COVID-19 vaccination produces exercise-responsive SARS-CoV-2 specific T-cells regardless of infection history

Background:The mobilization and redistribution of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)specific T-cells and neutralizing antibodies(nAbs)during exercise is purported to increase immune surveillance and protect against severe coronavirus disease 2019(COVID-19).We sought to determine if COVID-19 vaccination would elicit exercise-responsive SARS-CoV-2 T-cells and transiently alter nAb titers.Methods:Eighteen healthy participants completed a 20-min bout of graded cycling exercise before and/or after receiving a COVID-19 vaccine.All major leukocyte subtypes were enumerated before,during,and after exercise by flow cytometry,and immune responses to SARS-CoV-2 were determined using whole blood peptide stimulation assays,T-cell receptor(TCR)-βsequencing,and SARS-CoV-2 nAb serology.Results:COVID-19 vaccination had no effect on the mobilization or egress of major leukocyte subsets in response to intensity-controlled graded exercise.However,non-infected participants had a significantly reduced mobilization of CD4+and CD8+naive T-cells,as well as CD4+central memory T-cells,after vaccination(synthetic immunity group);this was not seen after vaccination in those with prior SARS-CoV-2 infection(hybrid immunity group).Acute exercise after vaccination robustly mobilized SARS-CoV-2 specific T-cells to blood in an intensity-dependent manner.Both groups mobilized T-cells that reacted to spike protein;however,only the hybrid immunity group mobilized T-cells that reacted to membrane and nucleocapsid antigens.nAbs increased significantly during exercise only in the hybrid immunity group.Conclusion:These data indicate that acute exercise mobilizes SARS-CoV-2 specific T-cells that recognize spike protein and increases the redistribution of nAbs in individuals with hybrid immunity.

Can physical activity eliminate the mortality risk associated with poor sleep?A 15-year follow-up of 341,248 MJ Cohort participants

Background:This study examined the joint associations of sleep patterns and physical activity(PA) with all-cause,cardiovascular disease(CVD),and cancer mortality.Methods:A total of 341,248 adults(mean age=39.7 years;men:48.3%) were included in the study,with a 15-year follow-up.Participants reported sleep duration and disturbances(difficulty falling asleep,easily awakened,or use of sleeping medication).PA was classified into 4 levels:<7.5,7.5-14.9,15.0-29.9,and>30.0 metabolic equivalent hours per week(MET-h/week).To understand the joint associations of sleep patterns and PA with mortality,Cox proportional hazard models were conducted,with exposure variables combining sleep duration/disturbances and PA.Results:Compared with the reference group(sleeping 6-8 h/day),individuals who slept>8 h/day had higher risk for all-cause mortality(hazard ratio(HR)=1.307,95% confidence interval(95%CI):1.248-1.369),CVD mortality(HR=1.298,95%CI:1.165-1.445),and cancer mortality(HR=1.128,95%CI:1.042-1.220).Short sleep duration was not associated with mortality risk.Increased risk of all-cause and CVD mortality was found in participants who had difficulty falling asleep(HR=1.120,95%CI:1.068-1.175;HR=1.163,95%CI:1.038-1.304,respectively),and used sleeping medication(HR=1.261,95%CI:1.159-1.372;HR=1.335,95%CI:1.102-1.618,respectively) compared with those who slept well.Long sleep duration and sleep disturbances were not associated with risk of all-cause and CVD mortality among individuals achieving a PA level of>15 MET-h/week,and in particular among those achieving> 30 MET-h/week.Conclusion:Long sleep duration,difficulty falling asleep,and use of sleeping medication were related to a higher risk of death.Being physically active at a moderate intensity for 25-65 min/day eliminated these detrimental associations.

Biological approaches to the repair and regeneration of the rotator cuff tendon-bone enthesis:a literature review

Entheses are highly specialised organs connecting ligaments and tendons to bones,facilitating force transmission,and providing mechanical strengths to absorb forces encountered.Two types of entheses,fibrocartilaginous and fibrous,exist in interfaces.The gradual fibrocartilaginous type is in rotator cuff tendons and is more frequently injured due to the poor healing capacity that leads to loss of the original structural and biomechanical properties and is attributed to the high prevalence of retears.Fluctuating methodologies and outcomes of biological approaches are challenges to overcome for them to be routinely used in clinics.Therefore,stratifying the existing literature according to different categories(chronicity,extent of tear,and studied population)would effectively guide repair approaches.This literature review supports tissue engineering approaches to promote rotator cuff enthesis healing employing cells,growth factors,and scaffolds period.Outcomes suggest its promising role in animal studies as well as some clinical trials and that combination therapies are more beneficial than individualized ones.It then highlights the importance of tailoring interventions according to the tear extent,chronicity,and the population being treated.Contributing factors such as loading,deficiencies,and lifestyle habits should also be taken into consideration.Optimum results can be achieved if biological,mechanical,and environmental factors are approached.It is challenging to determine whether variations are due to the interventions themselves,the animal models,loading regimen,materials,or tear mechanisms.Future research should focus on tailoring interventions for different categories to formulate protocols,which would best guide regenerative medicine decision making.

