Med Sci Sports Exerc [JOURNAL]
Sun
200 papers
High Test-Retest Reliability but Questionable Validity: Assessing a Step-Ramp-Step Protocol to Estimate Critical Power and W ' in Trained Triathletes.
Rousseau Q, Rabita G, Brunet E … +3 more , Dorel S, Siblot A, Morales-Artacho AJ
Med Sci Sports Exerc · 2026 Jun · PMID 41630099 · Publisher ↗
PURPOSE: This study aimed to assess (1) the concurrent validity between critical power (CP) and the corrected power output at the respiratory compensation point (PO RCP ) and between W' and the quantity of energy deplete...
PURPOSE: This study aimed to assess (1) the concurrent validity between critical power (CP) and the corrected power output at the respiratory compensation point (PO RCP ) and between W' and the quantity of energy depleted above PO RCP ( W'mod-SRS ) in a modified Step-Ramp-Step (mod-SRS) protocol; (2) the test-retest reliability of endurance variables derived from a mod-SRS protocol. METHODS: Twelve trained male triathletes (31 ± 6 yr, 67.9 ± 7.1 mL min -1 kg -1 ) performed (1) an SRS protocol, (2) 4-5 severe-intensity constant work rate trials, (3) two mod-SRS protocols (test/retest), and (4) a heavy-intensity constant work rate trial. CP and W' were computed using a "best individual fit" approach. PO RCP was corrected appropriately, while W'mod-SRS was computed as the energy depleted above PO RCP . Test-retest reliability was assessed with the intraclass correlation coefficient (ICC), the standard error of measurement (SEM), and the coefficient of variation (CV%). RESULTS: CP was higher than PO RCP in both trials (bias = 19 ± 19 W and 17 ± 20 W, P = 0.019 and 0.045). W' and W'mod-SRS were similar during both trials (bias = -2.8 ± 7.9 and -5.4 ± 8.8 kJ, P = 0.735 and 0.173). Test-retest reliability was moderate for W'mod-SRS (ICC = 0.66, SEM = 3.0 kJ, CV = 11.6%) and high for , gas exchange threshold (GET), RCP, and their associated PO values (ICCs = 0.85-0.95, SEMs = 68-184 mL min -1 , and 7-8 W, CVs = 2.1%-3.7%). CONCLUSIONS: The mod-SRS protocol reliably measures , gas exchange threshold, and RCP. Corrected PO RCP systematically underestimated CP, which consequently impacts the computation of W' using a mod-SRS protocol. The design of the protocol may allow a more complete depletion of energy available above RCP while still eliciting .
Can Knee Extensor Loading Deficits Be Diagnosed Using Variables from Force Plates during Squats Post-ACLr?
Wang J, Michener LA, Havens KL … +1 more , Sigward SM
Med Sci Sports Exerc · 2026 Jun · PMID 41630073 · Publisher ↗
UNLABELLED: The persistence of knee extensor moment (KEM) deficits across rehabilitation post-ACL reconstruction may be attributed to difficulty detecting and addressing deficits clinically. During squats, large KEM defi...
UNLABELLED: The persistence of knee extensor moment (KEM) deficits across rehabilitation post-ACL reconstruction may be attributed to difficulty detecting and addressing deficits clinically. During squats, large KEM deficits are present along with much smaller differences in joint or segment angles, making them difficult to detect visually. Data outputs from force plates and video technology may improve clinical identification. PURPOSE: Investigate the accuracy of three approaches to estimate KEM deficits using outputs from the force plate and two-dimensional (2D) position data to identify individuals with surgical limb KEM deficits during a bilateral squat. METHODS: Forty individuals post-ACLr performed bilateral squats. Kinematic and ground reaction force (GRF) data were collected via 3D motion capture system and triaxial force plates. Surgical limb deficits were calculated using limb symmetry index (LSI: nonsurgical/surgical) at peak knee flexion. Gold-standard KEM was calculated using inverse dynamics. Vertical GRF was considered alone, and together with the center of pressure (COP) position to estimate deficits in GRF, and GRF-COP Approaches. Vector Approach used the product of vertical GRF and moment arm calculated using vertical and anterior/posterior GRF, COP, and knee position in trigonometric equations. Separate linear regression and intraclass correlation coefficient (2,k) examined concurrent validity between gold-standard LSI and LSI from GRF, GRF-COP, and Vector Approaches. Specificity and sensitivity (LSI threshold ≥0.85) determined diagnostic accuracy. RESULTS: GRF, GRF-COP, and Vector LSI's predicted gold-standard LSI ( R2 = 0.56, 0.74, and 0.85, respectively) with intraclass correlation coefficient (2,k) 0.49, 0.92, and 0.96; sensitivity of 72.2%, 94.4%, 100%, and specificity of 100%, 50%, 100%, respectively. CONCLUSIONS: Vertical GRF alone is not adequate to detect KEM deficits. Additional force plate and 2D position data (COP position and moment arm) can strengthen predictive ability and diagnostic accuracy, supporting translation of these variables into commercial products to enhance clinical assessments.
Residence at 1200 m Induces a Threefold Reduction in the Risk of Acute Mountain Sickness After Rapid Ascent to 3600 m.
Figueiredo PS, Landspurg SD, Femling JK … +9 more , Williams JD, Staab JE, Buller MJ, Karl JP, Reilly AJ, Mayschak TJ, Atkinson EY, Hoyt RW, Beidleman BA
Med Sci Sports Exerc · 2026 Jun · PMID 41622511 · Full text
UNLABELLED: Moderate-altitude residence (1600-2400 m) elicits altitude acclimatization and reduces acute mountain sickness (AMS) after rapid ascent to higher altitude (HA). Cross-sectional studies suggest lower-altitude...
