SPORTS MEDICINE

Response to Comment on "Premature Death in Bodybuilders: What Do We Know?"
Smoliga JM, Wilber ZT and Robinson BT
The Training Intensity Distribution of Marathon Runners Across Performance Levels
Muniz-Pumares D, Hunter B, Meyler S, Maunder E and Smyth B
The training characteristics and training intensity distribution (TID) of elite athletes have been extensively studied, but a comprehensive analysis of the TID across runners from different performance levels is lacking.
Low Energy Availability and Relative Energy Deficiency in Sport: A Systematic Review and Meta-analysis
Gallant TL, Ong LF, Wong L, Sparks M, Wilson E, Puglisi JL and Gerriets VA
Low energy availability (LEA) occurs when energy expenditure from athletic training and bodily functions exceeds caloric intake. This imbalance results in declines in athletic performance and increases the risk of injury. Relative energy deficiency in sport (REDs) is a condition that occurs when the energy deficit is severe enough to cause alterations to metabolic rate, menstrual function, immune function, bone health, protein synthesis, and cardiovascular function. Many athletes, particularly those competing in endurance, aesthetic, or weight-class sports, are adversely impacted by this condition.
A Novel Method to Predict Carbohydrate and Energy Expenditure During Endurance Exercise Using Measures of Training Load
Rothschild JA, Hofmeyr S, McLaren SJ and Maunder E
Sports nutrition guidelines recommend carbohydrate (CHO) intake be individualized to the athlete and modulated according to changes in training load. However, there are limited methods to assess CHO utilization during training sessions.
Professional Male Soccer Players' Perspectives of the Nutrition Culture Within an English Premier League Football Club: A Qualitative Exploration Using Bourdieu's Concepts of Habitus, Capital and Field
Foo WL, Tester E, Close GL, Cronin CJ and Morton JP
Professional soccer players' self-reported dietary intakes often do not meet recommended sport nutrition guidelines. Although behaviour change models have previously explored barriers and enablers to nutritional adherence, the cultural factors influencing players' nutritional habits also warrant investigation. Accordingly, we aimed to explore players' perceptions of the nutrition culture within the professional soccer environment.
DyNamic Interactive Anticipation-Time for a Paradigmatic Shift
Cañal-Bruland R and Mann DL
Everyday human interactions require observers to anticipate the actions of others (e.g., when walking past another in a corridor or choosing where to hit a ground stroke in tennis). Yet, experimental paradigms that aim to examine anticipation continue to use simplistic designs that are not interactive and therefore fail to account for the real-life, social nature of these interactions. Here we propose a fundamental, paradigmatic shift toward a "dynamic interactive anticipation" paradigm that models real-life interactions. We propose that it will change the way behavioral experimentalists study anticipation and spark theory development by unravelling the mechanisms underlying anticipation in real-time interactions.
From Tissue to System: What Constitutes an Appropriate Response to Loading?
Gabbett TJ and Oetter E
Optimal loading involves the prescription of an exercise stimulus that promotes positive tissue adaptation, restoring function in patients undergoing rehabilitation and improving performance in healthy athletes. Implicit in optimal loading is the need to monitor the response to load, but what constitutes a normal response to loading? And does it differ among tissues (e.g., muscle, tendon, bone, cartilage) and systems? In this paper, we discuss the "normal" tissue response to loading schema and demonstrate the complex interaction among training intensity, volume, and frequency, as well as the impact of these training variables on the recovery of specific tissues and systems. Although the response to training stress follows a predictable time course, the recovery of individual tissues to training load (defined herein as the readiness to receive a similar training stimulus without deleterious local and/or systemic effects) varies markedly, with as little as 30 min (e.g., cartilage reformation after walking and running) or 72 h or longer (e.g., eccentric exercise-induced muscle damage) required between loading sessions of similar magnitude. Hyperhydrated and reactive tendons that have undergone high stretch-shorten cycle activity benefit from a 48-h refractory period before receiving a similar training dose. In contrast, bone cells desensitize quickly to repetitive loading, with almost all mechanosensitivity lost after as few as 20 loading cycles. To optimize loading, an additional dose (≤ 60 loading cycles) of bone-centric exercise (e.g., plyometrics) can be performed following a 4-8 h refractory period. Low-stress (i.e., predominantly aerobic) activity can be repeated following a short (≤ 24 h) refractory period, while greater recovery is needed (≥ 72 h) between repeated doses of high stress (i.e., predominantly anaerobic) activity. The response of specific tissues and systems to training load is complex; at any time, it is possible that practitioners may be optimally loading one tissue or system while suboptimally loading another. The consideration of recovery timeframes of different tissues and systems allows practitioners to determine the "normal" response to load. Importantly, we encourage practitioners to interpret training within an athlete monitoring framework that considers external and internal load, athlete-reported responses, and objective markers, to contextualize load-response data.
