Upper respiratory tract symptoms and salivary immunoglobulin A of elite female gymnasts : a full year longitudinal field study

The aim of this study was to determine the frequency of upper respiratory tract symptoms (URS) in elite female gymnasts during a training season. In addition, we aimed to observe the extent to which salivary immunoglobulin A (sIgA) is associated with URS in these athletes, including potential effects of the season and timing of sample collection. Over one year, 18 elite female gymnasts completed URS and fatigue questionnaires weekly and provided 1 mL of saliva after a minimum 36 h of rest (morning or afternoon) to measure relative sIgA concentration (= mean absolute sIgA value of the week divided by the mean absolute sIgA value of the weeks without URS). Mean weekly URS and mean relative sIgA values per gymnast correlated negatively (r = -0.606, P = 0.022). Most URS were noted in the most fatigued gymnasts (7.4 ± 10.1 vs. 2.5 ± 5.6 (P < 0.001) for ‘normal’ and 2.1 ± 3.7 (P = 0.001) for ‘better than normal’ rested). In spring, relative sIgA was higher compared to autumn (112 ± 55 vs. 89 ± 41%, P < 0.001) and winter (92 ± 35%, P = 0.001), while during summer, relative sIgA appeared higher compared to autumn (110 ± 55 vs. 89 ± 41%, P = 0.016). The interaction effect with timing of sample collection showed higher relative sIgA values in morning samples in spring and summer compared to afternoon samples, with the inverse observed in autumn and winter (F = 3.565, P = 0.014). During a gymnastics season, lower relative sIgA values were linked to higher susceptibility to URS in elite gymnasts. However, relative sIgA values were influenced by season and timing of sample collection and thus should be considered when interpreting sIgA data

Effects of Regular Physical Activity on the Immune System, Vaccination and Risk of Community-Acquired Infectious Disease in the General Population: Systematic Review and Meta-Analysis

BackgroundRegular physical activity is the prime modality for the prevention of numerous non-communicable diseases and has also been advocated for resilience against COVID-19 and other infectious diseases. However, there is currently no systematic and quantitative evidence synthesis of the association between physical activity and the strength of the immune system.ObjectiveTo examine the association between habitual physical activity and (1) the risk of community-acquired infectious disease, (2) laboratory‐assessed immune parameters, and (3) immune response to vaccination.MethodsWe conducted a systemic review and meta-analysis according to PRISMA guidelines. We searched seven databases (MEDLINE, Embase, Cochrane CENTRAL, Web of Science, CINAHL, PsycINFO, and SportDiscus) up to April 2020 for randomised controlled trials and prospective observational studies were included if they compared groups of adults with different levels of physical activity and reported immune system cell count, the concentration of antibody, risk of clinically diagnosed infections, risk of hospitalisation and mortality due to infectious disease. Studies involving elite athletes were excluded. The quality of the selected studies was critically examined following the Cochrane guidelines using ROB2 and ROBINS_E. Data were pooled using an inverse variance random-effects model.ResultsHigher level of habitual physical activity is associated with a 31% risk reduction (hazard ratio 0.69, 95% CI 0.61–0.78, 6 studies, N = 557,487 individuals) of community-acquired infectious disease and 37% risk reduction (hazard ratio 0.64, 95% CI 0.59–0.70, 4 studies, N = 422,813 individuals) of infectious disease mortality. Physical activity interventions resulted in increased CD4 cell counts (32 cells/µL, 95% CI 7–56 cells/µL, 24 studies, N = 1112 individuals) and salivary immunoglobulin IgA concentration (standardised mean difference 0.756, 95% CI 0.146–1.365, 7 studies, N = 435 individuals) and decreased neutrophil counts (704 cells/µL, 95% CI 68–1340, 6 studies, N = 704 individuals) compared to controls. Antibody concentration after vaccination is higher with an adjunct physical activity programme (standardised mean difference 0.142, 95% CI 0.021–0.262, 6 studies, N = 497 individuals).ConclusionRegular, moderate to vigorous physical activity is associated with reduced risk of community-acquired infectious diseases and infectious disease mortality, enhances the first line of defence of the immune system, and increases the potency of vaccination

Forearm muscle blood flow and deoxygenation during dynamic handgrip exercise in limb specific trained athletes

Sustainable Sportinfo:eu-repo/semantics/nonPublishe

Possible influences on the interpretation of functional domain (FD) near-infrared spectroscopy (NIRS): an explorative study