UNLABELLED: Moderate-altitude residence (1600-2400 m) elicits altitude acclimatization and reduces acute mountain sickness (AMS) after rapid ascent to higher altitude (HA). Cross-sectional studies suggest lower-altitude residence (800-1200 m) provides similar benefits, but conclusions are unclear due to a lack of control. PURPOSE: Determine whether moderate-altitude residents (MAR, 1200 m) experience less AMS than low-altitude residents (LAR) after active or passive ascent to HA (3600 m). METHODS: Seventy-eight soldiers (mean ± standard deviation; age = 26 ± 5 yr; women = 8) were tested at their baseline residence at 331 m (LAR; n = 41) or 1200 m (MAR; n = 37), transported to Taos, NM (2845 m), hiked ( n = 39) or were driven ( n = 39) to 3600 m and stayed for 4 d. AMS was assessed using the Environmental Symptoms Questionnaire twice on day 1 (HA1), five times on days 2 and 3 (HA2, HA3), and once on day 4 (HA4). Daily peak cerebral factor score (AMS-C) was recorded; if AMS-C was ≥0.7, individuals were considered sick that day. RESULTS: Ascent condition (active vs passive) did not demonstrate a significant main or interaction effect on AMS. The MAR versus LAR experienced lower AMS incidence on HA1 (16% vs 44%, P = 0.008) and HA2 (19% vs 39%, P = 0.05), similar incidence on HA3 (14% vs 29%, P = 0.08), and lower incidence on HA4 (0% vs. 17%, P = 0.007). AMS-C was lower in MAR versus LAR on HA1 (0.40 ± 0.49 vs 0.74 ± 0.86, P = 0.04), HA2 (0.30 ± 0.34 vs 0.86 ± 0.88, P = 0.001), HA3 (0.30 ± 0.36 vs 0.56 ± 0.69, P = 0.03), and HA4 (0.09 ± 0.14 vs 0.35 ± 0.58, P = 0.01). MAR exhibited an approximately threefold reduction in the odds of developing AMS at HA1 (odds ratio [OR] = 0.25, P = 0.01), HA2 (OR = 0.37, P = 0.05), and HA3 (OR = 0.38, P = 0.09) compared with LAR. CONCLUSIONS: Residence at 1200 m induces a threefold reduction in the odds of developing AMS after rapid ascent to 3600 m.
American College of Sports Medicine Expert Consensus Statement: Blood Doping in Sport.
Lewis L, Mørkeberg J, Chapman R … +4 more , Schumacher YO, Fedoruk M, Eichner D, Levine B
Med Sci Sports Exerc · 2025 Dec · PMID 41604578 · Publisher ↗
This Consensus statement provides an update to the 1996 American College of Sports Medicine Position Stand: The Use of Blood Doping as an Ergogenic Aid. Red blood cell (RBC) mass directly influences exercise performance...
This Consensus statement provides an update to the 1996 American College of Sports Medicine Position Stand: The Use of Blood Doping as an Ergogenic Aid. Red blood cell (RBC) mass directly influences exercise performance because RBCs are critical to the transport of oxygen to skeletal muscle, as well as their role in maintaining acid-base status and regulating blood flow. Blood doping is defined as the practice of artificially increasing RBC volume for the purpose of improving exercise performance. Blood doping methods have classically included reinfusion of stored blood as well as administration of pharmaceutical agents such as recombinant human erythropoietin, hypoxia-inducible factor stabilizers or nonpharmaceutical substances, like cobalt or xenon, which stimulate the erythropoietic pathway. It is clear through scientific consensus that other methods to naturally increase hemoglobin, such as hypoxic or hyperoxic exposure, are not considered blood doping. More recently, emerging blood doping threats through gene manipulation have received new attention. In the last 25 yr, the science and technology surrounding oxygen sensing and erythropoiesis, pharmacological intervention, and doping detection has advanced substantially, dictating this updated review. It is the position of the American College of Sports Medicine that any blood doping procedure used with the actual or potential to improve athletic performance is unethical and unfair and exposes the athlete to unwarranted and potentially serious health risks.
Characterizing Landing Strategies during the Drop Jump Task: A Proposed Data-Driven Approach to Identify Increased Exposure to Noncontact Anterior Cruciate Ligament Injury.
Smith SE, Sigward SM, Schweighofer N … +2 more , Straub RK, Powers CM
Med Sci Sports Exerc · 2026 Jun · PMID 41593848 · Publisher ↗
PURPOSE: To determine if distinct landing strategies could be delineated that could inform higher exposure to anterior cruciate ligament (ACL) injury. We also sought to determine whether a greater proportion of females w...
PURPOSE: To determine if distinct landing strategies could be delineated that could inform higher exposure to anterior cruciate ligament (ACL) injury. We also sought to determine whether a greater proportion of females would be assigned to a higher exposure cluster. METHODS: Kinematic and kinetic data from 74 healthy athletes (31 males and 43 females) were obtained during a drop jump task. Variables of interest included those previously shown in prospective studies to be predictive of future ACL injury. K-means clustering (k = 2) was used to determine if two (or more) distinct strategies could be delineated. Independent t tests were used to assess between-cluster differences for each biomechanical variable of interest. A chi-square test was utilized to explore the distribution of males and females across the two clusters. RESULTS: K-means clustering categorized participants into two groups (Cluster 1: N = 36; Cluster 2: N = 38). Two distinct landing strategies were identified as evident by the finding of statistically significant between-cluster differences in seven of the eight biomechanical variables evaluated. Of these differences, six have been identified in the literature as being predictive of future ACL injury. The proportion of females assigned to Cluster 1 was 69.4% ( N = 25), compared with 30.6% males ( N = 11). CONCLUSIONS: The results of this study revealed that the drop jump task can be used to characterize distinct landing strategies. Based on the coexistence of suspected risk factors, an argument could be made that Cluster 1 may be representative of a landing strategy representative of elevated exposure to ACL injury.
