Strength training as superior, dose-dependent and safe prevention of acute and overuse sports injuries: a systematic review, qualitative analysis and meta-analysis

Effect of an unsupervised multidomain intervention integrating education, exercises, psychological techniques and machine learning feedback, on injury risk reduction in athletics (track and field): protocol of a randomised controlled trial (I-ReductAI)

The primary aim is to assess the impact of a multidomain intervention that integrates education, exercise, psychological techniques and machine learning feedback on the duration athletes remain free from injury complaints leading to participation restriction (ICPR) during a 20-week summer competitive athletics season. The secondary aims are to assess the intervention's effect on reducing (i) the incidence, (ii) the burden, (iii) the period prevalence and (iv) the weekly prevalence of ICPR during the same timeframe. We will perform a two-arm randomised controlled trial. This study will involve an intervention group and a control group of competitive athletes licensed with the French Federation of Athletics, aged between 18 and 45, over an outdoor athletics competitive season lasting 20 weeks (March to July 2025). Data will be collected before the start (demographic, training and injury history) and one time per day (training and competition volume/intensity, perceived physical and psychological state, and illness and injury incidents) for both groups. The intervention group will be required to (i) view a series of 12 educational videos on injury prevention, (ii) engage in discipline-specific exercise programmes, (iii) implement stress and anxiety management techniques and (iv) view daily the injury prognostic feedback generated by the athlete's collected data based on machine learning. Outcomes will be analysed over the final 14 weeks of follow-up to allow time for the intervention to establish any potential efficacy. The primary outcome will be the time-to-event for each ICPR. Secondary outcomes will include (i) incidence, (ii) burden, (iii) period prevalence and (iv) weekly prevalence of ICPR. The primary outcome will be analysed using a Prentice-Williams-Peterson gap-time model. In contrast, the secondary outcomes will employ Poisson (i, ii), logistic (iii) and generalised estimating equations (iv) regression models, respectively.

Physiological Characteristics of Freestyle Snowboard and Freeski Athletes

PURPOSE

To investigate the physiological characteristics of freestyle snowboard and freeski athletes and explore potential differences between males and females.

METHODS

National-team athletes, snowboard (9 males, 21 [2.3] y; 8 females, 20 [4.1] y) and freeski (10 males, 21 [2.1] y; 8 females, 18 [2.2] y), underwent physiological assessments: maximal oxygen uptake (V˙O2max; indirect), countermovement-jump height, drop-jump (DJ) height, DJ contact time, reactive strength index, absolute peak force (PFabs), and relative peak force. Differences were analyzed using multivariate analyses of variance Wilks lambda (Λ) and magnitude with partial-eta squared (ηp2). Pairwise comparisons and the impact of sex and sport were analyzed with univariate tests, utilizing Cohen d.

RESULTS

No physiological differences were found between snowboard and freeski (Wilks Λ = 0.8, P > .251, ηp2 = .169). Sex differences were observed (Wilks Λ = 0.2, P < .001, ηp2=.79), without an interaction between sex and sport (Λ = 0.8, P > .449, ηp2=.120). For snowboard, sex differences included V˙O2max (P < .001, d = 1.04), countermovement-jump height (P < .001, d = 2.5), DJ height (P < .001, d = 1.45), DJ contact time (P < .001, d = 0.36), reactive strength index (P < .001, d = 1.36), front-limb PFabs (P < .001, d = 1.77), rear-limb PFabs (P < .001, d = 1.36), front-limb relative PF (P < .003, d = 0.88), and rear-limb relative PF (P < .021, d = 0.65). In freeski, differences included V˙O2max (P = .005, d = 0.81), countermovement-jump height (P < .001, d = 1.3), DJ height (P < .001, d = 1.17), DJ contact time (P < .040, d = 0.54), reactive strength index (P < .001, d = 1.0), left-limb PFabs (P < .001, d = 2.2), right-limb PFabs (P < .001, d = 1.88), left-limb relative PF (P < .001, d = 1.1), and right-limb relative PF (P < .001, d = 1.33).

CONCLUSIONS

Differences between the sexes, rather than between sports, explained the largest variance. A broad concurrent training approach with the aim of developing resilient athletes is likely warranted while acknowledging and adapting to individual needs.

Knowledge of gym goers on myths and truths in resistance training

Over the last decades, resistance training (RT) has experienced a surge in popularity, and compelling evidence underpins its beneficial effects on health, well-being, and performance. However, sports and exercise research findings may translate poorly into practice. This study investigated the knowledge of Austrian gym-goers regarding common myths and truths in RT. Based on topical systematic reviews (n = 45), a digital questionnaire with 14 statements on RT methods and practices, randomly phrased as myths or truths, was administered to Austrians exercising in local fitness centres. Chi-squared tests were used to check if a majority correctly identified true and false statements. A total of n = 721 (30.1 ± 14 years, 454 males) out of n = 790 contacted individuals completed the survey (response rate: 91.2 percent). Five out of fourteen statements (truth: protein augments strength and hypertrophy, creatine augments strength, superiority of full- vs. partial-ROM RT for hypertrophy; myth: RT reduces flexibility, low-load, high-volume RT is as effective as high-load RT with regard to maximal strength) were identified correctly by a majority (p < .01). The awareness of the scientific evidence on RT is low among gym-goers. Upcoming studies should be geared to improve science communication.

Injury prevention programmes (IPPs) for preventing anterior cruciate ligament injuries

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To determine the benefits and harms of injury prevention programmes on anterior cruciate ligament injuries.

Biopsychosocial approach to sports injury: a systematic review and exploration of knowledge structure

BACKGROUND

Sports injuries are influenced by biological, psychological, and social factors. Therefore, an integrated approach to address these factors is essential. This study aimed to analyze the research trends and biopsychosocial factors influencing sports injuries. It also explored the knowledge structure of the biopsychosocial approach to sports injuries.

METHODS

A literature search was conducted using the PubMed, Cochrane Library, and RISS databases with the keywords 'Biopsychosocial' and 'Sports injury' for studies published between January 1, 2014, and August 31, 2024. Studies in which the abstract content did not match the purpose of this study were excluded. Two independent reviewers conducted a qualitative content analysis of the selected literature. Data on the study design, year of publication, biopsychosocial factors, and main findings were extracted. To explore the knowledge structure, a keyword-network analysis was performed using Python NetworkX.

RESULT

Five studies were selected based on the inclusion and exclusion criteria. All selected studies were published after 2021, reflecting recent research trends. Biopsychosocial factors influencing the occurrence of sports injuries include sex, team sports, neuroticism, previous injury, postpartum-related factors, mental health, and sleep status. Biopsychosocial factors influencing return to play after sports injury include self-reported knee function and psychological readiness to return to sport. The five most frequently occurring keywords were 'injury', 'factors', 'sports', 'pain' and 'runners'. 'Factors-injury' had the highest co-occurrence frequency, and the 'injury', 'factors', and 'sports' showed high scores in the centrality analysis.

CONCLUSION

A biopsychosocial approach to sports injuries represents a recent research trend. Identifying the biopsychosocial factors of sports injuries can help prevent injuries and promote rehabilitation. Therefore, the development of a biopsychosocial model to prevent sports injuries and promote rehabilitation has been proposed.

Stay in the Game: Comprehensive Approaches to Decrease the Risk of Sports Injuries

Recurrent sports injuries present complex challenges that extend beyond the playing field, impacting athletes' physical well-being, mental resilience, and financial stability. This review outlines a comprehensive framework designed to prevent and manage these setbacks, empowering athletes to achieve sustained performance and recovery. This multidimensional issue requires an integrative approach encompassing physical rehabilitation, psychological resilience, and nutritional strategies. Physically, injury prevention relies on tailored rehabilitation programs that address athletes' specific injury histories and sport-related demands. Techniques such as biomechanical assessments and neuromuscular training correct faulty movement patterns, while workload monitoring ensures a balance between training and recovery. Strength and conditioning programs have demonstrated success in reducing injury rates and enhancing musculoskeletal resilience. Psychologically, reinjury anxiety and mental disengagement are key barriers to recovery and performance. Interventions such as goal setting, mindfulness, and cognitive restructuring rebuild confidence and foster readiness to return to play. Addressing psychological well-being is as critical as physical health in promoting sustained performance. Nutrition is equally pivotal, with balanced macronutrient intake supporting energy and tissue repair and micronutrients (magnesium, manganese, vitamin D, selenium, zinc, coenzyme Q10, etc.) bolstering bone health. Anti-inflammatory nutrients and proper hydration reduce muscle strain and aid recovery, while personalized dietary strategies meet the specific demands of individual sports. By integrating these physical, psychological, and nutritional dimensions, this framework empowers athletes, coaches, and medical teams to minimize injury recurrence and enhance long-term performance, ensuring athletes remain competitive and resilient in their sporting pursuits.

Examining the Effects of Dynamic and Isometric Resistance Training on Knee Joint Kinetics During Unplanned Sidesteps in Elite Female Athletes

ABSTRACT

Kadlec, D, Jordan, MJ, Alderson, J, and Nimphius, S. Examining the effects of dynamic and isometric resistance training on knee joint kinetics during unplanned sidesteps in elite female athletes. J Strength Cond Res 38(12): 2079-2087, 2024-The purpose of this study was to examine the effects of a 4-week block of isometric (isometric RT ) and dynamic resistance training (dynamic RT ) on kinetic variables associated with anterior cruciate ligament (ACL) injury risk during unplanned sidesteps in elite female athletes. Twenty-one elite female athletes competing for a women's international rugby union team were recruited with 15 ( n = 15; age: 23.4 ± 4.7 years; 170.7 ± 8.4 cm; 84.4 ± 15.4 kg) completing assessment of knee flexion moment, knee valgus moment (KVM), knee internal rotation moment (KIRM), knee joint power during unplanned sidesteps, and lower limb strength before and after a 4-week intervention. Linear mixed effects models and one-dimensional statistical parametric mapping assessed the effect of the interventions. Statistical significance was set at α = 0.05. Postintervention the isometric RT group revealed reduced peak KVM during early stance ( p = 0.04) while the dynamic RT group decreased peak KIRM ( p < 0.01) and KIRM over 8.8-86.6% ( p < 0.01) and 96.9-98.5% ( p = 0.047). An exploratory combined group analysis revealed reductions in KVM over 7.9-21.8% ( p = 0.002) and in KIRM over 8.3-90.5% ( p < 0.01) and 96.2-98.5% ( p = 0.046). Most lower limb isometric and dynamic strength measures increased after both resistance training interventions. Overall, both groups increased lower-body maximum strength while reducing kinetic knee joint variables associated with ACL injury risk during unplanned sidesteps. These results highlight the importance of increasing single-joint and multijoint strength in female athletes to mitigate the mechanical knee joint demands during sidestepping.

