Showing papers in "British Journal of Sports Medicine in 2019"

Mental health in elite athletes: International Olympic Committee consensus statement (2019).

Abstract: Mental health symptoms and disorders are common among elite athletes, may have sport related manifestations within this population and impair performance. Mental health cannot be separated from physical health, as evidenced by mental health symptoms and disorders increasing the risk of physical injury and delaying subsequent recovery. There are no evidence or consensus based guidelines for diagnosis and management of mental health symptoms and disorders in elite athletes. Diagnosis must differentiate character traits particular to elite athletes from psychosocial maladaptations.Management strategies should address all contributors to mental health symptoms and consider biopsychosocial factors relevant to athletes to maximise benefit and minimise harm. Management must involve both treatment of affected individual athletes and optimising environments in which all elite athletes train and compete. To advance a more standardised, evidence based approach to mental health symptoms and disorders in elite athletes, an International Olympic Committee Consensus Work Group critically evaluated the current state of science and provided recommendations.

Effects of physical activity interventions on cognitive and academic performance in children and adolescents: a novel combination of a systematic review and recommendations from an expert panel

Abstract: Objective To summarise the current evidence on the effects of physical activity (PA) interventions on cognitive and academic performance in children, and formulate research priorities and recommendations. Design Systematic review (following PRISMA guidelines) with a methodological quality assessment and an international expert panel. We based the evaluation of the consistency of the scientific evidence on the findings reported in studies rated as of high methodological quality. Data sources PubMed, PsycINFO, Cochrane Central, Web of Science, ERIC, and SPORTDiscus. Eligibility criteria for selecting studies PA-intervention studies in children with at least one cognitive or academic performance assessment. Results Eleven (19%) of 58 included intervention studies received a high-quality rating for methodological quality: four assessed effects of PA interventions on cognitive performance, six assessed effects on academic performance, and one on both. All high-quality studies contrasted the effects of additional/adapted PA activities with regular curriculum activities. For cognitive performance 10 of 21 (48%) constructs analysed showed statistically significant beneficial intervention effects of PA, while for academic performance, 15 of 25 (60%) analyses found a significant beneficial effect of PA. Across all five studies assessing PA effects on mathematics, beneficial effects were reported in six out of seven (86%) outcomes. Experts put forward 46 research questions. The most pressing research priority cluster concerned the causality of the relationship between PA and cognitive/academic performance. The remaining clusters pertained to PA characteristics, moderators and mechanisms governing the ‘PA–performance’ relationship and miscellaneous topics. Conclusion There is currently inconclusive evidence for the beneficial effects of PA interventions on cognitive and overall academic performance in children. We conclude that there is strong evidence for beneficial effects of PA on maths performance. The expert panel confirmed that more ‘high-quality’ research is warranted. By prioritising the most important research questions and formulating recommendations we aim to guide researchers in generating high-quality evidence. Our recommendations focus on adequate control groups and sample size, the use of valid and reliable measurement instruments for physical activity and cognitive performance, measurement of compliance and data analysis. PROSPERO registration number CRD42017082505.

American Medical Society for Sports Medicine position statement on concussion in sport

Abstract: Sport-related concussion (SRC) is a common injury in recreational and organised sport. Over the past 30 years, there has been significant progress in our scientific understanding of SRC, which in turn has driven the development of clinical guidelines for diagnosis, assessment and management of SRC. In addition to a growing need for knowledgeable healthcare professionals to provide evidence-based care for athletes with SRC, media attention and legislation have created awareness and, in some cases, fear about many issues and unknowns surrounding SRC. The American Medical Society for Sports Medicine (AMSSM) formed a writing group to review the existing literature on SRC, update its previous position statement, and to address current evidence and knowledge gaps regarding SRC. The absence of definitive outcomes-based data is challenging and requires relying on the best available evidence integrated with clinical experience and patient values. This statement reviews the definition, pathophysiology and epidemiology of SRC, the diagnosis and management of both acute and persistent concussion symptoms, the short-term and long-term risks of SRC and repetitive head impact exposure, SRC prevention strategies, and potential future directions for SRC research. The AMSSM is committed to best clinical practices, evidence-based research and educational initiatives that positively impact the health and safety of athletes.

How does light-intensity physical activity associate with adult cardiometabolic health and mortality? Systematic review with meta-analysis of experimental and observational studies

Abstract: Aim To assess the relationship between time spent in light physical activity and cardiometabolic health and mortality in adults. Design Systematic review and meta-analysis. Data sources Searches in Medline, Embase, PsycInfo, CINAHL and three rounds of hand searches. Eligibility criteria for selecting studies Experimental (including acute mechanistic studies and physical activity intervention programme) and observational studies (excluding case and case–control studies) conducted in adults (aged ≥18 years) published in English before February 2018 and reporting on the relationship between light physical activity ( Study appraisal and synthesis Study quality appraisal with QUALSYST tool and random effects inverse variance meta-analysis. Results Seventy-two studies were eligible including 27 experimental studies (and 45 observational studies). Mechanistic experimental studies showed that short but frequent bouts of light-intensity activity throughout the day reduced postprandial glucose (−17.5%; 95% CI −26.2 to −8.7) and insulin (−25.1%; 95% CI −31.8 to –18.3) levels compared with continuous sitting, but there was very limited evidence for it affecting other cardiometabolic markers. Three light physical activity programme intervention studies (n ranging from 12 to 58) reduced adiposity, improved blood pressure and lipidaemia; the programmes consisted of activity of >150 min/week for at least 12 weeks. Six out of eight prospective observational studies that were entered in the meta-analysis reported that more time spent in daily light activity reduced risk of all-cause mortality (pooled HR 0.71; 95% CI 0.62 to 0.83). Conclusions Light-intensity physical activity could play a role in improving adult cardiometabolic health and reducing mortality risk. Frequent short bouts of light activity improve glycaemic control. Nevertheless, the modest volume of the prospective epidemiological evidence base and the moderate consistency between observational and laboratory evidence inhibits definitive conclusions.

