Sports Medicine最新文献

{"title":"Iron Status, Muscle Oxygenation and Performance in Female Athletes During Repeated-Sprint Training in Hypoxia","authors":"Michelle Stein, Peter Peeling, Olivier Girard","doi":"10.1007/s40279-025-02371-7","DOIUrl":"https://doi.org/10.1007/s40279-025-02371-7","url":null,"abstract":"","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"2 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145717894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Running from Death: Can Fitness Outpace Alcohol's Harm? Changes in Alcohol Intake, Fitness and All-Cause Mortality in the HUNT Study, Norway.","authors":"Javaid Nauman,Emma M L Ingeström,Atefe R Tari,Ulrik Wisløff","doi":"10.1007/s40279-025-02360-w","DOIUrl":"https://doi.org/10.1007/s40279-025-02360-w","url":null,"abstract":"BACKGROUNDThere is no safe lower limit for alcohol intake, and even small amounts increase the risk of premature mortality. It is not known whether a change in cardiorespiratory fitness can modify the association between a change in alcohol intake and mortality.METHODSWe analysed data of the healthy adults from the second (HUNT2; 1995-7) and third (HUNT3; 2006-8) surveys of the population-based Trøndelag Health Study, Norway. Alcohol intake at HUNT2 and HUNT3 was divided into three groups: abstainers, within recommendations (≤ 140 g/week for men, ≤ 70 g/week for women) or above recommendations (> 140 g/week for men, > 70 g/week for women). Using a validated non-exercise prediction equation, we classified participants into two sex- and age-specific fitness groups (unfit: 20% least fit; fit: 80% most fit) at both HUNT2 and HUNT3. Using multi-variable-adjusted Cox analyses, adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were estimated for an association between all-cause mortality and a change in alcohol and fitness status.RESULTSA total of 24,853 healthy adults (mean [standard deviation] age, 54.7 [12] years; 54.1% women) were included. Over a median follow-up of 16.6 (interquartile range, 16.2-17.1) years, 3921 participants died. Increased alcohol intake from HUNT2 to HUNT3 was associated with an increased risk of mortality. Alcohol abstainers who reported to drink within the recommendations 10 years later (aHR, 1.20; 95% CI 1.00-1.44), and drinkers who increased their intake from within the recommendations at HUNT2 to above at HUNT3 (aHR, 1.25; 95% CI 0.99-1.57) had an increased risk of mortality, compared with the persistent abstainers. Participants drinking within the recommendations at HUNT2 but abstained from drinking at HUNT3 were not at a higher risk of mortality (aHR, 1.14; 95% CI 0.80-1.62). A change in fitness modified the relationship between alcohol intake and all-cause mortality (P = 0.03), and participants who remained unfit had higher mortality risks. Compared with the reference group who abstained from alcohol and remained fit from HUNT2 to HUNT3, those who remained unfit and persistently abstained, started drinking or consistently drank alcohol within the recommended limits had aHRs of 1.65 (95% CI 1.19-2.30), 1.46 (95% CI 1.04-2.06) and 1.68 (95% CI 1.36-2.08), respectively. For participants who remained fit, the mortality risk associated with changes in alcohol intake was not higher than for the reference group, except for those who started drinking [aHR, 1.32 (195% CI 04-1.68)]. Compared with peers remaining fit, decreasing fitness increased the mortality risk among persistent abstainers and consistent drinkers.CONCLUSIONSIncreased alcohol intake over the years was associated with an increased risk of mortality. A change in cardiorespiratory fitness was a better predictor of mortality, and maintaining fitness above the lowest 20% for one's age and sex attenuated the association between a change in alcohol inta","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"7 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145710798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of an Overload Period on Heart Rate Variability, Sleep Quality, Motivation, and Performance in High-level Swimmers: Use of Explainable Artificial Intelligence (XAI) to Assess Training Load Variations.","authors":"Diogo D Carvalho,Márcio Fagundes Goethel,Mégane Erblang,João Paulo Vilas-Boas,David B Pyne,Ricardo J Fernandes,Philippe Lopes","doi":"10.1007/s40279-025-02369-1","DOIUrl":"https://doi.org/10.1007/s40279-025-02369-1","url":null,"abstract":"BACKGROUNDUnderstanding the impact of training sessions on physiological, psychological, and immunological responses is crucial for adequate training periodization and preventing negative influences on health, training, and performance.OBJECTIVESTo characterize the responses of heart rate variability (HRV), sleep time and quality, motivation, dry-land strength, and swimming performance to an overload period of three consecutive 7-day cycles (cycles 1, 2, and 3) with different training intensity and volume dynamics. Secondly, to test