally, in study 3, tear AMPs were not influenced by dehydration, although tear AMP concentrations (but not secretion rates) displayed diurnal variation. We conclude that Lf and Lys have potential as biomarkers of mucosal immune competence; in particular, whether these markers are lower in infection-prone individuals warrants further investigation.

  • 11.
    Hanstock, Helen
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Govus, Andrew
    University of Agder, Norway.
    Stenqvist, Thomas B
    University of Copenhagen, Denmark.
    Melin, Anna K
    University of Copenhagen, Denmark.
    Sylta, Öystein
    Agder University, Norway.
    Torstveit, Monica K
    Agder University, Norway.
    Influence of interval duration on immunological responses to 4-weeks’ high-intensity interval training2018In: Journal of Sports Sciences: BASES Conference 2018 – Programme and Abstracts, Routledge, 2018, Vol. 36 (S1), p. 1-94Conference paper (Refereed)
    Abstract [en]

    High-intensity interval training (HIT) encompasses a wide range of training prescriptions where up to nine variables can be manipulated (Buchheit and Laursen, 2013, Sports Medicine, 43(5), 313–338). Four weeks of HIT with longer intervals and accumulated work durations (AWD) has been shown to elicit greater improvements in peak oxygen consumption (V O 2peak ) despite more modest physiological, hormonal and perceptual responses (Sylta et al., 2017, Medicine & Science in Sports & Exercise, 49(6), 1137–1146). However, immunological responses to different HIT pre- scriptions have rarely been investigated. The purpose of this study was to compare the cumulative effects of a four-week HIT intervention, performed either as short or long intervals with the same AWD, on V O 2peak , the immunological biomarker salivary secretory IgA (s-IgA) and upper respiratory illness (URI) incidence. In addition, we explored the influence of HIT on serum cortisol, testosterone, 25(OH)D and ferritin as biomarkers related to immune competence. Following local ethics committee approval, twenty-five well-trained male cyclists and triath- letes provided written consent to take part and were randomised to one of three HIT groups (Long Intervals [LI]: 4 × 8min; Short Intervals 1 [SI1]: 4×[12 × 40/20s]; Short Intervals 2 [SI2]: 4×[8 ×40/20s]). Participants per- formed three cycling HIT sessions per week for four weeks at maximal session effort (“isoeffort”) intensity, supplemented with ad libitumlow-intensity training. Participants recorded upper respiratory symptoms (URS) daily using the Jackson Common Cold Scale; episodes of URI were identified retrospectively. V O 2peak as well as rested saliva and blood biomarkers were analysed before and after the training period. Fourteen of twenty-five participants reported an episode of URI (LI: 4/8, SI1: 4/8, SI2: 6/9) but there were no differences in URI incidence, severity or duration between groups. Following the train- ing intervention, we observed a moderate increase in V O 2peak across the cohort (mean± SD: 4.75 ± 0.42 to 4.86 ± 0.43 L· min−1 ,Cohen’s d= 0.65, 90% confidence intervals: [0.16, 1.13]) but the change in V O 2peak was not different between groups. Serum cortisol displayed a moderate increase (367 ± 98 to 415 ± 108 nmol· L −1 ,d=0.60 [0.12, 1.08]) and 25(OH)D a large decrease (79.2 ± 17.1 to 70.4 ± 17.6 nmol· L −1 ,d= -0.87 [−1.36,−0.37]) from pre- to post-training, but there were no differences in the magnitude of the responses between groups. Four weeks’HIT did not influence s-IgA secretion rate, serum testosterone or ferritin. We conclude that four weeks’ AWD-matched HIT performed as short- or long-intervals at isoeffort intensity does not differentially influence ill- ness incidence, immunological responses to training nor other immune-related biomarkers. This observation can be viewed as a positive finding for training planning, since it could allow coaches some flexibility in constructing AWD-matched isoeffort HIT sessions to achieve performance goals, without concern about detrimental effects on athletes’ immune status.

  • 12.
    Hanstock, Helen
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Govus, Andrew
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Stenqvist, Thomas B.
    University of Agder, Norway.
    Melin, Anna K.
    University of Copenhagen, Denmark.
    Sylta, Øystein
    University of Agder, Norway.
    Torstveit, Monica K.
    University of Agder, Norway.
    Influence of Immune and Nutritional Biomarkers on Illness Risk During Interval Training2019In: International Journal of Sports Physiology and Performance, ISSN 1555-0265, E-ISSN 1555-0273Article in journal (Refereed)
    Abstract [en]