The influence of subcutaneous adipose tissue (ATT) and oxygen (O-2) delivery has been poorly defined in frequency domain (FD) near-infrared spectroscopy (NIRS). Therefore, the aim of this study was to investigate the possible influence of these variables on all FD NIRS responses using a reliable protocol. Moreover, these influences were also investigated when using relative oxy- and deoxyhemoglobin and -myoglobin (oxy[Hb+Mb] and deoxy[Hb+Mb]) values (in %). A regression analysis was carried out for ATT and maximal-minimum oxy[Hb+Mb], deoxy[Hb+Mb], oxygen saturation (SmO2), and total hemoglobin (totHb) amplitudes during an incremental cyclic contraction protocol (ICCP) in a group of 45 participants. Moreover, the same analysis was carried out between subcutaneous ATT and the relative oxy- and deoxy[Hb+Mb] values (in %). In the second part of this study, a regression analysis was performed for peak forearm blood flow (FBF) during ICCP and the absolute and relative NIRS values in a group of 37 participants. Significant exponential correlation coefficients were found between ATT and deoxy[Hb+Mb] (r = 0.53; P<0.001), oxy[Hb+Mb] (r = 0.57; P<0.001), and SmO2 amplitudes (r = 0.57; P<0.001). No significant relations were found between ATT and relative oxy[Hb+Mb] (r = 0.37; P = 0.07) and deoxy[Hb+Mb] (r = 0.09; P = 0.82). Significant positive correlation coefficients were found between force at exhaustion and maximal FBF (r = 0.66; P<0.001), maximal differences in deoxy[Hb+Mb] (r = 0.353; P = 0.032) and totHb (r = 0.512; P = 0.002) while no significant correlation coefficients were found between these maximal force values and maximal differences in oxy[Hb+Mb] (r = -0.267; P = 0.111) and SmO2 (r = -0.267; P = 0.111). Significant linear correlation coefficients were found between FBF and deoxy[Hb+Mb] (r = 0.51; P = 0.001), oxy[Hb+Mb] (r = -0.50; P = 0.001), SmO2 (r = -0.54; P = 0.001), and totHb amplitude (r = 0.61; P<0.001). No significant correlations were found when using relative oxy[Hb+Mb] (r = -0.01; P = 0.957) and deoxy[Hb+Mb] (r = -0.02; P = 0.895). Based on these findings, caution is advised when using NIRS values, as subcutaneous ATT and O-2 delivery significantly influence NIRS measurements. To eliminate these influences, use of relative deoxy[Hb+Mb] is advised, especially in clinical settings or in people with a higher subcutaneous ATT layer

Sleep, training load and performance in elite female gymnasts

Training load (TL) and recovery should be in optimal balance to obtain maximal performance gains. We aimed to study sleep as a recovery technique and its relationship with TL and performance in elite athletes. Twenty-six elite female artistic gymnasts were divided into an under 13 (n=6), an under 14 (n=6), a junior (n=7; 14-15y) and a senior (=World Championship (WC) competitors, n=7; 16y) category. Sleep, through sleep logs, and training parameters, using the session Rate of Perceived Exertion (sRPE) scale, were monitored to calculate total sleep time (TST), sleep efficiency (SE), TL, monotony and strain. Performance of WC competitors was evaluated through coach and WC qualification ranking. For the entire group, TST (effect sizes (ES)=-1.12, confidence intervals (CI)=-60:-47, P<.05) and SE (ES=-0.13, CI=-1.40:-0.10, P=.022) were shorter during week than weekend nights. TST and SE were highest in youngest gymnasts (P<.05). TL was lowest in under 13 and senior gymnasts (P<.05), while TL, monotony and strain were highest in junior gymnasts (P<.05). A negative regression was found between TST and TL the day after, while higher TL also led to lower TST the following night (P<.001). For the WC competitors, TST the night before the qualifications was shorter than the mean TST of the WC period (ES=-0.95, CI=-170:24, P=.030). TST correlated with coach ranking (r=-0.857, P=.014). Higher TL correlated with worse WC (r=0.829, P=.042) and coach (r=0.893, P=.007) ranking. This research in elite gymnasts indicated associations between decreased TST, augmented TL and inferior performance. Optimizing sleep and TL may therefore represent strategies to enhance performance