Upper limb muscle strength and wheelchair-related abilities following an exoskeleton-assisted walking programme in individuals with chronic spinal cord injury: An exploratory study

OBJECTIVES

To measure the potential effects of an overground exoskeleton-assisted walking programme on upper limb strength and mass, as well as on wheelchair propulsion performances and abilities in individuals with chronic spinal cord injury.

DESIGN

Prospective, single-group, pre-post intervention study.

PARTICIPANTS

Ten individuals with chronic (≥ 18 months) spinal cord injury who use a wheelchair as their primary mode of locomotion and who had little-to-no motor function in the lower limbs.

METHODS

Individuals completed a progressive 16-week exoskeleton-assisted walking programme (34 × 1-h sessions, 1-3 sessions/week). Upper limb muscle strength was measured with dynamometers (isokinetic, Jamar). Upper limb lean mass (dual-energy X-ray absorptiometry) was used to calculate relative strength. Field tests (20-m wheelchair propulsion, and slalom test) and the Wheelchair Skills Test Questionnaire determined performances and abilities. Wilcoxon signed-rank tests were used with the following criteria: p < 0.1, effect size ≥ 0.5, and relative variation > 5%.

RESULTS

Only natural velocity during the 20-m wheelchair propulsion test (i.e., fundamental wheelchair ability) changed following the intervention (p = 0.01, effect size = 0.82, relative variation = +14.5%).

CONCLUSION

Overall, upper limb muscle function did not significantly and meaningfully change following the exoskeleton-assisted walking programme in this population. Additional research is needed to verify how changes in training volume would affect strength and advanced wheelchair-related abilities and performance, as well as the response in individuals who are deconditioned or novices to wheelchair use (e.g., subacute spinal cord injury).

Prior Musculoskeletal Injury and Components of Physical Fitness in Military Personnel: A Systematic Review with Meta-analysis

INTRODUCTION

Military personnel confront heightened risks of musculoskeletal injuries (MSIs) because of the demanding nature of their duties, contributing to restricted active duty and financial burdens. Although preventable factors like training and physical fitness influence some injuries, understanding the enduring effects of previous MSIs on physical fitness in military personnel remains a critical gap. This study aimed to systematically review and meta-analyze this impact.

MATERIALS AND METHODS

In accordance with PRISMA guidelines, a systematic review with meta-analysis was conducted, focusing on military personnel with and without a history of MSIs. Physical fitness components were assessed via observational studies, with isokinetic peak torque values as primary metrics. Quality assessments utilized the NIH Quality Assessment Tool and GRADE framework.

RESULTS

Out of 36 papers, 6 met inclusion criteria, with 4 included in the meta-analysis. Across 1,267 participants, individuals with prior MSIs exhibited a significant reduction in the pooled effect size for isokinetic peak muscle force, with d+ = -0.25 (95% CI: -0.36 to -0.13), notably affecting knee and shoulder regions. These findings underscore the pervasive impact of MSIs on military personnel's physical performance, necessitating targeted interventions.

CONCLUSION

Military personnel with prior MSIs exhibit enduring deficits in isokinetic peak muscle force, particularly in knee and shoulder regions. However, evidence on the impact of previous injuries on other physical fitness components remains limited. Further research is crucial to understanding the multifaceted impact of MSIs on diverse aspects of physical performance, informing comprehensive injury prevention strategies and optimizing performance outcomes among military personnel.

Force-velocity-power variables derived from isometric and dynamic testing: metrics reliability and the relationship with jump performance

We investigated the convergent validity and intrasession reliability of force, velocity, and power (FVP) variables and the dynamic strength index (DSI) obtained from isometric midthigh pull (IMTP) and squat jump (SJ) testing. Fifteen male combat sports athletes (27 ± 5 years, 77 ± 9 kg, 1.76 ± 0.1 m, 14 ± 6% body fat) participated in a 2-days study. The first day involved testing familiarization, while the second was dedicated to IMTP and SJ testing. Maximal isometric force (Fiso ) was obtained from IMTP, while mean force, mean velocity, jump height, and jump impulse (J) were gathered from SJ. To analyze the FVP, we calculated the linear relationship between force and velocity, which allowed us to obtain the slope of the relationship (SFV ), the theoretical velocity at zero force (V0 ), and the theoretical maximal power (Pmax ). DSI was obtained as a ratio from SJ peak force and Fiso . The convergent validity was investigated using Spearman's ρ coefficients to assess the relationships between jump height and J with Fiso , V0 , SFV , Pmax , and DSI. The intrasession reliability was assessed using intraclass correlation coefficients (ICC) and coefficient of variations (CV). All variables demonstrated acceptable reliability scores. ICC ranged from moderate to excellent, and the mean CV was <10%. We found a "very large" correlation between jump J and Pmax , while jump height was not correlated with any variable. In conclusion, the IMTP and SJ combination is a practical way to determine FVP producing capacities that can be reliably measured (intrasession). The Pmax , derived from FVP, was correlated with jump performance, which might evidence the convergent validity of the method.

Hydrolyzed collagen supplementation prior to resistance exercise augments collagen synthesis in a dose-response manner in resistance-trained, middle-aged men

Resistance exercise (RE) increases collagen synthesis in young and older men, whereas hydrolyzed collagen (HC) ingestion improves this response to RE in a dose-response manner in young men. However, the collagen synthesis response to RE with and without HC in middle-aged men is unknown. Eight resistance-trained men (age: 49 ± 8 yr; height: 1.78 ± 0.02 m; mass: 90 ± 4 kg) took part in this double-blind, crossover design study and undertook 4 × 10 repetitions of lower-limb RE at maximum load, after consuming 0 g, 15 g, or 30 g vitamin C-enriched HC. We analyzed venous blood samples for N-terminal propeptide of type 1 pro-collagen (PINP), β-isomerized C-terminal telopeptide of type 1 collagen (β-CTx), and 18 collagen amino acids throughout all three interventions. The serum PINP concentration × time area-under-the-curve (AUC) was higher following 30 g (169 ± 28 µg/mL × h) than 15 g (134 ± 23 µg/mL × h, P < 0.05) HC ingestion, and both 15 g and 30 g were higher than 0 g HC (96 ± 23 µg/mL × h, P < 0.05). RE with 0 g HC showed no change in serum PINP concentration. The AUCs for glycine, proline, hydroxyproline, alanine, arginine, lysine, serine, leucine, valine, and isoleucine were greater with 30 g than 15 g and 0 g HC ingestion (P < 0.05) and greater with 15 g than 0 g HC ingestion (P < 0.05). Plasma β-CTx concentration decreased after RE independently of HC dose. Our study suggests connective tissue anabolic resistance to RE in middle-aged men but ingesting 15 g HC rescues the collagen synthesis response and 30 g augments that response further. This dose response is associated with the increased bioavailability of collagen amino acids in the blood, which stimulate collagen synthesis.NEW & NOTEWORTHY This study is the first to document the dose-response effect of hydrolyzed collagen (HC) ingestion before resistance exercise (RE) on collagen turnover in middle-aged, resistance-trained men. Strikingly, RE alone did not increase collagen synthesis (suggesting connective tissue anabolic resistance), but ingesting 15 g HC rescued the collagen synthesis response and 30 g augmented that response further. These results were associated with the increased bioavailability of collagen amino acids in the blood, which stimulate collagen synthesis.

Lower Extremity Asymmetry Values Derived From Multiple Strength Testing Modes Are Associated With Perceived Functional Capabilities Among University Athletes

Background: Muscle strength asymmetry and athlete introspective measures are associated with musculoskeletal (MSK) sport injury and reinjury. However, the interrelationship between mechanical and subjective measures of concentric and eccentric limb function needs further exploration. This includes investigating if an athlete's perception of their overall MSK function influences limb asymmetry across different testing modalities. Objectives: To (i) explore the interrelationship between mechanical and subjective measures of lower limb function in university athletes and (ii) compare the consistency in interlimb strength asymmetries across different strength tests in groups of athletes with good, fair, and poor perceived limb function. Methods: University athletes (n = 175; n = 87 females) from six sports completed four tests of muscle strength, power, and plyometric function along with an assessment of perceived limb function using the Sport Fitness Index (SFI). Participants were categorized into high (GOODSFI), fair (FAIRSFI), and poor (POORSFI) perceived overall MSK function (perceived function) groups. Strength asymmetry indexes evaluated interlimb differences in concentric and eccentric maximal strength, countermovement jump (CMJ) impulse, unilateral CMJ height, and reactive strength index in unilateral repeat hop testing. Cumulative link mixed-effects models assessed the relationship between strength asymmetries and perceived limb function. Results: The POORSFI group showed increased asymmetry in concentric strength testing (p = 0.022), more consistent interlimb asymmetries (p < 0.001), and reduced overall muscle strength compared to the GOODSFI group. Conclusion: Higher interlimb asymmetry in maximal concentric strength measures along with reduced muscle strength was found in the POORSFI group compared to the GOODSFI group. The POORSFI group also showed greater consistency in muscle strength asymmetry derived across different tasks.