    Intensive training periods may negatively influence immune function, but the immunological consequences of specific high-intensity training (HIT) prescriptions are not well defined. Purpose: This study explored whether three different HIT prescriptions influence multiple health-related biomarkers and whether biomarker responses to HIT were associated with upper respiratory illness (URI) risk. Methods: Twenty-five male cyclists and triathleteswere randomised to three HIT groups and completed twelve HIT sessions over four weeks. Peak oxygen consumption (V̇O2peak) was determined using an incremental cycling protocol, while resting serum biomarkers (cortisol, testosterone, 25(OH)D and ferritin), salivary immunoglobulin-A (s-IgA) and energy availability (EA) were assessed before and after the training intervention. Participants self-reported upper respiratory symptoms during the interventionand episodes of URI were identified retrospectively. Results: Fourteen athletes reported URIs, but there were no differences in incidence, duration or severity between groups. Increased risk of URI was associated with higher s-IgA secretion rates (odds ratio=0.90, 90% CI:0.83-0.97). Lower pre-intervention cortisol and higher EA predicted a 4% increase in URI duration. Participants with higher V̇O2peak reported higher total symptom scores (incidence rate ratio=1.07, 90% CI:1.01-1.13). Conclusions: Although multiple biomarkers wereweakly associated with risk of URI, the direction of associations between s-IgA, cortisol, EA and URI risk were inverse to previous observations and physiological rationale. There was a cluster of URIs within the first week of the training intervention, but no samples were collected at this time-point. Future studies should incorporate more frequent sample time-points, especially around the onset of new training regimes, and include athletes with suspected or known nutritional deficiencies.

  • 13.
    Hanstock, Helen
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Govus, Andrew
    University of Agder, Norway.
    Stenqvist, Thomas B
    University of Copenhagen, Denmark.
    Melin, Anna
    University of Copenhagen, Denmark.
    Sylta, Öystein
    University of Agder, Norway.
    Torstveit, Monica K
    University of Agder, Norway.
    Evaluation of physiological and nutritional risk factors for upper respiratory illness using a zero-inflated negative binomial model2018In: Journal of Sports Sciences: Volume 36, 2018 - Issue sup1: BASES Conference 2018 – Programme and Abstracts, Routledge, 2018, Vol. 36 (S1), p. 44-45Conference paper (Refereed)
    Abstract [en]

    Intensified training periods may increase incidence of upper respiratory illness (URI) in athletes (Meeusen et al., 2013,Medicine and Science in Sports and Exercise, 45(1), 186–205). Many physiological and nutritional risk factors have beenassociated with increased risk of URI (Bermon et al., 2017, Exercise Immunology Review, 23, 8–50), including reductionsin salivary IgA (sIgA), elevated cortisol, vitamin D insufficiency, iron deficiency and low energy availability (EA). However, few studies have explored the relative importance of each of thesehealth-related biomarkers in a multivariate model. Our aimwas therefore to investigate the relationship between multiplebiological risk factors for illness and incidence, duration andseverity of URIs that present during intensified training. 3815Twenty-five well-trained male cyclists and triathletes (age 30 ± 9 y, VO2peak 64 ± mL· kg−1· min−1) performed one ofthree different high-intensity interval training (HIT) programmes for three sessions per week over four weeks in November-December. The study received local ethical approval and participants provided written, informed consentto participate. Participants performed each HIT session at “isoeffort” intensity and sessions were matched for total accumulated work duration. Participants logged upper respiratorysymptoms (URS) daily using the Jackson Common Cold Scale; episodes of URI were identified retrospectively using the followinga priori criteria: weekly symptom score > 14 or selfreportedcommon cold for > 2 consecutive days (Jacksonet al., 1958, American Medical Association Archives of Internal Medicine, 101, 267–278). Before commencing the training period, VO2peak was determined using an incremental maximal cycling protocol and participants provided rested, fasted blood and saliva samples prior to the training period foranalysis of plasma 25(OH)D, ferritin, cortisol, testosterone and sIgA secretion rate. EA was calculated based on a 3-day registration of energy intake and expenditure relative to fat-free mass measured in a rested, fasted state using indirect calorimetry (Torstveit et al., 2018 February, International Journal of Sport Nutrition and Exercise Metabolism, 1–28). We used a zero-inflated negative binomial model to investigate the relationship between baseline VO2peak, health-related biomarkers and URI incidence/duration/global URS severity. Fourteen athletes(56%) reported an episode of URI during the four-week monitoring period. Higher sIgA was associated with reduced risk of URI (odds ratio = 0.90, 90% confidence interval (CI): [0.83,0.97]). Lower plasma cortisol (P = 0.02) and higher EA (P = 0.02) were associated with longer URI duration; holding cortisol constant, the incidence risk ratio (IRR) for a one-unit increase in EA was 1.04 (90% CI: [1.01, 1.07]). Participants with higher VO2peak reported higher total symptom scores during the intervention period (P = 0.03, IRR = 1.07, 90% CI: [1.01,1.13]). Several health-related biomarkers and physiological parameters may therefore be associated with risk and severityof URI, including sIgA, cortisol, EA and VO2peak.

