Peripheral adaptations to endurance training - Effect of active muscle mass

This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. © 2019 The Authors Translational Sports Medicine Published by John Wiley & Sons Ltd.The purpose of this study was to evaluate whether adaptations to endurance training are affected by active muscle mass during training. Eleven healthy subjects performed 5 weeks of one‐legged knee extension (1‐KE) training with both legs, separately. During the 1‐KE workouts for one of the legs, arm cycling was added (1L2A), while the other leg only performed 1‐KE (1L). During the training sessions, the 1‐KE power output and session duration were equal for both legs. Whole‐body oxygen uptake (V̇O2), adrenaline, and noradrenaline plasma concentrations were 112% ± 11%, 139% ± 144%, and 197% ± 101% higher during 1L2A than 1L, respectively. However, this did not affect the 1‐KE training adaptations since submaximal O2‐cost, heart rate and blood lactate concentration, maximal V̇O2, and power output all improved equally in both legs. This was supported by similar capillarization and concentration of oxidative enzymes in the legs after the training period. The present study therefore indicates that the size of active muscle mass per se during exercise does not affect adaptations to endurance training.publishedVersio

Block periodization of endurance training – a systematic review and meta-analysis

© 2019 Mølmen et al. This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms. php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php).Background: Block periodization (BP) has been proposed as an alternative to traditional (TRAD) organization of the annual training plan for endurance athletes. Objective: To our knowledge, this is the first meta-analysis to evaluate the effect BP of endurance training on endurance performance and factors determinative for endurance performance in trained- to well-trained athletes. Methods: The PubMed, SPORTdiscus and Web of Science databases were searched from inception to August 2019. Studies were included if the following criteria were met: 1) the study examined a block-periodized endurance training intervention; 2) the study had a one-, two or multiple group-, crossover- or case-study design; 3) the study assessed at least one key endurance variable before and after the intervention period. A total of 2905 studies were screened, where 20 records met the eligibility criteria. Methodological quality for each study was assessed using the PEDro scale. Six studies were pooled to perform meta-analysis for maximal oxygen uptake (VO2max) and maximal power output (Wmax) during an incremental exercise test to exhaustion. Due to a lower number of studies and heterogenous measurements, other performance measures were systematically reviewed. Results: The meta-analyses revealed small favorable effects for BP compared to TRAD regarding changes in VO2max (standardized mean difference, 0.40; 95% CI=0.02, 0.79) and Wmax (standardized mean difference, 0.28; 95% CI=0.01, 0.54). For changes in endurance performance and workload at different exercise thresholds BP generally revealed moderate- to large-effect sizes compared to TRAD. Conclusion: BP is an adequate, alternative training strategy to TRAD as evidenced by superior training effects on VO2max and Wmax in athletes. The reviewed studies show promising effects for BP of endurance training; however, these results must be considered with some caution due to small studies with generally low methodological quality (mean PEDro score =3.7/10).publishedVersio

Muscular performance decreases with increasing complexity of resistance exercises in subjects with chronic obstructive pulmonary disease

Chronic obstructive lung disease (COPD) is associated with impaired muscle functions in addition to the impaired cardiopulmonary capacity inherent to the disease. The purpose of this study was to compare muscular performance between COPD subjects (COPD, n = 11, GOLD grade II/III; FEV1 = 53 ± 14% predicted; 61 ± 7 years) and healthy controls (HC, n = 12, 66 ± 8 years) in three resistance exercises with different complexity: (a) one‐legged knee extension (1KE), and (b) one‐ and (c) two‐ legged leg press (1LP and 2LP, respectively). For each exercise, muscular performance was defined as repetitions to exhaustion at 60% of one‐repetition maximum or overall exercise volume, calculated as the sum of three exercise sets. In HC, muscular performance increased progressively with increasing physiological complexity: 1KE < 1LP 1LP), advocating utilization of one‐legged resistance protocols for rehabilitation purposes.publishedVersio

