INTRODUCTION/PURPOSE: Aging is associated with declines in muscle strength, lean mass, and bone mineral density (BMD), yet sex-specific lower-body trajectories and their interrelationships across the adult lifespan remai...INTRODUCTION/PURPOSE: Aging is associated with declines in muscle strength, lean mass, and bone mineral density (BMD), yet sex-specific lower-body trajectories and their interrelationships across the adult lifespan remain incompletely characterized. The purpose of this study was to determine whether lower-body strength and regional lean mass are differentially associated with hip and lumbar spine BMD across adulthood and whether these relationships vary by age and sex. METHODS: In this cross-sectional study (n = 251; 149 females, 102 males; 18-85 yr), maximal dynamic strength was assessed using a one-repetition maximum (1RM) leg press. Dual-energy x-ray absorptiometry quantified lumbar spine and hip BMD, lower-body lean mass, and visceral adipose tissue volume. Hierarchical regression models evaluated the effects of age, sex, and age × sex interactions on BMD, with additional models used to test associations between strength, lean mass, and BMD while controlling for adiposity. RESULTS: Hip BMD was lower with increasing age in both sexes, with higher values in males. Leg-press strength and lower-body lean mass were lower with increasing age but were positively associated with hip BMD (β = 0.32-0.45, p < 0.001) independent of age, sex, and adiposity. The strength-hip BMD association was stronger in younger relative to older adults (interaction p = 0.051). Spine BMD demonstrated a significant age × sex interaction, with age-related declines evident in females but not males. CONCLUSIONS: Maximal lower-body strength is strongly associated with hip BMD across adulthood and may serve as a functional marker of skeletal integrity. These findings highlight the need for caution when interpreting lumbar spine DXA measures in aging males and reinforce the importance of preserving neuromuscular quality for skeletal health across adulthood.
PURPOSE: Cardiorespiratory fitness (CRF) is a modifiable factor associated with the progression of chronic kidney disease (CKD). However, whether higher CRF levels can help prevent age-related kidney function decline in...PURPOSE: Cardiorespiratory fitness (CRF) is a modifiable factor associated with the progression of chronic kidney disease (CKD). However, whether higher CRF levels can help prevent age-related kidney function decline in the early stages before the onset of CKD remains unclear. This study aimed to investigate the effect of CRF on subsequent changes in kidney function in individuals with preserved kidney function under a prespecified causal framework. METHODS: This prospective cohort study assessed CRF by measuring oxygen uptake at the ventilatory threshold using gas exchange analysis during a submaximal exercise test. Kidney function was evaluated annually over 5 years (up to 6 time points per participant) using two estimates of glomerular filtration rate (GFR): serum cystatin C (eGFRcys) and serum creatinine (eGFRcr). The slopes were calculated separately for each estimated eGFR using linear mixed-effects models. Multiple linear regression analyses were conducted to examine the association between CRF and eGFR slope. RESULTS: A total of 198 participants (median age 61.4 years; 74% females) were included in the analyses. CRF was significantly correlated with the slopes of eGFRcys (r = 0.24). After adjusting for confounders, higher levels of CRF were significantly associated with a slower decline in the eGFRcys slope (β = 0.011, 95% confidence interval [CI] 0.002-0.020). Moreover, higher levels of CRF were significantly associated with a lower risk of rapid kidney function decline (odds ratio, 0.86; 95% CI, 0.75-0.99). These associations were not observed when creatinine-based eGFR was used. CONCLUSIONS: In individuals with preserved kidney function, higher levels of CRF were associated with a slower subsequent age-related decline in kidney function, suggesting a potential protective role of CRF.
