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Povzetek: This case study compared the acute effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on vascular and microva-scular function in a healthy male subject (age: 34 yrs; body mass index: 25.82 kg/m2). Key vascular parameters were assessed, including augmentation index (AIx), ca-rotid-femoral and brachial-ankle pulse wave velocity (cfPWV, baPWV), flow-mediated slowing (FMS%), and tissue saturation index (TSI) recovery slope. HIIT induced a greater reduction in baPWV (mean difference [MD]: 0.9 m/s) and a higher increase in FMS% (MD: 8%) compared to MICT, indicating more favourable changes in periphe-ral arterial stiffness and endothelial function. Additionally, the reoxygenation slope for TSI was more pronounced after HIIT, suggesting improved microvascular recove-ry. Interestingly, AIx increased following MICT (MD from baseline: 11%) but slightly decreased after HIIT (MD from baseline: −5%). These findings suggest that exercise intensity plays a critical role in determining vascular adaptations, with HIIT showing superior acute benefits
Objavljeno v DiRROS: 10.09.2025; Ogledov: 286; Prenosov: 115
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Povzetek: Evidence suggests athletes with lower baseline cognitive performance are at higher risk of musculoskeletal injuries. This prospective cohort study investigates basic and executive cognitive functions in predicting injuries in 78 professional male football (soccer) players from four Slovenian f irst league teams. Data were collected during the 2018/2019 winter break, and injuries recorded in the second half of that and the 2019/2020 season. Cognitive functions assessed by computerized tests (PsyToolkit) included psychomotor vigilance (simple, choice reaction time) and visuospatial memory (Corsi-block-tapping-test), while pen-and-paper tests assessed motor speed, visual scanning, and executive functions (TMT; Delis-Kaplan-Executive-Function-System). Forty-two players sustained at least one musculoskeletal injury (9 contact injuries), 36 remained injury-free. Logistic regression analyses indicated that none of the cognitive measures significantly influenced injury occurrence (p > 0.05). However, non-significant trends were observed for the TMT ratio score (p = 0.065, OR = 1.64), reflecting cognitive flexibility, and for TMT-A (p = 0.05, OR = 0.60), reflecting visual scanning. Specifically, players with lower cognitive flexibility showed a 64% increase in the odds of sustaining an injury, while better visual scanning performance was associated with a 40% reduction in injury odds. No significant association was found between basic or executive cognitive functions and musculoskeletal injuries in professional male football players. However, a non-significant trend suggested that lower cognitive flexibility may be associated with increased injury risk. These findings underscore the need for larger studies to better clarify the role of executive functions in assessing injury risk in football.
Ključne besede: neurocognitive testing, cognitive-motor tests, sports injury, risk screening
Objavljeno v DiRROS: 08.09.2025; Ogledov: 230; Prenosov: 109
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Povzetek: Previous studies showed that properties of higher‐threshold motor units (MUs) and neuromuscular junction (NMJ) function are preserved during short‐term disuse. This study aimed to test how a longer disuse period affects MU properties, NMJ transmission, and NMJ morphology remodeling. Nine young healthy males (age: 18‐29 years) underwent 21 days of horizontal bed rest. Pre‐ (BR0) and post‐bed rest (BR21), quadriceps maximal voluntary contraction (MVC), and size were assessed. We combined intramuscular electromyography (iEMG) and high‐density surface electromyography (HDsEMG) recordings on the vastus lateralis to assess MU properties at 25% and 50% of MVC. Muscle biopsies and blood samples were also collected. Quadriceps MVC and size decreased at BR21. We found alterations in MU properties at both contraction intensities, including reduced discharge rate, MU potential area changes, and increased complexity. NMJ transmission was found to be reduced at BR21 at 25% MVC. This functional NMJ impairment was biochemically corroborated by an increase in serum C‐terminal agrin fragment concentration, a biomarker of NMJ instability. In addition, a direct assessment of NMJ morphology revealed the presence of some denervated NMJs exclusively at BR21. In conclusion, 21‐day bed rest altered MU properties across different contraction intensities and impaired NMJ transmission with initial signs of remodeling/denervation. Disuse duration appears to be a critical factor, as previous shorter studies failed to detect some of these changes. We believe these findings are clinically relevant for disuse after trauma, surgery, or illness, and may support the development of effective countermeasures.