the capability of HRV to assess daily variation in training loads on the basis of explainable artificial intelligence (XAI) models.METHODSA total of 14 high-level swimmers (4 males and 10 females, aged 17.5 ± 1.5 years) were monitored via an orthostatic test, Hooper index, sleep questionnaires, and rating of perceived exertion (RPE) of each training session. The self-reported and prescribed training loads were compared. At the beginning of each cycle and at the end of cycle 3, swimmers completed anthropometric testing, countermovement jumps, hand-grip strength tests, and a 5 × 200 m incremental protocol.RESULTSHigh-level swimmers accurately perceived their daily training loads. However, differences between the training and RPE loads emerged on weekends, indicating that physiological and psychological loads have different influences and should be considered simultaneously when characterizing training loads. The overload period was characterized by an increase in both training (27%) and RPE (20%) loads without eliciting a negative effect on sleep quantity and quality. During the overload period, supine (F2.18 = 3.448, η2 = 0.28; p = 0.05) and standing (F2.18 = 3.809, η2 = 0.30; p = 0.04) mean heart rate (HR) increased and supine log root mean square of the successive differences (LnRMSSD; F2.18 = 4.379, η2 = 0.33; p = 0.028) and maximal blood lactate (F3.27 = 3.441, η2 = 0.28; p = 0.03) decreased during and after cycle 3 (respectively). Dry-land and swimming performances were maintained, indicating that the autonomic nervous system appears to be more sensitive (XAI models r2 = 0.91 and 0.9) to changes in acute/short-term training load.CONCLUSIONSHRV indices, particularly supine RMSSD and mean HR, were the most sensitive markers of training load variation, while sleep, strength and power, and swimming performance remained stable. HRV can be employed as a practical tool for monitoring training responses and managing training loads in competitive swimmers.","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"33 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nutrition for Tactical Athletes: Insights, Applications and Research Gaps.","authors":"Jamie Ching Ting Lye,Jason Kai Wei Lee","doi":"10.1007/s40279-025-02363-7","DOIUrl":"https://doi.org/10.1007/s40279-025-02363-7","url":null,"abstract":"Tactical athletes, including military personnel, firefighters and rescue responders, operate in unpredictable and extreme environments that impose high physical and cognitive demands with life-and-death stakes. Tactical operations demonstrate metabolic demands akin to elite sports. Unlike sports competitions, tactical operations often involve prolonged exertion, limited food/water, disrupted recovery windows and circadian rhythms. This review draws on sports nutrition research to adapt evidence-based strategies for tactical athletes, highlighting key overlaps and distinctions. First, achieving adequate optimal energy availability in tactical athletes is challenging because of unpredictable demands, which makes it important to leverage training sessions to optimise nutrition strategies and energy availability. Second, when operational timelines are predictable, sport nutrient timing principles can be applied. However, under tight operational timelines, tactical athletes should aim for 1-4 g·kg-1 body mass of portable, easily digested carbohydrates with fluids in the 1-4 h before deployment, guided by practicality, logistics and individual gastrointestinal tolerance. When operations are expected to involve moderate-to-high intensity activity within the first 2 h, lower fibre, lower fat and rapidly digestible carbohydrate forms (e.g. gels, sports drinks or soft bars) may be preferred to minimise gastrointestinal discomfort. In such situations, aggressive recovery and rehydration post-operation should also be prioritised. Under high environmental heat, high carbohydrate (≥ 7 g·kg-1 BM) and low-FODMAP (Fermentable Oligo-, Di-, Monosaccharides and Polyols) intakes may mitigate heat-induced physiological changes, which include increased carbohydrate oxidation and appetite suppression. Last, evidence for creatine, nitrate, beta-alanine and bicarbonate in tactical athletes closely reflects findings in sport populations. The use of caffeine, however, requires more careful consideration as it may disrupt sleep.","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"159 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inertial Head Accelerations in Front-On, One-on-One Tackles in Professional Women Rugby League Players.","authors":"Georgia Page,Andrew J Gardner,Suzanne J Snodgrass,Ken Quarrie,Timana Tahu,Oscar Stelzer-Hiller,Suzi Edwards","doi":"10.1007/s40279-025-02355-7","DOIUrl":"https://doi.org/10.1007/s40279-025-02355-7","url":null,"abstract":"BACKGROUNDRugby league tackles are a primary mechanism for head injuries, yet there is limited evidence on tackle-specific head kinematics in professional women's rugby league players.OBJECTIVESWe aimed to identify factors that predict the ball carrier and the tackler inertial head kinematics in professional women rugby league players during self-selected, front-on, one-on-one tackles.METHODSNineteen professional women's rugby league players had their inertial head kinematics and the instantaneous resultant speed measured by a three-dimensional optoelectronic motion capture system during front-on, one-on-one tackles. Players were instructed to perform their own self-selected tackles over (i.e. 