PURPOSE: Cardiorespiratory fitness is a modifiable physiological trait linked to dementia risk, but whether objectively measured peak oxygen uptake (VO2peak) and short-term changes fitness in older adults associates with...PURPOSE: Cardiorespiratory fitness is a modifiable physiological trait linked to dementia risk, but whether objectively measured peak oxygen uptake (VO2peak) and short-term changes fitness in older adults associates with Alzheimer's disease (AD) remains unknown. We examined whether baseline levels and one-year changes in VO2peak were associated with subsequent risk of AD in older adults. METHODS: This prospective cohort study included participants from the Generation 100 Study. VO2peak was measured at baseline (2012-13) and 1-year follow-up. Participants were categorized as unfit (<80% of the sex-specific mean VO2peak), moderately fit (80-99%), or fit (≥100%). Incident AD was identified through national health registries, hospital records, and the Norwegian Prescribed Drug Registry. Cox proportional hazards models estimated associations between VO2peak and incident AD. RESULTS: A total of 1491 participants free from dementia, aged 70-77 years were included. Mean VO2peak at baseline was 28.7 mL/kg/min. During a median follow-up of 8.7 years, 77 developed AD. Compared with unfit, moderately fit (aHR 0.54, 95% CI 0.29-0.98) and fit (aHR 0.52, 95% CI 0.29-0.93) participants had a lower AD risk. Each 1 mL/kg/min higher baseline VO2peak was associated with a 4% lower risk of AD (HR 0.96, 95% CI 0.92-1.00). Staying above 80% of sex-specific mean VO2peak (25.1 mL/kg/min for men and 20.9 mL/kg/min for women) was identified as a threshold of AD risk stratification of which below the risk increased substantially. Weaker associations were observed between one-year changes in VO2peak and subsequent AD risk. CONCLUSIONS: Higher VO2peak in older adults was associated with a substantially lower risk of developing AD, whereas short-term changes in fitness did not confer additional benefit. These findings suggest that entering older age with fitness >80% of sex-specific mean may be more important for reducing late-life AD risk than achieving short-term improvements after the age of 70. CRF emerged as a clinically relevant biomarker for AD, that may help stratify risk and inform preventive strategies in ageing populations.
PURPOSE: This study examined the effects of an eight-week exergaming (EG) program compared with traditional aerobic exercise on dual-task performance and prefrontal hemodynamics in middle-aged and older adults. METHODS:...PURPOSE: This study examined the effects of an eight-week exergaming (EG) program compared with traditional aerobic exercise on dual-task performance and prefrontal hemodynamics in middle-aged and older adults. METHODS: Thirty-three older adults (21 females, 12 males; mean age = 64.2 ± 5.5 years) were randomly assigned to either an EG group (n = 16) or an aerobic exercise (AE) group (n = 17). Both groups completed supervised moderate-intensity training thrice per week for 30 minutes per session. Before and after the intervention, the participants performed a Stroop task under single-task, slow dual-task, and fast dual-task conditions. Behavioral accuracy was recorded, and prefrontal oxygenated, deoxygenated, and total hemoglobin concentrations were analyzed utilizing functional near-infrared spectroscopy. Physical fitness measures included estimated VO₂max, chair stand, arm curl, and timed up-and-go performance. RESULTS: Both interventions substantially enhanced VO₂max (p <.001), chair stand repetitions (p =.009), and timed up-and-go performance (p <.001). Behavioral findings exhibited elevated accuracy across all task conditions after training (p <.001). The EG group displayed superior performance only in the fast dual-task condition (p =.005), whereas no between-group differences were observed in single-task or slow dual-task conditions. Hemodynamic analyses revealed significant reductions in oxygenated (p <.003) and total hemoglobin (p =.015) over time, with larger reductions observed in the EG group. Deoxygenated hemoglobin did not show significant effects. CONCLUSIONS: Both training modalities improved physical fitness and task performance. EG provided additional benefits under the most demanding dual-task condition and was associated with more efficient prefrontal activation.