Health And Performance Promotion in Youth (HAPPY) hybrid effectiveness-implementation cluster randomised trial: comparison of two strategies to implement an injury prevention exercise programme in Danish youth handball

OBJECTIVE

To investigate if a combination of an online and onsite implementation strategy was superior to an online-only strategy in enhancing the use of an injury prevention exercise programme (IPEP) and in reducing the risk of shoulder, knee and ankle injuries in youth community handball players (age 11-17) over a handball season.

METHODS

In this 30-week hybrid effectiveness-implementation cluster randomised type 3 study, 20 youth handball clubs were randomly assigned 1:1 to either a combined online and onsite implementation strategy (coach workshop using the health action process approach behaviour change model and health service provider (HSP) support) or an online-only strategy (control group). The primary implementation outcome was coach-reported adherence, measured as the average IPEP exercise usage by the team over 30 weeks. The primary effectiveness outcome was player-reported handball playing time to any new handball-related shoulder, knee and ankle injuries, reported weekly using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems.

RESULTS

We enrolled 63 coaches (27% women) and 945 players (mean age 14.5 years, 55% girls). Intention-to-treat analyses showed no statistically significant difference between implementation strategies in adherence (between-group difference 1.4, 95% CI -0.5 to 3.4) or in cumulative injury risk (between-group difference 5.5% points, 95% CI -2.2 to 13.1).

CONCLUSION

Our findings demonstrate that in youth community handball, a combined online and onsite implementation strategy, including a coach workshop and HSP support, was not superior to an online-only strategy regarding adherence to an IPEP or in reducing shoulder, knee and ankle injury risk.

TRIAL REGISTRATION NUMBER

NCT05294237.

A systematic review of resistance training methodologies for the development of lower body concentric mean power, peak power, and mean propulsive power in team-sport athletes

This study aimed to systematically review training methods prescribed to develop lower-body power, determine their effectiveness for the development of lower-body mechanical power and their implementation in an annual training cycle amongst team-sport athletes. The absolute and relative outcome values of concentric mean power, peak power and mean propulsive power were extracted from 19 studies. Outcomes were assessed using baseline to post intervention percent change, effect sizes, and the level of evidence concerning the method's effectiveness. A thorough analysis of the literature indicated that, based on the high level of evidence, traditional (e.g., strength training alone) and combination training (e.g., complex and contrast) methods should be considered. Further, optimal load and velocity-based training can be implemented if coaches have access to the appropriate equipment to monitor movement velocity and mechanical power in every session. This is of particular importance in periods of the season where high volumes of technical-tactical training and congested fixture periods are present. Also, flywheel, eccentric overload and weightlifting methods have been shown to be effective although the level of evidence is low. Future research should expand on current training practices whilst adequately reporting actual training loads from sport-specific training and games alongside strength-power training protocols.

"Varus knee dysfunction contributing to early medial knee arthritis: Novel pathomechanics, diagnosis and multi-modal conservative interventions"

OBJECTIVE

Evaluate whether the three-planar spring test and pathomechanics-based interventions (manual therapy, strengthening, orthosis) increase the range of motion and explore potential changes in joint space of varus knee dysfunction, further investigating their potential association with the early development of medial knee arthritis (MKA).

METHODS

Single group, pre-and post-test design. Adults (n = 54) exhibiting a positive spring test for varus knee dysfunction, characterised by extension lag with proximal tibia externally rotated and subluxed laterally, completed the study. Outcome measures include pain intensity, ROM, functional abilities and X-ray measures (joint space, tilt, and tibia position relative to the femur) following the interventions.

RESULTS

After interventions, the spring test has become negative at the pre-assessment range. There is an increased ROM [internal rotation by 3.61° (95CI 3.22, 4.01) and extension by 3.92° (95CI -4.51, -3.33)], and X-ray measurements showed an increase in both medial and lateral joint space by 0.78 mm (95CI 0.63, 0.92) and 0.13 mm (95CI -0.03, 0.24) respectively. Additionally, total joint space expansion happened by 0.28 ± 0.23 mm. The proximal tibia medially shifted by 0.85 ± 0.96 mm, and the medial tilt was reduced by 1.79°±1.28°. A significant decrease in pain by five points (NPRS) and an increase in the overall functional abilities of participants by 36.9 points (95CI 34.72, 39.09).

CONCLUSION

The study results indicate that diagnosis with a spring test and interventions have increased the medial joint space and ROM, possibly improved alignment and synovial fluid, contributing to decreasing the pain and improving the functional abilities, thereby supporting the study's objective.

Effects of In-Season Strength Training on Physical Fitness and Injury Prevention in North African Elite Young Female Soccer Players

BACKGROUND

Strength training (ST) primarily enhances physical fitness (e.g., muscle strength, power, speed) and bone density in female soccer players. Less information is available on the injury preventive effects of ST in female athletes. Accordingly, this study aimed to investigate the effects of a 12-week in-season ST on measures of physical fitness and injury occurrence in young elite female soccer players.

METHODS

Thirty elite female soccer players (15.4 ± 1.9 years; maturity offset + 2.3 ± 1.1 years) participated in this study, and were randomly assigned to a strength training group (STG, n = 14) or an active control (CG, n = 16) group. ST lasted twelve weeks and included full body muscle strengthening exercises using primarily weight machines at progressive intensities ranging between 40 and 85% of the one-repetition-maximum (1-RM). The CG practiced a traditional soccer training program. Overall, training volumes of the two groups were similar with a training load (rating of perceived exertion × time) of 1158.4 ± 67.7 arbitrary unity (AU) for the STG and 1188.8 ± 44.1 AU for the CG. Pre and post training, the following physical fitness tests were applied: dynamic muscle strength (relative [to body mass] and absolute 1-RM bench/leg press, lat-pull down), jump performance (countermovement jump [CMJ], squat jump [SJ], five-jump-test [5JT]), linear-sprint speed (5-m, 10-m, 30-m), change-of-direction speed (T-test with and without ball), sport-specific performance (Yo-Yo Intermittent Level1 [YYIRTL1], and repeated shuttle sprint ability [RSSA]). The injury rate per 1000-h exposure was monitored throughout the soccer season.

RESULTS

No significant baseline differences were observed between groups. Statistically significant group-by-time interactions were found for absolute (p < 0.001, d = 2.59) and relative 1-RM bench press (p < 0.001, d = 2.39), absolute 1-RM lat-pull down (p < 0.001, d = 1.68), and relative 1-RM leg press (p < 0.001, d = 1.72). Significant group-by-time interactions were observed for CMJ (p = 0.005, d = 1.27), RSSAmean (p = 0.007, d = 0.81), and RSSAtotal (p < 0.001, d = 1.90). Post-hoc tests indicated that the STG group demonstrated greater improvements in all tested variables compared to CG (1.2 < d < 2.5). However, no significant interaction effects were noted for measures of linear sprint speed and YYIRTL1 performance. Additionally, non-contact injuries during the season were significantly lower (p = 0.003, d = 1.31) in the STG (0.48/1000 h of exposure) than the CG (2.62/1000 h of exposure).

CONCLUSIONS

Twelve weeks of an in-season ST resulted in larger physical fitness improvements and fewer injuries compared with an active control in elite young female soccer players. Accordingly, ST should be systematically applied in female soccer to enhance performance and prevent injuries.

Effect of supervision and athlete age and sex on exercise-based injury prevention programme effectiveness in sport: A meta-analysis of 44 studies

We aimed to evaluate the influence of supervision, athlete age and sex and programme duration and adherence on exercise-based injury prevention programme effectiveness in sport. Databases were searched for randomized controlled trials evaluating exercise-based injury prevention programme effectiveness compared to "train-as-normal". A random effects meta-analysis for overall effect and pooled effects by sex and supervision and meta-regression for age, intervention duration and adherence were performed. Programmes were effective overall (risk ratio (RR) 0.71) and equally beneficial for female-only (0.73) and male-only (0.65) cohorts. Supervised programmes were effective (0.67), unlike unsupervised programmes (1.04). No significant association was identified between programme effectiveness and age or intervention duration. The inverse association between injury rate and adherence was significant (β=-0.014, p = 0.004). Supervised programmes reduce injury by 33%, but there is no evidence for the effectiveness of non-supervised programmes. Females and males benefit equally, and age (to early middle age) does not affect programme effectiveness.

Applying a Holistic Injury Prevention Approach to Elite Triathletes

(1) Background: Studies on injury prevention programs are lacking for triathletes. The aim of the present study was to describe the results of a holistic (injury) training prevention program (HITP), based on training load control and strength training, in elite triathletes. (2) Methods: The study was conducted over 2021-2023 and involved 18 males and 10 females from the same training group. The HITP itself included various methods of fatigue monitoring, strength training focused on the prevention of overuse injuries (OIs), cycling skills training, and recovery strategies. The total number and type of injuries that were sustained, subsequent training/competition absence time, and injury incidence were determined. (3) Results: Twenty-four injuries were recorded over all three seasons, i.e., 0.65 injuries per 1000 h of training and competition exposure. Fourteen injuries were traumatic injuries (TIs) and ten were OIs. Of the OIs, four were of minimal severity, two were mild, three were moderate, and one was severe (accounting for 1-3, 4-7, 8-28, and >28 days of training absenteeism, respectively). A total of 46.4% of the participants did not present any type of injury and 71,4% did not incur any OIs. Average absenteeism was 17.3 days per injury. (4) Conclusions: The HITP design and implementation resulted in low OI and severe injury incidence. Due to their unpredictable nature, the number of TIs was not reduced. The TIs were suffered more frequently by men. Women are more likely to suffer from OIs, so it is particularly important to prevent OIs in women.

