association between SIgA and upper respiratory tract infections (URTI), in which a high incidence of infections was reported in individuals with a selective deficiency of SIgA or low saliva flow rates. Additionally, these researchers reported some findings suggesting that a high level of SIgA was associated
Kizzy Antualpa, Marcelo Saldanha Aoki and Alexandre Moreira
Craig A. Rubenstein
Column-editor : Tracy Ray
Gal Dubnov-Raz, Harri Hemilä, Avner H. Cohen, Barak Rinat, Lauryn Choleva and Naama W. Constantini
Observational studies identified associations between vitamin D insufficiency (serum 25(OH)D > 30ng·ml−1) and risk of upper respiratory infection (URI). Swimmers are highly prone to URIs, which might hinder their performance. The aim of this study was to examine if vitamin D3 supplementation reduces URI burden in vitamin D-insufficient swimmers. Fifty-five competitive adolescent swimmers with vitamin D insufficiency were randomized to receive vitamin D3 (2,000IU·d4) or placebo for 12 winter weeks. A URI symptom questionnaire was completed weekly. Serum 25(OH)D concentrations were measured by radio-immunoassay before and after supplementation. We used linear regression to examine the relation between the change in 25(OH)D concentrations during the trial, and the duration and severity of URIs. There were no between-group differences in the frequency, severity, or duration of URIs. Exploratory analyses revealed that in the placebo group only, the change in 25(OH)D concentrations during the trial was highly associated with the duration of URIs (r = −0.90,p > .001), and moderately associated with the severity of URIs (r = −0.65,p = .043). The between-group differences for duration were highly significant. Vitamin D3 supplementation in adolescent swimmers with vitamin D insufficiency did not reduce URI burden. However, larger decreases in serum 25(OH)D concentrations were associated with significantly longer and more severe URI episodes.
Gabriella Berwig Möller, Maria Júlia Vieira da Cunha Goulart, Bruna Bellincanta Nicoletto, Fernanda Donner Alves and Cláudia Dornelles Schneider
(salivary IgA, whole blood cultures of IL-4, IL-12, and IFN-γ); and respiratory tract (infection or illnesses) Lower symptom days of respiratory tract illnesses (30 vs. 70; p < .001). No effect on treadmill performance or immunity parameters (salivary IgA, whole blood cultures of IL-4, IL-12, and IFN
Eric S. Rawson, Mary P. Miles and D. Enette Larson-Meyer
to exercise, improving brain performance, decreasing delayed onset muscle soreness or pain, reducing injury severity, enhancing recovery from injury, reducing gastrointestinal problems, and decreasing respiratory tract infection illness load. For the most part, these effects are not ergogenic, but
Riina A. Kekkonen, Tommi J. Vasankari, Timo Vuorimaa, Tari Haahtela, Ilkka Julkunen and Riitta Korpela
Heavy exercise is associated with an increased risk of upper respiratory tract infections. Strenuous exercise also causes gastrointestinal (GI) symptoms. In previous studies probiotics have reduced respiratory tract infections and GI symptoms in general populations including children, adults, and the elderly. These questions have not been studied in athletes before. The purpose of this study was to investigate the effect of probiotics on the number of healthy days, respiratory infections, and GI-symptom episodes in marathon runners in the summer. Marathon runners (N = 141) were recruited for a randomized, double-blind intervention study during which they received Lactobacillus rhamnosus GG (LGG) or placebo for a 3-mo training period. At the end of the training period the subjects took part in a marathon race, after which they were followed up for 2 wk. The mean number of healthy days was 79.0 in the LGG group and 73.4 in the placebo group (P = 0.82). There were no differences in the number of respiratory infections or GI-symptom episodes. The duration of GI-symptom episodes in the LGG group was 2.9 vs. 4.3 d in the placebo group during the training period (P = 0.35) and 1.0 vs. 2.3 d, respectively, during the 2 wk after the marathon (P = 0.046). LGG had no effect on the incidence of respiratory infections or GI-symptom episodes in marathon runners, but it seemed to shorten the duration of GI-symptom episodes.