Is the time right for quantitative public health guidelines on sitting? A narrative review of sedentary behaviour research paradigms and findings

Abstract: Sedentary behaviour (SB) has been proposed as an ‘independent’ risk factor for chronic disease risk, attracting much research and media attention. Many countries have included generic, non-quantitative reductions in SB in their public health guidelines and calls for quantitative SB targets are increasing. The aim of this narrative review is to critically evaluate key evidence areas relating to the development of guidance on sitting for adults. We carried out a non-systematic narrative evidence synthesis across seven key areas: (1) definition of SB, (2) independence of sitting from physical activity, (3) use of television viewing as a proxy of sitting, (4) interpretation of SB evidence, (5) evidence on ‘sedentary breaks’, (6) evidence on objectively measured sedentary SB and mortality and (7) dose response of sitting and mortality/cardiovascular disease. Despite research progress, we still know little about the independent detrimental health effects of sitting, and the possibility that sitting is mostly the inverse of physical activity remains. Unresolved issues include an unclear definition, inconsistencies between mechanistic and epidemiological studies, over-reliance on surrogate outcomes, a very weak epidemiological evidence base to support the inclusion of ‘sedentary breaks’ in guidelines, reliance on self-reported sitting measures, and misinterpretation of data whereby methodologically inconsistent associations are claimed to be strong evidence. In conclusion, public health guidance requires a consistent evidence base but this is lacking for SB. The development of quantitative SB guidance, using an underdeveloped evidence base, is premature; any further recommendations for sedentary behaviour require development of the evidence base and refinement of the research paradigms used in the field.

Role of kinesiophobia on pain, disability and quality of life in people suffering from chronic musculoskeletal pain:: a systematic review

Abstract: Objective (1) To explore the level of association between kinesiophobia and pain, disability and quality of life in people with chronic musculoskeletal pain (CMP) detected via cross-sectional analysis and (2) to analyse the prognostic value of kinesiophobia on pain, disability and quality of life in this population detected via longitudinal analyses. Design A systematic review of the literature including an appraisal of the risk of bias using the adapted Newcastle Ottawa Scale. A synthesis of the evidence was carried out. Data sources An electronic search of PubMed, AMED, CINAHL, PsycINFO, PubPsych and grey literature was undertaken from inception to July 2017. Eligibility criteria for selecting studies Observational studies exploring the role of kinesiophobia (measured with the Tampa Scale for Kinesiophobia) on pain, disability and quality of life in people with CMP. Results Sixty-three articles (mostly cross-sectional) (total sample=10 726) were included. We found strong evidence for an association between a greater degree of kinesiophobia and greater levels of pain intensity and disability and moderate evidence between a greater degree of kinesiophobia and higher levels of pain severity and low quality of life. A greater degree of kinesiophobia predicts the progression of disability overtime, with moderate evidence. A greater degree of kinesiophobia also predicts greater levels of pain severity and low levels of quality of life at 6 months, but with limited evidence. Kinesiophobia does not predict changes in pain intensity. Summary/conclusions The results of this review encourage clinicians to consider kinesiophobia in their preliminary assessment. More longitudinal studies are needed, as most of the included studies were cross-sectional in nature. Trial registration number CRD42016042641.

Do the associations of sedentary behaviour with cardiovascular disease mortality and cancer mortality differ by physical activity level? A systematic review and harmonised meta-analysis of data from 850 060 participants.

Abstract: Objective To examine whether the associations between sedentary behaviours (ie, daily sitting/TV-viewing time) and mortality from cardiovascular disease (CVD) and cancer differ by different levels of physical activity (PA). Design Harmonised meta-analysis of prospective cohort studies. Data on exposure variables were harmonised according to a predefined protocol and categorised into four groups for sedentary behaviours and into quartiles of PA (MET-hour/week). Data sources PubMed, PsycINFO, Embase, Web of Science, Sport Discus and Scopus. Eligibility criteria for selecting studies Individual level data on both sedentary behaviours and PA and reported effect estimates for CVD or cancer mortality. Results Nine studies (n=850 060; deaths=25 730) and eight studies (n=777 696; deaths=30 851) provided data on sitting time and CVD and cancer mortality, respectively. Five studies had data on TV-viewing time and CVD (n=458 127; deaths=13 230) and cancer (n=458 091; deaths=16 430) mortality. A dose–response association between sitting time (9%–32% higher risk; p for trend Conclusion PA modifies the associations between sedentary behaviours and CVD and cancer mortality. These findings emphasise the importance of higher volumes of moderate and vigorous activity to reduce, or even eliminate these risks, especially for those who sit a lot in their daily lives.

Occurrence of mental health symptoms and disorders in current and former elite athletes: a systematic review and meta-analysis

Abstract: Objectives To present an overview of the existing epidemiological evidence regarding the occurrence of mental health symptoms and disorders among current and former elite athletes. Design Systematic review and meta-analysis. Data sources Five electronic databases were searched from inception to November 2018: PubMed (MEDLINE), SportDiscus via EBSCO, PSycINFO via ProQuest, Scopus and Cochrane. Eligibility criteria for selecting studies We included original quantitative studies that were written in English, were conducted exclusively among current or former elite athletes, and presented incidence or prevalence rates of symptoms of mental disorders. Results Twenty-two relevant original studies about mental health symptoms and disorders among current elite athletes were included: they presented data especially on symptoms of distress, sleep disturbance, anxiety/depression and alcohol misuse. Meta-analyses comprising 2895 to 5555 current elite athletes showed that the prevalence of mental health symptoms and disorders ranged from 19% for alcohol misuse to 34% for anxiety/depression. Fifteen relevant original studies about mental health symptoms and disorders among former elite athletes were included: they similarly presented data especially about symptoms of distress, sleep disturbance, anxiety/depression and alcohol misuse. Meta-analyses comprising 1579 to 1686 former elite athletes showed that the prevalence of mental health symptoms and disorders ranged from 16% for distress to 26% for anxiety/depression. Conclusions Our meta-analyses showed that the prevalence of mental health symptoms and disorders ranged from 19% for alcohol misuse to 34% for anxiety/depression for current elite athletes, and from 16% for distress to 26% for anxiety/depression for former elite athletes.