MRI Findings of Femoral Neck Bone Stress Injuries in Army Trainees and Their Association with Basic Training Graduation: A Retrospective Cohort Study.
Dredge GF, Rhon DI, Dummar AR … +3 more , Noehren BW, Hoch JM, Heebner NR
Med Sci Sports Exerc · 2026 Jun · PMID 41593838 · Publisher ↗
PURPOSE: Femoral neck bone stress injuries (FNBSIs) are severe overuse injuries associated with high rates of noncompletion of training and medical separation in military personnel. While the negative impact of an FNBSI...
PURPOSE: Femoral neck bone stress injuries (FNBSIs) are severe overuse injuries associated with high rates of noncompletion of training and medical separation in military personnel. While the negative impact of an FNBSI diagnosis is known, it remains unclear how specific magnetic resonance imaging (MRI)-defined injury characteristics, such as grade, location, and unilateral versus bilateral presentation, relate to graduation outcomes. This study aimed to determine the association between these FNBSI characteristics and graduation from Basic Combat Training (BCT). METHODS: In this matched retrospective cohort study of 208,540 U.S. Army trainees (2015-2019), trainees with MRI-confirmed FNBSIs ( n = 682) were matched 1:3 by sex and age to controls without bone stress injuries ( n = 2046). Logistic regression was used to model the associations between FNBSI features and BCT graduation. RESULTS: Graduation rates were significantly lower for trainees with an FNBSI, with matched controls having seven times higher odds of graduating (odds ratio [OR] = 7.38, 95% confidence interval: 5.95-9.16). Lower MRI grades were associated with significantly higher odds of graduation (e.g., grade 1 vs. 3, OR = 4.65), while bilateral injuries were associated with lower odds of graduation than unilateral injuries (OR = 0.72, 95% confidence interval: 0.53-0.98). No significant difference was observed between compression- and tension-sided injuries. In the matched cohort, male sex and older age were also associated with higher graduation odds. CONCLUSIONS: FNBSIs are strongly associated with lower odds of completing BCT, particularly when injuries are bilateral, of a higher MRI grade, or occur in younger or female trainees. These findings highlight the critical need for early detection, standardized reporting of MRI injury characteristics, and targeted interventions to improve military training retention.
Driving after Concussion: The Influence of Days since Concussion on Simulated Driving Performance Recovery.
Schmidt JD, Hashida K, Drattell JD … +4 more , Lynall RC, Love K, Devos H, Gore RK
Med Sci Sports Exerc · 2026 Jun · PMID 41593834 · Publisher ↗
PURPOSE: The aim of this study was to determine whether simulated driving performance improves as the days since concussion increase. METHODS: This is a cross-sectional study. Forty-nine young-adult patients diagnosed wi...
PURPOSE: The aim of this study was to determine whether simulated driving performance improves as the days since concussion increase. METHODS: This is a cross-sectional study. Forty-nine young-adult patients diagnosed with concussion (19.3 ± 1.5 yr, female 61.2%) completed a driving simulation assessment at an initial clinic visit between 0 and 12 d postconcussion. Primary outcome variables included the total number of collisions, speed exceedances, stop signs missed, lane excursions, total drive time, percent time over the speed limit, and percent time out of the lane. For each of the 11 drive segments, we examined the average speed, standard deviation of speed, average lateral lane position, and standard deviation of lateral lane position. Driving simulation outcomes were modeled using a negative binomial regression for count variables and linear regression for continuous variables, using the predictor of days since concussion. RESULTS: Fewer days since concussion was associated with more frequent centerline crossings ( P = 0.046); greater time spent out of the lane ( P = 0.045); a lateral lane position closer to the centerline while navigating a left residential curve ( P < 0.001) and while incurring a vehicle in the lane ( P = 0.026); and greater standard deviation of lateral lane position while navigating a crosswalk ( P < 0.001) and while navigating around a crash in the road ( P = 0.018). CONCLUSIONS: Clinicians should consider recommendations that support limited driving during the acute stages (24-72 h) of concussion followed by a gradual return to driving. A longitudinal study design in a larger sample is needed to better define driving performance recovery following concussion.
Clinical Cut Point for the Postconcussion Symptom Inventory Following Adolescent Concussion.
Donahue CC, Smulligan KL, Wingerson MJ … +3 more , Kniss JR, Wilson JC, Howell DR
Med Sci Sports Exerc · 2026 Jun · PMID 41593831 · Full text
BACKGROUND: The Postconcussion Symptom Inventory (PCSI) evaluates the severity of 21 concussion-related symptoms, yielding a total symptom severity between 0 and 126. Although widely used in concussion research and care...
BACKGROUND: The Postconcussion Symptom Inventory (PCSI) evaluates the severity of 21 concussion-related symptoms, yielding a total symptom severity between 0 and 126. Although widely used in concussion research and care as a key element in diagnosis and management decisions, no clinically validated cut point exists to distinguish adolescents with and without a recent concussion. Therefore, the purpose of our study was to establish a PCSI cut point with adequate sensitivity, specificity, and classification accuracy for clinical use. METHODS: Adolescents within 21 days of concussion and uninjured controls completed the PCSI, and total symptom severity score was calculated. We used independent samples t tests to compare total PCSI symptom severity scores between groups, and multivariable logistic regression to calculate adjusted odds ratios (outcome = group, predictor = PCSI score, covariates = age, biological sex, concussion history, history of anxiety, and/or depression). A receiver operating characteristic (ROC) curve was used to evaluate the area under the ROC curve and determine the optimal cut point to distinguish between adolescents with and without a concussion. RESULTS: One hundred fifty-three adolescents with a concussion (15.4 ± 1.6 years; 54% female; 8.2 ± 3.6 days since injury), and 200 uninjured controls (15.8 ± 1.1 years; 84% female) were included. The concussion group had significantly higher PCSI scores than the control group (47.4 ± 26.8 vs 20.9 ± 19.4; P < 0.001). The univariable area under the ROC curve value for the PCSI to differentiate between groups was 0.80 (95% confidence interval = 0.75-0.85), and correctly classified 74% of participants as concussion or control group using a PCSI cut point of 23 (sensitivity = 68%, specificity = 83%). CONCLUSIONS: Our results suggest a PCSI cut point of 23 can distinguish between adolescents with and without a recent concussion and may provide enhanced accuracy to identify a suspected concussion in the subacute time after injury.