Resistance exercise training increases skeletal muscle mitochondrial respiration in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is associated with skeletal muscle mitochondrial dysfunction. Resistance exercise training (RT) is a training modality with a relatively small pulmonary demand that has been suggested to increase skeletal muscle oxidative enzyme activity in COPD. Whether a shift into a more oxidative profile following RT also translates into increased mitochondrial respiratory capacity in COPD is yet to be established. This study investigated the effects of 13 weeks of RT on m. vastus lateralis mitochondrial capacity in 11 per sons with moderate COPD [45% females, age: 69 ± 4 years (mean ± SD), predicted forced expiratory volume in 1 s (FEV1): 56 ± 7%] and 12 healthy controls (75% females, age: 66 ± 5 years, predicted FEV1: 110 ± 16%). RT was supervised and carried out two times per week. Leg exercises included leg press, knee extension, and knee flexion and were performed unilaterally with one leg conducting high-load training (10 repetitions maximum, 10RM) and the other leg conducting low-load training (30 repetitions maximum, 30RM). One-legged muscle mass, maximal muscle strength, and endurance performance were determined prior to and after the RT period, together with mitochondrial respiratory capacity using high-resolution respirometry and citrate synthase (CS) activity (a marker for mitochondrial volume density). Transcriptome analysis of genes associated with mitochondrial function was performed. Resistance exercise training led to similar improvements in one-legged muscle mass, muscle strength, and endurance performance in COPD and healthy individuals. In COPD, mitochondrial fatty acid oxidation capacity and oxidative phosphorylation increased following RT (+13 ± 22%, P = 0.033 and +9 ± 23%, P = 0.035, respectively). Marked increases were also seen in COPD for mitochondrial volume density (CS activity, +39 ± 35%, P = 0.001), which increased more than mitochondrial respiration, leading to lowered intrinsic mitochondrial function (respiration/CS activity) for complex-1- supported respiration ( 12 ± 43%, P = 0.033), oxidative phosphorylation ( 10 ± 42%, P = 0.037), and electron transfer system capacity ( 6 ± 52%, P = 0.027). No differences were observed between 10RM and 30RM RT, nor were there any adaptations in mitochondrial function following RT in healthy controls. RT led to differential expression of numerous genes related to mitochondrial function in both COPD and healthy controls, with no difference being observed between groups. Thirteen weeks of RT resulted in augmented skeletal muscle mitochondrial respiratory capacity in COPD, accompanied by alterations in the transcriptome and driven by an increase in mitochondrial quantity rather than improved mitochondrial quality.publishedVersio

Chronic obstructive pulmonary disease does not impair responses to resistance training

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Vitamin D3 supplementation does not enhance the effects of resistance training in older adults

Background: Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner. This phenomenon is particularly common among older adults and those with chronic diseases (e.g. chronic obstructive pulmonary disease, COPD) and may involve endocrine variables such as vitamin D. At present, the effects of vitamin D supplementation on responses to resistance training remain largely unexplored. Methods: Ninety-five male and female participants (healthy, n = 71; COPD, n = 24; age 68 ± 5 years) were randomly assigned to receive either vitamin D3 or placebo supplementation for 28 weeks in a double-blinded manner (latitude 61°N, September-May). Seventy-eight participants completed the RCT, which was initiated by 12 weeks of supplementation-only (two weeks with 10 000 IU/day, followed by 2000 IU/day), followed by 13 weeks of combined supplementation (2000 IU/day) and supervised whole-body resistance training (twice weekly), interspersed with testing and measurements. Outcome measures included multiple assessments of muscle strength (nvariables = 7), endurance performance (n = 6), and muscle mass (n = 3, legs, primary), as well as muscle quality (legs), muscle biology (m. vastus lateralis; muscle fibre characteristics, transcriptome), and health-related variables (e.g. visceral fat mass and blood lipid profile). For main outcome domains such as muscle strength and muscle mass, weighted combined factors were calculated from the range of singular assessments. Results: Overall, 13 weeks of resistance training increased muscle strength (13% ± 8%), muscle mass (9% ± 8%), and endurance performance (one-legged, 23% ± 15%; whole-body, 8% ± 7%), assessed as weighted combined factors, and were associated with changes in health variables (e.g. visceral fat, -6% ± 21%; [LDL]serum , -4% ± 14%) and muscle tissue characteristics such as fibre type proportions (e.g. IIX, -3% points), myonuclei per fibre (30% ± 65%), total RNA/rRNA abundances (15%/6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in [25(OH)D]serum (∆49% vs. placebo). No conditional effects were observed for COPD vs. healthy or pre-RCT [25(OH)D]serum . In secondary analyses, vitamin D3 affected expression of gene sets involved in vascular functions in muscle tissue and strength gains in participants with high fat mass, which advocates further study. Conclusions: Vitamin D3 supplementation did not affect muscular responses to resistance training in older adults with or without COPD. Keywords: Cholecalciferol; Muscle plasticity; Strength training. © 2021 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders.publishedVersio