Change in physical activity from adolescence to early adulthood: a systematic review and meta-analysis of longitudinal cohort studies

Abstract: Funding for this study and the work of all authors was supported, wholly or in part, by the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence (RES-590-28-0002). Funding from the British Heart Foundation, Department of Health, Economic and Social Research Council, Medical Research Council, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. The work of Kirsten Corder, Helen Brown, Eleanor Winpenny and Esther M F van Sluijs was supported by the Medical Research Council (MC_UU_12015/7). Rebecca Love is funded by a Gates Cambridge Scholarship.

Which specific modes of exercise training are most effective for treating low back pain? Network meta-analysis

Abstract: Objective Examine the effectiveness of specific modes of exercise training in non-specific chronic low back pain (NSCLBP). Design Network meta-analysis (NMA). Data sources MEDLINE, CINAHL, SPORTDiscus, EMBASE, CENTRAL. Eligibility criteria Exercise training randomised controlled/clinical trials in adults with NSCLBP. Results Among 9543 records, 89 studies (patients=5578) were eligible for qualitative synthesis and 70 (pain), 63 (physical function), 16 (mental health) and 4 (trunk muscle strength) for NMA. The NMA consistency model revealed that the following exercise training modalities had the highest probability (surface under the cumulative ranking (SUCRA)) of being best when compared with true control: Pilates for pain (SUCRA=100%; pooled standardised mean difference (95% CI): −1.86 (–2.54 to –1.19)), resistance (SUCRA=80%; −1.14 (–1.71 to –0.56)) and stabilisation/motor control (SUCRA=80%; −1.13 (–1.53 to –0.74)) for physical function and resistance (SUCRA=80%; −1.26 (–2.10 to –0.41)) and aerobic (SUCRA=80%; −1.18 (–2.20 to –0.15)) for mental health. True control was most likely (SUCRA≤10%) to be the worst treatment for all outcomes, followed by therapist hands-off control for pain (SUCRA=10%; 0.09 (–0.71 to 0.89)) and physical function (SUCRA=20%; −0.31 (–0.94 to 0.32)) and therapist hands-on control for mental health (SUCRA=20%; −0.31 (–1.31 to 0.70)). Stretching and McKenzie exercise effect sizes did not differ to true control for pain or function (p>0.095; SUCRA Summary/conclusion There is low quality evidence that Pilates, stabilisation/motor control, resistance training and aerobic exercise training are the most effective treatments, pending outcome of interest, for adults with NSCLBP. Exercise training may also be more effective than therapist hands-on treatment. Heterogeneity among studies and the fact that there are few studies with low risk of bias are both limitations.

Temporal trends in the cardiorespiratory fitness of children and adolescents representing 19 high-income and upper middle-income countries between 1981 and 2014.

Abstract: Objective To estimate international and national temporal trends in the cardiorespiratory fitness (CRF) of children and adolescents and to examine relationships between temporal trends in CRF and temporal trends in broad socioeconomic and health-related indicators across countries. Methods Data were obtained from a systematic search of studies that explicitly reported 20 m shuttle run test (a validated measure of CRF) descriptive data on apparently healthy individuals aged 9–17 years. Following the estimation of relative peak oxygen uptake (mL/kg/min) as a measure of CRF, sample-weighted temporal trends were estimated at the country–sex–age level using best-fitting linear or polynomial regression models relating the year of testing to mean CRF. Poststratified population-weighted mean changes in absolute and per cent CRF were estimated. Pearson’s correlations were used to describe the association between linear temporal trends in CRF and linear temporal trends in broad socioeconomic and health-related indicators. Results Temporal trends were estimated from 965 264 children and adolescents from 19 high-income and upper middle-income countries between 1981 and 2014, using data from 137 studies. Collectively, there was a moderate decline in CRF of 3.3 mL/kg/min (95% CI −3.5 to −3.1), equivalent to a decline of 7.3% (95% CI −7.8% to −6.7%) over the 33-year time period. This international decline diminished with each decade and stabilised near zero around 2000. The decline was larger for boys than girls and was similar for children and adolescents. Trends also differed in magnitude and direction between countries, with most showing declines. There was a strong negative association between country-specific trends in income inequality (Gini index) and trends in CRF across 18 countries; meaning, countries approaching income equality had more favourable trends in CRF. Conclusions There has been a substantial decline in CRF since 1981, which is suggestive of a meaningful decline in population health. However, the international trend in CRF has not followed the anticipated trajectory, diminishing and stabilising with negligible change since 2000. CRF data are needed from children in low-income and middle-income countries to more confidently determine true international trends and determine whether temporal trends are similar to those observed in high-income and upper middle-income countries.

How does exercise treatment compare with antihypertensive medications? A network meta-analysis of 391 randomised controlled trials assessing exercise and medication effects on systolic blood pressure.