Optimising the Dose of Static Stretching to Improve Flexibility: A Systematic Review, Meta-analysis and Multivariate Meta-regression
Ingram LA, Tomkinson GR, d'Unienville NMA, Gower B, Gleadhill S, Boyle T and Bennett H
Static stretching is widely used to increase flexibility. However, there is no consensus regarding the optimal dosage parameters for increasing flexibility.
The Relationship Between Length and Active Force for Submaximal Skeletal Muscle Contractions: a Review
Zimmermann HB, Macintosh BR and Pupo JD
The force-length relationship is usually obtained for isometric contractions with maximal activation, but less is known about how sarcomere length affects force during submaximal activation. During submaximal activation, length-dependent alterations in calcium sensitivity, owing to changes in cross-bridge kinetics (rate of attachment and/or detachment), result in an activation-dependent shift in optimal length to longer sarcomere lengths. It is known that sarcomere length, as well as temperature and phosphorylation of the regulatory light chains of myosin, can modify Ca⁺ sensitivity by altering the probability of cross-bridge interaction. This altered calcium sensitivity is particularly important for submaximal force levels, as it can change the shape of the length dependence of force, with peak force occurring at sarcomere lengths longer than those associated with maximal filament overlap. In athletic contexts, contractions typically do not reach maximal intensity. Therefore, understanding that the ability to produce force under both maximal and submaximal conditions can differ, and that peak force can be generated at different lengths, could influence the development of targeted training regimens optimal for each sport.
Head Kinematics Associated with Off-Field Head Injury Assessment (HIA1) Events in a Season of English Elite-Level Club Men's and Women's Rugby Union Matches
Allan D, Tooby J, Starling L, Tucker R, Falvey É, Salmon D, Brown J, Hudson S, Stokes K, Jones B, Kemp S, O'Halloran P, Cross M, Bussey M and Tierney G
The purpose of this study was to investigate head kinematic variables in elite men's and women's rugby union and their ability to predict player removal for an off-field (HIA1) head injury assessment.
Associations Between Instrumented Mouthguard-Measured Head Acceleration Events and Post-Match Biomarkers of Astroglial and Axonal Injury in Male Amateur Australian Football Players
Evans LJ, O'Brien WT, Spitz G, Mutimer S, Xie B, Giesler LP, Major BP, Hickey JW, Roberts SSH, Mitra B, O'Brien TJ, Shultz SR and McDonald SJ
Advances in instrumented mouthguards (iMGs) allow for accurate quantification of single high-acceleration head impacts and cumulative head acceleration exposure in collision sports. However, relationships between these measures and risk of brain cell injury remain unclear.
Fourier Transform Infrared (FTIR) Spectroscopy as a Tool to Characterize Exercise and Physical Activity: A Systematic Review
Valente PA, Mota SI, Teixeira A, Ferreiro E, Sarmento H, Cipriano I, Campos JR, Rama L and Oliveira PJ
Over the past few decades, the scientific community has recognized the impact of physical activity on health and performance. In parallel, researchers have been actively exploring novel methodologies to analyze the physiological and metabolic responses to exercise. Fourier transform infrared spectroscopy has emerged as a powerful tool in this effort, offering the potential to provide unique insights into exercise-related changes at the molecular level.
The Influence of Kinesiophobia on Time to Clinical Recovery in Collegiate Athletes with Concussion
Rosenblum DJ and Resch JE
Several factors such as acute symptom severity, premorbid anxiety, and depression have been associated with concussion recovery. Elevated kinesiophobia has been associated with recovery from musculoskeletal conditions, as well as increased reaction time and vestibular-ocular motor dysfunction following concussion. However, kinesiophobia has yet to be evaluated as a modifier of concussion recovery time.
Guiding Evidence-Based Classification in Para Sporting Populations: A Systematic Review of Impairment Measures and Activity Limitations
Wileman TM, McKay MJ, Hackett DA, Watson TJ, Fleeton J and Fornusek C
As the focus of classification shifts towards an evidence-based approach, it is crucial to establish a robust system that relies on valid and reliable measures of impairment to ensure legitimate and competitive opportunities for all Para athletes. However, the lack of methods that possess the necessary measurement properties for assessing impairments in Para sporting populations presents significant challenges to developing an evidence-based classification system.