Combined Effects of Vestibular Dysfunction and Mild Cognitive Impairment on Reactive Stepping Responses in Older Adults.
Pitts J, Mehta T, Kannan L … +6 more , Wang S, Master M, Sahu U, Deshmukh S, Purohit R, Bhatt T
Med Sci Sports Exerc · 2026 Jun · PMID 41593829 · Publisher ↗
PURPOSE: Vestibular dysfunction (VD) is associated with fall risk and is more common in older adults with mild cognitive impairment (OAwMCI) than cognitively intact older adults (CIOA). However, it is unknown if VD contr...
PURPOSE: Vestibular dysfunction (VD) is associated with fall risk and is more common in older adults with mild cognitive impairment (OAwMCI) than cognitively intact older adults (CIOA). However, it is unknown if VD contributes to the reactive balance deficits observed in OAwMCI (e.g., higher fall rate, lower reactive center of mass stability). METHODS: This study examined how VD affected reactive stepping kinematics and neuromuscular control in OAwMCI ( n = 28) and CIOA ( n = 35) when exposed to a large anterior support surface perturbation. VD was identified by a positive score on ≥2/3 clinical tests (head thrust, vestibular ocular reflex slow, vestibular ocular reflex cancelation), and was more common in OAwMCI (46%) than CIOA (23%) ( P < 0.05). RESULTS: Only OAwMCI with VD showed a higher fall rate, lower reactive center of mass stability, delayed step initiation, and longer onset latencies of the bilateral medial gastrocnemius than those without VD (significant group × VD interaction, P < 0.05). However, both OAwMCI and CIOA with VD showed longer step execution, reduced activation amplitude of the stepping limb hamstrings and tibialis anterior during step initiation and execution (relative to peak activation), and longer burst durations of the stepping limb quadriceps than those without VD (significant main effect of VD, P < 0.05). CONCLUSIONS: This suggests that VD may affect reactive balance control in OAwMCI more than CIOA by interfering with reactive step triggering/initiation, although it may affect reactive step execution in both CIOA and OAwMCI. Vestibular inputs may contribute to both perturbation detection/response triggering and motor execution, and OAwMCI may have reduced capacity to compensate for unreliable vestibular sensory inputs due to impaired sensory reweighting. Comprehensive fall risk screenings could consider the combination of both cognitive decline and VD.
Sexual Dimorphism in Clinical Manifestations of Knee Osteoarthritis.
Hoki A, Iwasaki T, Matsuda Y … +2 more , Ambrosio F, Iijima H
Med Sci Sports Exerc · 2026 Jun · PMID 41593828 · Full text
OBJECTIVES: While sexual dimorphism of knee osteoarthritis (KOA) is well established, sex-specific clinical manifestations-particularly involving periarticular tissues undetectable by radiography-remain underexplored. Th...
OBJECTIVES: While sexual dimorphism of knee osteoarthritis (KOA) is well established, sex-specific clinical manifestations-particularly involving periarticular tissues undetectable by radiography-remain underexplored. This study aimed to define female-specific alterations in joint integrity, periarticular muscle quality, symptom presentation, and the transcriptomic landscape of periarticular muscles, with the goal of uncovering the mechanistic contributions of each to KOA pathophysiology. METHODS: Forty-nine participants (32 females, 17 males; Kellgren-Lawrence grade 1-2) underwent clinical assessment, including (1) quantitative ultrasound assessment of the vastus medialis and rectus femoris muscles; (2) magnetic resonance imaging to assess joint integrity; and (3) patient-reported outcomes. Principal component analysis followed by receiver operating characteristic curve analysis was conducted to identify discriminative sex-specific imaging and symptom features. Correlation-based network analysis examined sex-specific interdependencies among clinical variables. Publicly available transcriptomic datasets were analyzed to identify molecular drivers underlying female-specific muscle quality changes. RESULTS: Despite similar radiographic severity and symptom presentation across the sexes, female individuals exhibited greater cartilage degeneration and higher fatty infiltration in the vastus medialis and rectus femoris. These features were central to sex separation in the principal component analysis, with both features identified as network hubs in female individuals, indicating interconnected muscle-joint degeneration. Transcriptomic analysis revealed enrichment of adipogenic reprogramming in female individuals, suggesting aberrant intramuscular fat programming. DISCUSSION: Our findings uncover a distinct female-specific musculoskeletal phenotype in early-stage KOA, characterized by muscle degeneration and cartilage deterioration undetectable by radiography. These female-specific clinical manifestations may be due, at least partly, to aberrant adipogenic programming in muscle. These findings provide mechanistic and clinical insight into sexual dimorphism in KOA.
Geospatial and Sociodemographic Variability in Youth Sport Participation: 2021-2022 National Survey of Children's Health.
Rogers AE, Prokasky A, VON Seggern MJ … +2 more , Dzewaltowski DA, Schenkelberg MA
Med Sci Sports Exerc · 2026 Jun · PMID 41593827 · Publisher ↗
PURPOSE: This cross-sectional study used data from the 2021-2022 National Survey of Children's Health to examine the sociodemographic characteristics associated with youth sport (YS) participation in the United States by...