'smother' tackle) and under the ball (i.e. 'dominant' tackle) that they would use in-game. A generalised linear mixed model using a backward elimination method was used to predict peak inertial head kinematics.RESULTSPeak resultant linear (g) and angular (deg/s2) head accelerations in both the tackler and ball carrier were significantly predicted by tackle type (smother vs dominant; p ≤ 0.02) and a faster speed of the tackler (p ≤ 0.02). Higher resultant peak acceleration was predicted when the tackler's head contacted the ball carrier's body (p < 0.001) and was significantly correlated if the ball carrier showed whiplash-like mechanics after contact (p < 0.01).CONCLUSIONSTacklers should ensure their head alignment is positioned outside of the ball carrier's body to avoid direct body contact to reduce their risk of high inertial head kinematics. When coaches observe signs of whiplash-like mechanics, in a ball carrier during a tackle, they can use this visual cue to identify and then coach athletes how to brace better for impact. Caution is advised when considering a simplistic approach such as reducing tackle height to mitigate peak resultant head accelerations, as this strategy may reduce the impact on the ball carrier but increase the impact on the tackler.","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"128 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145664106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoregulation and Hydration Dynamics in a 160-km Ultra-Endurance Race in a Tropical Environment: A Field Study on 80 Runners.","authors":"Nicolas Bouscaren,Laetitia Berly,Guillaume Descombes,Babacar Tounkara,Eric Lacroix,Bruno Lemarchand,Sébastien Racinais,Guillaume Y Millet","doi":"10.1007/s40279-025-02356-6","DOIUrl":"https://doi.org/10.1007/s40279-025-02356-6","url":null,"abstract":"PURPOSEThis study investigated thermoregulation and hydration dynamics in 80 runners (33 women, 41.3%; 47 men, 58.7%) during a 160-km ultra-endurance race with 9400 m of elevation gain in a tropical environment, where ambient temperatures ranged from 10.2 °C to 28.3 °C and relative humidity varied between 35 and 100%.METHODSCore temperature (Tcore; measured via ingestible telemetric capsules), body mass, fluid intake, and environmental conditions were recorded at key checkpoints. A linear mixed-effects model was used.RESULTSMean Tcore was 37.9 ± 0.3°C (range 36.9-38.8 °C), with a peak of 38.9 ± 0.3 °C (range 38.1-39.96 °C). Faster runners exhibited higher Tcore (r = -0.31, p = 0.024). While mean Tcore was 37.9 ± 0.3 °C in male and 37.8 ± 0.3 °C in female, with peak values of 39.0 ± 0.4 °C and 38.7 ± 0.2 °C, respectively (p < 0.05), sex was not a significant predictor in multivariate analysis. Mean body mass loss was - 4.8%, with 31% of runners losing > 6%, yet showed no correlation with Tcore or performance. Key predictors of Tcore were body mass index (BMI), age, speed, air temperature, humidity, radiation, race cumulative distance, and elevation changes (all p < 0.05).CONCLUSIONSUltra-endurance runners maintained core temperatures < 40 °C despite significant body mass losses. These findings suggest that substantial body mass change may be a normal physiological adaptation during ultra-endurance running rather than a performance-limiting factor or a risk for hyperthermia. The study highlights the multifactorial nature of thermoregulation in ultra-endurance events and supports the need for individualized hydration strategies based on field data from prolonged, real-world conditions. The study was registered on ClinicalTrials.gov (NCT05098925).","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"30 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145664105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tailored Exercise Prescription for People with COPD and Clinically Relevant Comorbidities: A Consensus Statement of the EXPERT Working Group and Experts in Pulmonary Rehabilitation.","authors":"Felipe V C Machado,Karin Coninx,Daniel Neunhaeuserer,Cajsa Tonoli,Josef Niebauer,Massimo Piepoli,Roberto Pedretti,Evangelia Kouidi,Marco Ambrosetti,Paul Dendale,Birna Bjarnason-Wehrens,Paul Beckers,Véronique Cornelissen,Olga Barna,Patrick Doherty,Bernhard Rauch,Frank Edelmann,Bernhard Schwaab,Tim Takken,Rona Reibis,Constantinos H Davos,Esteban Garcia-Porrero,Fabio Pitta,Nidia A Hernandes,Michael K Stickland,Elena Gimeno-Santos,Jana