Oldies, but goldies—preserved morphology and stability of antigenic determinants in decades-old cryosections of human m. vastus lateralis

Fibre typing by immunohistochemistry on cryosections from human skeletal muscle biopsies is an essential tool in the diagnosis and research of muscular diseases, ageing, and responses to exercise training and disuse. Preserving a good quality in these frozen specimens can be challenging especially if they are stored for longer periods before histological processing, which is often the case in studies with a large number of test subjects and/or repeated sampling separated by multiple years. We demonstrate in this article that both, the morphology and reactivity of epitopes to myosin heavy chain isoforms and dystrophin are well preserved in up to 18-year-stored unfixed and unstained cryosections of human m. vastus lateralis (n = 241). Any variation in staining intensity between samples was unrelated to the age of the biopsy donor or the storage period of the unstained cryosections, and in all cases, the obtained images were appropriate for image analysis, such as the determination of the fibre type composition and the fibre cross-sectional area, and quantitative analysis of muscle capillarisation

No ageing-related increase in fibre type grouping in sprint-trained masters runners: a 10-year follow-up study

Background Previous research suggests that an ageing-associated remodelling and loss of motor units due to motor neuron death contributes significantly to muscle weakness in old age. In histological sections, motor unit remodelling is reflected by increased fibre type grouping. While regular exercise may not attenuate the loss of motor units during ageing, it has been suggested to facilitate reinnervation resulting in larger motor units, and a higher number and larger fibre type groups in histological sections of muscles from aged individuals. Methods In a 10-year follow-up study, we assessed changes in the prevalence and size of fibre type groups in the vastus lateralis muscle from 34 male masters sprinters (40–85 years at start). Results Over the 10 years, there was an ageing-related reduction in performance in the 60-m sprint (P < 0.001) without significant changes in fibre type composition and fibre cross-sectional area. Neither the number of fibre type groups, defined as a fibre surrounded exclusively by fibres of the same type, nor the group size changed significantly in the 10-year period. Conclusions These histological data show that there is limited to no significant fibre type grouping over a 10-year period in masters athletes who continued sprint run training. This observation challenges the paradigm that ageing, at least in systematically trained sprinters, is associated with motor unit remodelling

Longitudinal Associations of High-Volume and Vigorous-Intensity Exercise With Hip Fracture Risk in Men

Maintenance of vigorous exercise habits from young to old age is considered protective against hip fractures, but data on fracture risk in lifelong vigorous exercisers are lacking. This longitudinal cohort study examined the hazard of hip fractures in 1844 male former athletes and 1216 population controls and in relation to exercise volume and intensity in later years. Incident hip fractures after age 50 years were identified from hospital discharge register from 1972 to 2015. Exercise and covariate information was obtained from questionnaires administered in 1985, 1995, 2001, and 2008. Analyses were conducted using extended proportional hazards regression model for time-dependent exposures and effects. During the mean +/- SD follow-up of 21.6 +/- 10.3 years, 62 (3.4%) athletes and 38 (3.1%) controls sustained a hip fracture. Adjusted hazard ratio (HR) indicated no statistically significant difference between athletes and controls (0.84; 95% confidence interval [CI], 0.55-1.29). In subgroup analyses, adjusted HRs for athletes with recent high (>= 15 metabolic equivalent hours [MET-h]/week) and low (= 6 METs at least 75 minutes/week) had initially 77% lower hazard rate (adjusted HR 0.23; 95% CI, 0.06-0.86) than controls. However, the HR was time-dependent (adjusted HR 1.04; 95% CI, 1.01-1.07); by age 75 years the HRs for the athletes with vigorous-intensity exercise reached the level of the controls, but after 85 years the HRs for these athletes increased approximately 1.3-fold annually relative to the controls. In conclusion, these data suggest that continuation of vigorous-intensity exercise is associated with lower HR of hip fracture up to old age. (c) 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).Peer reviewe

Ankle and knee extensor muscle effort during locomotion in young and older athletes : Implications for understanding age-related locomotor decline

Age-related reduction in muscle force generation capacity is similarly evident across different lower limb muscle groups, yet decline in locomotor performance with age has been shown to depend primarily on reduced ankle extensor muscle function. To better understand why ageing has the largest detrimental effect on ankle joint function during locomotion, we examined maximal ankle and knee extensor force development during a two-leg hopping test in older and young men, and used these forces as a reference to calculate relative operating efforts for the knee and ankle extensors as participants walked, ran and sprinted. We found that, across locomotion modes in both age groups, ankle extensors operated at a greater relative effort compared to knee extensors; however, slightly less pronounced differences between ankle and knee extensor muscle efforts were present among older men, mainly due to a reduction in the ankle extensor force generation during locomotion modes. We consider these findings as evidence that reduced ankle push-off function in older age is driven by a tendency to keep ankle extensor effort during locomotion lower than it would otherwise be, which, in turn, may be an important self-optimisation strategy to prevent locomotor-induced fatigue of ankle extensor muscles.Peer reviewe

