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Leucine Supplementation Increases Muscle Strength and Volume, Reduces Inflammation, and Affects Wellbeing in Adults and Adolescents with Cerebral Palsy.
Theis, N, Brown, MA, Wood, P, Waldron, M
The Journal of nutrition. 2021;(1):59-64
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Abstract
BACKGROUND Spastic cerebral palsy (CP) is characterized by muscle weakness owing, in part, to a blunted muscle protein synthetic response. This might be normalized by long-term leucine supplementation. OBJECTIVES The study assessed the effects of 10 wk leucine supplementation in adolescents and adults with CP. METHODS The study was a single-center randomized controlled trial. Twenty-four participants were randomly assigned to a control group (n = 12) or a leucine group (n = 12). l-Leucine (192 mg/kg body mass) was dissolved in water and administered daily for 10 wk. The primary outcome measures of elbow flexor muscle strength and muscle volume (measured by 3D ultrasound technique) and inflammation [C-reactive protein (CRP) concentration] were assessed before and after the 10 wk, alongside the secondary outcomes of body composition (measured by CP-specific skinfold assessment), metabolic rate (measured by indirect calorimetry), and wellbeing (measured by a self-reported daily questionnaire). Data were compared via a series of 2-factor mixed ANOVAs. RESULTS Twenty-one participants completed the intervention (control group: n = 11, mean ± SD age: 18.3 ± 2.8 y, body mass: 48.8 ± 11.9 kg, 45% male; leucine group: n = 10, age: 18.6 ± 1.7 y, body mass: 58.3 ± 20.2 kg, 70% male). After 10 wk, there was a 25.4% increase in strength (P = 0.019) and a 3.6% increase in muscle volume (P = 0.001) in the leucine group, with no changes in the control group. This was accompanied by a 59.1% reduction in CRP (P = 0.045) and improved perceptions of wellbeing (P = 0.006) in the leucine group. No changes in metabolism or body composition were observed in either group (P > 0.05). CONCLUSIONS Improvements in muscle strength and volume with leucine supplementation might provide important functional changes for adults and adolescents with CP and could be partly explained by reduced inflammation. The improved wellbeing highlights its capacity to improve the quality of daily living. This trial was registered at clinicaltrials.gov as NCT03668548.
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Order of same-day concurrent training influences some indices of power development, but not strength, lean mass, or aerobic fitness in healthy, moderately-active men after 9 weeks of training.
Lee, MJ, Ballantyne, JK, Chagolla, J, Hopkins, WG, Fyfe, JJ, Phillips, SM, Bishop, DJ, Bartlett, JD
PloS one. 2020;(5):e0233134
Abstract
BACKGROUND The importance of concurrent exercise order for improving endurance and resistance adaptations remains unclear, particularly when sessions are performed a few hours apart. We investigated the effects of concurrent training (in alternate orders, separated by ~3 hours) on endurance and resistance training adaptations, compared to resistance-only training. MATERIALS AND METHODS Twenty-nine healthy, moderately-active men (mean ± SD; age 24.5 ± 4.7 y; body mass 74.9 ± 10.8 kg; height 179.7 ± 6.5 cm) performed either resistance-only training (RT, n = 9), or same-day concurrent training whereby high-intensity interval training was performed either 3 hours before (HIIT+RT, n = 10) or after resistance training (RT+HIIT, n = 10), for 3 d.wk-1 over 9 weeks. Training-induced changes in leg press 1-repetition maximal (1-RM) strength, countermovement jump (CMJ) performance, body composition, peak oxygen uptake ([Formula: see text]), aerobic power ([Formula: see text]), and lactate threshold ([Formula: see text]) were assessed before, and after both 5 and 9 weeks of training. RESULTS After 9 weeks, all training groups increased leg press 1-RM (~24-28%) and total lean mass (~3-4%), with no clear differences between groups. Both concurrent groups elicited similar small-to-moderate improvements in all markers of aerobic fitness ([Formula: see text] ~8-9%; [Formula: see text] ~16-20%; [Formula: see text] ~14-15%). RT improved CMJ displacement (mean ± SD, 5.3 ± 6.3%), velocity (2.2 ± 2.7%), force (absolute: 10.1 ± 10.1%), and power (absolute: 9.8 ± 7.6%; relative: 6.0 ± 6.6%). HIIT+RT elicited comparable improvements in CMJ velocity only (2.2 ± 2.7%). Compared to RT, RT+HIIT attenuated CMJ displacement (mean difference ± 90%CI, -5.1 ± 4.3%), force (absolute: -8.2 ± 7.1%) and power (absolute: -6.0 ± 4.7%). Only RT+HIIT reduced absolute fat mass (mean ± SD, -11.0 ± 11.7%). CONCLUSIONS In moderately-active males, concurrent training, regardless of the exercise order, presents a viable strategy to improve lower-body maximal strength and total lean mass comparably to resistance-only training, whilst also improving indices of aerobic fitness. However, improvements in CMJ displacement, force, and power were attenuated when RT was performed before HIIT, and as such, exercise order may be an important consideration when designing training programs in which the goal is to improve lower-body power.