The Effects of a Four-Week Neuromuscular Training Program on Landing Kinematics in Pre-and Post-Peak Height Velocity Male Athletes

Purpose Neuromuscular training aims to enhance motor skill competency and increase muscle strength.However,the effectiveness of short-duration interventions focused on addressing lower limb injury risk factors in male youth athletes at different stages of maturity remains unknown.Methods Forty-eight young male academy cricket players[pre-peak height velocity(PHV)(n=26)and post-PHV(n=22)]were subdivided into an experimental group(EXP)who completed a 4-week progressive neuromuscular training program and controls(CON)participating in sport training only.Changes in injury risk were examined using the Tuck Jump Assess-ment(TJA)and Landing Error Scoring System(LESS).Results Total LESS score was significantly lower in both EXP maturity groups compared to CON following the 4-week program(10 to 6 and 6 to 4(~20%to 40%))in the pre-and post-PHV EXP groups,respectively.Significant within-group reductions in total LESS score were shown for the pre-PHV EXP group only(P<0.05).Conversely,greater changes in TJA total score were shown in post-PHV(5 to 3;40%)versus pre-PHV EXP(6 to 4.5;26%).Pre-PHV players showed positive changes in individual LESS criteria indicative of frontal plane control but not in knee valgus during the TJA,whereas post-PHV players did improve this criterion.Conclusion This study indicates it is possible to reduce TJA and LESS scores in male youth athletes by performing a 4-week neuromuscular training program,improving landing mechanics and reducing injury risk irrespective of maturity,but their effects are somewhat influenced by stage of maturation and the task performed.

Utility of Kinetic and Kinematic Jumping and Landing Variables as Predictors of Injury Risk: A Systematic Review

Purpose Jump-landing assessments provide a means to quantify an individual’s ability to attenuate ground reaction forces,generate lower limb explosive power and maintain joint alignment.In order to identify risk factors that can be targeted through appropriate training interventions,it is necessary to establish which(scalar)objective kinetic,kinematic,and performance measures are most associated with lower-extremity injury.Methods Online searches of MEDLINE,SCOPUS,EBSCOHost,SPORTDiscus and PubMed databases were completed for all articles published before March 2020 in accordance with PRISMA guidelines.Results 40 articles investigating nine jump-landing assessments were included in this review.The 79%of studies using drop jump(n=14)observed an association with future injury,while only 8%of countermovement jump studies(n=13)observed an association with injury risk.The 57%of studies using unilateral assessments found associations with risk of injury(n=14).Studies using performance measures(jump height/distance)as outcome measure were only associated with injury risk in 30%of cases.However,those using kinetic and/or kinematic analyses(knee abduction moment,knee valgus angle,knee separation distance,peak ground reaction force)found associations with injury in 89%of studies.Conclusion The landing element of jump-landing assessments appears to be superior for identifying individuals at greater risk of injury;likely due to a closer representation of the injury mechanism.Consequently,jump-landing assessments that involve attenuation of impact forces such as the drop jump appear most suited for this purpose but should involve assessment of frontal plane knee motion and ground reaction forces.

Physical Characteristics Explain Ball-Carrying Capability in Sub-Elite Rugby Union Players

Purpose The aims of the present study were two-fold:(i)to investigate the relationship between physical characteristics and the game statistics associated with ball-carrying capability amongst sub-elite rugby union players,and(ii)to predict the level of change in these physical characteristics required to improve the associated game statistic via regression analysis.Methods Thirty-eight senior professional players(forwards,n=22;backs,n=16)were assessed for body mass(BM),back squat(BS)single-repetition maximum(1RM)normalised to BM(1RM/BM),10 m sprint velocity(S10),10 m sprint momentum(SM10),and the game statistics from 22 games within the 2019/20 RFU Championship season.The relationship between these measures and the predicted level of change in a physical measure required to improve the total number of the associated game statistic by one were assessed by Pearson’s correlation coefficient and simple regression analyses.Results In forwards,an~11.5%reduction in BM,an~11.8%improvement in BS 1RM/BM,or an~11.5%increase in S10 was required to improve the game statistics associated with ball-carrying capability.In backs,a~19.3%increase in BM or a~15.6%improvement in SM10 was required.Conclusions These findings demonstrate that improvements in lower-body relative strength,acceleration performance,and position-specific alterations in body mass are required to maximise the ball-carrying capability and therefore match outcome of sub-elite rugby union players.