PURPOSE: This cross-sectional study used data from the 2021-2022 National Survey of Children's Health to examine the sociodemographic characteristics associated with youth sport (YS) participation in the United States by state among youth 6 to 17 yr of age. The study also examined state-level associations between YS participation and meeting physical activity (PA) guidelines. METHODS: A logistic regression model evaluated the associations of sociodemographic characteristics of age, sex, race/ethnicity, household income, special healthcare needs (SHCN) status, and health insurance type with YS participation by state. Rao-Scott chi-square tests computed by state determined whether YS participation was associated with meeting PA guidelines. RESULTS: The analytic sample included 64,535 youth. Approximately 51% reported past-year YS participation (range = 39.8%-64.6% across states). Household income was significantly associated with YS participation for 43 states. Youth from lower-income households had lower odds of participating in sport than youth from higher-income households (odds ratio range = 0.24-0.49). In 35 states, youth with SHCN had lower odds of participating in sport than youth without SHCN (odds ratio range = 0.35-0.72). Race/ethnicity and age were significantly associated with YS participation in 13 and 7 states, respectively, and the sociodemographic subgroups more likely to participate varied by geographic location. YS participation was significantly associated with meeting PA guidelines in 20 states. CONCLUSIONS: YS is a critical developmental setting for youth. Youth with lower incomes and SHCN were consistently less likely to participate in sport than their peers. Associations between other sociodemographic characteristics (e.g., race/ethnicity) and YS participation varied geospatially, highlighting the need for state-specific approaches to improve YS so that all youth have opportunities to participate.
The Role of Lower-Limb Muscle Volumes in Vertical Jump Performance in NCAA Division I Athletes.
O'Brien DE, Ito N, Kliethermes S … +1 more , Heiderscheit B
Med Sci Sports Exerc · 2026 Jun · PMID 41591279 · Publisher ↗
INTRODUCTION/PURPOSE: This study examined the relationship between lower extremity muscle volumes and countermovement jump (CMJ) performance in 207 (43 female, 164 male) National Collegiate Athletic Association Division...
INTRODUCTION/PURPOSE: This study examined the relationship between lower extremity muscle volumes and countermovement jump (CMJ) performance in 207 (43 female, 164 male) National Collegiate Athletic Association Division I collegiate basketball, football, hockey, and soccer athletes. The primary aim was to determine which combination of lower extremity muscle volumes was most strongly associated with CMJ performance across a large subset of high-level college athletes. METHODS: Athletes underwent bilateral magnetic resonance imaging scans, and muscle volumes were quantified using machine-learning-based auto-segmentation. CMJ height (cm) and peak power (W/kg) were measured using dual force plates. Backward selection regression analyses determined muscle combinations that best explained variance in jump performance after adjusting for sex and sport. RESULTS: Vastus lateralis muscle volume was related to both jump height (β = 0.36, P < 0.01) and peak power (β = 0.41, P < 0.01). In addition to the vastus lateralis, the jump height model retained rectus femoris, and the peak power model retained soleus, gluteus medius, adductor magnus, and biceps femoris long head. The differing muscle candidates in the two models likely reflect the distinct features of each CMJ metric: jump height reflects force over time while peak power reflects the rapid generation of force. Sport-specific differences emerged, with hockey and football athletes displaying greater jump heights and generating greater peak power when compared with basketball players. Male athletes outperformed females in both jump metrics. CONCLUSIONS: These findings, derived from over 200 National Collegiate Athletic Association Division I athletes, highlight the crucial role of the quadriceps in CMJ performance in high-level athletes. Strength and conditioning and rehabilitation programs may consider targeting quadriceps hypertrophy to improve vertical jump performance.
Plasma Proteomic Signatures of Physical Activity Provide Insights into Biological Impacts and its Protective Role against Dementia.
Arani G, Arora A, Yang S … +21 more , Wu J, Kraszewski JN, Martins A, Miller A, Zeba Z, Jafri A, Hu C, Farland LV, Bea JW, Coletta DK, Aslan DH, Sayre MK, Bharadwaj PK, Ally M, Maltagliati S, Lai MHC, Wilcox R, DE Geus E, Alexander GE, Raichlen DA, Klimentidis YC
Med Sci Sports Exerc · 2026 Jun · PMID 41582318 · Full text
PURPOSE: Physical activity (PA) and sedentary behavior (SB) are associated with many diseases, including Alzheimer disease and all-cause dementia. However, the specific biological mechanisms through which PA protects aga...
PURPOSE: Physical activity (PA) and sedentary behavior (SB) are associated with many diseases, including Alzheimer disease and all-cause dementia. However, the specific biological mechanisms through which PA protects against disease are not entirely understood. This study aims to address this gap, with a specific focus on all-cause dementia. METHODS: We first assessed the conventional observational associations of three self-reported and three device-based PA/SB measures with circulating levels of 2911 plasma proteins measured in the UK Biobank ( nmax = 39,160) and assessed functional enrichment of identified proteins. We then used bidirectional Mendelian randomization to further evaluate the evidence for causal relationships of PA/SB with protein levels. Finally, we performed mediation analyses to identify proteins that may mediate the relationship of PA with incident all-cause dementia. RESULTS: Our findings revealed 41 proteins consistently associated with all PA measures and 1027 proteins associated with at least one PA measure. Both conventional observational and Mendelian randomization study designs converged on proteins that appear to increase as a result of PA, including integrins such as ITGAV and ITGAM, as well as MXRA8, CLEC4A, CLEC4M, LPL, and ADGRG2; and on proteins that appear to decrease as a result of PA such as LEP, INHBC, CLMP, PTGDS, ADM, OGN, and PI3; and on proteins that are more responsive to high-intensity PA, such as CA14, CA6, CA4, KIT, and ANGPT2. Functional enrichment analyses revealed processes such as cell-matrix adhesion, integrin-mediated signaling, and collagen binding. Finally, GDF15, ITGAV, ITGAM, ITGA11, HPGDS, GFAP, ADM, AHNAK, and DPP4 were among 21 unique proteins found to mediate the relationship of PA with all-cause dementia, implicating processes such as synaptic plasticity, neurogenesis, and inflammation. CONCLUSIONS: Our results provide insights into how PA affects biological processes and protects against dementia, and provide avenues for future research into the health-promoting effects of PA.