Michael Gleeson, Nicolette C. Bishop, Marta Oliveira and Pedro Tauler
The purpose of this study was to examine the effects of a probiotic supplement during 4 mo of winter training in men and women engaged in endurance-based physical activities on incidence of upper respiratory-tract infections (URTIs) and immune markers. Eighty-four highly active individuals were randomized to probiotic (n = 42) or placebo (n = 42) groups and, under double-blind procedures, received probiotic (PRO: Lactobacillus casei Shirota [LcS]) or placebo (PLA) daily for 16 wk. Resting blood and saliva samples were collected at baseline and after 8 and 16 wk. Weekly training and illness logs were kept. Fifty-eight subjects completed the study (n = 32 PRO, n = 26 PLA). The proportion of subjects on PLA who experienced 1 or more weeks with URTI symptoms was 36% higher than those on PRO (PLA 0.90, PRO 0.66; p = .021). The number of URTI episodes was significantly higher (p < .01) in the PLA group (2.1 ± 1.2) than in the PRO group (1.2 ± 1.0). Severity and duration of symptoms were not significantly different between treatments. Saliva IgA concentration was higher on PRO than PLA, significant treatment effect F(1, 54) = 5.1, p = .03; this difference was not evident at baseline but was significant after 8 and 16 wk of supplementation. Regular ingestion of LcS appears to be beneficial in reducing the frequency of URTI in an athletic cohort, which may be related to better maintenance of saliva IgA levels during a winter period of training and competition.
Michael Gleeson, Nicolette C. Bishop, Marta Oliveira, Tracey McCauley, Pedro Tauler and Claire Lawrence
The purpose of this study was to examine the effects of a probiotic supplement during 4 mo of spring training in men and women engaged in endurance-based physical activities on incidence of upper respiratory tract infections (URTI) and mucosal immune markers. Sixty-six highly active individuals were randomized to probiotic (n = 33) or placebo (n = 33) groups and, under double-blind procedures, received probiotic (PRO: Lactobacillus salivarius, 2 × 1010 bacterium colony-forming units) or placebo (PLA) daily for 16 wk. Resting blood and saliva samples were collected at baseline and after 8 and 16 wk. Weekly training and illness logs were kept. Fifty-four subjects completed the study (n = 27 PRO, n = 27 PLA). The proportion of subjects on PRO who experienced 1 or more wk with URTI symptoms was not different from that of those on PLA (PRO .58, PLA .59; p = .947). The number of URTI episodes was similar in the 2 groups (PRO 1.6 ± 0.3, PLA 1.4 ± 0.3; p = .710). Severity and duration of symptoms were not significantly different between treatments. Blood leukocyte, neutrophil, monocyte, and lymphocyte counts; saliva IgA; and lysozyme concentrations did not change over the course of the study and were not different on PRO compared with PLA. Regular ingestion of L. salivarius does not appear to be beneficial in reducing the frequency of URTI in an athletic cohort and does not affect blood leukocyte counts or levels of salivary antimicrobial proteins during a spring period of training and competition.
Christine V. Crooks, Clare R. Wall, Martin L. Cross and Kay J. Rutherfurd-Markwick
Secretory IgA in saliva (s-IgA) is a potential mucosal immune correlate of upper respiratory tract infection (URTI) status. Nutritional supplements may improve mucosal immunity, and could be beneficial to athletes who are at increased risk of URTI. In this study, 35 distance runners (15 female, 20 male, age 35 to 58 y) consumed a supplement of either bovine colostrum or placebo for 12 wk. Saliva samples were taken prior to training at baseline, monthly during supplementation, and 2 wk post supplementation. Median levels of s-IgA increased by 79% in the colostrum group after 12 wk intervention, and the time-dependent change from baseline value was significant (P = 0.0291). This significance was still apparent after adjusting for training volume and self-reporting of upper respiratory symptoms. This study has demonstrated increased s-IgA levels among a cohort of athletes following colostrum supplementation. While this result is statistically significant, its physiological interpretation must be viewed with caution due to the small numbers in this study and the large variability in s-IgA levels.
Camila G. Freitas, Marcelo S. Aoki, Clovis A. Franciscon, Ademir F.S. Arruda, Christopher Carling and Alexandre Moreira
This study investigated the effect of a 2-week overloading training phase followed by a 2-week tapering phase on internal training load (ITL), salivary cortisol, stress tolerance, and upper respiratory tract infections symptoms (URTI) in 11 male young soccer players (16.0 ± 0.5 yrs). Ratings of perceived exertion (session-RPE) were taken after each training session (N = 194) to determine ITL. Saliva sampling was conducted at the end of each week and cortisol concentration assessed by ELISA. DALDA and WURSS-21 questionnaires were administered every week to evaluate stress tolerance and severity of URTI respectively. The number of athletes reporting URTI symptoms was recorded. The overloading phase promoted greater ITL and a higher resting cortisol concentration than the tapering phase (P < .05). While no significant changes in stress tolerance or URTI severity were observed, the number of athletes reporting URTI symptoms was higher during the overloading phase. A significant correlation was observed between symptoms of stress and severity of URTI (rs=-.71; P = .01). The results indicate that an integrated approach using psychological measures (session-RPE and DALDA), self-reports of URTI symptoms, and endocrine responses (cortisol) to training are pertinent for monitoring young soccer players.