Body composition in male lifelong trained strength, sprint and endurance athletes and healthy age-matched controls

IntroductionAging involves many physiological processes that lead to decreases in muscle mass and increases in fat mass. While regular exercise can counteract such negative body composition outcomes, masters athletes maintain high levels of exercise throughout their lives. This provides a unique model to assess the impact of inherent aging. The present study compared lean mass and fat mass in young and masters athletes from different sports to age-matched non-athletic individuals.MethodsParticipants included young (20–39 years, n = 109) and older (70–89 years, n = 147) competitive male athletes, and 147 healthy age-matched controls (young = 53, older = 94 males). Athletes were separated into strength (e.g., weightlifters, powerlifters), sprint (e.g., sprint runners, jumpers) and endurance (e.g., long-distance runners, cross-country skiers) athletic disciplines. Body composition was assessed by dual-energy x-ray absorptiometry (DXA). Upper and lower limb lean mass was combined for appendicular lean mass as well as appendicular lean mass index (ALMI; kg/m2). Individuals’ scores were assessed against established cut-offs for low muscle mass, obesity, and sarcopenic obesity to determine prevalence in each group.ResultsALMI was greater in young strength (0.81–2.36 kg/m2, ∼15% and 1.24–2.74 kg/m2, ∼19%) and sprint (95% CI = 0.51–1.61 kg/m2, ∼11% and 0.96–1.97 kg/m2, ∼15%) athletes than in endurance and controls, respectively (all P &lt; 0.001). In masters athletes, only strength athletes had greater ALMI than endurance athletes, but both older strength and sprint athletes had greater ALMI than older controls (0.42–1.27 kg/m2, ∼9% and 0.73–1.67 kg/m2, ∼13%, respectively, both P &lt; 0.001). Fat mass was significantly lower in sprint and endurance athletes compared to strength athletes and controls in both age-groups. Sarcopenic obesity was identified in one young (2%) and eighteen (19%) older controls, while only two older endurance athletes (3%) and one older strength athlete (2%) were identified.DiscussionLifelong competitive sport participation leads to lower prevalence of sarcopenic obesity than a recreationally active lifestyle. This is achieved in strength athletes by emphasizing muscle mass, while sprint and endurance athletes demonstrate low fat mass levels. However, all older athlete groups showed higher fat mass than the young groups, suggesting that exercise alone may not be sufficient to manage fat mass

Soluble CD73 in Critically Ill Septic Patients Data from the Prospective FINNAKI Study

Background CD73 dephosphorylates adenosine monophosphate to adenosine that is an anti-inflammatory molecule inhibiting immune activation and vascular leakage. Therefore, CD73 could be an interesting mediator both in sepsis and acute kidney injury (AKI). We aimed to explore the soluble CD73 (sCD73) levels and their evolution in critically ill patients with severe sepsis and, second, to scrutinize the potential association of sCD73 levels with AKI and 90-day mortality. Methods This was a post-hoc laboratory analysis of the prospective, observational FINNAKI study conducted in 17 Finnish ICU during 5 months in 2011-2012. Plasma samples of 588 patients admitted with severe sepsis/shock or with developing severe sepsis were analyzed at 0h (ICU admission) and 24h, and additionally, on day 3 or day 5 from a subset of the patients. Results The median [IQR] sCD73 levels at 0h were 5.11 [3.29-8.28] ng/mL and they decreased significantly from 0h to 4.14 [2.88-7.11] ng/mL at 24h, P Conclusions Compared to normal population, the sCD73 levels were generally low at 0h, showed a decrease to 24h, and later an increase by day 5. The sCD73 levels do not seem useful in predicting the development of AKI or 90-day mortality among patients with severe sepsis or shock.Peer reviewe

Does Longer Leukocyte Telomere Length and Higher Physical Fitness Protect Master Athletes From Consequences of Coronavirus (SARS-CoV-2) Infection?

peerReviewe

Absence of an ageing-related increase in fibre type grouping in athletes and non-athletes.

