Jesper L Andersen's research while affiliated with Bispebjerg Hospital, Copenhagen University and other places

Publications (101)

Article
Muscle fiber denervation is a major contributor to the decline in muscle mass and function during aging. Heavy resistance exercise is an effective tool for increasing muscle mass and strength, but whether it can rescue denervated muscle fibers remains unclear. Therefore, the purpose of this study was to investigate the potential of heavy resistance...
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Aim & methods: Extreme endurance exercise provides a valuable research model for understanding the adaptive metabolic response of older and younger individuals to intense physical activity. Here, we compare a wide range of metabolic and physiologic parameters in two cohorts of seven trained men, age 30±5 years or age 65±6 years, before and after t...
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Key points: The detrimental effects of ageing can be partially offset by lifelong self-organized recreational exercise, as evidence by preserved type II myofibre associated satellite cells, a beneficial muscle innervation status and greater fatigue resistance under challenged conditions Satellite cell function (in vitro), muscle fibre size and mus...
Article
Muscle fiber denervation is a major contributor to the decline in physical function observed with aging. Denervation can occur through breakdown of the NMJ itself, affecting only that particular fiber, or through the death of a motoneuron, which can lead to a loss of all the muscle fibers in that motor unit. In this review we discuss the muscle-ner...
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Objective Age-related loss of muscle mass and function can be attenuated in rodents with life-long voluntary wheel running with moderate resistance. The present study assessed if sarcopenia could be counteracted with ten weeks high intensity training. Method Old (22–23 months) and middle-aged (11 months) mice were divided into three physical activ...
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Prolonged physical inactivity in young adults may lead to deficiencies in musculoskeletal fitness, and thus a need exists to develop physical activity and exercise programmes that are effective of increasing musculoskeletal fitness. The aim of this study, therefore, was to investigate the effects of small-sided team handball training on lower limb...
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Objectives Optimized concurrent training regimes are warranted in physical training of military-, law enforcement- and rescue-personnel. This study investigated if four 15-min endurance training sessions weekly improve aerobic capacity and performance more than one 60-min endurance session weekly during the initial phase of a Basic Military Trainin...
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Background The aim of the current study was to examine different features of the rectus abdominis muscle (RA) in patients with and without a midline incisional hernia to characterize the effects of a hernia on abdominal wall skeletal muscle. Material and methods RA tissue from patients undergoing surgical repair of a large midline incisional herni...
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The current model for repair of damaged tissue includes immune cells, mediating the progression from a pro-inflammatory to an anti-inflammatory environment. How this process changes with aging in human skeletal muscle under conditions of physiological exercise loading remains unclear. To investigate this, 25 elderly males (mean age 70 ± SD 7 years)...
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The decline in muscle mass and function with age is partly caused by a loss of muscle fibres through denervation. The purpose of this study was to investigate the potential of exercise to influence molecular targets involved in neuromuscular junction (NMJ) stability in healthy elderly individuals. Participants from two studies (one group of 12 youn...
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Objectives Military-, rescue- and law-enforcement personnel require a high physical capacity including muscular strength. The present study hypothesized that 9 weeks of volume matched concurrent short frequent training sessions increases strength more efficiently than less frequent longer training sessions. Design A randomized training interventio...
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Blunted muscle hypertrophy and impaired regeneration with aging have been partly attributed to satellite cell (SC) dysfunction. However, true muscle regeneration has not yet been studied in elderly individuals. To investigate this, muscle injury was induced by 200 electrically stimulated (ES) eccentric contractions of the vastus lateralis (VL) of o...
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Purpose: We tested the hypothesis that participation in small-sided team handball training could provide beneficial effects on cardiovascular and metabolic parameters in overweight premenopausal women with special focus on the importance of prior team handball experience. Methods: A 16-week RCT training intervention was conducted in overweight p...
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Aims To examine satellite cell and myonuclear content in very old (>83 yrs) individuals, and the response to heavy resistance training. Methods A group of very old men and women (Old, 83‐94 yrs, n=29) was randomized to 12 weeks of heavy resistance training or untrained controls. A group of young men who did not resistance train (Young, 19‐27 yrs,...
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Introduction: The majority of young women use oral contraceptives (OCs). Use of OCs has been associated with lower myofibrillar protein and tendon collagen synthesis rates, but it is unknown whether OCs will limit the adaptive response of myotendinous tissue to resistance training. Design and Methods: Fourteen healthy untrained young regular OC use...