  • 14.
    Hanstock, Helen
    et al.
    Bangor University, UK.
    Walsh, Neil P
    Bangor University, UK.
    Edwards, Jason P
    Bangor University, UK.
    Fortes, Matthew B
    Bangor University, UK.
    Cosby, Sarah L
    Queen’s University Belfast, Northern Ireland, UK.
    Nugent, Aaron
    Queen’s University Belfast, Northern Ireland, UK.
    Curran, Tanya
    Royal Victoria Hospital, Belfast, UK.
    Coyle, Peter V
    Royal Victoria Hospital, Belfast, UK.
    Ward, Mark D
    Bangor University, UK.
    Aw Yong, Xin Hui
    Bangor University, UK.
    Tear Fluid SIgA as a Noninvasive Biomarker of Mucosal Immunity and Common Cold Risk2016In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 48, no 3, p. 569-577Article in journal (Refereed)
    Abstract [en]

    Purpose: Research has not convincingly demonstrated the utility of saliva secretory Immunoglobulin-A (SIgA) as a biomarker of upper-respiratory-tract-infection (URTI) risk and disagreement exists about the influence of heavy exercise ('open-window-theory') and dehydration on saliva SIgA. Prompted by the search for viable alternatives, we compared the utility of tear and saliva SIgA to predict URTI prospectively (study-one) and assessed the influence of exercise (study-two) and dehydration (study-three) using a repeated-measures-crossover design.Methods: In study-one, forty subjects were recruited during the common-cold season. Subjects provided tear and saliva samples weekly and recorded upper-respiratory-symptoms (URS) daily for 3-weeks. RT-PCR confirmed common-cold pathogens in 9 of 11 subjects reporting URS (82%). Predictive utility of tear and saliva SIgA was explored by comparing healthy samples with those collected the week pre-URS. In study-two, thirteen subjects performed a 2-hour run at 65% VO2peak. In study-three, thirteen subjects performed exercise-heat-stress to 3% body-mass-loss followed by overnight fluid restriction.Results: Tear SIgA concentration and secretion rate were 48% and 51% lower respectively during URTI and 34% and 46% lower the week pre-URS (P<0.05) but saliva SIgA remained unchanged. URS risk the following week increased 9-fold (95% CI: 1.7 to 48) when tear SIgA secretion rate <5.5 μg[BULLET OPERATOR]min and 6-fold (95% CI: 1.2 to 29) when tear SIgA secretion rate decreased >30%. Tear SIgA secretion rate >5.5 μg[BULLET OPERATOR]min or no decrease >30% predicted subjects free of URS in >80% of cases. Tear SIgA concentration decreased post-exercise (-57%: P<0.05) in line with the 'open-window-theory' but was unaffected by dehydration. Saliva flow rate decreased and saliva SIgA concentration increased post-exercise and during dehydration (P<0.05).Conclusion: Tear SIgA has utility as a non-invasive biomarker of mucosal immunity and common-cold risk.

  • 15.
    Sjöström, Rita
    et al.
    Umeå Universitet; Östersund sjukhus.
    Söderström, Lars
    Östersunds sjukhus.
    Klockmo, Carolina
    Kommunförbundet Västernorrland.
    Patrician, Alexander
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Sandström, Thomas
    Umeå Universitet.
    Björklund, Glenn
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Hanstock, Helen
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Stenfors, Nikolai
    Umeå Universitet.
    Qualitative identification and characterisation of self-reported symptoms arising in humans during experimental exposure to cold air2019In: International Journal of Circumpolar Health, ISSN 2242-3982, E-ISSN 2242-3982, Vol. 78, no 1, article id 1583528Article in journal (Refereed)
    Abstract [en]

    Background: Exposure to cold air is associated with increased morbidity and mortality in the general population. It is difficult to study the effects of whole-body exposure to cold air under controlled conditions in real life. Objectives: The aim of this study was to (1) explore and describe the experience of symptoms in humans during experimental and controlled exposures to cold air, by using controlled environmental chamber exposures and qualitative methodology, and to (2) categorise the symptoms. Method: The study used a randomised, double blind design, in which 34 subjects undertook rest and moderate-intensity exercise in an environmental chamber set to two or three different temperatures (0, −10, and −17°C) on separate occasions. During the chamber exposures, subjects were interviewed. Qualitative content analysis was selected as the method of analysis. Findings: Subjects reported 50 distinct symptoms during the exposures. The symptoms were grouped into ten sub-categories and two major categories; airway versus whole-body symptoms. Conclusion: We have identified a broad range of symptoms in humans undertaking rest and moderate-intensity exercise at sub-zero temperatures. The symptoms and their categories may well be used to more extensively and quantitatively map cold-induced morbidity.

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