Med Sci Sports Exerc
· 2026 Jun · PMID 42374691
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PURPOSE: Cardiorespiratory fitness (CRF) is associated with enhanced leukocyte metabolism. Whether CRF impacts the metabolism of specific leukocytes such as cytotoxic T cells (Tc) is unknown. As Tc metabolism and functio...PURPOSE: Cardiorespiratory fitness (CRF) is associated with enhanced leukocyte metabolism. Whether CRF impacts the metabolism of specific leukocytes such as cytotoxic T cells (Tc) is unknown. As Tc metabolism and function, including interferon (IFN)-γ production, are linked, metabolic changes associated with higher CRF could impact Tc function. Therefore, this study aimed to determine whether CRF predicted Tc metabolism and function. METHODS: Forty-three adults (16 women) underwent a maximal oxygen consumption (VO2peak) test, had body fat percentage (BF%) measured, and donated resting blood. Tc mitochondrial mass, mitochondrial membrane potential, fatty acid and amino acid oxidation (FAO and AAO) capacity, glycolytic capacity, and IFN-γ expression were assessed via flow cytometry. Linear regression assessed CRF and BF% as predictors of metabolism and function. Analyses were conducted within total Tc and in Tc subsets. RESULTS: CRF predicted FAO and AAO capacity of Tc (ꞵ= 0.362; p= 0.017) and Tc subsets, and glycolytic capacity of Tc (ꞵ= 0.495; p< 0.001), central memory Tc (ꞵ= 0.304; p= 0.047), and effector memory re-expressing CD45RA (EMRA) Tc subsets (ꞵ= 0.451; p= 0.003). CRF also predicted IFN-γ expression by Tc (ꞵ= 0.384; p= 0.011), naïve Tc (ꞵ= 0.358; p= 0.020), and EMRA Tc subsets (ꞵ= 0.349; p= 0.022). Inclusion of BF% in models partially abrogated these relationships. CRF remained a significant predictor of Tc and EMRA Tc glycolytic capacity, and Tc function. CONCLUSIONS: CRF predicts Tc metabolism and function in healthy adults, where greater CRF associates with greater Tc FAO and AAO capacity, glycolytic capacity, and function. However, these relationships are in part attenuated by BF%, and Tc subsets exhibit differences in the degree to which they relate to CRF and BF%.
Sylvester J, Baez S, Charity D
… +6 more, DelBiondo G, Duncan C, Hill C, Adams Morancie N, Tayne S, Smith-Ryan A
Med Sci Sports Exerc
· 2026 Jun · PMID 42366521
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Females across the lifespan continue to engage in sport and fitness, continuously redefining the boundaries of previously recognized athletic potential. However, this rise in participation has been accompanied by a dispr...Females across the lifespan continue to engage in sport and fitness, continuously redefining the boundaries of previously recognized athletic potential. However, this rise in participation has been accompanied by a disproportionate prevalence of injuries and health-related conditions that uniquely affect female athletes and active females. Despite these trends, resources tailored to the needs of active females remain limited, particularly as females transition through key life stages, such as puberty, pregnancy, postpartum, perimenopause, and post-menopause. Females in the United States are left to traverse a disjointed healthcare system in hopes of receiving proper care, which can delay diagnosis and treatment. This review highlights primary injuries and other conditions that impact the active female, as well as calls for comprehensive sports medicine care.