Hypohydration Decreases Neuromuscular Performance before and after Intermittent Exercise in the Heat.
Elliott KB, Keefe MS, Dunn RA … +3 more , Palmer TB, Lepley AS, Sekiguchi Y
Med Sci Sports Exerc · 2026 Jun · PMID 41572530 · Publisher ↗
PURPOSE: To examine the effect of hydration status on neuromuscular performance before and after intermittent exercise in the heat. METHODS: Eleven male soccer players (age, 20 ± 2 years; height, 179.0 ± 7.9 cm; body mas...
PURPOSE: To examine the effect of hydration status on neuromuscular performance before and after intermittent exercise in the heat. METHODS: Eleven male soccer players (age, 20 ± 2 years; height, 179.0 ± 7.9 cm; body mass, 74.9 ± 10.3 kg; maximal oxygen consumption, 62.4 ± 11.5 mL·kg -1 ·min -1 ) performed a familiarization trial involving ultrasound (cross-sectional area and muscle thickness), landing error scoring system, and isometric knee extensions (rate of torque development [RTD]; time intervals of 0-30 ms [RTD 30], 0-50 ms [RTD 50], 0-100 ms [RTD 100], and 0-200 ms [RTD 200] from contraction onset). After this, participants completed 45-min of intermittent exercise in the heat (33ºC, 30% relative humidity) as part of familiarization. Experimental trials replicated the same protocol of pre and post neuromuscular testing separated by two 45-minute intermittent exercise bouts in the heat. Two experimental trials (euhydrated [EUH] and hypohydrated [HYP]) were randomly assigned; EUH maintained euhydration throughout the trial; HYP performed a 24-h fluid restriction before the trial. Before and after exercise, urine specific gravity, urine osmolality, and body mass loss were measured. A linear mixed effect model with Tukey post hoc was utilized to assess differences between trials. RESULTS: Cross-sectional area of the rectus femoris was smaller in HYP pre (13.3 ± 2.4 cm 2 ) compared with EUH pre (14.0 ± 2.6 cm 2 ), and in HYP post (12.7 ± 2.4 cm 2 ) compared with EUH post (14.0 ± 2.6 cm 2 ) ( P < 0.05). Independent of time, muscle thickness was also smaller in HYP (2.27 ± 0.2 cm) compared with EUH (2.45 ± 0.2 cm, P < 0.05). Furthermore, landing error scoring system scores were higher in HYP (4.1 ± 2.0) compared with EUH (2.9 ± 2.0, P < 0.05). RTD 30, 50, and 100 were all lower in HYP (326 ± 138 Nm·s -1 ; 441 ± 207 Nm·s -1 ; 648 ± 302 Nm·s -1 ) compared with EUH (427 ± 175 Nm·s -1 ; 584 ± 282 Nm·s -1 ; 796 ± 392 Nm·s -1 , P < 0.05), respectively. Additionally, urine specific gravity, urine osmolality, and body mass loss were all higher in HYP compared with EUH (P < 0.05). CONCLUSIONS: Hypohydration can negatively impact neuromuscular performance before and after intermittent exercise in the heat.
Stem Cell Transplant Patients' Activity Decline, Outpatient Resumption, and Intervention Effectiveness Identified by Wearable Activity Monitoring.
Brakenridge CJ, Dillon HT, Hakamuwa Lekamlage D … +6 more , Owen N, Dunstan DW, Lynch BM, Saner NJ, Salim A, Howden EJ
Med Sci Sports Exerc · 2026 Jun · PMID 41572528 · Full text
INTRODUCTION: We compared 16-wk wearable activity monitor trajectories of patients receiving hematopoietic stem cell transplants (SCT) engaged in an activity intervention trial. METHODS: Forty adults with hematological m...
INTRODUCTION: We compared 16-wk wearable activity monitor trajectories of patients receiving hematopoietic stem cell transplants (SCT) engaged in an activity intervention trial. METHODS: Forty adults with hematological malignancy scheduled to undergo SCT were randomized to an exercise and sedentary behavior intervention (INT; n = 22) or usual care ( n = 19). Participants were observed continuously for the duration of inpatient hospitalization for SCT (approximately 4 wk) and outpatient (12 wk) care. Between-group differences were determined by 16-wk trajectories of Fitbit-derived variables of physical activity and sedentary time (ST). RESULTS: Inpatient hospitalization for SCT led to higher levels of ST and lower levels of physical activity in both groups relative to preadmission. Across the ~16-wk period, the INT group had significantly higher physical activity and lower ST. During the 16-wk study period and independent of INT group assignment, a higher prehospitalization cardiorespiratory fitness was associated with higher levels of moderate-to-vigorous intensity physical activity; being female had stronger associations with step counts; older age and myeloablative SCT were associated with higher ST; and higher proportions of lean mass were associated with higher levels of light-intensity physical activity. CONCLUSIONS: Wearable activity monitors can continuously assess the behavioral impacts of SCT and the efficacy of activity INT in patients receiving hospital treatment for hematological malignancy. Tracker data showed that the activity INT protected against declines in physical activity and increases in ST with usual hospital care in SCT. Higher prehospitalization cardiorespiratory fitness and proportion of lean mass were associated with preservation and recuperation of activity levels.