The ageing-related loss of muscle mass is thought to be partly attributable to motor neuron loss and motor unit remodelling that result in fibre type grouping. We examined fibre type grouping in 19- to 85-year-old athletes and non-athletes and evaluated to which extent any observed grouping is explained by the fibre type composition of the muscle. Since regular physical activity may stimulate reinnervation, we hypothesised that fibre groups are larger in master athletes than in age-matched non-athletes. Fibre type grouping was assessed in m. vastus lateralis biopsies from 22 young (19-27 years) and 35 healthy older (66-82 years) non-athletes, and 14 young (20-29 years), 51 middle-aged (38-65 years) and 31 older (66-85 years) athletes. An 'enclosed fibre' was any muscle fibre of a particular type surrounded by fibres of the same type only. A fibre type group was defined as a group of fibres with at least one enclosed fibre. Only type II fibre cross-sectional area (FCSA) showed an age-related decline that was greater in athletes (p < 0.001) than in non-athletes (p = 0.012). There was no significant age-related effect on fibre group size or fibre group number in athletes or non-athletes, and the observed grouping was similar to that expected from the fibre type composition. At face value these observations do 1) neither show evidence for an age-related loss and remodelling of motor units nor 2) improved reinnervation with regular physical activity, but 3) histological examination may not reveal the full extent of ageing-related motor unit remodelling

Kustannusvaikuttavat keinot metsäluonnon monimuotoisuuden köyhtymisen pysäyttämiseksi

Metsäluonnon monimuotoisuuden köyhtymisen pysäyttämiseksi tarvitaan metsien suojelun ja talousmetsien luonnonhoidon lisäämistä. Raportissa tarkastellaan monimuotoisuuden turvaamisen toimenpiteiden ja ohjauskeinojen kustannusvaikutuksia tilanteessa, jossa puusta valmistettujen tuotteiden kysynnän kasvu lisää metsien hakkuita. Suomessa metsien suojelun ja talousmetsien luonnonhoidon ja hakkuiden voimakas lisääminen voi aiheuttaa pitkällä aikavälillä sen, että metsäteollisuuden käyttöön ei riitä kotimaista puuta. Luontokadon kustannustehokas pysäyttäminen edellyttää, että pinta-alatavoitteiden lisäksi pystytään tunnistamaan monimuotoisuuden turvaamisen kannalta tällä hetkellä parhaat kohteet ja puuntuotannon kannalta vähämerkityksiset alueet, joita voidaan kehittää monimuotoisuutta edistävästi. METSO- ja Helmi-ohjelmien tunnettuuden lisääminen ja tilakohtaisten luonnonhoitosuunnitelmien laatiminen olisivat kustannustehokkaita keinoja saada metsänomistajat tarjoamaan lisää kohteita suojeluun ja kiinnostumaan luonnonhoidosta. Ohjelmien rahoituksen lisääminen ja kohteiden kriteerien väljentäminen toisi suojeluun luontoarvoiltaan kehittyviä kohteita. Luonnonhoitoon voitaisiin kehittää pinta-alaan perustuva tuki metsien rakennepiirteiden säilyttämiseksi. Monimuotoisuuden turvaamiseen voitaisiin kehittää vastaavia kompensaatiomekanismeja kuin kasvihuonekaasupäästöjen kompensoimiseen.Tämä julkaisu on toteutettu osana valtioneuvoston selvitys- ja tutkimussuunnitelman toimeenpanoa. (tietokayttoon.fi) Julkaisun sisällöstä vastaavat tiedon tuottajat, eikä tekstisisältö välttämättä edusta valtioneuvoston näkemystä

Effects of aging and training on sprint performance, muscle structure and contractile function in athletes