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Higher Muscle Mass Implies Increased Free-Thyroxine to Free-Triiodothyronine Ratio in Subjects With Overweight and Obesity.
Zupo, R, Castellana, F, Sardone, R, Lampignano, L, Paradiso, S, Giagulli, VA, Triggiani, V, Di Lorenzo, L, Giannelli, G, De Pergola, G
Frontiers in endocrinology. 2020;:565065
Abstract
UNLABELLED Thyroid hormones control both metabolic pathways and body composition, whereas little knowledge is available about the possible influence of skeletal muscle mass (MM) on thyroid hormone metabolism and circulating levels. This was a cross-sectional study conducted at the Population Health Unit of the National Institute of Gastroenterology IRCCS "S. de Bellis" (Italy) and investigating the extent to which skeletal MM affects thyroid function in obesity. Two hundred twenty-seven consecutive healthy volunteers (155 women and 72 men) with overweight and obesity (BMI ≥ 25 kg/m2) and taking no medication or supplement were assessed for hormone, metabolic and routine laboratory parameters. Body composition parameters were collected by using bioelectrical impedance analysis (BIA). MM was directly related to the body mass index (BMI), waist circumference (WC), insulin, triglycerides, uric acid and free-triiodothyronine (FT3) serum levels, FT3 to the free-thyroxine (FT4) ratio, and insulin-resistance (HOMA-IR), and inversely related to age, total, and HDL-cholesterol serum levels. Multiple regression models confirmed the relationship between MM and the FT3 to FT4 ratio, independently of age, BMI, TSH, triglycerides, and insulin serum levels. The same analyses run by gender showed that this relationship maintained significance only in men. Increased skeletal MM in obesity results in improved thyroid activity mediated by increased T4 conversion to T3, and higher FT3 circulating levels, particularly in men. In conclusion, preserving a greater skeletal MM in obesity helps to enhance thyroid activity. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, identifier NCT04327375.
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Resistance training does not induce uniform adaptations to quadriceps.
Mangine, GT, Redd, MJ, Gonzalez, AM, Townsend, JR, Wells, AJ, Jajtner, AR, Beyer, KS, Boone, CH, La Monica, MB, Stout, JR, et al
PloS one. 2018;(8):e0198304
Abstract
Resistance training may differentially affect morphological adaptations along the length of uni-articular and bi-articular muscles. The purpose of this study was to compare changes in muscle morphology along the length of the rectus femoris (RF) and vastus lateralis (VL) in response to resistance training. Following a 2-wk preparatory phase, 15 resistance-trained men (24.0 ± 3.0 y, 90.0 ± 13.8 kg, 174.9 ± 20.7 cm) completed pre-training (PRE) assessments of muscle thickness (MT), pennation angle (PA), cross-sectional area (CSA), and echo-intensity in the RF and VL at 30, 50, and 70% of each muscle's length; fascicle length (FL) was estimated from respective measurements of MT and PA within each muscle and region. Participants then began a high intensity, low volume (4 x 3-5 repetitions, 3min rest) lower-body resistance training program, and repeated all PRE-assessments after 8 weeks (2 d ∙ wk-1) of training (POST). Although three-way (muscle [RF, VL] x region [30, 50, 70%] x time [PRE, POST]) repeated measures analysis of variance did not reveal significant interactions for any assessment of morphology, significant simple (muscle x time) effects were observed for CSA (p = 0.002) and FL (p = 0.016). Specifically, average CSA changes favored the VL (2.96 ± 0.69 cm2, p < 0.001) over the RF (0.59 ± 0.20 cm2, p = 0.011), while significant decreases in average FL were noted for the RF (-1.03 ± 0.30 cm, p = 0.004) but not the VL (-0.05 ± 0.36 cm, p = 0.901). No other significant differences were observed. The findings of this study demonstrate the occurrence of non-homogenous adaptations in RF and VL muscle size and architecture following 8 weeks of high-intensity resistance training in resistance-trained men. However, training does not appear to influence region-specific adaptations in either muscle.
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Physical Activity, Sedentary Time, and Bone Strength From Childhood to Early Adulthood: A Mixed Longitudinal HR-pQCT study.