Testing in Intermittent Sports-Importance for Training and Performance Optimization in Adult Athletes

ABSTRACT

Performance in intermittent sports relies on the interplay between multiple physiological systems determining the capacity to perform short explosive efforts as well as repeated intense actions with limited recovery over the course of an entire game. Testing should reflect these demands to allow for sport- and position-specific capacity analyses that eventually may translate into optimized training and improved performance. This may include individual load management and optimized training prescription, intensity targeting for specific positions or individual athletes, as well as benchmarking for monitoring of training progression and enhanced engagement of athletes. This review provides an overview of available tests in different exercise domains identified as relevant (from assessment of single explosive actions to intermittent endurance capacity), forming the basis for recommendations on how to compose a comprehensive yet feasible test battery that may be integrated into the seasonal competition and training plan. The test procedures should cover the performance spectrum of relevance for the individual athlete-also in team sports to account for positional differences. We emphasize the benefits of sport-specific tests, highlight parameters of importance for test standardization, and discuss how the applied test battery may be supplemented with secondary tests directed toward specific energy systems to allow for more in-depth analyses when required (e.g., in terms of an underperforming athlete). The synergy between testing and tracking of match performance (utilizing time-motion or global positioning systems) is highlighted, and although tracking cannot substitute for testing, combining the tools may provide a comprehensive overview of the physiological demands and performance during competition contextualized to the athletes' maximal exercise capacity.

Role of strengthening exercises in management and prevention of overuse sports injuries of lower extremity: a systematic review

INTRODUCTION

Overuse injuries are common in sports involving jumping, running, and landing, due to the repetitive nature of these activities and the strain they place on the lower extremity. The objective of the study was to determine the role of strengthening exercises in the management of overuse sports injuries of lower extremity and its effects on prevention of injury recurrence.

EVIDENCE ACQUISITION

This study employed a systematic review design. The author extracted and reviewed the papers for this study in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria, and then used the PEDro scale to rate the articles' quality. For the most recent and well-developed primary data, several electronic databases including Google Scholar, PubMed Central, MEDLINE, Cochrane Library, and PEDro were exhaustively searched. Inclusion criteria were based on PICO (T) model and included study population, intervention nature, outcome measures, time period, methodological quality, and linguistic extent.

EVIDENCE SYNTHESIS

The data synthesis involved analyzing randomized control/clinical trials on strengthening exercises for lower extremity overuse sports injuries in athletes, considering outcomes including muscle strength, pain scores, return to sports, and injury prevention.

CONCLUSIONS

The methodological quality of the recruited articles ranged from excellent to fair on PEDro scale. Three included studies investigated the effects of strengthening exercises on management of lower extremity injuries of athletes. Four studies evaluated its role on prevention from recurrence of injuries. This study has concluded that strength training plays a fundamental role in management and prevention of overuse injuries. It not only improves the muscle performance, fitness level, speed and agility in sports but also decreases the pain, and aids in early recovery from an injury.

The Value of Strength as a Predictor of Musculoskeletal Injury in Canadian Armed Forces Basic Infantry Candidates

INTRODUCTION

Musculoskeletal injuries (MSKI) impact military organizations by threatening their operational readiness, warranting investigation into relevant factors to inform risk reduction strategies. While several self-reported and physical performance measures have been associated with MSKI among military personnel, few have been validated and none have been reported in Canadian basic infantry candidates. The purpose of this study was to investigate associations between self-reported and physical performance measures and MSKI, and determine their validity as predictors of MSKI, in Canadian basic infantry candidates.

METHODS

This was a planned secondary analysis of a study tracking MSKI at a basic infantry training facility in Ontario, Canada approved by Defence Research & Development Canada. Before the basic infantry training, consenting candidates completed a baseline testing session including self-reported questionnaires, measures of anthropometry, and physical performance previously associated with MSKI (ankle dorsiflexion test, Y-Balance Test, Isometric Mid-Thigh Pull, and the Fitness for Operational Requirements of CAF Employment (FORCE) evaluation). All MSKI reported by candidates were diagnosed by licensed healthcare providers. From a total sample of 129 candidates, 76% (n = 98) were used to determine any associations between baseline testing variables and MSKI and to develop a predictive model (Development Sample), while 24% (n = 33) were used to offer preliminary validation of the same predictive model (Validation Sample). The binary logistic regression and independent sample t-testing determined independent associations with MSKI in the Development Sample. All continuous variables and dichotomous variables previously associated with MSKI risk (Smoker Yes/No, previous history of MSKI, and physical inactivity) were entered into a backward stepwise logistic regression analysis to assess the predictive association with MSKI incidence in the Development Sample. The regression model was then applied to the Validation Sample.

RESULTS

A total of 35 MSKI were diagnosed by Health Services Centre staff. The majority of the MSKI were acute (63%), sustained to the hip, knee, and ankle (74%). The most common diagnoses were strains and sprains (71%). Uninjured participants performed significantly better on the Relative Isometric Mid-Thigh Pull, FORCE 20 mR, FORCE ILS, and FORCE Estimated VO2peak compared to injured participants. Logistic regression analysis showed that the only variable with significant independent association with diagnosed MSKI incidence was self-reported previous history of MSKI. However, the backward stepwise logistic regression analysis retained self-reported previous history of MSKI, FORCE SBD, FORCE Estimated VO2peak, and Isometric Mid-Thigh Pull Peak Force as predictors of MKSI. The logistic regression model including these variables could predict MSKI with an accuracy of 79% in the Development Sample and 67% in the Validation Sample.

CONCLUSION

This study provides preliminary support for the value of measures of absolute muscular strength and cardiorespiratory fitness as predictors of MSKI in Canadian basic infantry candidates. Given the associations between physical performance measures and MSKI, and their necessity during occupational tasks, it is recommended that Canadian basic infantry training facilities integrate resistance training with external loads to best prepare their candidates to meet their occupational demands and potentially minimize MSKI. Further investigations to confirm the predictive capacity of these variables in a larger sample across additional facilities are warranted.

The Collagen Synthesis Response to an Acute Bout of Resistance Exercise Is Greater when Ingesting 30 g Hydrolyzed Collagen Compared with 15 g and 0 g in Resistance-Trained Young Men

BACKGROUND

Resistance exercise (RE) stimulates collagen synthesis in skeletal muscle and tendon but there is limited and equivocal evidence regarding an effect of collagen supplementation and exercise on collagen synthesis. Furthermore, it is not known if a dose-response exists regarding the effect of hydrolyzed collagen (HC) ingestion and RE on collagen synthesis.

OBJECTIVE

To determine the HC dose-response effect on collagen synthesis after high-intensity RE in resistance-trained young men.

METHODS

Using a double-blind, randomized crossover design, 10 resistance-trained males (age: 26 ± 3 y; height: 1.77 ± 0.04 m; mass: 79.7 ± 7.0 kg) ingested 0 g, 15 g, or 30 g HC with 50 mg vitamin C 1 h before performing 4 sets' barbell back squat RE at 10-repetition maximum load, after which they rested for 6 h. Blood samples were collected throughout each of the 3 interventions to analyze procollagen type Ⅰ N-terminal propeptide (PINP) and β-isomerized C-terminal telopeptide of type I collagen (β-CTX) concentration, and the concentration of 18 collagen amino acids.

RESULTS

The serum PINP concentration × time area under the curve (AUC) was greater for 30 g (267 ± 79 μg·L-1·h) than for 15 g (235 ± 70 μg·L-1·h, P = 0.013) and 0 g HC (219 ± 88 μg·L-1·h, P = 0.002) but there was no difference between 0 and 15 g HC (P = 0.225). The AUCs of glycine and proline were greater for 30 g than for 15 and 0 g HC (P < 0.05). Plasma β-CTX concentration decreased from -1 to +6 h (P < 0.05), with no differences between interventions.

CONCLUSIONS

Ingesting 30 g HC before high-intensity RE augments whole-body collagen synthesis more than 15 g and 0 g HC in resistance-trained young males.

The Role of Musculoskeletal Training During Return to Performance Following Relative Energy Deficiency in Sport

BACKGROUND

Relative energy deficiency in sport (REDs) is a condition that is associated with negative health and performance outcomes in athletes. Insufficient energy intake relative to exercise energy expenditure, resulting in low energy availability, is the underlying cause, which triggers numerous adverse physiological consequences including several associated with musculoskeletal (MSK) health and neuromuscular performance.

PURPOSE

This commentary aims to (1) discuss the health and performance implications of REDs on the skeletal and neuromuscular systems and (2) examine the role that MSK training (ie, strength and plyometric training) during treatment and return to performance following REDs might have on health and performance in athletes, with practical guidelines provided.

CONCLUSIONS

REDs is associated with decreases in markers of bone health, lean body mass, maximal and explosive strength, and muscle work capacity. Restoration of optimal energy availability, mainly through an increase in energy intake, is the primary goal during the initial treatment of REDs with a return to performance managed by a multidisciplinary team of specialists. MSK training is an effective nonpharmacological component of treatment for REDs, which offers multiple long-term health and performance benefits, assuming the energy needs of athletes are met as part of their recovery. Supervised, prescribed, and gradually progressive MSK training should include a combination of resistance training and high-impact plyometric-based exercise to promote MSK adaptations, with an initial focus on achieving movement competency. Progressing MSK training exercises to higher intensities will have the greatest effects on bone health and strength performance in the long term.

What We Do Not Know About Stretching in Healthy Athletes: A Scoping Review with Evidence Gap Map from 300 Trials

BACKGROUND

Stretching has garnered significant attention in sports sciences, resulting in numerous studies. However, there is no comprehensive overview on investigation of stretching in healthy athletes.

OBJECTIVES

To perform a systematic scoping review with an evidence gap map of stretching studies in healthy athletes, identify current gaps in the literature, and provide stakeholders with priorities for future research.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and PRISMA-ScR guidelines were followed. We included studies comprising healthy athletes exposed to acute and/or chronic stretching interventions. Six databases were searched (CINAHL, EMBASE, PubMed, Scopus, SPORTDiscus, and Web of Science) until 1 January 2023. The relevant data were narratively synthesized; quantitative data summaries were provided for key data items. An evidence gap map was developed to offer an overview of the existing research and relevant gaps.