Cross-sectional studies were conducted to examine sprint running, anaerobic energy production and muscle properties in male sprinters aged 17-88 years. In addition, a 20-week training intervention was carried out to determine whether older runners can further improve their neuromuscular and performance characteristics by a greater emphasis on strength training. With age, sprint performance declined gradually (5-6%/decade). The slowing of maximum speed was characterized by a reduction in stride length and an increase in contact time along with lower ground reaction forces (GRF) and smaller leg and vertical stiffness during the contact phase. Stride frequency showed small decline while swing time remained unaffected with age.Variability in the biomechanical parameters that showed good repeatability (CV 1-6%) was the same in the older as younger runners, and no age effect was seen in the symmetry of the measures. [La]b peak declined with age after races over 100-400 m, the decrease becoming more evident from age 70. Running times correlated inversely with [La]b peak. Leg muscle thickness, type II fiber size and myosin heavy chain (MyHC) II isoform content decreased with age, while type I fiber size, fiber distribution and fascicle length showed no age differences. In single type I and IIa MyHC fibers, neither force adjusted for fiber size nor contractile speed differed between the groups. There was an age-related decline in maximal (8-9%/decade) and explosive (10-11%/decade) isometric and dynamic leg strength. The differences in maximal, but not in explosive, isometric strength were eliminated when normalized for muscle thickness. Muscle thickness was the strongest predictor of GRF in the braking phase, while the countermovement jump explained most of the variance in push-off GRF. The sprint training, including heavy-resistance and high-power strength exercises, resulted in significant gains in maximal and explosive strength and improvements in force production during running.The improvements were mainly related to hypertrophic adaptations. The results show that the deterioration in sprint performance with age is a complex phenomenon that may be affected by the interaction of changes in biomechanical, neuromuscular and metabolic factors. A major contributor appears to be reduced muscle mass, caused partially by decreased type II fiber size, which affects the GRFs required to achieve fast running speeds. However, habitual sprint training seems to maintain speed, strength and glycolytic energy production at high levels into older age and is effective in preventing the age-related decline in single fiber function and fascicle length. The data also suggest that to maximize the training effects on fast fibers, rapid strength and speed performance, the optimal training regimen requires a strength training component.Ikääntyvät urheilijat tarjoavat tutkijoille vanhenemismallin, jossa fysiologiset muutokset ovat selvemmin yhteydessä biologiseen vanhenemiseen kuin elimistön vajaakäyttöön ja kroonisiin sairauksiin. Tähänastiset tutkimukset urheilijoilla ovat osoittaneet, että säännöllinen voima- ja kestävyysharjoittelu voi ylläpitää lihasten ja hengitys- ja verenkiertoelimistön kuntoa pitkälle vanhuuteen asti. Edelleen on kuitenkin epäselvää, missä määrin nopeussuorituskyvyn heikkenemistä, jota pidetään yhtenä kriittisenä vanhenemismuutoksena, voitaisiin vastustaa asianmukaisen harjoittelun avulla. Marko Korhonen tutki väitöskirjatyössään ikään liittyviä eroja maksimaalisessa juoksunopeudessa, voimantuotto-ominaisuuksissa, lihasrakenteessa ja anaerobisessa energiantuotossa 17-88-vuotiailla pikajuoksijoilla. Tutkimus koostui kahdesta havainnoivasta poikittaistutkimuksesta ja yhdestä kokeellisesta, 20 viikon harjoittelututkimuksesta, joihin osallistui yhteensä 173 urheilijaa.Tulokset osoittivat että pikajuoksun lajisuorituskyky heikkenee keskimäärin noin puoli prosenttiyksikköä vuodessa 35.-40. ikävuoden jälkeen. 70–vuotiaiden veteraaniurheilijoiden maksimaalinen juoksunopeus vastasi kuitenkin 30 vuotta nuorempien harjoittelemattomien henkilöiden tasoa. Eri-ikäisten urheilijoiden vertailu viittaa siihen, että keskeinen mekanismi on lihasmassan väheneminen, mikä ilmenee erityisesti nopeiden lihassolujen koon pienenemisenä. Maksimijuoksussa tämä rajoittaa ponnistusvoimaa lyhyen kontaktivaiheen aikana ja sitä kautta lyhentää askelpituutta. Tulokset viittaavat myös siihen, että pikajuoksusuorituksen heikkeneminen iän myötä johtuu osittain elimistön kyvystä tuottaa energiaa ilman happea.Alaraajojen lihasten voimantuottonopeuden hidastuminen näyttäisi kytkeytyvän nopean lihassolukon pienenemisen lisäksi heikentyneeseen kykyyn aktivoida lihasta. Vastoin aikaisempia havaintoja pikajuoksijoiden nopea voimantuottokyky säilyi kuitenkin erittäin hyvin suhteessa maksimivoimaan. Veteraanipikajuoksijoilla ei havaittu reiden tai pohkeen lihaskimppujen pituudessa ikään liittyvää lyhenemistä, mikä yleensä hidastaa lihaksen supistumisnopeutta. Lihassolujen pinta-alaan suhteutettu voima ja supistumisnopeus eivät myöskään muuttuneet iän myötä.Interventiotutkimus osoitti, että yhdistämällä maksimi- ja nopeusvoimatyyppisiä harjoitteita lajinomaiseen juoksuharjoitteluun voidaan edelleen parantaa voima- ja nopeusominaisuuksia, nopeiden lihassolujen kokoa ja mahdollisesti myös lihaksen nopeaa aktivointikykyä. Valmennuksen näkökulmasta vaikuttaa siltä, että intensiivisiä voimaharjoitteita kannattaa sisällyttää ikääntyvien urheilijoiden harjoitusohjelmiin.Heikentynyt kyky nopeisiin koordinoituihin liikesuorituksiin on tärkeä taustatekijä iäkkäiden ihmisten liikkumis- ja tasapainovaikeuksissa. Tästä syystä voidaan suositella, että myös tavallisten kuntoilijoiden ja aikaisemmin harjoittelemattomien keski-ikäisten ja iäkkäiden ihmisten liikuntaohjelmiin liitetään nopeusvoimatyyppisiä harjoitusärsykkeitä