The impact of vitamin D3 supplementation, chronic obstructive pulmonary disease and exercise load on resistance training-associated adaptations in older adults

Background: Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner to such treatment. This phenomenon is particularly common among older adults and those with chronic diseases such as chronic obstructive pulmonary disease (COPD) and may involve endocrine characteristics such as low vitamin D status and low-grade inflammation, as well as suboptimal training protocols. Aims: The Granheim COPD Study consisted of two studies; a preparatory study and a RCT study. COPD is associated with impaired cardiorespiratory capacity, but it remains uncertain if this affects muscular performance. Therefore, in the preparatory study, the aim was to compare muscular performance in three resistance exercises of the legs involving different amounts of active muscle mass in COPD and healthy control (Healthy) persons (Paper I). In the RCT study, the aim was to investigate the effects of 12 weeks of vitamin D3 supplementation-only, followed by 13 weeks of combined vitamin D3 supplementation and resistance training, on muscle functional and biological training-associated adaptations in a mixed group of older adults, and also to compare the muscle functional and biological effects of resistance training for COPD and Healthy, as well as high-load vs low-load resistance training (Paper II-IV). Participants and methods: In the preparatory study, 11 COPD (GOLD grade II/III; forced expiratory volume in first second (FEV1), 53±14% of predicted value; age 66±8 years) and 12 Healthy (FEV1, 117±12% of predicted value; age 62±7 years) participants performed tests of muscular performance in three resistance exercises with different complexity and physiological demand; (i) one-legged knee extension, (ii) one- and (iii) two-legged leg press. In the RCT study, 95 older individuals (56-77 years) were randomly assigned to receive either vitamin D3 or placebo supplementation, stratified by health status (COPD, n=24; Healthy, n=71) and sex. The intervention was initiated by 12 weeks of supplementation-only (two weeks with 10 000 international units (IU) vitamin D3 .day-1, thereafter 10 weeks with 2 000 IU.day-1), followed by 13 weeks of combined supplementation (2 000 IU.day-1) and supervised whole-body resistance training (twice weekly). In the training sessions, leg exercises were performed unilaterally, with one leg randomized to high-load training (10 repetitions maximum; RM) and the contralateral leg randomized to low-load training (30RM). This unilateral training protocol served two purposes: i) to circumvent issues relating to conduction of training with two-legged exercises and ii) to investigate the relative efficacy of two different training modalities. Outcome measures included multiple assessments of muscle strength (nvariables=7), endurance performance (nvariables=6), muscle mass (nvariables=2), muscle quality, muscle biology (m. vastus lateralis; muscle fiber characteristics, RNA content including transcriptome) and health-related variables (body composition, lung function, blood, health-related quality of life). For a subset of participants (COPD, n=11; Healthy, n=12), outcome measures also included mitochondrial quantity (citrate synthase activity) and respiratory capacity. For core outcome domains (muscle strength/mass/quality and lower-limb/whole-body endurance performance), weighted combined factors were calculated from the range of singular assessments. Main results: In the preparatory study, muscular performance was impaired for COPD in two-legged leg press compared to Healthy, but not in one-legged leg press, suggesting that the cardiorespiratory limitations inherent to the disease seems to negatively influence the performance in resistance exercises involving larger amounts of active muscle mass (>one-legged leg press) (Paper I). In the RCT study, 13 weeks of resistance training increased muscle strength (13%), muscle mass (9%) and endurance performance (one-legged, 23%; whole-body, 8%), assessed as weighted combined factors, and were associated with beneficial changes in health variables (e.g. visceral fat, -6%; lowdensity lipoprotein levels, -4%) and muscle tissue characteristics such as muscle fiber type proportions (e.g. IIX, -3%-points), myonuclei·fiber-1 (30%), total RNA/rRNA abundances (15%/6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in serum 25(OH)D levels (Δ49% vs placebo) (Paper II). In secondary analyses, resistance training with vitamin D3 supplementation resulted in higher expression of gene sets involved in vascular functions in muscle tissue and larger strength gains in participants with high fat mass, compared to resistance training-only (Paper II). In the RCT study, COPD participants displayed wellknown disease-related pathophysiologies compared to Healthy at baseline, including impaired lung function, higher levels of systemic low-grade inflammation (serum c-reactive protein levels), lower muscle mass and functionality, and muscle biological aberrancies such as lower mitochondrial oxidative capacity, higher proportions of muscle fiber type IIA and IIX and genome-wide differences in transcriptome profiles (differential mRNA expression of 227 genes) (Paper III-IV). However, despite these adversities, COPD participants showed similar or larger improvements to resistance training for health and muscle functional and biological variables compared to Healthy (Paper III-IV). 10RM and 30RM training were associated with similar ratings of perceived exertion. When combining the data from the two study clusters (i.e. COPD and Healthy), 30RM training led to more pronounced increases in lower-body muscle mass compared to 10RM, while 10RM training led to a larger fiber type conversion from IIX to IIA and larger improvements in cycling economy compared to 30RM, but this was not associated with differential changes in muscle strength and muscle performance between the two exercise modalities. Furthermore, 10RM resistance training was associated with improved ability to maintain bone mineral density compared to 30RM resistance training. Conclusions: Vitamin D3 supplementation did not affect muscular responses to resistance training. This rejects the notion that vitamin D3 supplementation is necessary to obtain adequate muscular responses to resistance training in the general older population, at least for the enrolled clusters of COPD and Healthy participants with mostly sufficient vitamin D levels at pre-RCT. Although COPD participants showed clear functional and biological deviations compared to Healthy at baseline, which previously has been speculated to be associated with impaired training responsiveness, they did not show such impaired responses to resistance training in this training setting. Generally, lowload resistance training was associated with larger lower-body muscle mass gains and similar muscle strength and performance improvements compared to high-load resistance training, and can therefore be advocated as an effective resistance training modality alternative for older adults. Importantly, the beneficial effects of high-load resistance training on bone health, emphasizes that resistance training programs for this population should include elements of such training. In general, the training intervention was associated with pronounced health effects, emphasizing the potency of resistance training for preventing/relieving sarcopenia in the general older population and for improving COPD-specific pathophysiologies

Kan kroppens totale energiomsetning påvirke de muskulære tilpasningene til utholdenhetstrening?: treningstilpasninger etter 5 ukers kneekstensjonstrening med eller uten samtidig trening av armene