Abstract: Objective To compare the effect of exercise regimens and medications on systolic blood pressure (SBP). Data sources Medline (via PubMed) and the Cochrane Library. Eligibility criteria Randomised controlled trials (RCTs) of angiotensin-converting enzyme inhibitors (ACE-I), angiotensin-2 receptor blockers (ARBs), β-blockers, calcium channel blockers (CCBs) and diuretics were identified from existing Cochrane reviews. A previously published meta-analysis of exercise interventions was updated to identify recent RCTs that tested the SBP-lowering effects of endurance, dynamic resistance, isometric resistance, and combined endurance and resistance exercise interventions (up to September 2018). Design Random-effects network meta-analysis. Outcome Difference in mean change from baseline SBP between comparator treatments (change from baseline in one group minus that in the other group) and its 95% credible interval (95% CrI), measured in mmHg. Results We included a total of 391 RCTs, 197 of which evaluated exercise interventions (10 461 participants) and 194 evaluated antihypertensive medications (29 281 participants). No RCTs compared directly exercise against medications. While all medication trials included hypertensive populations, only 56 exercise trials included hypertensive participants (≥140 mmHg), corresponding to 3508 individuals. In a 10% random sample, risk of bias was higher in exercise RCTs, primarily due to lack of blinding and incomplete outcome data. In analyses that combined all populations, antihypertensive medications achieved higher reductions in baseline SBP compared with exercise interventions (mean difference −3.96 mmHg, 95% CrI −5.02 to −2.91). Compared with control, all types of exercise (including combination of endurance and resistance) and all classes of antihypertensive medications were effective in lowering baseline SBP. Among hypertensive populations, there were no detectable differences in the SBP-lowering effects of ACE-I, ARB, β-blocker and diuretic medications when compared with endurance or dynamic resistance exercise. There was no detectable inconsistency between direct and indirect comparisons. Although there was evidence of small-study effects, this affected both medication and exercise trials. Conclusions The effect of exercise interventions on SBP remains under-studied, especially among hypertensive populations. Our findings confirm modest but consistent reductions in SBP in many studied exercise interventions across all populations but individuals receiving medications generally achieved greater reductions than those following structured exercise regimens. Assuming equally reliable estimates, the SBP-lowering effect of exercise among hypertensive populations appears similar to that of commonly used antihypertensive medications. Generalisability of these findings to real-world clinical settings should be further evaluated.

Objectively measured physical activity, sedentary behaviour and all-cause mortality in older men: does volume of activity matter more than pattern of accumulation?

Abstract: OBJECTIVES: To understand how device-measured sedentary behaviour and physical activity are related to all-cause mortality in older men, an age group with high levels of inactivity and sedentary behaviour. METHODS: Prospective population-based cohort study of men recruited from 24 UK General Practices in 1978-1980. In 2010-2012, 3137 surviving men were invited to a follow-up, 1655 (aged 71-92 years) agreed. Nurses measured height and weight, men completed health and demographic questionnaires and wore an ActiGraph GT3x accelerometer. All-cause mortality was collected through National Health Service central registers up to 1 June 2016. RESULTS: After median 5.0 years' follow-up, 194 deaths occurred in 1181 men without pre-existing cardiovascular disease. For each additional 30 min in sedentary behaviour, or light physical activity (LIPA), or 10 min in moderate to vigorous physical activity (MVPA), HRs for mortality were 1.17 (95% CI 1.10 to 1.25), 0.83 (95% CI 0.77 to 0.90) and 0.90 (95% CI 0.84 to 0.96), respectively. Adjustments for confounders did not meaningfully change estimates. Only LIPA remained significant on mutual adjustment for all intensities. The HR for accumulating 150 min MVPA/week in sporadic minutes (achieved by 66% of men) was 0.59 (95% CI 0.43 to 0.81) and 0.58 (95% CI 0.33 to 1.00) for accumulating 150 min MVPA/week in bouts lasting ≥10 min (achieved by 16% of men). Sedentary breaks were not associated with mortality. CONCLUSIONS: In older men, all activities (of light intensity upwards) were beneficial and accumulation of activity in bouts ≥10 min did not appear important beyond total volume of activity. Findings can inform physical activity guidelines for older adults.

Precision exercise medicine: understanding exercise response variability

Abstract: There is evidence from human twin and family studies as well as mouse and rat selection experiments that there are considerable interindividual differences in the response of cardiorespiratory fitness (CRF) and other cardiometabolic traits to a given exercise programme dose. We developed this consensus statement on exercise response variability following a symposium dedicated to this topic. There is strong evidence from both animal and human studies that exercise training doses lead to variable responses. A genetic component contributes to exercise training response variability.In this consensus statement, we (1) briefly review the literature on exercise response variability and the various sources of variations in CRF response to an exercise programme, (2) introduce the key research designs and corresponding statistical models with an emphasis on randomised controlled designs with or without multiple pretests and post-tests, crossover designs and repeated measures designs, (3) discuss advantages and disadvantages of multiple methods of categorising exercise response levels-a topic that is of particular interest for personalised exercise medicine and (4) outline approaches that may identify determinants and modifiers of CRF exercise response. We also summarise gaps in knowledge and recommend future research to better understand exercise response variability.

Knee osteoarthritis risk is increased 4-6 fold after knee injury - a systematic review and meta-analysis.