Ključne besede: disuse, unloading, physical inactivity, electrophysiology, electromyography
Objavljeno v DiRROS: 13.05.2025; Ogledov: 572; Prenosov: 253
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Povzetek: The neuromuscular junction (NMJ) plays a key role in modulating muscle contraction,but the impact of short-term disuse on NMJ structure and function, particularly in older humans,remains unclear. This study aimed to investigate NMJ alterations following 10 days of horizontalbed rest in 10 older males (68.5 ± 2.6 years). Before and after bed rest, vastus lateralis musclebiopsies were obtained to evaluate NMJ morphology, intramuscular EMG (iEMG) was recordedto assess NMJ function and blood samples were collected to determine circulating C-terminal agrinfragment (CAF) concentration, a biomarker of NMJ remodelling. In a sub-cohort of six participantswho had NMJs in both pre- and post-bed rest biopsies, we observed altered NMJ morphology,including reduced overlap between NMJ terminals, as well as increased endplate area and peri-meter. CAF concentration was elevated after bed rest, suggesting ongoing NMJ remodelling. iEMGanalysis showed increased motor unit potential complexity and reduced firing rate. In addition,we observed impaired NMJ transmission, inferred from increased near-fibre jiggle and segmentjitter. These findings suggest that older male individuals are susceptible to NMJ remodelling andimpaired transmission with short-term disuse, providing valuable insights into the morphologicaland functional consequences of inactivity in an ageing population. Our study highlights theimportance of developing interventions for mitigating the detrimental consequences of inactivityon neuromuscular health in older adults, which they frequently experience following injury, trauma,illness or surgery.
Ključne besede: ageing, C-terminal agrin, fragment disuse, electromyography, motor unit, NMJ unloading
Objavljeno v DiRROS: 19.03.2025; Ogledov: 682; Prenosov: 428
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Povzetek: The paradox of rest lies in its dual nature: essential for recovery yet potentially harmful when prolonged. Prolonged physical inactivity (PI) significantly contributes to non-communicable diseases (NCDs). Studies show nearly a third of adults worldwide were insufficiently active in 2022, with the economic costs of PI projected to reach INT$520 billion by 2030. Bedrest models have illuminated the rapid onset of insulin resistance, general functional decline and muscle atrophy associated with PI, particularly in hospitalised older adults. Innovative technologies, such as extended reality (XR), offer promising solutions for mitigating the effects of PI and can enhance non-physical rehabilitation techniques such as motor imagery and action observation. These technologies provide immersive, personalised therapeutic experiences that engage multiple senses, transforming passive recovery into an active process and addressing both the physical and cognitive consequences of inactivity. Results of bedrest study showed significant preservation of muscle mass, improved strength and enhanced insulin sensitivity in the intervention group compared to controls. These findings highlight the potential of XRbased strategies in addressing structural and functional declines during inactivity. As part of the Interreg VI-A Italia-Slovenija project X-BRAIN.net, advanced XR-equipped active rooms were developed to aid post-stroke rehabilitation in acute care settings. XR technologies, particularly VR, have shown promise in providing dynamic and adaptable therapeutic environments that facilitate early and targeted interventions. Future advancements focus on integrating XR with brain-computer interfaces (BCIs) and synchronised visual-haptic neurofeedback, enhancing sensorimotor cortical activation and improving rehabilitation outcomes. Comprehensive multimodal approaches, including nutritional, physical and non-physical interventions, are emerging as effective strategies to personalise and optimise patient recovery.
Ključne besede: physical inactivity, functional and cognitive decline, rehabilitation, extended reality, multimodal interventions
Objavljeno v DiRROS: 05.03.2025; Ogledov: 482; Prenosov: 287
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