RESULTS

Of ~ 220,000 screened records, we included 300 trials involving 7080 athletes [mostly males (~ 65% versus ~ 20% female, and ~ 15% unreported) under 36 years of age; tiers 2 and 3 of the Participant Classification Framework] across 43 sports. Sports requiring extreme range of motion (e.g., gymnastics) were underrepresented. Most trials assessed the acute effects of stretching, with chronic effects being scrutinized in less than 20% of trials. Chronic interventions averaged 7.4 ± 5.1 weeks and never exceeded 6 months. Most trials (~ 85%) implemented stretching within the warm-up, with other application timings (e.g., post-exercise) being under-researched. Most trials examined static active stretching (62.3%), followed by dynamic stretching (38.3%) and proprioceptive neuromuscular facilitation (PNF) stretching (12.0%), with scarce research on alternative methods (e.g., ballistic stretching). Comparators were mostly limited to passive controls, with ~ 25% of trials including active controls (e.g., strength training). The lower limbs were primarily targeted by interventions (~ 75%). Reporting of dose was heterogeneous in style (e.g., 10 repetitions versus 10 s for dynamic stretching) and completeness of information (i.e., with disparities in the comprehensiveness of the provided information). Most trials (~ 90%) reported performance-related outcomes (mainly strength/power and range of motion); sport-specific outcomes were collected in less than 15% of trials. Biomechanical, physiological, and neural/psychological outcomes were assessed sparsely and heterogeneously; only five trials investigated injury-related outcomes.

CONCLUSIONS

There is room for improvement, with many areas of research on stretching being underexplored and others currently too heterogeneous for reliable comparisons between studies. There is limited representation of elite-level athletes (~ 5% tier 4 and no tier 5) and underpowered sample sizes (≤ 20 participants). Research was biased toward adult male athletes of sports not requiring extreme ranges of motion, and mostly assessed the acute effects of static active stretching and dynamic stretching during the warm-up. Dose-response relationships remain largely underexplored. Outcomes were mostly limited to general performance testing. Injury prevention and other effects of stretching remain poorly investigated. These relevant research gaps should be prioritized by funding policies.

REGISTRATION

OSF project ( https://osf.io/6auyj/ ) and registration ( https://osf.io/gu8ya ).

Do Exercise-Based Prevention Programs Reduce Injury in Endurance Runners? A Systematic Review and Meta-Analysis

BACKGROUND

Endurance running is a popular sport and recreational activity yet is associated with a high prevalence of injury. Running related injuries (RRIs) are a leading cause of drop-out and represent a substantial financial burden to runners and healthcare services. There is clear evidence for the use of exercise-based injury prevention programs in games-based and youth sport settings, yet the research investigating the use of exercise to reduce injury risk in endurance runners has not been adequately reviewed recently.

OBJECTIVES

The aim of this review and meta-analysis was to systematically summarize the current research that has investigated the effect of exercise-based prevention programs and their state of supervision on the risk of RRIs in endurance runners.

METHODS

Three databases were searched for relevant studies. Selection and review were completed by two independent reviewers using the following inclusion criteria: (1) study population used endurance running training for health, occupational, or performance outcome(s); (2) participants performed running as their main form of exercise (> 50% of their total training time); (3) study was a randomized controlled trial; (4) a non-running-based exercise intervention was used; (5) a running-only or placebo exercise control group was included; (6) injury rate or incidence was reported; (7) injuries were recorded prospectively alongside the exercise training. Two meta-analyses were conducted using random-effects models, one based on log risk ratio and one based on log incidence rate ratio. The Cochrane Risk of Bias Assessment Tool 2 was used to evaluate the quality of studies and the Grading of Recommendations Assessment, Development and Evaluations approach was employed to grade the certainty of evidence.

RESULTS

A total of nine articles containing 1904 participants were included in analysis. Overall pooled results showed no significant differences between intervention and control groups in injury risk (z = - 1.60; p = 0.110) and injury rate (z = - 0.98; p = 0.329), while a post hoc analysis evaluating supervised interventions only showed that injury risk was significantly lower in the intervention group compared to the control group (z = - 3.75, p < 0.001). Risk of bias assessment revealed that seven studies included in the analysis were of low quality.

CONCLUSIONS

Exercise-based interventions do not appear to reduce the risk and rate of running-related injuries. Supervision may be essential for exercise-based intervention programs to reduce risk of RRIs, possibly due to increased compliance. Studies with more robust designs that include supervised exercise interventions should be prioritized in the future.

TRIAL REGISTRY

Clinical Trial Registration: PROSPERO CRD42021211274.

Longitudinal analysis of the incidence rate of injury in elite youth football: Trends over six years including the COVID-19 pandemic period

OBJECTIVES

We aimed to analyze injury trends and the possible effects of the coronavirus disease (COVID-19) pandemic on the incidence rates of injury in young elite football players.

DESIGN

A prospective cohort study design was adopted.

PARTICIPANTS

Our study included 832 male football players who suffered an injury during any of the six competitive seasons.

SETTING

An elite youth football academy.

MAIN OUTCOME MEASURE

Descriptive data and the incidence of injury were calculated. A generalized linear mixed model was used to assess differences in the occurrence of injury among the various age groups. Joinpoint regression was used to analyze injury trends.

RESULTS

Joinpoint regression models showed a statistically significant decrease in the incidence of injury in all age groups with an average annual percent change (AAPC) of 13.9 (95 %Confidence Interval [CI]:-23.2 - 3.4) and -13.5 (95 %CI:-24.5 to -0.9) for models with zero and one joinpoint, respectively. Football players in older age groups sustain a higher number of injuries, probably due to a higher number of matches and greater training intensity.

CONCLUSION

This study showed a downward trend in injuries in the participants prior to the pandemic, with an evident increase in the incidence rate of injury during the COVID-19 pandemic.

COVID-19 National Football League (NFL) Injury Analysis: Follow-Up Study

Background

In 2020, COVID-19 spread across the world and brought normal daily life to a halt, causing the shutdown of nearly everything in order to prevent its spread. The National Football League (NFL) similarly experienced shutdowns and the resulting effects, leaving athletes unable to train in some of the most advanced facilities with many of the best trainers in the world. A previous study, titled COVID-19 Return to Sport: NFL Injury Prevalence Analysis, determined that there was increased injury prevalence during the 2020 season, likely due to decreased physiological adaptations within athletes' bodies as a result of facility shutdowns. Understanding injury epidemiology is vital to the prevention of injuries and the development of return-to-play protocols.

Objective

The objective of this study is to perform a follow-up study to COVID-19 Return to Sport: NFL Injury Prevalence Analysis in order to examine the longitudinal effects of the COVID-19 pandemic on injury epidemiology. This study examines if there was a recovery to baseline levels of injuries or if there are still lingering effects from the COVID-19 pandemic-induced spike in injuries.

Methods

To determine if there was change in the number of injuries for each season, injury tallies collected from the 17-week-long 2018, 2019, and 2020 NFL regular seasons were compared with those from the 18-week-long 2021 and 2022 NFL regular seasons. A Kruskall-Wallis test with post hoc Dunn analysis was conducted to compare the rate of injuries per team per week between each of the 2018, 2019, 2020, 2021, and 2022 regular seasons.

Results

The Kruskall-Wallis test revealed an H statistic of 32.61 (P<.001) for the comparison of the injury rates across the 5 seasons. The post hoc Dunn analysis showed that 2020 had a statistically significant difference when compared with each of the 2018 (P<.001), 2019 (P=.04), 2021 (P=.02), and 2022 (P=.048) seasons. The 2019 season showed no statistical significance when compared with the 2021 (P=.23) and 2022 (P=.13) seasons.

Conclusions

The results of this follow-up study, combined with the previous study, show that extended training interruptions stemming from COVID-19 in 2020 induced detraining and led to increased injuries. Additionally, the results of this study show that retraining can occur, resulting in the development of injury protective factors, as injury rates returned to baseline levels after 2020. This is the first large-scale and long-term opportunity to demonstrate the effects of these principles and how they are important to understanding injury epidemiology.

Acute Effects of Resistance Exercise on Intraocular Pressure in Healthy Adults: A Systematic Review

ABSTRACT

Hackett, DA, Li, J, Wang, B, Way, KL, Cross, T, and Tran, DL. Acute effects of resistance exercise on intraocular pressure in healthy adults: A systematic review. J Strength Cond Res 38(2): 394-404, 2024-Intraocular pressure (IOP) tends to fluctuate during a resistance exercise (RE). This systematic review examines the acute effects of RE on IOP in healthy adults and factors that influence changes in IOP. Five electronic databases were searched using terms related to RE and IOP. A strict inclusion criterion was applied, which included being 55 years or younger with no medical conditions and RE intensity needing to be quantifiable (e.g., based on a maximal effort). Thirty-four studies met the inclusion criteria for this review. Isometric and isotonic contractions produced similar changes in IOP during RE up to 28.7 mm Hg. Exercises that involved larger muscle mass, such as squats and leg press, were found to produce changes in IOP during exercise ranging from 3.1 to 28.7 mm Hg. Smaller changes in IOP during RE were found for exercises engaging less muscle mass (e.g., handgrip and bicep curls). Intraocular pressure was found to increase during RE when lifting heavier loads and with longer exercise durations (e.g., greater repetitions). The Valsalva maneuver (VM) and breath-hold during RE accentuated the change in IOP, with more extreme changes observed with the VM. However, most studies showed that postexercise IOP returned to baseline after approximately 1 minute of recovery. An acute increase in IOP is observed during RE in healthy adults with fluctuations of varying magnitude. Factors that independently increase IOP during RE include exercises involving larger muscle mass, heavy loads, greater set duration, and when the VM or breath-hold is performed.

Load monitoring, strength training, and recovery in futsal: Practitioners' perspectives

This study aimed to describe the current practices in futsal regarding a variety of topics related to performance and injury risk mitigation. Thirty-seven coaches from Spain and Portugal completed a questionnaire consisting of 28 closed questions organized in four categories: a) background information; b) training load (TL) monitoring and assessment of players' physical qualities; c) strength training (ST) practices; and d) recovery (REC) methods. The results showed that coaches varied in experience (1-8 years) and age (from 20 years to >50 years). Overall, 97.3% of the participants declared monitoring TL, with rating of perceived exertion, heart rate monitors, and wearable technology being used by 86.5%, 40.5%, and 37.8%, respectively. Neuromuscular and strength testing are the most common practices to evaluate performance and fatigue during the season. ST is a significant component of futsal, being performed 3 times/week during the pre- and in-season. ST is prescribed via %1RM - XRM (59.5%), velocity-based training (21.7%), repetitions in reserve (18.9%), until failure (10.8%), and circuit training (2.7%). 'Better Monitoring', 'More Individualized', 'Better Facilities', 'More Staff', and 'More Time' were the main aspects to improve ST. Multiple post-match REC strategies are used, with durations ranging from 0-15 to 16-30 min independently of game location.