Alver SK, Cuthbertson CC, Evenson KR
… +14 more, Schrack JA, Sotres-Alvarez D, Anita NZ, Mossavar-Rahmani Y, Gallo LC, Carlson JA, Allison M, Daviglus ML, Garcia-Bedoya O, Cordero C, Xue X, Cai J, Matsushita K, Kaplan RC
Med Sci Sports Exerc
· 2026 May · PMID 42350300
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PURPOSE: This study assessed whether greater physical activity (PA) and lesser sedentary behavior (SB) reduce hospitalization risk equally among those with and without prediabetes, diabetes, or peripheral artery disease...PURPOSE: This study assessed whether greater physical activity (PA) and lesser sedentary behavior (SB) reduce hospitalization risk equally among those with and without prediabetes, diabetes, or peripheral artery disease (PAD). METHODS: We studied PA, SB and hospitalizations in 12,734 adults from the Hispanic Community Health Study/Study of Latinos, who were 52.2% female with mean (SD) age 41.1 (14.9) years at baseline. Participants reported 10,025 non-pregnancy-related hospitalizations (excluding emergency room only) over 13 years. We modeled the association between accelerometer-measured activity (SB; light/LPA; moderate/MPA; vigorous/VPA) and hospitalization, using Andersen-Gill proportional intensity models, adjusted for demographic, lifestyle, and clinical factors. We tested whether the association differed by baseline diabetes and PAD status: normoglycemia (without diabetes or prediabetes) and no PAD, n=4589; normoglycemia and PAD, n=505; prediabetes and no PAD, n=3987; prediabetes and PAD, n=947; diabetes and no PAD, n=1829; diabetes and PAD, n=877. RESULTS: Greater SB and lesser LPA were significantly associated with hospitalization risk in the overall population, with intensity ratios (IR, generalization of hazard ratio) of 1.03 (95% CI 1.00, 1.05) per hour/day SB, and 0.97 (0.95, 1.00) per hour/day LPA. MPA was inversely associated with hospitalization only when comparing the second tertile to the first; IR (95% CI) 0.88 (0.79, 0.98). Categorical VPA results suggest benefit in those with normoglycemia (regardless of PAD) or prediabetes with no PAD. Among those with diabetes, we observed a direct association between VPA and hospitalization in those without PAD and no association in those with PAD. CONCLUSIONS: Lower risk of hospitalization was associated with lesser SB and greater LPA, while MPA was associated with fewer hospitalizations only when performed for a duration of >8 to ≤22 minutes/day.
Riebe D, Magal M, Kaminsky LA
… +18 more, Ross R, Phillips SM, Alhassan S, Arena R, Behm DG, Camhi SM, Church TS, Evans EM, Feito Y, Faigenbaum AD, Heymsfield SB, Hillman CH, Jankowski CM, Konrad A, Liguori G, Robinson LE, Shanely RA, Garber CE
Med Sci Sports Exerc
· 2026 Mar · PMID 42350265
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The American College of Sports Medicine (ACSM) has included a description of the components of physical fitness (PF) in their publications for 40 years. Because new scientific evidence has emerged, ACSM convened a scient...The American College of Sports Medicine (ACSM) has included a description of the components of physical fitness (PF) in their publications for 40 years. Because new scientific evidence has emerged, ACSM convened a scientific roundtable to reexamine the components of PF. The scientific roundtable agreed upon standardized definitions and an updated evidence-informed model of PF consisting of five interconnected components of PF: 1) cardiorespiratory fitness; 2) muscular fitness; 3) body composition; 4) neuromotor fitness; and 5) flexibility; with muscular fitness, body composition and neuromotor fitness further separated into subcomponents. These components met four inclusion criteria; they: 1) are changeable by exercise; 2) affect the ability to participate in physical activity or exercise; 3) contribute to health; and 4) can be feasibly assessed in professional practice. Additional overriding themes that emerged from the scientific roundtable included the complexity of PF and the interrelated nature of the components. Furthermore, it was agreed that when applied in practice, PF is best addressed in an individualized manner. Therefore, the components of PF should be considered dynamic as the focus on any given component can shift when considering individual needs, goals, health status, and priorities/interests.
