Sportolás elektronikus monitorozással időskorban

Összefoglaló. Idősebb korban a testgyakorlás különösen fontos az izmok sorvadásának megelőzése, valamint a vérnyomás és a testsúly kontrollja céljából. Ma már egyre gyakoribb az időskorúak részvétele sportversenyeken is. Esettanulmányunk célja a késő felnőttkori, illetve időskori versenyszerű sportolás egészségi alkalmassági feltételeinek, kockázatainak és a teljesítőképesség változásainak bemutatása az elektronikus monitorozás és virtuális versenyzés korában. Esetünkben ez egy időskorú személy 16 év során (54–70 éves kor) teljesített maratoni futóversenyeinek, valamint virtuális evezőversenyek részvételi és felkészülési adatainak elemzésével valósul meg. Esetünk illusztrálja, hogy az észszerű túlterhelés elve alapján az izmok adaptációja akkor következik be, amikor az edzés terhelése meghaladja az addig már elért terhelési szintet. A sportóra használata az elektronikus pulzusszám és a teljesítmény monitorozásával nemcsak a versenyek és edzések alatt a pulzusszám céltartományban tartására, de hosszabb távú tendenciák felismerésére is hasznosnak bizonyult. Az egészségi állapotnak megfelelő (sportág és intenzitás) időskori testgyakorlás és sportversenyen való részvétel nemcsak az erőnlét megtartását tűzheti ki célul, hanem értékes erőnlétfejlesztést is. Orv Hetil. 2021; 162(51): 2061–2066. Summary. With advancing age, exercise becomes particularly important to prevent muscle atrophy and to control blood pressure and weight. Today, participation of aging people in athletic competitions is increasingly common. The aim of our case study is to explore and illustrate the health conditions, development and risk factors of competitive sporting activities of late adult and elderly athletes in the age of electronic monitoring and virtual racing. We processed the preparation and participation data of a total of 16 years of marathon races as well as rowing machine races of an elderly male person (age 54–70). Using a sports watch with electronic heart rate and performance monitoring has proved useful not only for keeping the heart rate in target range, but also for assessing trends in the long run. Our case underscores the value of reasonable overload with advancing age; beneficial muscle adaptation occurs when the workload of an exercise exceeds the previously reached level. Gradual exercise of older adults and participation in athletic competitions can not only maintain fitness but also develop valuable additional strength. Orv Hetil. 2021; 162(51): 2061–2066.

Transcriptomic adaptation during skeletal muscle habituation to eccentric or concentric exercise training

Eccentric (ECC) and concentric (CON) contractions induce distinct muscle remodelling patterns that manifest early during exercise training, the causes of which remain unclear. We examined molecular signatures of early contraction mode-specific muscle adaptation via transcriptome-wide network and secretome analyses during 2 weeks of ECC- versus CON-specific (downhill versus uphill running) exercise training (exercise ‘habituation’). Despite habituation attenuating total numbers of exercise-induced genes, functional gene-level profiles of untrained ECC or CON were largely unaltered post-habituation. Network analysis revealed 11 ECC-specific modules, including upregulated extracellular matrix and immune profiles plus downregulated mitochondrial pathways following untrained ECC. Of 3 CON-unique modules, 2 were ribosome-related and downregulated post-habituation. Across training, 376 ECC-specific and 110 CON-specific hub genes were identified, plus 45 predicted transcription factors. Secreted factors were enriched in 3 ECC- and/or CON-responsive modules, with all 3 also being under the predicted transcriptional control of SP1 and KLF4. Of 34 candidate myokine hubs, 1 was also predicted to have elevated expression in skeletal muscle versus other tissues: THBS4, of a secretome-enriched module upregulated after untrained ECC. In conclusion, distinct untrained ECC and CON transcriptional responses are dampened after habituation without substantially shifting molecular functional profiles, providing new mechanistic candidates into contraction-mode specific muscle regulation.

Variability of in vivo sarcomere length measures in the upper limb obtained with second harmonic generation microendoscopy

The lengths of a muscle's sarcomeres are a primary determinant of its ability to contract and produce force. In addition, sarcomere length is a critical parameter that is required to make meaningful comparisons of both the force-generating and excursion capacities of different muscles. Until recently, in vivo sarcomere length data have been limited to invasive or intraoperative measurement techniques. With the advent of second harmonic generation microendosopy, minimally invasive measures of sarcomere length can be made for the first time. This imaging technique expands our ability to study muscle adaptation due to changes in stimulus, use, or disease. However, due to the prior inability to measure sarcomeres outside of surgery or biopsy, little is known about the natural, anatomical variability in sarcomere length in living human subjects. To develop robust experimental protocols that ensure data provide accurate representations of a muscle's sarcomere lengths, we sought to quantify experimental uncertainty associated with in vivo measures of sarcomere lengths. Specifically, we assessed the variability in sarcomere length measured 1) within a single image, along a muscle fiber, 2) across images captured within a single trial, across trials, and across days, as well as 3) across locations in the muscle using second harmonic generation in two upper limb muscles with different muscle architectures, functions, and sizes. Across all of our measures of variability we estimate that the magnitude of the uncertainty in in vivo sarcomere length are on the order of 0.25 microns. In the two upper limb muscles studied we found larger variability in sarcomere length within a single insertion than across locations. We also developed custom code to make measures of sarcomere length variability across a single fiber and determined that this codes' accuracy is an order of magnitude smaller than our measurement uncertainty due to sarcomere variability. Together, our findings provide guidance for the development of robust experimental design and analysis of in vivo sarcomere lengths in the upper limb.