Abstract: Objective To estimate knee osteoarthritis (OA) risk following anterior cruciate ligament (ACL), meniscus or combined ACL and meniscus injury. Design Systematic review and meta-analysis. Data sources MEDLINE, Embase, SPORTDiscus, CINAHL and Web of Science until November 2018. Eligibility criteria for selecting studies Prospective or retrospective studies with at least 2-year follow-up including adults with ACL injury, meniscal injury or combined injuries. Knee OA was defined by radiographs or clinical diagnosis and compared with the contralateral knee or non-injured controls. Study appraisal and synthesis Risk of bias was assessed using the SIGN50 checklist. ORs for developing knee OA were estimated using random effects meta-analysis. Results 53 studies totalling ∼1 million participants were included: 185 219 participants with ACL injury, mean age 28 years, 35% females, 98% surgically reconstructed; 83 267 participants with meniscal injury, mean age 38 years, 36% females, 22% confirmed meniscectomy and 73% unknown; 725 362 participants with combined injury, mean age 31 years, 26% females, 80% treated surgically. The OR of developing knee OA were 4.2 (95% CI 2.2 to 8.0; I2=92%), 6.3 (95% CI 3.8 to 10.5; I2=95%) and 6.4 (95% CI 4.9 to 8.3; I2=62%) for patients with ACL injury, meniscal injury and combined injuries, respectively. Conclusion The odds of developing knee OA following ACL injury are approximately four times higher compared with a non-injured knee. A meniscal injury and a combined injury affecting both the ACL and meniscus are associated with six times higher odds compared with a non-injured knee. Large inconsistency (eg, study design, follow-up period and comparator) and few high-quality studies suggest that future studies may change these estimates. Clinical relevance Patients sustaining a major knee injury have a substantially increased risk of developing knee OA, highlighting the importance of knee injury prevention programmes and secondary prevention strategies to prevent or delay knee OA development. PROSPERO registration number CRD42015016900

Which criteria are used to clear patients to return to sport after primary ACL reconstruction? A scoping review

Abstract: Objective To describe the criteria used to clear athletes to return to sport (RTS) following primary ACL reconstruction. Design Scoping review. Data sources MEDLINE, Embase, CINAHL and SPORTDiscus electronic databases were searched using keywords related to ACL and RTS. Eligibility criteria Prospective or retrospective studies reporting at least one RTS criterion for athletes who had primary ACL reconstruction with an autograft. Results In total, 209 studies fulfilled the inclusion criteria. RTS criteria were categorised into six domains: time, strength, hop testing, clinical examination, patient-report and performance-based criteria. From the 209 included studies, time was used in 178 studies (85%), and in 88 studies (42%) was the sole RTS criterion. Strength tests were reported in 86 studies (41%). Sixteen different hop tests were used in 31 studies (15%). Clinical examination was used in 54 studies (26%), patient report in 26 studies (12%) and performance-based criteria in 41 studies (20%). Summary Time and impairment-based measures dominated RTS criteria, despite sport being a complex physical and biopsychosocial activity with demands across all aspects of function. Time was included as a criterion in 85% of studies, and over 80% of studies allowed RTS before 9 months. Whether RTS tests are valid—do they predict successful RTS?—is largely unknown.

Including the Nordic hamstring exercise in injury prevention programmes halves the rate of hamstring injuries: A systematic review and meta-analysis of 8459 athletes

Abstract: Research question Does the Nordic hamstring exercise (NHE) prevent hamstring injuries when included as part of an injury prevention intervention? Design Systematic review and meta-analysis. Eligibility criteria for selecting studies We considered the population to be any athletes participating in any sporting activity, the intervention to be the NHE, the comparison to be usual training or other prevention programmes, which did not include the NHE, and the outcome to be the incidence or rate of hamstring injuries. Analysis The effect of including the NHE in injury prevention programmes compared with controls on hamstring injuries was assessed in 15 studies that reported the incidence across different sports and age groups in both women and men. Data sources MEDLINE via PubMed, CINAHL via Ebsco, and OpenGrey. Results There is a reduction in the overall injury risk ratio of 0.49 (95% CI 0.32 to 0.74, p=0.0008) in favour of programmes including the NHE. Secondary analyses when pooling the eight randomised control studies demonstrated a small increase in the overall injury risk ratio 0.52 (95% CI 0.32 to 0.85, p=0.0008), still in favour of the NHE. Additionally, when studies with a high risk of bias were removed (n=8), there is an increase of 0.06 in the risk ratio to 0.55 (95% CI 0.34 to 0.89, p=0.006). Conclusions Programmes that include the NHE reduce hamstring injuries by up to 51%. The NHE essentially halves the rate of hamstring injuries across multiple sports in different athletes. Trial registration number PROSPERO CRD42018106150.

Prevalence of knee osteoarthritis features on magnetic resonance imaging in asymptomatic uninjured adults: a systematic review and meta-analysis

Abstract: Background Knee MRI is increasingly used to inform clinical management. Features associated with osteoarthritis are often present in asymptomatic uninjured knees; however, the estimated prevalence varies substantially between studies. We performed a systematic review with meta-analysis to provide summary estimates of the prevalence of MRI features of osteoarthritis in asymptomatic uninjured knees. Methods We searched six electronic databases for studies reporting MRI osteoarthritis feature prevalence (ie, cartilage defects, meniscal tears, bone marrow lesions and osteophytes) in asymptomatic uninjured knees. Summary estimates were calculated using random-effects meta-analysis (and stratified by mean age: Results We included 63 studies (5397 knees of 4751 adults). The overall pooled prevalence of cartilage defects was 24% (95% CI 15% to 34%) and meniscal tears was 10% (7% to 13%), with significantly higher prevalence with age: cartilage defect Conclusions Summary estimates of MRI osteoarthritis feature prevalence among asymptomatic uninjured knees were 4%–14% in adults aged

Effects of chronic exercise interventions on executive function among children and adolescents: a systematic review with meta-analysis

Abstract: Objective To synthesise randomised controlled trials (RCTs) regarding the effects of chronic exercise interventions on different domain-specific executive functions (EFs) among children and adolescents. Design Systematic review with meta-analysis. Data sources PsycINFO, PubMed, SPORTDiscus, Academic Search Premier, Embase and Web of Science were searched. Eligibility criteria for selecting studies RCTs or cluster RCT design, which employ chronic exercise interventions and target healthy children (age 6–12 years) and adolescents (age 13–17 years). We defined chronic exercise as physical activity (PA) which consists of multiple exercise sessions per week and lasts for an extended period of time (typically over 6 weeks). Results We included 19 studies, with a total of 5038 participants. The results showed that chronic exercise interventions improved overall EFs (standardised mean difference (SMD)=0.20, 95% CI 0.09 to 0.30, p 0.05). Interventions with a session length Conclusions Despite small effect sizes, chronic exercise interventions, implemented in curricular or sports and PA programme settings, might be a promising way to promote multiple aspects of executive functions, especially inhibitory control.