Enoki T, Ogasawara Y, Kitano Y
… +1 more, Nishiguchi H
Med Sci Sports Exerc
· 2026 Jun · PMID 42330072
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PURPOSE: This study examined whether progressive high-load resistance training (RT) modifies the PDH regulatory axis governing glycolysis-derived pyruvate handling in fast-twitch flexor hallucis longus (FHL) muscles. MET...PURPOSE: This study examined whether progressive high-load resistance training (RT) modifies the PDH regulatory axis governing glycolysis-derived pyruvate handling in fast-twitch flexor hallucis longus (FHL) muscles. METHODS: Male Wistar rats (n = 18) completed a 5-week progressive high-load RT program using a voluntary ladder-carrying model. FHL muscles were obtained either 24 h after the final session (RT-at-rest) or immediately after the final bout (Post-RT). Enzyme activities, metabolite levels, protein expression, and PDH phosphorylation were assessed using biochemical assays and Western blotting. RESULTS: High-load RT induced significant FHL hypertrophy despite lower body weight and food intake. RT increased the activities of lactate dehydrogenase, citrate synthase, and PDH and elevated total PDH expression (approximately 30%, P < 0.01). PDK4 expression increased, whereas PDK2 and PDP1 remained unchanged. PDH phosphorylation was significantly higher at rest but markedly reduced immediately after exercise, indicating contraction-associated PDH activation. RT also increased markers related to glucose transport, lactate export, and anabolic/energy signaling, whereas PGC-1α and FAT/CD36 expression remained unchanged. CONCLUSIONS: Progressive high-load RT induces metabolic remodeling in fast-twitch muscle characterized by increased PDH abundance, activity, and dynamic phosphorylation regulation. These findings suggest altered PDH-mediated regulation of glycolysis-derived pyruvate metabolism at the muscle level, rather than direct evidence of increased mitochondrial oxidative capacity. PDH regulation may represent a key regulatory interface linking glycolytic metabolism to downstream mitochondrial metabolism in response to progressive high-load RT.
Med Sci Sports Exerc
· 2026 Jun · PMID 42319301
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BACKGROUND: The preservation of shoulder muscle function is essential for independent daily living throughout the lifespan. Intermuscular electromyographic coherence analysis provides a measure of shared neural input acr...BACKGROUND: The preservation of shoulder muscle function is essential for independent daily living throughout the lifespan. Intermuscular electromyographic coherence analysis provides a measure of shared neural input across motor neuron pools, providing insight into neuromuscular control strategies of shoulder muscles, which is important as changes occur during aging. METHODS: Younger (n = 18, 24 ± 5 yrs) and older (n = 20, 71 ± 6 yrs) adults performed an isometric contraction at 30° of shoulder scaption, maintaining 25% of their maximal voluntary contraction until task failure. Intermuscular EMG coherence was measured in three muscle pairs of the dominant shoulder (supraspinatus-infraspinatus, supraspinatus-middle deltoid, and infraspinatus-middle deltoid) during the initial and final 30 s of the fatigue task. RESULTS: There was a significant increase in alpha- and beta-band coherence during fatigue in both age groups across all muscle pairs. However, beta-band coherence was significantly lower in the older adults than in the younger adults across all muscle pairs and fatigue phases. CONCLUSIONS: The results of this study show that older adults have reduced common oscillatory drive from the corticospinal pathway to the shoulder muscles. However, common cortical and subcortical drive to rotator cuff and deltoid muscles increase in both age groups to sustain muscle force during fatigue.