Gabel, L, Macdonald, HM, Nettlefold, L, McKay, HA
Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. 2017;(7):1525-1536
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Abstract
Bone strength is influenced by bone geometry, density, and bone microarchitecture, which adapt to increased mechanical loads during growth. Physical activity (PA) is essential for optimal bone strength accrual; however, less is known about how sedentary time influences bone strength and its determinants. Thus, our aim was to investigate the prospective associations between PA, sedentary time, and bone strength and its determinants during adolescence. We used HR-pQCT at distal tibia (8% site) and radius (7% site) in 173 girls and 136 boys (aged 9 to 20 years at baseline). We conducted a maximum of four annual measurements at the tibia (n = 785 observations) and radius (n = 582 observations). We assessed moderate-to-vigorous PA (MVPA) and sedentary time with accelerometers (ActiGraph GT1M). We aligned participants on maturity (years from age at peak height velocity) and fit a mixed-effects model adjusting for maturity, sex, ethnicity, leg muscle power, lean mass, limb length, dietary calcium, and MVPA in sedentary time models. MVPA was a positive independent predictor of bone strength (failure load [F.Load]) and bone volume fraction (BV/TV) at the tibia and radius, total area (Tt.Ar) and cortical porosity (Ct.Po) at the tibia, and negative predictor of load-to-strength ratio at the radius. Sedentary time was a negative independent predictor of Tt.Ar at both sites and Ct.Po at the tibia and a positive predictor of cortical thickness (Ct.Th), trabecular thickness (Tb.Th), and cortical bone mineral density (Ct.BMD) at the tibia. Bone parameters demonstrated maturity-specific associations with MVPA and sedentary time, whereby associations were strongest during early and mid-puberty. Our findings support the importance of PA for bone strength accrual and its determinants across adolescent growth and provide new evidence of a detrimental association of sedentary time with bone geometry but positive associations with microarchitecture. This study highlights maturity-specific relationships of bone strength and its determinants with loading and unloading. Future studies should evaluate the dose-response relationship and whether associations persist into adulthood. © 2017 American Society for Bone and Mineral Research.
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Skeletal muscle depletion during chemotherapy has a large impact on physical function in elderly Japanese patients with advanced non-small-cell lung cancer.
Naito, T, Okayama, T, Aoyama, T, Ohashi, T, Masuda, Y, Kimura, M, Shiozaki, H, Murakami, H, Kenmotsu, H, Taira, T, et al
BMC cancer. 2017;(1):571
Abstract
BACKGROUND Elderly patient with advanced cancer is one of the most vulnerable populations. Skeletal muscle depletion during chemotherapy may have substantial impact on their physical function. However, there is little information about a direct relationship between quantity of muscle and physical function. We sought to explore the quantitative association between skeletal muscle depletion, and muscle strength and walking capacity in elderly patients with advanced non-small cell lung cancer (NSCLC). METHODS Thirty patients aged ≥70 years with advanced NSCLC (stage III-IV) scheduled to initiate first-line chemotherapy were prospectively enrolled between January 2013 and November 2014. Lumbar skeletal muscle index (LSMI, cm2/m2), incremental shuttle walking distance (ISWD, m), and hand-grip strength (HGS, kg) were assessed at baseline, and 6 ± 2 weeks (T2) and 12 ± 4 weeks (T3) after study enrollment. Associations were analyzed using linear regression. RESULTS Altogether, 11 women and 19 men with a median age of 74 (range, 70-82) years were included in the study; 24 received cytotoxic chemotherapy and 6, gefitinib. Mean ± standard deviation of LSMI, ISWD and HGS were 41.2 ± 7.8 cm2/m2, 326.0 ± 127.9 m, and 29.3 ± 8.5 kg, respectively. LSMI and ISWD significantly declined from baseline to T2 and T3. HGS significantly declined from baseline to T2 and T3 only in men. Change in LSMI was significantly associated with change in HGS (β = 0.3 ± 0.1, p = 0.0127) and ISWD (β = 8.8 ± 2.4, p = 0.0005). CONCLUSIONS Skeletal muscle depletion accompanied with physical functional decline started in the early phase of the chemotherapy in elderly patients with advanced NSCLC. Our results suggest that there may be a need for early supportive care in these patients to prevent functional decline during chemotherapy. TRIAL REGISTRATION Trial registration number: UMIN000009768 Name of registry: UMIN (University hospital Medical Information Network). URL of registry: Date of registration: 14 January 2013. Date of enrolment of the first participant to the trial: 23 January 2013.
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25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 exert distinct effects on human skeletal muscle function and gene expression.