Copenhagen Consensus statement 2019: physical activity and ageing.

Abstract: From 19th to 22nd November 2018, 26 researchers representing nine countries and a variety of academic disciplines met in Snekkersten, Denmark, to reach evidence-based consensus about physical activity and older adults. It was recognised that the term ‘older adults’ represents a highly heterogeneous population. It encompasses those that remain highly active and healthy throughout the life-course with a high intrinsic capacity to the very old and frail with low intrinsic capacity. The consensus is drawn from a wide range of research methodologies within epidemiology, medicine, physiology, neuroscience, psychology and sociology, recognising the strength and limitations of each of the methods. Much of the evidence presented in the statements is based on longitudinal associations from observational and randomised controlled intervention studies, as well as quantitative and qualitative social studies in relatively healthy community-dwelling older adults. Nevertheless, we also considered research with frail older adults and those with age-associated neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease, and in a few cases molecular and cellular outcome measures from animal studies. The consensus statements distinguish between physical activity and exercise. Physical activity is used as an umbrella term that includes both structured and unstructured forms of leisure, transport, domestic and work-related activities. Physical activity entails body movement that increases energy expenditure relative to rest, and is often characterised in terms of intensity from light, to moderate to vigorous. Exercise is defined as a subset of structured physical activities that are more specifically designed to improve cardiorespiratory fitness, cognitive function, flexibility balance, strength and/or power. This statement presents the consensus on the effects of physical activity on older adults’ fitness, health, cognitive functioning, functional capacity, engagement, motivation, psychological well-being and social inclusion. It also covers the consensus on physical activity implementation strategies. While it is recognised that adverse events can occur during exercise, the risk can be minimised by carefully choosing the type of activity undertaken and by consultation with the individual’s physician when warranted, for example, when the individual is frail, has a number of co-morbidities, or has exercise-related symptoms, such as chest pain, heart arrhythmia or dizziness. The consensus was obtained through an iterative process that began with the presentation of the state-of-the-science in each domain, followed by group and plenary discussions. Ultimately, the participants reached agreement on the 30-item consensus statements.

Low energy availability surrogates correlate with health and performance consequences of Relative Energy Deficiency in Sport

Abstract: Low energy availability (EA) is suspected to be the underlying cause of both the Female Athlete Triad and the more recently defined syndrome, Relative Energy Deficiency in Sport (RED-S). The International Olympic Committee (IOC) defined RED-S as a syndrome of health and performance impairments resulting from an energy deficit. While the importance of adequate EA is generally accepted, few studies have attempted to understand whether low EA is associated with the health and performance consequences posited by the IOC. Objective The purpose of this cross-sectional study was to examine the association of low EA with RED-S health and performance consequences in a large clinical population of female athletes. Methods One thousand female athletes (15–30 years) completed an online questionnaire and were classified as having low or adequate EA. The associations between low EA and the health and performance factors listed in the RED-S models were evaluated using chi-squared test and the odds ratios were evaluated using binomial logistic regression (p Results Athletes with low EA were more likely to be classified as having increased risk of menstrual dysfunction, poor bone health, metabolic issues, haematological detriments, psychological disorders, cardiovascular impairment and gastrointestinal dysfunction than those with adequate EA. Performance variables associated with low EA included decreased training response, impaired judgement, decreased coordination, decreased concentration, irritability, depression and decreased endurance performance. Conclusion These findings demonstrate that low EA measured using self-report questionnaires is strongly associated with many health and performance consequences proposed by the RED-S models.

Wake up call for collegiate athlete sleep: narrative review and consensus recommendations from the NCAA Interassociation Task Force on Sleep and Wellness.

Abstract: Sleep is an important determinant of collegiate athlete health, well-being and performance. However, collegiate athlete social and physical environments are often not conducive to obtaining restorative sleep. Traditionally, sleep has not been a primary focus of collegiate athletic training and is neglected due to competing academic, athletic and social demands. Collegiate athletics departments are well positioned to facilitate better sleep culture for their athletes. Recognising the lack of evidence-based or consensus-based guidelines for sleep management and restorative sleep for collegiate athletes, the National Collegiate Athletic Association hosted a sleep summit in 2017. Members of the Interassociation Task Force on Sleep and Wellness reviewed current data related to collegiate athlete sleep and aimed to develop consensus recommendations on sleep management and restorative sleep using the Delphi method. In this paper, we provide a narrative review of four topics central to collegiate athlete sleep: (1) sleep patterns and disorders among collegiate athletes; (2) sleep and optimal functioning among athletes; (3) screening, tracking and assessment of athlete sleep; and (4) interventions to improve sleep. We also present five consensus recommendations for colleges to improve their athletes’ sleep.