Hammert WB, Yamada Y, Sallberg RW
… +5 more, Moreno EN, Metcalf EE, Young EW, Kataoka R, Loenneke JP
Med Sci Sports Exerc
· 2026 Jun · PMID 42319300
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PURPOSE: To compare the effects of high- versus low-load isotonic resistance training performed to task failure on skeletal muscle growth and distal biceps brachii tendon thickness, while incorporating a time-matched non...PURPOSE: To compare the effects of high- versus low-load isotonic resistance training performed to task failure on skeletal muscle growth and distal biceps brachii tendon thickness, while incorporating a time-matched non-exercise control group. METHODS: 201 non-resistance trained individuals [20.9 (3.0) years] were randomly assigned to one of four groups: High-Load (n=45), Low-Load (n=48), Mid-Point (n=54), or Control (n=54). High- and Low-Load completed 4 sets of unilateral elbow flexions to task failure 3x/week for 6-weeks (8-12RM and 20-30RM, respectively). Mid-Point completed pre- and post-testing, plus a 1RM test at 3-weeks, whereas Control performed pre- and post-testing only. Muscle thickness of the elbow flexors and distal biceps brachii tendon thickness (short- and long-head regions) were assessed via B-mode ultrasound before and after the intervention. Group differences in pre- to post-intervention changes were evaluated using Bayesian ANCOVA with informative hypotheses, supplemented by Bayesian regression models to estimate adjusted between-group differences. RESULTS: Low-Load produced greater increases in muscle thickness than High-Load (~0.30 cm versus ~0.20 cm), with both exceeding changes observed in Mid-Point and Control. In contrast, distal biceps brachii tendon thickness demonstrated small increases at the short-head across all training groups (High-Load, Low-Load, and Mid-Point; ~0.02-0.03 cm) relative to Control, whereas no detectable changes occurred at the long-head. CONCLUSIONS: When resistance exercise is performed to task failure, skeletal muscle and tendon tissues demonstrate distinct adaptation patterns; muscle growth may be augmented by low-load failure training, whereas tendon morphological adaptations may be driven more by localized strain exposure rather than the external load lifted per repetition.
Sakamoto Y, Alhadad SB, Zhang X
… +11 more, Tan BY, Ang WH, Law LYL, Prakaash S, Racinais S, Muniz-Pardos B, Bandiera D, de Barnola EC, Iglesias DP, Pitsiladis Y, Lee JKW
Med Sci Sports Exerc
· 2026 Jun · PMID 42319298
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PURPOSE: To determine the physiological demands and their associations with body core temperature (Tc) of tropical recreational runners during mass participation distance running in a warm-humid environment (Dry bulb Tem...PURPOSE: To determine the physiological demands and their associations with body core temperature (Tc) of tropical recreational runners during mass participation distance running in a warm-humid environment (Dry bulb Temperature: 27.2±0.4°C, relative humidity: 87±2%). METHODS: 162 individuals participated in a 21km (n=84) or 10km (n=78) race. Participants demographics were recorded in a pre-race questionnaire, and in-race measurements of environmental conditions, heart rate (HR, n=115), Tc (n=102), four-site skin temperature (Tsk, n=34) and fluid balance (n=36) were assessed. Real-time monitoring of HR, Tc and geolocation was conducted via a multi-user dashboard. Race split and finishing times were extracted from official results. Correlation and multiple linear regression analyses were performed between various parameters and peak Tc. RESULTS: Participants achieved peak HR (21km: 183±9(154-209)bpm, 10km: 180±10(156-204)bpm), Tc (21km: 39.4±0.6(38.3-40.8)°C, 10km: 39.3±0.6(38.2-41.1)°C) and Tsk (21km: 34.0±0.6(32.8-35.4) °C, 10km: 33.7±0.8(31.9-35.3) °C). Mean Tc was higher (p<0.05) in 21km (38.7±0.5(37.9-39.8)°C) than in 10km (38.5±0.4(37.2-39.9)°C). Tsk exhibited an 'inverted-U' profile in the 21km but plateaued in the 10km race. Body mass loss was -2.5±1.1(-5.5 to -0.7)% and -1.3±0.7(-2.4 to +0.5)% for the 21km and 10km participants, respectively. Starting Tc (18%), mean HR (13%), Body Surface Area (11%), and average speed (9%), but not age, estimated maximal aerobic capacity nor finishing time, to peak Tc. CONCLUSIONS: Recreational runners experienced high cardiovascular and thermal demands. We observed an 'inverted-U' Tsk profile in the 21km race in contrast to a plateau commonly described in laboratory-based findings. Starting Tc, mean HR, Body Surface Area, and average speed were independently associated with inter-individual differences in peak Tc. Real-time monitoring and contributors of peak Tc may inform future development of targeted strategies to optimise safety of recreational populations competing in the heat.