From skeletal muscle damage and regeneration to the hypertrophy induced by exercise: What is the role of different macrophages subsets?

Macrophages are one of the top players when considering immune cells involved with tissue homeostasis. Recently, increasing evidence has demonstrated that these macrophages could also present two major subsets during tissue healing; proliferative macrophages (M1-like), which are responsible for increasing myogenic cell proliferation, and restorative macrophages (M2-like), which are accountable for the end of the mature muscle myogenesis. The participation and characterization of these macrophage subsets is critical during myogenesis, not only to understand the inflammatory role of macrophages during muscle recovery but also to create supportive strategies that can improve mass muscle maintenance. Indeed, most of our knowledge about macrophage subsets comes from skeletal muscle damage protocols, and we still do not know how these subsets can contribute to skeletal muscle adaptation. This narrative review aims to collect and discuss studies demonstrating the involvement of different macrophage subsets during the skeletal muscle damage/regeneration process, showcasing an essential role of these macrophage subsets during muscle adaptation induced by acute and chronic exercise programs.

Transcriptomic analysis for pork color – the ham halo effect in biceps femoris

Pork color is a major indicator of product quality that guides consumerpurchasing decisions. Recently, industry has received an increase in consumercomplaints about the lightness and non-uniformity of ham color, primarilylighter color in the periphery termed “ham halo” that is not caused bymanufacturing procedures. This effect is seen in fresh and processed hams andthe outer, lighter muscle is associated with lower myoglobin concentration, pHand type I fibers. The objective of this study was to identify differences ingene expression profiles between light and normal colored portions of biceps femoris muscle from pork hams.RNA-sequencing was performed for paired light and normal colored muscle samplesfrom 10 animals showing the ham halo effect. Over 50 million paired-end reads(2x75bp) per library were obtained. An average of 99.74% of trimmed high-qualityreads were mapped to the Sscrofa 11.1 genome assembly. Differentially expressedgenes (DEGs) were identified using both the DESeq2 and GFOLD software packages.A total of 14,049 genes were expressed in bicepsfemoris; 13,907 were expressed in both light and normal muscle, while 56and 86 genes were only expressed in light and normal muscle, respectively. Analysiswith DESeq2 identified 392 DEGs with 359 genes being more highly expressed innormal colored muscle. A total of 61 DEGs were identified in the DESeq2analysis and also were identified in at least 7 of the 10 individual animalanalyses. All 61 of these DEGs were up-regulated in normal colored muscle. Geneontology (GO) enrichment analysis of DEGs identified the transition betweenfast and slow fibers, and skeletal muscle adaptation and contraction as themost significant biological process terms. The evaluation of gene expression byRNA-Seq identified DEGs between regions of the biceps femoris with the ham halo effect that are associated with thevariation in pork color.

Response to Electrostimulation Is Impaired in Muscle Cells from Patients with Chronic Obstructive Pulmonary Disease

Among the comorbidities associated with chronic obstructive pulmonary disease (COPD), skeletal muscle weakness and atrophy are known to affect patient survival rate. In addition to muscle deconditioning, various systemic and intrinsic factors have been implicated in COPD muscle dysfunction but an impaired COPD muscle adaptation to contraction has never been extensively studied. We submitted cultured myotubes from nine healthy subjects and nine patients with COPD to an endurance-type protocol of electrical pulse stimulation (EPS). EPS induced a decrease in the diameter, covered surface and expression of MHC1 in COPD myotubes. Although the expression of protein degradation markers was not affected, expression of the protein synthesis marker mTOR was not induced in COPD compared to healthy myotubes after EPS. The expression of the differentiation markers p16INK4a and p21 was impaired, while expression of Myf5 and MyoD tended to be affected in COPD muscle cells in response to EPS. The expression of mitochondrial biogenesis markers PGC1α and MFN2 was affected and expression of TFAM and COX1 tended to be reduced in COPD compared to healthy myotubes upon EPS. Lipid peroxidation was increased and the expression of the antioxidant enzymes SOD2 and GPx4 was affected in COPD compared to healthy myotubes in response to EPS. Thus, we provide evidence of an impaired response of COPD muscle cells to contraction, which might be involved in the muscle weakness observed in patients with COPD.

Effects of Exercise-Induced ROS on the Pathophysiological Functions of Skeletal Muscle

Oxidative stress is the imbalance of the redox system in the body, which produces excessive reactive oxygen species, leads to multiple cellular damages, and closely relates to some pathological conditions, such as insulin resistance and inflammation. Meanwhile, exercise as an external stimulus of oxidative stress causes the changes of pathophysiological functions in the tissues and organs, including skeletal muscle. Exercise-induced oxidative stress is considered to have different effects on the structure and function of skeletal muscle. Long-term regular or moderate exercise-induced oxidative stress is closely related to the formation of muscle adaptation, while excessive free radicals produced by strenuous or acute exercise can cause muscle oxidative stress fatigue and damage, which impacts exercise capacity and damages the body’s health. The present review systematically summarizes the relationship between exercise-induced oxidative stress and the adaptions, damage, and fatigue in skeletal muscle, in order to clarify the effects of exercise-induced oxidative stress on the pathophysiological functions of skeletal muscle.