Determinants of anxiety in elite athletes: a systematic review and meta-analysis

Abstract: OBJECTIVE: To identify and quantify determinants of anxiety symptoms and disorders experienced by elite athletes. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Five online databases (PubMed, SportDiscus, PsycINFO, Scopus and Cochrane) were searched up to November 2018 to identify eligible citations. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Articles were included if they were published in English, were quantitative studies and measured a symptom-level anxiety outcome in competing or retired athletes at the professional (including professional youth), Olympic or collegiate/university levels. RESULTS AND SUMMARY: We screened 1163 articles; 61 studies were included in the systematic review and 27 of them were suitable for meta-analysis. Overall risk of bias for included studies was low. Athletes and non-athletes had no differences in anxiety profiles (d=-0.11, p=0.28). Pooled effect sizes, demonstrating moderate effects, were identified for (1) career dissatisfaction (d=0.45; higher anxiety in dissatisfied athletes), (2) gender (d=0.38; higher anxiety in female athletes), (3) age (d=-0.34; higher anxiety for younger athletes) and (4) musculoskeletal injury (d=0.31; higher anxiety for injured athletes). A small pooled effect was found for recent adverse life events (d=0.26)-higher anxiety in athletes who had experienced one or more recent adverse life events. CONCLUSION: Determinants of anxiety in elite populations broadly reflect those experienced by the general population. Clinicians should be aware of these general and athlete-specific determinants of anxiety among elite athletes.

What's the rate of knee osteoarthritis 10 years after anterior cruciate ligament injury? An updated systematic review.

Abstract: Background This updated systematic review reports data from 2009 on the prevalence, and risk factors, for knee osteoarthritis (OA) more than 10 years after anterior cruciate ligament (ACL) tear Methods We systematically searched five databases (PubMed, EMBASE, AMED, Cinahl and SPORTDiscus) for prospective and retrospective studies published after 1 August 2008 Studies were included if they investigated participants with ACL tear (isolated or in combination with medial collateral ligament and/or meniscal injuries) and reported symptomatic and/or radiographic OA at a minimum of 10 years postinjury We used a modified version of the Downs and Black checklist for methodological quality assessment and narrative synthesis to report results The study protocol was registered in PROSPERO Results Forty-one studies were included Low methodological quality was revealed in over half of the studies At inclusion, age ranged from 23 to 38 years, and at follow-up from 31 to 51 years Sample sizes ranged from 18 to 780 participants The reported radiographic OA prevalence varied between 0% and 100% >10 years after injury, regardless of follow-up time The studies with low and high methodological quality reported a prevalence of radiographic OA between 0%–100% and 1%–80%, respectively One study reported symptomatic knee OA for the tibiofemoral (TF) joint (35%), and one study reported symptomatic knee OA for the patellofemoral (PF) joint (15%) Meniscectomy was the only consistent risk factor determined from the data synthesis Conclusion Radiographic knee OA varied between 0% and 100% in line with our previous systematic review from 2009 Symptomatic and radiographic knee OA was differentiated in two studies only, with a reported symptomatic OA prevalence of 35% for the TF joint and 15% for PF joint Future cohort studies need to include measurement of symptomatic knee OA in this patient group PROSPERO registration number CRD42016042693

"What's my risk of sustaining an ACL injury while playing sports?" A systematic review with meta-analysis.

Abstract: Objective To estimate the incidence proportion (IP) and incidence rate (IR) for ACL injury in athletes. Design Systematic review with meta-analysis Data sources The PubMed, CINAHL and SPORTDiscus electronic databases were searched from inception to 20 January 2017. Eligibility criteria for selecting studies Studies were included if they reported total number of participants/population by sex, total number of ACL injuries by sex and total person-time by sex. Results Fifty-eight studies were included. The IP and IR of ACL injury in female athletes were 3.5% (1 out of every 29 athletes) and 1.5/10 000 athlete-exposures over a period of 1 season-25 years. The IP and IR of ACL injury in male athletes were 2.0% (1 out of every 50 athletes) and 0.9/10 000 athlete-exposures over a period of 1–25 years. Female athletes had a higher relative risk (RR) for ACL injury compared with males (RR=1.5; 95% CI 1.2 to 1.9; P Summary/conclusions One in 29 female athletes and 1 in 50 male athletes ruptured their ACL in a window that spanned from 1season to 25 years. The IR of ACL injury among female athletes in a season was 1.7 times higher than the IR of ACL injury among male athletes and the IP of ACL injury among female athletes was 1.5 times higher than the IP of ACL injury among male athletes. The reported sex disparity in ACL injury rates is independent of participation level and length of follow-up.

Mental health symptoms and disorders in elite athletes: a systematic review on cultural influencers and barriers to athletes seeking treatment.

Abstract: Objective To summarise the literature on the barriers to athletes seeking mental health treatment and cultural influencers of mental health in elite athletes. Design Systematic review Data sources PubMed, Cochrane, Scopus, SportDiscus (Ebsco), and PsycINFO (ProQuest) up to November 2018. Eligibility criteria for selecting studies Qualitative and quantitative original studies of elite athletes (those who competed at the professional, Olympic, or collegiate/university levels), published in any language. Results Stigma, low mental health literacy, negative past experiences with mental health treatment-seeking, busy schedules, and hypermasculinity are barriers to elite athletes seeking mental health treatment. Cultural influencers of mental health in elite athletes include: (1) the lack of acceptance of women as athletes; (2) lower acceptability of mental health symptoms and disorders among non-white athletes; (3) non-disclosure of religious beliefs; and (4) higher dependence on economic benefits. Coaches have an important role in supporting elite athletes in obtaining treatment for mental illness. Brief anti-stigma interventions in elite athletes decrease stigma and improve literary about mental health. Conclusion There is a need for various actors to provide more effective strategies to overcome the stigma that surrounds mental illness, increase mental health literacy in the athlete/coach community, and address athlete-specific barriers to seeking treatment for mental illness. In this systematic review, we identified strategies that, if implemented, can overcome the cultural factors that may otherwise limit athletes seeking treatment. Coaches are critical for promoting a culture within elite athletes’ environments that encourages athletes to seek treatment.