May the Force Be with Youth: Foundational Strength for Lifelong Development

ABSTRACT

Today's youth are weaker than previous generations, and measurable reductions in physical fitness are beginning to emerge. Without targeted initiatives that recognize the foundational importance of resistance training, weaker children and adolescents may be more likely to experience the inevitable consequences of neuromuscular dysfunction and less likely to experience the pleiotropic benefits of exercise and sport. Early exposure to strength-building activities is needed to prepare today's youth for ongoing participation in varied physical activities throughout this developmental phase of life. The novel iceberg of physical development is a metaphoric image that illustrates the sequential and cumulative influence of muscular strength on motor skills and physical abilities. Efforts to enhance the physical capacity of youth should include resistive skills that improve basic movement patterns and enhance motoric competence. A shift in our conceptual thinking about youth resistance training is needed to alter the current trajectory toward physical inactivity and related comorbidities.

A Finger in the Game: Sport-Specific Finger Strength Training and Onset of Injury

INTRODUCTION

Strength training has proved to be an effective way to prevent injuries, but the evidence of the impact of strength training on finger injuries is lacking. A fingerboard is a sport-specific tool used by climbers for strength training of fingers. In this study, we searched for associations between fingerboard training and finger injuries in climbers with different lengths of climbing experience and levels of performance.

METHODS

A web-based survey was used to collect information on self-perceived pain or injury in fingers (SPIIF) and regular fingerboard training (RFT). The survey was administered to the Finnish climbing community. Data were analyzed using contingency tables; chi-square was used to evaluate statistical significance.

RESULTS

No significant correlations between SPIIF and RFT were found when analyzing all the participants (n=434) together. In climbers with 6 y or more in the sport, SPIIF was not common and RFT was negatively associated with SPIIF (χ2 [1, n=200]=4.57; P=0.03). In contrast to this, in male climbers who had been climbing for less than 6 y and had advanced to 7a level or higher (French lead/Font bouldering), SPIIF was common and RFT was positively associated with SPIIF (χ2 [1, n=75]=4.61; P=0.03).

CONCLUSIONS

We suggest that doing RFT may prevent SPIIF in climbers with a long background in the sport as fingerboard training can help build stronger fingers and thereby stronger tendons and ligaments. Climbers with fewer years in the sport and less adaptation to the fingers should be cautious with their training loads and RFT to avoid finger injuries and pain.

Is two-point method a valid and reliable method to predict 1RM? A systematic review

This systematic review aimed to evaluate the reliability and validity of the two-point method in predicting 1RM compared to the direct method, as well as analyze the factors influencing its accuracy. A comprehensive search of PubMed, Web of Science, Scopus, and SPORTDiscus databases was conducted. Out of the 88 initially identified studies, 16 were selected for full review, and their outcome measures were analyzed. The findings of this review indicated that the two-point method slightly overestimated 1RM (effect size = 0.203 [95%CI: 0.132, 0.275]; P < 0.001); It showed that test-retest reliability was excellent as long as the test loads were chosen reasonably (Large difference between two test loads). However, the reliability of the two-point method needs to be further verified because only three studies have tested its reliability. Factors such as exercise selection, velocity measurement device, and selection of test loads were found to influence the accuracy of predicting 1RM using the two-point method. Additionally, the choice of velocity variable, 1RM determination method, velocity feedback, and state of fatigue were identified as potential influence factors. These results provide valuable insights for practitioners in resistance training and offer directions for future research on the two-point method.

Force plate methodologies applied to injury profiling and rehabilitation in sport: A scoping review protocol

Musculoskeletal injuries are a common health problem among sporting populations. Such injuries come with a high financial burden to the involved organisations and can have a detrimental impact on the career attainment of injured individuals. Force plates are now a common tool available to sport and exercise science and medicine professionals to enable them to profile injury risk predisposition and modulate the rehabilitation process within sporting environments. This is because contemporary force plate technology is portable and affordable and often comes with software that enables the automatic and immediate feedback of test variables to key stakeholders. However, to our knowledge, to date, there has been no comprehensive review of the scientific literature pertaining to clinical applications of force plate technology. Therefore, this article presents a protocol and a methodological framework to perform a scoping review to identify and map the available scientific literature in which force plates have been applied to the injury profiling and rehabilitation of athletes. The specific aims of the scoping review are 1) to identify and describe the force plate tests, methodologies, and metrics used to screen for injury risk and guide the return of injured athletes to full-time training and competition, 2) to identify potential trends and/or differences by participants' age, sex, and/or level of performance in tests, methodologies, and metrics selected, and 3) to identify key gaps in the existing evidence base and new questions that should be addressed in future research. The global aim of the scoping review is to improve practitioner decision-making around force plate test and variable selection when applied to the injury prevention and rehabilitation of sporting populations.

Running-Related Overuse Injuries and Their Relationship with Run and Resistance Training Characteristics in Adult Recreational Runners: A Cross-Sectional Study

This study aimed to characterize running-related injuries (RRIs), explore their relationship with run and resistance training (RT) parameters, and identify perceived prevention measures among adult recreational runners. An anonymous online survey was designed and distributed via social media and email. Data were analyzed with chi-square, t-test, or analysis of variance (ANOVA), with significance accepted at p ≤ 0.05. Data from 616 participants (76.8% female, age: 42.3 ± 10.5 y) were analyzed. Most runners (84.4%) had an injury history, with 44.6% experiencing one in the past year. The most common RRI sites included the foot/ankle (30.9%) and knee (22.2%). RRI prevalence was higher in those running >19 miles weekly (48.4%, p = 0.05), but there were no differences based on RT participation status. Among those using RT, relatively more RRIs were observed in runners who trained the hip musculature (50.3%, p = 0.005) and did not include the upper body (61.6%, p < 0.001). A disproportionately high RRI prevalence was found for several of the other risk-reduction strategies. RRIs remain a substantial problem, particularly around the ankle/foot and knee. Higher run volume and performance motives were positively associated with RRIs. Most runners incorporated RRI risk-reduction techniques, with over half using RT. The current study did not determine whether preventative strategies were implemented before or after injury; therefore, prospective studies controlling for previous injuries are required to evaluate the effectiveness of RT in preventing future RRIs.

Players', Head Coaches', And Medical Personnels' Knowledge, Understandings and Perceptions of Injuries and Injury Prevention in Elite-Level Women's Football in Ireland

BACKGROUND

To manage injuries effectively, players, head coaches, and medical personnel need to have excellent knowledge, attitudes, and behaviours in relation to the identification of risk factors for injuries, the implementation of injury prevention initiatives, as well as the implementation of effective injury management strategies. Understanding the injury context, whereby specific personal, environmental, and societal factors can influence the implementation of injury prevention initiatives and injury management strategies is critical to player welfare. To date, no qualitative research investigating the context of injuries, has been undertaken in elite-level women's football. The aim of our study was to explore the knowledge, attitudes, and behaviours of players, head coaches, and medical personnel in the Irish Women's National League (WNL) to injury prevention and injury management.

METHODS

We used qualitative research methods to explore the knowledge, attitudes, and behaviours of players, head coaches, and medical personnel in the Irish WNL to injury prevention and injury management. Semi-structured interviews were undertaken with 17 players, 8 medical personnel, and 7 head coaches in the Irish WNL. The data were analysed using thematic analysis. Our study is located within an interpretivist, constructivist research paradigm.

RESULTS

The participants had incomplete knowledge of common injuries in elite-level football, and many held beliefs about risk factors for injuries, such as menstrual cycle stage, which lacked evidence to support them. Jumping and landing exercises were commonly used to reduce the risk of injuries but evidence-based injury prevention exercises and programmes such as the Nordic hamstring curl, Copenhagen adduction exercise, and the FIFA 11+ were rarely mentioned. Overall, there was dissatisfaction amongst players with their medical care and strength and conditioning (S & C) support, with resultant inadequate communication between players, head coaches, and medical personnel.

CONCLUSION

Poor quality and availability of medical care and S & C support were considered to be a major obstacle in the effective implementation of injury risk reduction strategies and successful return-to-sport practices. More original research is required in elite-level women's football to explore injury risk factors, injury prevention initiatives, and contextual return-to-sport strategies, so that players, head coaches, and medical personnel can use evidence that is both up-to-date and specific to their environment.

SARS-CoV-2 Infection Increases the Risk of Muscle Injury in Professional Male Soccer Players-A Retrospective Analysis of the Italian and Spanish Major Leagues

A retrospective cohort study on professional soccer players from the Serie A and LaLiga was conducted to investigate the correlation between SARS-CoV-2 infection and muscle injuries. Players were divided into two groups based on whether they contracted the SARS-CoV-2 infection (C+) or not (C-) during the 2020/2021 season. In the 2019-2020 season, both championships showed a similar number of muscular injuries (MI) between C+ and C- (Serie A: p = 0.194; 95% CI: -0.044 to 0.215, LaLiga p = 0.915; 95% CI: -0.123 to 0.137). In the 2020-2021 season, C+ had a significantly higher number of MI compared to C- in both championships (Serie A: p < 0.05; 95% CI 0.731 to 1.038; LaLiga: p < 0.05; 95% CI: 0.773 to 1.054). Multiple linear regression analysis confirmed that belonging to C+ in the season 2020/2021 was the variable that most strongly influenced the probability of having a muscle injury. Survival analysis revealed a hazard ratio of 3.73 (95% CI 3.018 to 4.628) and of 5.14 (95% CI 3.200 to 8.254) for Serie A and LaLiga respectively. We found an association between SARS-CoV-2 infection and increased risk of muscle injury, emphasizing the importance of carefully considering the infection in the decision-making process for returning to sport. Therefore, SARS-CoV-2 infection should be judged as a real injury requiring specific assessment and training programs.