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Introduction: Muscle fiber denervation increases with age and yet studies at the tissue level are sparse, due to the challenging nature of establishing the relative role of regeneration and denervation. Methods: Muscle biopsies were obtained from the vastus lateralis of 70 healthy male participants (72±6 yrs, range: 65-94 yrs). mRNA levels of ac...
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The decline in skeletal muscle regenerative capacity with age is partly attributed to muscle stem cell (satellite cell) dysfunction. Recent evidence has pointed to a strong interaction between myoblasts and fibroblasts, but the influence of age on this interaction is unknown. Additionally, while the native tissue environment is known to determine t...
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PURPOSE: To investigate the potential of blocking the angiotensin II type I receptor (AT1R) on the hypertrophy response of elderly human skeletal muscle to four months of heavy resistance exercise training. METHODS: 58 healthy elderly men (+65 years) were randomized into three groups, consuming either AT1R blocker (losartan, 100mg/day) or placebo f...
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Purpose: To investigate the effect of blocking the angiotensin II type I receptor (AT1R) upon the response to acute heavy resistance exercise in elderly human skeletal muscle. The hypothesis was that AT1R blocking would result in a superior myogenic response accompanied by downregulation of TGF-β and upregulation of IGF-1 signalling. Methods: 28...
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Purpose: The present study evaluated the effects of regular participation in small-sided team handball training on body composition, osteogenic response, physical performance, and cardiovascular risk factors, as well as well-being and motivation, in young untrained women. Methods: Twenty-eight untrained 20- to 30-year-old women were randomized t...
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Purpose: The purpose of the present controlled cross-sectional study was to investigate proximal femur and whole-body bone mineral density (BMD), as well as bone turnover profile, in lifelong trained elderly male football players and young elite football players compared with untrained age-matched men. Methods: One hundred and forty healthy, non...
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Introduction: Patients with Ehlers Danlos Syndrome are known to have genetically impaired connective tissue and skeletal muscle symptoms in form of pain, fatigue and cramps, however earlier studies have not been able to link these symptoms to morphological muscle changes. Methods: We obtained skeletal muscle biopsies in patients with classic EDS...
Article
Age-related loss of muscle mass and function represents personal and socioeconomic challenges. The purpose of this study was to determine the adaptation of skeletal musculature in very old individuals (83+ years) performing 12weeks of heavy resistance training (3?/week) (HRT) compared to a non-training control group (CON). Both groups received simi...
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Introduction: Stroke is a leading cause of disability worldwide. High-intensity physical training can improve muscle strength and gait speed, but adaptive mechanisms at the muscle cellular level are largely unknown. Methods: Outpatients with post-stroke hemiparesis participated in a 3-month rehabilitation program combining high-intensity strengt...
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Ceramide and diacylglycerol (DAG) may be involved in the early phase of insulin resistance but data are inconsistent in man. We evaluated if an increase in insulin sensitivity after endurance training was accompanied by changes in these lipids in skeletal muscle. Nineteen first-degree type 2 diabetes Offsprings (Offsprings) (age: 33.1 ± 1.4 yrs; BM...
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Introduction/purpose: Fat metabolism and muscle adaptation was investigated in 6 older trained men (age: 61 ± 4 years; VO2max: 48 ± 2 mL kg min) following repeated prolonged exercise). Methods: 2706 km (1,681 miles) cycling was performed over 14 days and a blood sample and a muscle biopsy were obtained at rest after an overnight fast before and...
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Recent studies have shown that vitamin-D intake can improve skeletal muscle function and strength in frail vitamin-D insufficient individuals. We investigated whether vitamin-D intake can improve the muscular response to resistance training in healthy young and elderly individuals, respectively. Healthy untrained young (n = 20, age 20–30) and elder...
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Matters of fiber size and myonuclear domain; does size matter more than age? The relationship between fiber size and myonuclear content is understood poorly. Biopsy cross-sections from young and old trained and untrained healthy individuals were analyzed for fiber area and myonuclei, and 2 fiber size-dependent cluster analyses were performed. Compa...
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Introduction. The aim was to investigate the effect of high-intensity resistance training on satellite cell (SC) and myonuclear number in the muscle of patients undergoing dialysis. Methods. Patients (n=21) underwent a 16-week control period, followed by 16 weeks of resistance training thrice weekly. SC and myonuclear number were determined by immu...
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OBJECTIVE: To determine the effect of aerobic retraining as rehabilitation after short-term leg immobilization on leg strength, leg work capacity, leg lean mass, leg muscle fibre type composition and leg capillary supply, in young and older men. Subjects and design: Seventeen young (23 ± 1 years) and 15 older (68 ± 1 [standard error of the mean; SE...