Relationship Between Physical Literacy and Cardiorespiratory Fitness in Children and Adolescents: A Systematic Review and Meta-analysis
Jiang T, Zhao G, Fu J, Sun S, Chen R, Chen D, Hu X, Li Y, Shen F, Hong J and Hu H
Physical literacy (PL) can positively affect the health of children, adolescents, and adults, and is closely related to cardiorespiratory fitness (CRF).
High-Intensity Interval Training for Cancer Patients: A Review of Key Considerations for Exercise Prescription
Dias-da-Silva G, Panissa VLG, Derchain SFM, Ferreira MLV, Telles GD, Buzaglo GBB, Araújo RB, Vechin FC and Conceição MS
High-intensity interval training (HIIT) performed before, during, and after cancer treatment can attenuate the adverse effects induced by anti-cancer drugs. A clear presentation and rationale of characteristics of HIIT variables is vital to produce the expected HIIT adaptations in cancer patients. However, there are concerns regarding the HIIT protocols used in the cancer literature.
Changes in Cardiorespiratory Fitness Following Exercise Training Prescribed Relative to Traditional Intensity Anchors and Physiological Thresholds: A Systematic Review with Meta-analysis of Individual Participant Data
Meyler SJR, Swinton PA, Bottoms L, Dalleck LC, Hunter B, Sarzynski MA, Wellsted D, Williams CJ and Muniz-Pumares D
It is unknown whether there are differences in maximal oxygen uptake ( O) response when prescribing intensity relative to traditional (TRAD) anchors or to physiological thresholds (THR).
The Battle of the Equations: A Systematic Review of Jump Height Calculations Using Force Platforms
Eythorsdottir I, Gløersen Ø, Rice H, Werkhausen A, Ettema G, Mentzoni F, Solberg P, Lindberg K and Paulsen G
Vertical jump height measures our ability to oppose gravity and lower body neuromuscular function in athletes and various clinical populations. Vertical jump tests are principally simple, time-efficient, and extensively used for assessing athletes and generally in sport science research. Using the force platform for jump height estimates is increasingly popular owing to technological advancements and its relative ease of use in diverse settings. However, ground reaction force data can be analyzed in multiple ways to estimate jump height, leading to distinct outcome values from the same jump. In the literature, four equations have been commonly described for estimating jump height using the force platform, where jump height can vary by up to 15 cm when these equations are used on the same jump. There are advantages and disadvantages to each of the equations according to the intended use. Considerations of (i) the jump type, (ii) the reason for testing, and (iii) the definition of jump height should ideally determine which equation to apply. The different jump height equations can lead to confusion and inappropriate comparisons of jump heights. Considering the popularity of reporting jump height results, both in the literature and in practice, there is a significant need to understand how the different mathematical approaches influence jump height. This review aims to investigate how different equations affect the assessment of jump height using force platforms across various jump types, such as countermovement jumps, squat jumps, drop jumps, and loaded jumps.
Cardiac Fatigue in Male Athletes with Exercise-Induced Pulmonary Impairments After a Very Long-Distance Triathlon
Hédon C, Gouzi F, Padovani C, Schuster I, Maufrais C, Cade S, Cransac F, Bui G, Morcillo S, Ayoub B, Thireau J, Izem O, Reboul C, Walther G, Hayot M, Nottin S and Cazorla O
Prolonged strenuous exercise can transiently decrease cardiac function. Other studies have identified three major exercise-induced pulmonary changes: bronchoconstriction, dynamic hyperinflation and pulmonary oedema with reduced alveolar-capillary membrane diffusing capacity. This study investigated whether athletes with one of these pulmonary dysfunctions following a very long-distance triathlon exhibit similar cardiac alterations as those without dysfunctions.
Hop to It! A Systematic Review and Longitudinal Meta-analysis of Hop Performance After ACL Reconstruction
Girdwood MA, Crossley KM, Rio EK, Patterson BE, Haberfield MJ, Couch JL, Mentiplay BF, Hedger M and Culvenor AG
Hop testing is widely used by clinicians to monitor rehabilitation and decide when to return to sport following anterior cruciate ligament reconstruction (ACLR); however, the trajectory of long-term hop performance has not been summarised.
Relationship between Cognitive Demands and Biomechanical Indicators Associated with Anterior Cruciate Ligament Injury: A Systematic Review
Jiménez-Martínez J, Gutiérrez-Capote A, Alarcón-López F, Leicht A and Cárdenas-Vélez D
Anterior cruciate ligament (ACL) injury during contact sports has a high incidence that has not been reduced despite the immense resources devoted to understanding its aetiology. A neurocognitive approach could increase knowledge of the mechanisms contributing to ACL injury enabling practitioners to address and minimise future risk.