Mild Hemophilia in a Competitive High School Soccer Player: A Case Report

In this report, we discuss the case of a now 23-year-old athlete who was diagnosed with mild hemophilia, successfully played varsity soccer throughout high school, and continued to play intramural and club soccer while in college. A prophylactic protocol was developed by the athlete's hematologist to allow his safe participation in contact sports. Similar prophylactic protocols have been discussed by Maffet et al that successfully allowed an athlete to participate in high-level basketball. However, significant barriers still exist for an athlete with hemophilia who wants to engage in contact sports. We discussed how athletes with adequate support networks can participate in contact sports. Decisions need to be made on a case-by-case basis and involve the athlete, family, team, and medical personnel.

Stretching and Releasing of Iliotibial Band Complex in Patients with Iliotibial Band Syndrome: A Narrative Review

Iliotibial band syndrome (ITBS) is one of the most common overuse syndromes causing knee pain; it is especially prevalent in runners and also common in cyclists, rowers, and field athletes, with occasional cases occurring in non-athletes too. ITBS symptoms can negatively affect not only knee function, but also mental and physical aspects of health-related quality of life. Although various conservative treatment options have been investigated and discussed, there is still no consensus on a standard of care for ITBS. Moreover, the literature on the etiology and risk factors of ITBS, which could help in selecting appropriate treatment methods, is conflicting and inconclusive. The role of individual treatment modalities such as stretching and releasing techniques has not been extensively studied and remains unclear. In this article, we will critically review the available evidence for the benefits of ITB stretching and "release" methods in the treatment of ITBS. In addition to the direct evidence (clinical studies examining the effects of ITB stretching and other methods that purportedly stretch or "release" the ITB), we present several additional lines of reasoning that discuss the rationale for ITB stretching/releasing in terms of the etiology of ITBS, the mechanical properties and behavior of the ITB, and the risk factors for ITBS development. We conclude that the current literature provides some evidence for the inclusion of stretching or other "release" methods in the early rehabilitation of ITBS. Long-term interventions typically include ITB stretching; however, it remains unclear to what extent stretching within a multimodal treatment actually contributes to resolving the symptoms. At the same time, there is no direct evidence to suggest that stretching and "release" methods have any negative effects.

Training for "Worst-Case" Scenarios in Sidestepping: Unifying Strength and Conditioning and Perception-Action Approaches

Sidesteps can impose high demands on the knee joint and lead to non-contact anterior cruciate ligament (ACL) injuries. Understanding how different constraints shape an athlete's movement strategy and the associated joint demands can help design training interventions to increase injury resilience. Motor capacities, such as muscular strength and power, act as boundaries for the safe execution of perceptual-motor skills and co-determine the emergence of unique movement strategies. Increasing single- and multi-joint strength enables a broader solution space for movement strategies and increases load tolerance. Manipulating task constraints during sidesteps can be used in the training process to systematically expose athletes to increasing demands (on the knee joint or any joint or structure) in preparation for "worst-case" scenarios. In particular, the type and timing of information available influence the preparation time, subsequently affecting the movement strategy and the associated magnitude of external knee joint loading (e.g., knee valgus moment). While an athlete's perceptual-cognitive skills contribute to the preparation time during in situ scenarios, attempts to further improve those skills with the aim of increasing athlete preparation time prior to "worst-case" scenarios are yet to demonstrate conclusive evidence of transfer to on-field situations. Therefore, in the current article, we reflect on the impact of different interacting constraints that influence the execution of sidesteps during in situ scenarios and impose high demands on the knee joint. Subsequently, we discuss how an integrated perspective, drawing on knowledge and perspectives from strength and conditioning and perception-action, may enhance an athlete's ability to withstand "worst-case" scenarios and adapt to perform varied movement executions when sidestepping.

Is it Time to Consider Quaternary Injury Prevention in Sports?

Prevention has traditionally been categorized into three main areas: primary, secondary, and tertiary. In this Current Opinion, we present and discuss the concept of quaternary prevention in sports. Quaternary prevention aims to protect individuals from interventions that likely cause more harm than good, such as overdiagnosis, overtreatment, and overmedication. It includes preventing all types of harm associated with training and clinical interventions. Therefore, any sports injury prevention model or strategy should acknowledge the risks associated with training-related (i.e., overreaching and overuse) and clinical-related (i.e., overdiagnosis, over medicalization, and overtreatment) features. We propose a conceptual framework that integrates quaternary prevention into the contemporary injury prevention models in sports, taking into account that injury prevention is just one branch of the managerial, decision-making, and active hazard control process of risk management that athletes, coaches, and health and performance staff need to deal with. Therefore, we argue that integrating the concept of quaternary prevention into any form of prevention will significantly protect athletes from excessive, inappropriate, and ethically questionable interventions that may likely cause more harm than good.

Healthcare providers have insufficient up-to-date knowledge of lower limb sports injuries, and their knowledge is similar to that of athletes

BACKGROUND

Being up-to-date with evidence-based knowledge of lower limb sports injuries is essential for Healthcare professionals (HCPs).

PURPOSE

To assess whether HCPs possess up-to-date knowledge of lower limb sports injuries by comparing their knowledge to that of athletes.

METHODS

With an expert panel, we developed an online quiz of 10 multiple-choice questions on various topics related to lower-limb sports injuries. Maximal score was 100. We used social media to invite HCPs (5 groups: Physiotherapists, Chiropractors, Medical Doctors, Trainers, and Other therapists) and athletes of all levels (amateur, semi-pro, and pro) to participate. We drafted the questions according to conclusions from the latest systematic reviews and meta-analyses.

RESULTS

1526 participants completed the study. Final quiz scores ranged from zero (n = 28, 1.8%) to 100 (n = 2, 0.1%) and were distributed normally with a mean score of 45.4 ± 20.6. None of the 6 groups' means surpassed the set threshold of 60 points. Multiple linear regressions of covariates indicated that age, gender, engagement in physical activity, learning hours per week, reading scientific journals, reading popular magazines and blogs, trainers, and other therapists' groups explained 19% of the variances (-5.914<β < 15.082, 0.000<p < 0.038).

CONCLUSIONS

HCPs have insufficient up-to-date knowledge of lower limb sports injuries, and their knowledge is similar to that of athletes of all levels. HCPs probably do not possess the proper tools to assess scientific literature Academic and sports medicine societies should look into ways to improve the scientific knowledge integration of HCPs.

Effect of Running-Induced Fatigue on Tibial Acceleration and the Role of Lower Limb Muscle Strength, Power, and Endurance

BACKGROUND

High-impact loads have been linked with running injuries. Fatigue has been proposed to increase impact loads, but this relationship has not been rigorously examined, including the associated role of muscle strength, power, and endurance.

PURPOSE

This study aimed to investigate the effect of fatigue on impact loading in runners and the role of muscle function in mediating changes in impact loading with fatigue.

METHODS

Twenty-eight trained endurance runners performed a fixed-intensity time to exhaustion test at 85% of V̇O 2max . Tibial accelerations were measured using leg-mounted inertial measurement units and sampled every minute until volitional exhaustion. Tests of lower limb muscle strength, power, and endurance included maximal isometric strength (soleus, knee extensors, and knee flexors), single leg hop for distance, and the one leg rise test. Changes in peak tibial acceleration (PTA, g ) were compared between time points throughout the run (0%, 25%, 50%, 75%, and 100%). Associations between the change in PTA and lower limb muscle function tests were assessed (Spearman's rho [ rs ]).

RESULTS

PTA increased over the duration of the fatiguing run. Compared with baseline (0%) (mean ± SD, 9.1 g ± 1.6 g ), there was a significant increase at 75% (9.9 g ± 1.7 g , P = 0.001) and 100% (10.1 g ± 1.8 g , P < 0.001), with no change at 25% (9.6 g ± 1.6 g , P = 0.142) or 50% (9.7 g ± 1.7 g , P = 0.053). Relationships between change in PTA and muscle function tests were weak and not statistically significant ( rs = -0.153 to 0.142, all P > 0.05).

CONCLUSIONS

Peak axial tibial acceleration increased throughout a fixed-intensity run to exhaustion. The change in PTA was not related to performance in lower limb muscle function tests.

Influence of Cluster Sets on Mechanical and Perceptual Variables in Adolescent Athletes

Cluster sets (CS) are effective in maintaining performance and reducing perceived effort compared to traditional sets (TRD). However, little is known about these effects on adolescent athletes. The purpose of this study was to compare the effect of CS on the performance of mechanical and perceptual variables in young athletes. Eleven subjects [4 boys (age = 15.5 ± 0.8 years; body mass = 54.3 ± 7.0 kg; body height = 1.67 ± 0.04 m; Back Squat 1RM/body mass: 1.62 ± 0.19 kg; years from peak height velocity [PHV]: 0.94 ± 0.50) and 7 girls (age = 17.2 ± 1.4 years; body mass = 54.7 ± 6.3 kg; body height = 1.63 ± 0.08 m; Back Squat 1RM/body mass: 1.22 ± 0.16 kg; years from PHV: 3.33 ± 1.00)] participated in a randomized crossover design with one traditional (TRD: 3 × 8, no intra-set and 225 s interest rest) and two clusters (CS1: 3 × 2 × 4, one 30 s intra-set and 180 s inter-set rest; and CS2: 3 × 4 × 2, three 30 s intra-set and 90 s inter-set rest) protocols. The subjects were assessed for a Back Squat 1RM for the first meet, then performed the three protocols on three different days, with at least 48 h between them. During experimental sessions, a back squat exercise was performed, and mean propulsive velocity (MPV), power (MPP), and force (MPF) were collected to analyze performance between protocols, together with measures of countermovement jump (CMJ) and perceptual responses through Rating of Perceived Exertion for each set (RPE-Set) and the overall session (S-RPE), and Muscle Soreness (DOMS). The results showed that velocity and power decline (MVD and MPD) were favorable for CS2 (MVD: -5.61 ± 14.84%; MPD: -5.63 ± 14.91%) against TRD (MVD: -21.10 ± 11.88%; MPD: -20.98 ± 11.85%) (p < 0.01) and CS1 (MVD: -21.44 ± 12.13%; MPD: -21.50 ± 12.20%) (p < 0.05). For RPE-Set, the scores were smaller for CS2 (RPE8: 3.23 ± 0.61; RPE16: 4.32 ± 1.42; RPE24: 4.46 ± 1.51) compared to TRD (RPE8: 4.73 ± 1.33; RPE16: 5.46 ± 1.62; RPE24: 6.23 ± 1.97) (p = 0.008), as well as for Session RPE (CS2: 4.32 ± 1.59; TRD: 5.68 ± 1.75) (p = 0.015). There were no changes for jump height (CMJ: p = 0.985), and the difference between time points in CMJ (ΔCMJ: p = 0.213) and muscle soreness (DOMS: p = 0.437) were identified. Our findings suggest that using CS with a greater number of intra-set rests is more efficient even with the total rest interval equalized, presenting lower decreases in mechanical performance and lower perceptual effort responses.