De Brandt,Andre Nyberg,Ana Machado,Alda Marques,Chris Burtin,Rainer Gloeckl,Ioannis Vogiatzis,Bruno Balbi,Dennis Jensen,William D-C Man,Carolyn L Rochester,Sally J Singh,Frits M E Franssen,Martijn A Spruit,Dominique Hansen","doi":"10.1007/s40279-025-02353-9","DOIUrl":"https://doi.org/10.1007/s40279-025-02353-9","url":null,"abstract":"Chronic obstructive pulmonary disease (COPD) is a heterogeneous chronic lung condition often accompanied by comorbidities and systemic manifestations that affect the person's clinical condition and prognosis and often require specific treatment. Therefore, the management of COPD extends beyond treatment for the lungs per se. Pulmonary rehabilitation (PR) should be considered as part of person-centered management, and supervised exercise training is a core component of this intervention. PR exercise training parameters (e.g., frequency, intensity, time, and type) should be individualized to maximize each individual's functional gains while targeting systemic manifestations and comorbidities. This manuscript presents evidence-based tailored recommendations for optimizing exercise interventions for people with COPD and comorbidities that significantly affect prognosis (e.g., mortality, hospitalizations) including cardiovascular disease (CVD) (e.g., chronic coronary syndrome, heart failure), CVD risk factors (e.g., type 2 diabetes mellitus [T2DM], hypertension), and sarcopenia. To achieve these goals, existing guidelines and evidence for exercise training in COPD, CVD, CVD risk factors, and sarcopenia have been reviewed to identify synergies between PR and cardiac rehabilitation, as well as the treatment of T2DM and sarcopenia. In addition, we provided clinical cases to illustrate how PR can be adapted to accommodate specific comorbidities. These examples offer practical guidance for tailoring exercise prescriptions within PR programs to address the unique needs of people with COPD and clinically relevant comorbidities, thereby enhancing overall treatment effectiveness and optimizing health outcomes.","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"28 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145664104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Narrative Review of the High-Carbohydrate Fueling Revolution (≥ 100 g/h) in the Professional Peloton.","authors":"Patrick B Wilson","doi":"10.1007/s40279-025-02372-6","DOIUrl":"https://doi.org/10.1007/s40279-025-02372-6","url":null,"abstract":"High-carbohydrate fueling in cycling (defined as ≥ 100 g/h for this paper) has received significant media attention in recent years. Whether this practice improves performance, however, remains an unresolved issue in the scientific literature. The purpose of this narrative review is to provide an up-to-date analysis of the practice of high-carbohydrate fueling, with a specific focus on potential performance implications in professional cycling. Topics covered include historical carbohydrate intake guidelines, research directly comparing high-carbohydrate fueling with traditional fueling guidelines, theorized benefits of high-carbohydrate fueling specific to cycling, potential risks associated with high-carbohydrate fueling, and personalizing carbohydrate intakes. Among a small number of experimental studies that have compared high-carbohydrate fueling with somewhat lower rates (e.g., 60-90 g/h), there is not clear evidence that it reduces reliance on endogenous carbohydrate stores or improves performance. However, these studies have not closely mimicked the demands of multi-day and multi-week stage races, when ingesting carbohydrate at ≥ 100 g/h may be more likely to produce performance benefits. Observational data from professional cyclists suggest that carbohydrate consumption during racing is strongly associated with total daily carbohydrate intakes; therefore, ingesting carbohydrate at ≥ 100 g/h on the bike could facilitate performance over multiple days or weeks by enhancing glycogen resynthesis and recovery. In addition, circumstantial evidence suggests that high-carbohydrate fueling could reduce low energy availability, reduce within-day energy deficits, and stimulate the central nervous system. Personalizing carbohydrate intakes through individual assessments of exogenous carbohydrate oxidation is a novel strategy that should be further explored in the future.","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"29 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145663942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Resistance Training Dose Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength Gains.","authors":"Joshua C Pelland,Jacob F Remmert,Zac P Robinson,Seth R Hinson,Michael C Zourdos","doi":"10.1007/s40279-025-02344-w","DOIUrl":"https://doi.org/10.1007/s40279-025-02344-w","url":null,"abstract":"BACKGROUNDWeekly set volume and frequency are used to manipulate resistance training dosage. Previous research