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tendon and skeletal muscle function adapts to physical training of resistive nature, but it is unknown to what extent persons with genetically altered connective tissue - who have a higher than normal tendon extensibility - will obtain any effect upon their tendon and muscle when undergoing muscle strength training. We investigated patients with cl...
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Context: Testicular germ cell cancer (GCC) patients treated with cisplatin-etoposide-bleomycin chemotherapy (BEP) have excellent prognosis but have an increased risk of late-occurring morbidities, which may be associated with changes in the inflammatory profile. Objective: The objective of the study was to explore plasma cytokine concentrations...
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Abstract The aim was to investigate performance variables and indicators of cardiovascular health profile in elderly soccer players (SP, n = 11) compared to endurance-trained (ET, n = 8), strength-trained (ST, n = 7) and untrained (UT, n = 7) age-matched men. The 33 men aged 65-85 years underwent a testing protocol including measurements of cycle p...
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Background: We investigated serum testosterone and insulin-like growth factor 1 (IGF-1) levels' associations with muscle fibre size and resistance training in male dialysis patients. Methods: Male patients were included in a 16-week control period followed by 16 weeks of resistance training thrice weekly. Blood samples were obtained to analyse t...
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Background. The aim of this study was to investigate IL-6 and 25-hydroxyvitamin D (25-OH D) associations with muscle size and muscle function in dialysis patients. Methods. Patients were included in a 16-week control period followed by 16 weeks of high-intensity resistance training thrice weekly. IL-6 and 25-OH D were analysed after an over-night f...
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Skeletal muscle energy metabolism has been a research focus of physiologists for more than a century. Yet, how the use of intramuscular carbohydrate and lipid energy stores are coordinated during different types of exercise remains a subject of debate. Controversy arises from contradicting data from numerous studies, which used different methodolog...
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The aim of this study was to investigate the effects of high load resistance training on the rate of force development and neuromuscular function in patients undergoing dialysis. Twenty-nine patients were tested before and after 16 weeks of resistance training. The rate of force development was tested using the "Good Strength" dynamometer chair. Mu...
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Background/aims: The aim of this controlled study was to investigate the effect of high-load strength training on glucose tolerance in patients undergoing dialysis. Methods: 23 patients treated by dialysis underwent a 16-week control period followed by 16 weeks of strength training three times a week. Muscle fiber size, composition and capillary...
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Recovery of skeletal muscle mass from immobilisation-induced atrophy is faster in young than older individuals, yet the cellular mechanisms remain unknown. We examined the cellular and molecular regulation of muscle recovery in young and old human subjects subsequent to 2 weeks of immobility-induced muscle atrophy. Re-training consisted of 4 weeks...
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Important insights concerning the molecular basis of skeletal muscle disuse-atrophy and aging related muscle loss have been obtained in cell culture and animal models, but these regulatory signaling pathways have not previously been studied in aging human muscle. In the present study, muscle atrophy was induced by immobilization in healthy old and...
Data
Changes in the transcriptional status of NF-κB, TNF-α and IL-6 as a result of immobility induced disuse muscle atrophy. The mRNA level of NF-κB, TNF-α and IL-6 was determined using qRT-PCR. A–B. A part from a small increase in the expression of NF-κB at 14 d, we did not find any change in the mRNA expression of NF-κB or TNF-α at any time-point in n...
Data
Primers for the qRT-PCR and TaqMan Low Density array (LDA) assay ID. A. The mRNA expression of FoxO1, FoxO3, FoxO4, PGC-1α, PGC-1β, IL-6, MGF, IGF-1Ea and RPLP0 were analyzed by quantitative real-time RT-PCR. B. TaqMan based quantitative real-time RT-PCR of MuRF-1, Atrogin-1, NF-κB, Bax, BCL2L1, p53, TNF-α, ATG4B, GABARAPL1, and RPLP0 mRNA were per...
Data
Subject characteristics. There was no difference between subjects from the 14 days and 4 days immobilization study with respect to age, weight and BMI, young and old respectively, however, old subjects weighed more and had a higher body mass index (BMI) than young subjects. # Age effect, p<0.05 old compared to young within time point. Data are mean...
Data
Unchanged actin protein levels during skeletal muscle disuse-atrophy. A. Western blotting of whole muscle protein isolates; quantified in B. Protein levels of actin were unchanged at the early (2–4 days) phase of immobility in both young and aged skeletal muscle. Data are geometric means ± back-transformed SEM. Due to lack of muscle tissue n = 6 (3...