Patients with Achilles Tendinopathy Show Reduced Intratendinous Sliding during Dynamic Exercises.
Lecompte L, Crouzier M, Bogaerts S … +1 more , Vanwanseele B
Med Sci Sports Exerc · 2026 Jun · PMID 41572520 · Publisher ↗
PURPOSE: Intratendinous sliding, that is, nonuniform motions between the superficial and deep layers of the Achilles tendon, is reduced in individuals with Achilles tendinopathy compared with healthy controls during isom...
PURPOSE: Intratendinous sliding, that is, nonuniform motions between the superficial and deep layers of the Achilles tendon, is reduced in individuals with Achilles tendinopathy compared with healthy controls during isometric contractions. Previous work has shown that intratendinous sliding can be increased by performing isometric contractions with a horizontally outward-rotated ("toes-out") foot position. The purpose of this study was to compare intratendinous sliding between healthy individuals and patients with Achilles tendinopathy during dynamic exercises, and to determine the effect of a toes-out foot position. METHODS: Forty participants (20 healthy and 20 Achilles tendinopathy) performed dynamic exercises, including bilateral heel rise/drop (sitting and standing), unilateral heel rise/drop (knee extended and bent), and squat. Exercises were performed in a neutral and toes-out foot position, with ultrasound images captured using an external probeholder. Intratendinous sliding (mm) was estimated via a speckle tracking algorithm as the difference between displacement of the superficial and deep layers of the Achilles tendon. RESULTS: Main effects of group, foot position, and exercise were found, indicating that Achilles tendinopathy patients have reduced intratendinous sliding, that intratendinous sliding can be increased in a toes-out foot position, and that some exercises induce more intratendinous sliding than others. CONCLUSIONS: These findings support intratendinous sliding as a marker of tendon health and suggest that foot positioning may be a simple way to enhance sliding. Given the poor rehabilitation outcomes for Achilles tendinopathy patients, implementing an external foot position during rehabilitation protocols could offer a low-cost and easy-to-implement method to improve rehabilitation success rates.
Metabolic Effects of Isoenergetic High-Intensity Interval Training and Moderate-Intensity Continuous Training in Adults with Type I Diabetes.
Baker PA, Moore SR, Delbiondo GM … +3 more , Ilkayeva OR, Newgard CB, Smith-Ryan AE
Med Sci Sports Exerc · 2026 Jun · PMID 41572518 · Publisher ↗
UNLABELLED: Type 1 diabetes (T1D) is characterized by insulin deficiency and impaired glucose homeostasis. Exercise is recommended for individuals with T1D, with moderate-intensity continuous training (MICT) favored due...
UNLABELLED: Type 1 diabetes (T1D) is characterized by insulin deficiency and impaired glucose homeostasis. Exercise is recommended for individuals with T1D, with moderate-intensity continuous training (MICT) favored due to concerns of hypoglycemia with high-intensity interval training (HIIT). PURPOSE: The extent to which these exercise strategies alter metabolomic signatures of macronutrient metabolism in T1D is unknown. The current study evaluated glycemic variability and metabolomic responses around energy-matched HIIT and MICT in individuals with T1D. METHODS: Fourteen adults with T1D (7 females, 7 males) completed three conditions in a randomized crossover design: HIIT (10 1-minute intervals at 90% VO 2 peak), MICT (15-20 min steady-state cycling at 65% VO 2 peak), and no exercise (control, CON). Twenty-four-hour glycemic responses via continuous glucose monitor and metabolomics assessed by blood samples before, after, and 1 h after exercise by targeted mass spectrometry and nontargeted gas chromatography-mass spectrometry. RESULTS: Average whole-day glucose levels were higher on the day of HIIT (167.48 ± 66.96 mg/dL; group × time P = 0.021) and MICT (166.46 ± 61.35 mg/dL; group × time P = 0.039) compared with CON (150.43 ± 61.69 mg/dL) with no difference between HIIT and MICT (group × time P = 0.999). Area under the curve for glucose was not different between HIIT, MICT, and CON on the day of exercise (group × time P = 0.961). After MICT, long-chain acylcarnitine C14:2 (0.06 ± 0.04 µmol/L) was higher than after HIIT (0.04 ± 0.02 µmol/L; group × time P = 0.008), with C16:1 (group × time P = 0.046) and C16:2 (group × time P = 0.021) higher than CON. CONCLUSIONS: In adults with T1D, HIIT and MICT elevated average glucose on the day of exercise, with greater fatty acid oxidation after MICT. These data support the metabolic safety and distinct fuel utilization of both exercise modalities in T1D.
Working Memory Performance is Reduced after a Marathon Race and Associated with Low Energy Availability in Females.
Boere K, Young N, Dauphinee R … +4 more , Copithorne F, Kirby BS, Krigolson OE, Stellingwerff T
Med Sci Sports Exerc · 2026 Jun · PMID 41572516 · Publisher ↗
PURPOSE: We tested the hypothesis that marathon racing reduces working memory performance and increases frontal theta activity in trained female endurance athletes. We further examined whether changes in cognitive perfor...