The effect of specific bioactive collagen peptides on function and muscle remodeling during human resistance training

AIM

Bioactive collagen peptides (CP) have been suggested to augment the functional, structural (size and architecture), and contractile adaptations of skeletal muscle to resistance training (RT), but with limited evidence. This study aimed to determine if CP vs. placebo (PLA) supplementation enhanced the functional and underpinning structural, and contractile adaptations after 15 weeks of lower body RT.

METHODS

Young healthy males were randomized to consume either 15 g of CP (n = 19) or PLA (n = 20) once every day during a standardized program of progressive knee extensor, knee flexor, and hip extensor RT 3 times/wk. Measurements pre- and post-RT included: knee extensor and flexor isometric strength; quadriceps, hamstrings, and gluteus maximus volume with MRI; evoked twitch contractions, 1RM lifting strength, and architecture (with ultrasound) of the quadriceps.

RESULTS

Percentage changes in maximum strength (isometric or 1RM) did not differ between-groups (0.684 ≤ p ≤ 0.929). Increases in muscle volume were greater (quadriceps 15.2% vs. 10.3%; vastus medialis (VM) 15.6% vs. 9.7%; total muscle volume 15.7% vs. 11.4%; [all] p ≤ 0.032) or tended to be greater (hamstring 16.5% vs. 12.8%; gluteus maximus 16.6% vs. 12.9%; 0.089 ≤ p ≤ 0.091) for CP vs. PLA. There were also greater increases in twitch peak torque (22.3% vs. 12.3%; p = 0.038) and angle of pennation of the VM (16.8% vs. 5.8%, p = 0.046), but not other muscles, for CP vs. PLA.

CONCLUSIONS

CP supplementation produced a cluster of consistent effects indicating greater skeletal muscle remodeling with RT compared to PLA. Notably, CP supplementation amplified the quadriceps and total muscle volume increases induced by RT.

The Acute and Chronic Effects of Implementing Velocity Loss Thresholds During Resistance Training: A Systematic Review, Meta-Analysis, and Critical Evaluation of the Literature

BACKGROUND

Velocity loss (VL) experienced in a set during resistance training is often monitored to control training volume and quantify acute fatigue responses. Accordingly, various VL thresholds are used to prescribe resistance training and target different training adaptations. However, there are inconsistencies in the current body of evidence regarding the magnitude of the acute and chronic responses to the amount of VL experienced during resistance training.

OBJECTIVE

The aim of this systematic review was to (1) evaluate the acute training volume, neuromuscular, metabolic, and perceptual responses to the amount of VL experienced during resistance training; (2) synthesize the available evidence on the chronic effects of different VL thresholds on training adaptations; and (3) provide an overview of the factors that might differentially influence the magnitude of specific acute and chronic responses to VL during resistance training.

METHODS

This review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five databases were searched, and studies were included if they were written in English, prescribed resistance training using VL, and evaluated at least one (1) acute training volume, neuromuscular, metabolic, or perceptual response or (2) training adaptation. Risk of bias was assessed using a modified Cochrane Collaboration's tool for assessing the risk of bias in randomized trials. Multilevel and multivariate meta-regressions were performed where possible.

RESULTS

Eighteen acute and 19 longitudinal studies met the inclusion criteria, of which only one had more than one risk of bias item assessed as high risk. Based on the included acute studies, it seems that the number of repetitions per set, blood lactate concentration, and rating of perceived exertion generally increase, while countermovement jump height, running sprint times, and velocity against fixed loads generally decrease as VL increases. However, the magnitude of these effects seems to be influenced, among other factors, by the exercise and load used. Regarding training adaptations, VL experienced during resistance training did not influence muscle strength and endurance gains. Increases in VL were associated with increases in hypertrophy (b = 0.006; 95% confidence interval [CI] 0.001, 0.012), but negatively affected countermovement jump (b = - 0.040; 95% CI - 0.079, - 0.001), sprint (b = 0.001; 95% CI 0.001, 0.002), and velocity against submaximal load performance (b = - 0.018; 95% CI - 0.029, - 0.006).

CONCLUSIONS

A graded relationship exists between VL experienced during a set and acute training volume, neuromuscular, metabolic, and perceptual responses to resistance training. However, choice of exercise, load, and individual trainee characteristics (e.g., training history) seem to modulate these relationships. The choice of VL threshold does not seem to affect strength and muscle endurance gains whereas higher VL thresholds are superior for enhancing hypertrophy, and lower VL thresholds are superior for jumping, sprinting, and velocity against submaximal loads performance.

CLINICAL TRIAL REGISTRATION

The original protocol was prospectively registered ( https://osf.io/q4acs/ ) with the Open Science Framework.

Context of injury prevention strategies in Swiss basketball: survey of athletes, medical staff and coaches

Objectives

This project aims to assess opinions, attitudes, knowledge, beliefs, practices and perceived barriers and facilitators of injury prevention (IP) strategies in Swiss basketball teams.

Methods

An online survey was sent to athletes, coaches and medical staff of the three best basketball leagues in Switzerland. The survey was subdivided in four sections: (1) characteristic of participants, (2) knowledge, opinions, attitudes and beliefs, (3) practices and (4) barriers and facilitators.

Results

Among 105 persons (n=45 female, n=60 male) who answered the survey, more than 60% (n=68) considered the risk of injury for basketball athletes as being high to very high. The ankle, knee and the hand were considered as being the most at risk. More than 80% of participants considered that recovery, training load and the warm-up quality were very important factors for IP. More than 90% of participants considered IP as either important or very important with 53 (50.5%) of the participants indicating using exercise-based IP in their clubs. Athletes and coaches' motivation and compliance were judged as either important or very important for successful IP implementation by more than 80% of participants, with the coach being reported as the most influential person. Environmental barriers towards human or infrastructural resources were also reported as factors influencing IP strategies, namely by female participants.

Conclusion

Good knowledge and positive attitude towards IP were reported by participants, but exercise-based IP strategies lack implementation. The coach was considered as the most influential person and was reported with the athletes as playing an important role towards successful implementation.

Relationship of Training Factors and Resilience with Injuries in Ski Mountaineers

Ski mountaineering is an increasingly popular sport with a relatively high risk of injury. Therefore, several studies have analyzed factors related to the likelihood of injury, including athlete characteristics, training, resilience and equipment. Thus, the aim of this study was to identify factors that may influence injury risk. A 15-minute online survey was sent to various ski mountaineering groups of different ages and levels. Both the Mann-Whitney U test and odds ratio analysis were performed in order to analyze the data. Results from 104 skiers showed that most injuries occurred in the lower extremities, especially in the knee (29.6%). The findings indicated that skiers who had suffered an injury performed in more competitions per year (p = 0.046), more ski mountaineering sessions per week (p = 0.022) and fewer core training sessions per week (0.029), although core training and competition were not statistically significant factors. Likewise, non-injured athletes had fewer pairs of skis (p = 0.019), which were also wider (p = 0.04). However, no difference was found for warm up and resilience between both groups (p = 0.275). In conclusion, it is important to implement preventive measures based on these factors, even if more research is needed.

Observed Injury Rates Did Not Follow Theoretically Predicted Injury Risk Patterns in Professional Human Circus Artists

OBJECTIVE

Identifying which types of athletes have increased injury risk (ie, predictive risk factors) should help develop cost-effective selective injury prevention strategies. Our objective was to compare a theoretical injury risk classification system developed by coaches and rehabilitation therapists, with observed injury rates in human circus acts across dimensions of physical stressors, acrobatic complexity, qualifications, and residual risks.

DESIGN

Descriptive epidemiological study.

SETTING

professional circus company.

PATIENTS OR OTHER PARTICIPANTS

Human circus artists performing in routine roles between 2007 and 2017.

ASSESSMENT OF RISK FACTORS

Characteristics of circus acts categorized according to 4 different dimensions.

MAIN OUTCOME MEASURES

Medical attention injury rates (injury requiring a visit to the therapist), time-loss injury rates (TL-1; injury resulting in at least one missed performance), and time-loss 15 injury rates (TL-15; injury resulting in at least 15 missed performances).

RESULTS

Among 962 artists with 1 373 572 performances, 89.4% (860/962) incurred at least one medical attention injury, 74.2% (714/962) incurred at least one TL-1 injury, and 50.8% (489/962) incurred at least one TL-15 injury. There were important inconsistencies between theoretical and observed injury risk patterns in each of the 4 dimensions for all injury definitions (medical attention, TL-1, and TL-15).

CONCLUSIONS

Although theoretical classifications are the only option when no data are available, observed risk patterns based on injury surveillance programs can help identify artists who have a high (or low) theoretical risk but are nonetheless actually at low (or high) risk of injury, given their current roles. This will help develop more cost-effective selective injury prevention programs.