Effects of training and competition on the sleep of elite athletes: a systematic review and meta-analysis

Abstract: Objectives To characterise the sleep of elite athletes and to identify factors associated with training and competition that negatively affect sleep Design Prognosis systematic review Data sources Three databases (PubMed, SCOPUS and SPORTDiscus) were searched from inception to 26 February 2018 Eligibility criteria for selecting studies Included studies objectively reported total sleep time (TST) and/or sleep efficiency (SE) in elite athletes Studies were required to be observational or to include an observational trial Results Fifty-four studies were included During training, many studies reported athletes were unable to achieve TST (n=23/41) and/or SE (n=16/37) recommendations On the night of competition, most studies reported athletes were unable to achieve TST (n=14/18) and/or SE (n=10/16) recommendations TST was shorter (60 min) the night of competition compared with previous nights SE was lower (1%) the night of competition compared with the previous night TST was shorter the night of night competition (start ≥18:00; 80 min) and day competition (20 min) compared with the previous night SE was lower (3%–4%) the night of night competition but unchanged the night of day competition compared with previous nights Early morning training (start 25%), late night/early morning travel departure times, eastward air travel and altitude ascent impaired sleep Conclusion Athletes were often unable to achieve sleep recommendations during training or competition periods Sleep was impaired the night of competition compared with previous nights Early morning training, increases in training load, travel departure times, jet lag and altitude can impair athletes’ sleep PROSPERO registration number CRD42017074367

Recommendations for hamstring injury prevention in elite football: translating research into practice

Abstract: Injuries in football exert negative impacts on team performance1 and club finance.2 Hamstring strain injuries (HSI) are consistently the most prevalent time loss injury in football3 and as such are an important issue in football medicine. Despite an ever-increasing wealth of information emerging on the aetiology of HSIs, their incidence in football is increasing.3 This could be explained by the increased intensity and physical demands of football match play over the last decade4; but practitioners should also question their approach to injury prevention and physical preparation of players, an area where research is lacking.5–8 There is an evidence-based strategy to prevent HSIs, however, there appears to be a large disconnect between this available evidence and its adoption in elite football.5 6 For example, the Nordic hamstring exercise (NHE) programme has been shown to effectively reduce HSIs by 65%–70%.9 10 But recent surveys of elite European Champions League (n=32) and Norwegian Premier League (n=18) teams showed that only 11% of these teams fully adopt the programme.11 Within elite football, there is a large disconnect between evidence-based practice and the actual interventions used by science and medical teams to prevent injuries.12 In line with an emerging body of evidence-based research, we believe that preventing HSIs in elite football requires a holistic approach, which considers multiple risk factors and their inter-relations, implemented effectively.6–8 13 In designing our injury prevention programme, we combine both the theory and the available evidence on HSI risk factors and intervention studies, as well as considering the context surrounding the player when designing our overall injury prevention approach. ### Why do HSIs happen? Risk factor analysis and programme planning To prevent HSIs, it is important to understand why they occur, so that an appropriate intervention can be developed, targeted at the specific risk factors. Importantly, there is not a …

Arthrogenic muscle inhibition after ACL reconstruction: a scoping review of the efficacy of interventions

Abstract: Objective To determine whether reported therapeutic interventions for arthrogenic muscle inhibition (AMI) in patients with ACL injuries, following ACL reconstruction, or in laboratory studies of AMI, are effective in improving quadriceps activation failure when compared with standard therapy in control groups Design A scoping review of the efficacy of interventions was conducted in accordance with the methodological framework of Arksey and O’Malley and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines Search terms included ‘arthrogenic muscle inhibition’, ‘quadriceps activation following knee injuries’, ‘anterior cruciate’ or ‘knee’ combined with ‘quadriceps activation’, ‘quadriceps inhibition’, ‘corticomotor’, ‘arthrogenic’, ‘brain activation’ and ‘neuroplasticity’ Articles were evaluated for risk of bias using the PEDro (Physiotherapy Evidence Database) criteria The overall quality of evidence for each intervention was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) Data sources PubMed, EMBASE and Cumulative Index to Nursing and Allied Health Literature databases Eligibility criteria for selecting studies Isolated case reports and articles reporting outcomes in patients with chronic disease or major trauma were excluded All other original research articles were included Results 780 potential articles were identified 20 met the inclusion criteria These studies provided a moderate quality of evidence to support the efficacy of cryotherapy and physical exercises in the management of AMI There was low-quality evidence for efficacy of neuromuscular electrical stimulation and transcutaneous electrical nerve stimulation, and very low-quality evidence for efficacy of ultrasound and vibration Conclusions This scoping review demonstrated moderate-quality evidence for the efficacy of cryotherapy and physical exercises in improving quadriceps activation failure after ACL injury and reconstruction These therapeutic modalities are therefore recommended in the management of AMI

Is interval training the magic bullet for fat loss? A systematic review and meta-analysis comparing moderate-intensity continuous training with high-intensity interval training (HIIT)

Abstract: Objectives To compare the effects of interval training and moderate-intensity continuous training (MOD) on body adiposity in humans, and to perform subgroup analyses that consider the type and duration of interval training in different groups. Design Systematic review and meta-analysis. Data sources English-language, Spanish-language and Portuguese-language searches of the electronic databases PubMed and Scopus were conducted from inception to 11 December 2017. Eligibility criteria for selecting studies Studies that met the following criteria were included: (1) original articles, (2) human trials, (3) minimum exercise training duration of 4 weeks, and (4) directly or indirectly compared interval training with MOD as the primary or secondary aim. Results Of the 786 studies found, 41 and 36 were included in the qualitative analysis and meta-analysis, respectively. Within-group analyses showed significant reductions in total body fat percentage (%) (interval training: −1.50 [95% CI −2.14 to −0.86, p Conclusion Interval training and MOD both reduce body fat percentage (%). Interval training provided 28.5% greater reductions in total absolute fat mass (kg) than MOD. Trial registration number CRD42018089427.