Data
Immobility-induced decrease in maximal contractile muscle strength and atrophy of type I and type II muscle fibers. A. Four days of immobility revealed a rapid decrease in maximal contractile muscle in both young and old. The rate of loss in muscle strength seemed to slow down in both groups at 14 d. B. The relative decreases in muscle fiber area o...
Data
Changes in the transcriptional status of GAPDH as a result of immobility induced disuse muscle atrophy. mRNA expression levels of GAPDH were determined using qRT-PCR. * Time effect, p<0.05 compared to pre. Data are geometric means ± back-transformed SEM. (TIF)
Article
Objective: The aim of this study was to investigate the effects of high-load strength training and protein intake in patients undergoing dialysis with a focus on muscle strength, physical performance, and muscle morphology. Design: This was a randomized controlled study conducted in three dialysis centers. Subjects: Subjects for the study incl...
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Purpose: Effects of resistance training and detraining on glucose and insulin responses to an oral glucose load, muscle fiber type, and muscular performance in the offspring of those with type 2 diabetes (familial insulin resistant (FIR)) were investigated. Methods: Six FIR participants and 10 controls (C) completed 9 wk of resistance training a...
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The aim of this study was to make a comprehensive gathering of consecutive detailed blood samples from professional soccer players, and to analyze different blood parameters in relation to seasonal changes in training and match exposure.Blood samples were collected five times during a six months period and analyzed for 37 variables in 27 profession...
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Hemiparesis-disability and muscle weakness of 1 side of the body-is a common consequence of stroke. High-intensity strength training may be beneficial to regain function, but strength coaches in the field of rehabilitation need evidence-based guidelines. The purpose of this study was to evaluate the effect of intensive physical rehabilitation on ne...
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Standard treatment for patients with disseminated germ cell tumors is combination chemotherapy with bleomycin, etoposide and cisplatin (BEP). This treatment is highly effective, but the majority of patients experience severe adverse effects during treatment and are at risk of developing considerable long-term morbidity, including second malignant n...
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Very little attention has been given to the combined effects of aging and disuse as separate factors causing deterioration in muscle mechanical function. Thus the purpose of this study was to investigate the effects of 2 wk of immobilization followed by 4 wk of retraining on knee extensor muscle mechanical function (e.g., maximal strength and rapid...
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The aims of this study were to (1) determine the reproducibility of sub-maximal and maximal versions of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2 test), (2) assess the relationship between the Yo-Yo IE2 test and match performance and (3) quantify the sensitivity of the Yo-Yo IE2 test to detect test-retest changes and discriminate bet...
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Hypertrophy of developing skeletal muscle involves stimulation by insulin-like growth factor-I (IGF-I), however, the role of IGF-I in adult muscle is less clarified. In the present study, the mRNA splice variants of IGF-I (IGF-IEa and MGF) and the changes in muscle fiber cross sectional area after 12 weeks of training were studied in elderly post-o...
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In a sheep model, we investigated diet effects on skeletal muscle mitochondria to look for fetal programming. During pregnancy, ewes were fed normally (N) or were 50% food restricted (L) during the last trimester, and lambs born to these ewes received a normal (N) or a high-fat diet (H) for the first 6 mo of life. We examined mitochondrial function...
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Rapid force capacity of chronically painful muscles is inhibited markedly more than maximal force capacity and is therefore relevant to assess in rehabilitation settings. Our objective was to investigate the effect of two contrasting types of physical exercise on rapid force capacity, as well as neural and muscular adaptations in women with chronic...
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The purpose of this study was to compare changes in muscle strength, power, and morphology induced by conventional strength training vs. plyometric training of equal time and effort requirements. Young, untrained men performed 12 weeks of progressive conventional resistance training (CRT, n = 8) or plyometric training (PT, n = 7). Tests before and...
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Trapezius myalgia - chronic pain from the upper trapezius muscle - is frequent in female employees in monotonous stressful jobs, potentially due to chronic overload of type I muscle fibers. In this study, we investigated the intra-individual distribution of trapezius muscle fiber size, and hypothesized that females with myalgia compared with matche...
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Although the negative effects of bed rest on muscle strength and muscle mass are well established, it still remains a challenge to identify effective methods to restore physical capacity of elderly patients recovering from hospitalization. The present study compared different training regimes with respect to muscle strength, muscle fiber size, musc...
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Chronic uraemia is associated with abnormalities in skeletal muscles, which can affect their working capacity. It is also well known that the fibre-type composition of skeletal muscles influences endurance, muscle strength and power. In this study we therefore determined the size and distribution of muscle fibres and the myosin heavy-chain (MHC) is...