Hassan-Smith, ZK, Jenkinson, C, Smith, DJ, Hernandez, I, Morgan, SA, Crabtree, NJ, Gittoes, NJ, Keevil, BG, Stewart, PM, Hewison, M
PloS one. 2017;(2):e0170665
Abstract
Age-associated decline in muscle function represents a significant public health burden. Vitamin D-deficiency is also prevalent in aging subjects, and has been linked to loss of muscle mass and strength (sarcopenia), but the precise role of specific vitamin D metabolites in determining muscle phenotype and function is still unclear. To address this we quantified serum concentrations of multiple vitamin D metabolites, and assessed the impact of these metabolites on body composition/muscle function parameters, and muscle biopsy gene expression in a retrospective study of a cohort of healthy volunteers. Active serum 1,25-dihydroxyvitamin D3 (1α,25(OH)2D3), but not inactive 25-hydroxyvitamin D3 (25OHD3), correlated positively with measures of lower limb strength including power (rho = 0.42, p = 0.02), velocity (Vmax, rho = 0.40, p = 0.02) and jump height (rho = 0.36, p = 0.04). Lean mass correlated positively with 1α,25(OH)2D3 (rho = 0.47, p = 0.02), in women. Serum 25OHD3 and inactive 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) had an inverse relationship with body fat (rho = -0.30, p = 0.02 and rho = -0.33, p = 0.01, respectively). Serum 25OHD3 and 24,25(OH)2D3 were also correlated with urinary steroid metabolites, suggesting a link with glucocorticoid metabolism. PCR array analysis of 92 muscle genes identified vitamin D receptor (VDR) mRNA in all muscle biopsies, with this expression being negatively correlated with serum 25OHD3, and Vmax, and positively correlated with fat mass. Of the other 91 muscle genes analysed by PCR array, 24 were positively correlated with 25OHD3, but only 4 were correlated with active 1α,25(OH)2D3. These data show that although 25OHD3 has potent actions on muscle gene expression, the circulating concentrations of this metabolite are more closely linked to body fat mass, suggesting that 25OHD3 can influence muscle function via indirect effects on adipose tissue. By contrast, serum 1α,25(OH)2D3 has limited effects on muscle gene expression, but is associated with increased muscle strength and lean mass in women. These pleiotropic effects of the vitamin D 'metabolome' on muscle function indicate that future supplementation studies should not be restricted to conventional analysis of the major circulating form of vitamin D, 25OHD3.
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Effect of sex and menstrual cycle in women on starting speed, anaerobic endurance and muscle power.
Wiecek, M, Szymura, J, Maciejczyk, M, Cempla, J, Szygula, Z
Physiology international. 2016;(1):127-32
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Abstract
The aim of our study was to compare the indicators of starting speed, anaerobic endurance and power in women as well as men, and to investigate whether the values of these indicators differ in women during the follicular and luteal phases of the menstrual cycle. The studied group included 16 men and 16 women. The subjects performed the 20-second maximal cycling sprint test. The men performed the test twice at 14-day intervals. The women undertook the test 4 times: twice during the middle of follicular phase and twice in the middle of luteal phase in separate menstrual cycles. Hormonal changes during the menstrual cycle do not influence anaerobic performance, starting speed or anaerobic endurance in women. Anaerobic performance in men is higher than in women with similar aerobic performance expressed as VO2max/LBM (lean body mass). A lower power decrease with time was noted for women than men, with a similar time of maintaining power in both groups. This is evidence of women's better anaerobic endurance compared to men. At the same time, the men had significantly better starting speed rates than women.
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Endurance training decreases the non-linearity in the oxygen uptake-power output relationship in humans.
Majerczak, J, Korostynski, M, Nieckarz, Z, Szkutnik, Z, Duda, K, Zoladz, JA
Experimental physiology. 2012;(3):386-99
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Abstract
In this study, we hypothesized that 5 weeks of cycling endurance training can decrease the magnitude of the non-proportional increase in oxygen uptake (V(O(2))) to power output relationship (V(O(2)) 'excess') at exercise intensities exceeding the lactate threshold (LT). Ten untrained, physically active men performed a bout of incremental cycling exercise until exhaustion before and after training. The mitochondrial DNA copy number, myosin heavy chain composition and content of uncoupling protein 3 and sarcoplasmic reticulum Ca(2+)-ATPases (SERCAs) were analysed in muscle biopsies taken from vastus lateralis before and after training. The training resulted in an enhancement of the power-generating capabilities at maximal oxygen uptake (V(O(2)max)) by ∼7% (P = 0.002) despite there being no changes in V(O(2)max) (P = 0.49). This effect was due to a considerable reduction in the magnitude of the V(O(2)) 'excess' (P < 0.05) above the LT. A decrease in plasma ammonia concentration was found during exercise after training (P < 0.05). A downregulation of SERCA2 in vastus lateralis (P = 0.006) was observed after training. No changes in myosin heavy chain composition, selected electron transport chain proteins, uncoupling protein 3 or the mitochondrial DNA copy number (P > 0.05) were found after training. We conclude that the training-induced increase in power-generating capabilities at V(O(2)max) was due to attenuation of the V(O(2)) 'excess' above the LT. This adaptive response seems to be related to the improvement of muscle metabolic stability, as judged by a lowering of plasma ammonia concentration. The enhancement of muscle metabolic stability after training could be caused by a decrease in ATP usage at a given power output owing to downregulation of SERCA2 pumps.