PURPOSE: We tested the hypothesis that marathon racing reduces working memory performance and increases frontal theta activity in trained female endurance athletes. We further examined whether changes in cognitive performance or brain activity were associated with either acute and/or chronic risk of low energy availability. METHODS: Sixteen female Tier 2 runners (42 ± 9 yr; VO 2 max 45.6 ± 6 mL·kg - ¹·min - ¹) underwent VO 2 max testing and the Low Energy Availability in Females Questionnaire (LEAF-Q) 7-14 d before a marathon. Participants completed 1-back (low-load) and 3-back (high-load) working memory tasks during electroencephalogram recordings, performed before and immediately after the race (<10 min). Accuracy and reaction time measured cognitive performance, and frontal theta power measured cognitive effort. RESULTS: Sixteen runners completed the marathon in 4:16 ± 37 min (70 ± 6% VO 2 max), with a mean carbohydrate intake of 28 ± 14 g·h -1 . Six athletes exceeded the LEAF-Q threshold (≥8) and eight reported menstrual dysfunction. Postrace, 3-back accuracy declined (-18.8%, P = 0.003) while reaction time shortened for both task versions (5.3%-6.6%, P = 0.002). Frontal theta increased postrace (1-back: +26.8%; 3-back: +29.6%, P < 0.001). Regression models showed that 3-back accuracy changes were predicted by LEAF-Q score (β = 0.494, P = 0.016). In contrast, theta increases were predicted by a combination of lower carbohydrate intake (β = -0.025, P = 0.005), longer race time (β = 0.008, P = 0.005), and higher LEAF-Q score (β = 0.121, P < 0.001). CONCLUSIONS: Working memory performance is reduced and cognitive effort is increased after marathon racing in trained female athletes. These effects are linked to both acute and chronic risk of low energy availability, emphasizing the need for individualized fueling strategies to preserve cognitive performance during endurance events.
Long-Term Resistance Training Improves Cardiac Structure and Function in Older Women: A 2-yr Randomized Controlled Trial.
Rodrigues RJ, Cunha PM, Nunes JP … +17 more , Mesas AE, Cardoso CG, Barbosa DS, Brum PC, Santarém JM, Fernandes RR, Sugihara P, Prado A, Comar LCC, Antunes M, Junior LCM, Bragatto GA, Batistella E, Venturini D, Sardinha LB, Vianna LC, Cyrino ES
Med Sci Sports Exerc · 2026 Jun · PMID 41572515 · Publisher ↗
PURPOSE: This randomized controlled trial investigated the effects of a supervised progressive resistance training (RT) program conducted over 2 yr on cardiac structure and function in older women. METHODS: Sixty-four ph...
PURPOSE: This randomized controlled trial investigated the effects of a supervised progressive resistance training (RT) program conducted over 2 yr on cardiac structure and function in older women. METHODS: Sixty-four physically independent older women (≥60 yr) were recruited for this investigation. Participants were randomly assigned to either a training group (TG, n = 33) or a control group (CG, n = 31). The RT program was conducted over 2 yr, in three sessions per week, on nonconsecutive days, and included eight whole-body exercises performed in three sets of 8-12 repetitions. Echocardiographic assessments were performed both before and after a 2-yr period by an experienced echocardiographer who was blinded to the participant's status and group assignment. RESULTS: A group-by-time interaction was found ( P < 0.05) for the left ventricular mass index (TG = -5.5% vs CG = +11%), septal thickness (TG = -3.8% vs CG = +7.3%), posterior wall thickness (TG = -2.8% vs CG = +13.6%), left ventricular end-diastolic volume (TG = -9.0% vs CG = +20.0%), left ventricular end-systolic volume (TG = -7.8% vs CG = +23.3%), left atrial volume index (TG = -7.1% vs CG = +28,1%), the left ventricular ejection fraction (TG = -1.0% vs CG = -4.9%), the E'/E septal (TG = -11.0% vs CG = +22.1%), the E septal (TG = +14.9% vs CG = -19.2%), and the E lateral (TG = +12.7% vs CG = -22.8%). CONCLUSIONS: Our results suggest that a 2-yr follow-up of the RT intervention may improve both the cardiac morphological and functional parameters in older women.
Effects of Modifiable Footwear Features on Anterior Cruciate Ligament Force in Young Females during a Drop-Lateral-Jump Task.
Chi PW, Paterson KL, Hinman RS … +7 more , Wu W, McNamara S, Maniar N, Akhundov R, Saxby DJ, Nasseri A, Bryant AL
Med Sci Sports Exerc · 2026 May · PMID 41569145 · Publisher ↗
PURPOSE: Aberrant lower limb biomechanics of young females contribute to elevated knee loads and a susceptibility to noncontact anterior cruciate ligament (ACL) injury. Specific design features of athletic footwear may a...
PURPOSE: Aberrant lower limb biomechanics of young females contribute to elevated knee loads and a susceptibility to noncontact anterior cruciate ligament (ACL) injury. Specific design features of athletic footwear may alter impact-related loads transferred up the kinetic chain to the knee. This cross-sectional biomechanical study examined the effects of modifiable footwear design features (heel height/pitch and medial arch support) on ACL force-time parameters of females during single-limb landing. METHODS: Fifty-two healthy late/postpubertal females (Tanner stage IV-V) performed a single-limb drop-lateral-jump task in nine footwear conditions, with different combinations of shoe pitch (4, 7, and 10 mm) and medial arch support (no support, low support, and high support). Using three-dimensional joint kinematics, ground-reaction forces, and electromyography data, an electromyography-informed neuromusculoskeletal computational model predicted ACL force during the weight-acceptance phase of the drop-lateral-jump task. A mixed-effects linear regression model was used to compare the magnitude and temporal characteristics of ACL force between footwear conditions. Tukey's post hoc comparisons were conducted for significant ( P < 0.05) main effects or interactions. RESULTS: For peak ACL force, no significant main effect or interaction was found. A significant main effect of shoe pitch was found for time-to-peak ACL force ( P < 0.001), where the 4-mm shoe pitch delayed time-to-peak by 3.23 and 4.28 ms compared with the 7 mm ( P < 0.001) and 10 mm ( P < 0.001) conditions, respectively. CONCLUSIONS: Although a delayed time-to-peak ACL force was observed with the 4-mm shoe pitch condition, the relatively small temporal differences observed, and the fact that peak ACL force did not differ across pitch variants, suggest that these findings may have few real-world implications.
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