Formål: Formålet med denne studien var å undersøke om de muskulære tilpasningene til utholdenhetstrening påvirkes av kroppens totale energiomsetning. Metode: Elleve moderat utholdenhetstrente personer (52 ± 6 ml.kg-1.min-1; 27 ± 5 år) ble rekruttert og fullførte studien. Forsøkspersonene trente ettbeins kneekstensjoner (1KE) med venstre og høyre bein separat. Det ene beinet (randomisert) trente samtidig med dette armsykling (1B2A), mens overkroppen var i ro når det andre beinet trente (1B). Begge beina trente 20-30 min submaksimal 1KE tre-fire g/uka i 5 uker med identisk treningsbelastning. Før og etter treningsperioden ble det gjennomført maksimale og submaksimale tester med 1KE (henholdsvis 1KEmaks og 1KEsubmaks) i tillegg til maksimale tester med kun armsykling og ordinær ergometersykling. Det maksimale/høyeste oksygenopptaket per tidsenhet (ergometersykling: V̇ O2maks; 1KE og armsykling: V̇ O2peak) ble målt pulmonært. Etter treningsperioden ble biopsier tatt av forsøkspersonenes bein. Disse ble seinere analysert for kapillarisering og konsentrasjon av oksidative enzymer. Resultater: Treningen gav økning i 1KE V̇ O2peak for 1B2A-beinet (8% ± 10%; p<0,05; ES=0,39), men ingen signifikant endring for 1B-beinet (4% ± 9%; p=0,11; ES=0,24). Det var imidlertid ingen forskjell i endring mellom beina (p=0,41; ES=0,12). I tillegg økteV̇ O2peak ved armsykling (8% ± 8%; p<0,01; ES=0,27) og V̇ O2maks ved ergometersykling (3% ± 3%; p<0,01; ES=0,15). Ved 1KEsubmaks gav treningen redusert laktat (La-), hjertefrekvens (HF) og V̇ O2 (bedret arbeidsøkonomi). Under 1B2A-treningen var total aerob energiomsetning og katekolaminrespons større enn ved 1B-trening. Dette førte imidlertid ikke til større økning i V̇ O2peak, høyeste oppnådde effekt eller tid til utmattelse (TTU) ved 1KEmaks og gav ikke forskjell i reduksjon av La-, HF eller V̇ O2 ved 1KEsubmaks. Etter treningsperioden var det heller ingen forskjell i kapillarisering eller konsentrasjon av oksidative enzymer mellom beina. Konklusjon: Fem ukers 1KE-trening med og uten samtidig trening av armene gav samme treningsrespons til tross for at den totale aerobe energiomsetningen og katekolaminresponsen var forskjellig mellom treningsøvelsene

Peripheral adaptations to endurance training - Effect of active muscle mass

The purpose of this study was to evaluate whether adaptations to endurance training are affected by active muscle mass during training. Eleven healthy subjects performed 5 weeks of one‐legged knee extension (1‐KE) training with both legs, separately. During the 1‐KE workouts for one of the legs, arm cycling was added (1L2A), while the other leg only performed 1‐KE (1L). During the training sessions, the 1‐KE power output and session duration were equal for both legs. Whole‐body oxygen uptake (V̇O2), adrenaline, and noradrenaline plasma concentrations were 112% ± 11%, 139% ± 144%, and 197% ± 101% higher during 1L2A than 1L, respectively. However, this did not affect the 1‐KE training adaptations since submaximal O2‐cost, heart rate and blood lactate concentration, maximal V̇O2, and power output all improved equally in both legs. This was supported by similar capillarization and concentration of oxidative enzymes in the legs after the training period. The present study therefore indicates that the size of active muscle mass per se during exercise does not affect adaptations to endurance training

Peripheral adaptations to endurance training - Effect of active muscle mass

The purpose of this study was to evaluate whether adaptations to endurance training are affected by active muscle mass during training. Eleven healthy subjects performed 5 weeks of one‐legged knee extension (1‐KE) training with both legs, separately. During the 1‐KE workouts for one of the legs, arm cycling was added (1L2A), while the other leg only performed 1‐KE (1L). During the training sessions, the 1‐KE power output and session duration were equal for both legs. Whole‐body oxygen uptake (V̇O2), adrenaline, and noradrenaline plasma concentrations were 112% ± 11%, 139% ± 144%, and 197% ± 101% higher during 1L2A than 1L, respectively. However, this did not affect the 1‐KE training adaptations since submaximal O2‐cost, heart rate and blood lactate concentration, maximal V̇O2, and power output all improved equally in both legs. This was supported by similar capillarization and concentration of oxidative enzymes in the legs after the training period. The present study therefore indicates that the size of active muscle mass per se during exercise does not affect adaptations to endurance training