has identified higher weekly set volume as enhancing muscle hypertrophy and strength gains, but the nature of the dose-response relationship still needs to be investigated. Mixed evidence exists regarding the effects of higher weekly frequency.OBJECTIVEWe aimed to explore the dose-response relationships between key resistance training dosage variables (weekly set volume and frequency) and strength and hypertrophy.METHODSBefore meta-analyzing the volume and frequency research, all contributing resistance training sets were classified as direct or indirect, depending on their specificity to the hypertrophy/strength measurement. Then, weekly set volume/frequency for indirect sets was quantified as 1 for 'total,' 0.5 for 'fractional,' and 0 for 'direct.' A series of multi-level meta-regressions were performed for muscle hypertrophy and strength, utilizing 67 total studies of 2058 participants (79.1% male, 20.9% female; average age 25.16 ± 5.22 years). All models were adjusted for the duration of the intervention and training status.RESULTSThe relative evidence for the 'fractional' quantification method was strongest; therefore, this quantification method was used for the primary meta-regression models. The posterior probability of the marginal slope exceeding zero for the effect of volume on both hypertrophy and strength was 100%, indicating that gains in muscle size and strength increase as volume increases. However, both best-fit models suggest diminishing returns, with the diminishing returns for strength being considerably more pronounced. The posterior probability of the marginal slope exceeding zero for frequency's effect on hypertrophy was less than 100%, indicating compatibility with negligible effects. In contrast, the posterior probability for strength was 100%, suggesting strength gains increase with increasing frequency, albeit with diminishing returns.CONCLUSIONSDistinguishing between direct and indirect sets appears essential for predicting adaptations to a given resistance training protocol, such as using the 'fractional' quantification method. This method's dose-response models revealed that volume and frequency have unique dose-response relationships with each hypertrophy and strength gains. The dose-response relationship between volume and hypertrophy appears to differ from that with strength, with the latter exhibiting more pronounced diminishing returns. The dose-response relationship between frequency and hypertrophy appears to differ from that with strength, as only the latter exhibits consistently identifiable effects.","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"157 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145664107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Contact Conundrum: Are We Introducing Contact at the Correct Time in Youth Sports?","authors":"Stephen W West,Sharief Hendricks,Sean P Cumming,Kathryn Dane,Siobhán O'Connor,Ben Jones,Brooke Patterson,Ash T Kolstad,Steven Broglio,Carolyn A Emery,Carly D McKay","doi":"10.1007/s40279-025-02348-6","DOIUrl":"https://doi.org/10.1007/s40279-025-02348-6","url":null,"abstract":"Participation in sport offers numerous physiological, psychological, and social benefits, yet injury remains an inherent risk, particularly in collision-based sports. Increasing scrutiny surrounds these sports, especially for youth, with inconsistency in the age for introducing deliberate contact (e.g., body checking, tackle) and debate regarding proposals for banning high-risk actions to reduce injuries. This article explores the policies and controversies regarding how, and when, physical contact is introduced in sports. Current policies vary significantly across sports, sexes, and national jurisdictions, leading to inconsistent implementation and outcomes. We outline arguments for both delaying and lowering the contact introduction age, including implications for participation rates, skill acquisition, and injury risk. Raising the age may reduce injury history and cumulative head impacts, while earlier, progressive contact training may enhance technical competence. Growth, maturation and size discrepancies further complicate such policy decisions. Evidence supports multimodal approaches, including training guidelines (e.g., reduced contact in practices), neuromuscular training, and rule modifications, to enhance safety without compromising play. Weight-based categorisation and bio-banding (grouping players by attributes associated with growth and/or maturation instead of chronological age) strategies show potential for injury-risk reduction but lack comprehensive evaluation. Despite polarised opinions, developing sport-specific recommendations on best practices for contact introduction remains critical to ensuring athlete welfare and sustainable participation in collision sports.","PeriodicalId":21969,"journal":{"name":"Sports Medicine","volume":"35 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}