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Jakyakgamcho-tang in the relief of delayed-onset muscle soreness in healthy adults: study protocol for a randomized, double-blind, placebo-controlled, crossover design clinical trial.
Han, K, Kwon, O, Jung, SY, Park, IH, Hwang, MS, Park, SY, Hwang, EH, Lee, JH
Trials. 2020;(1):211
Abstract
BACKGROUND Muscle soreness after exercise, called delayed-onset muscle soreness (DOMS), may cause significant changes in muscle function and may increase the risk of sports injuries. Therefore, various therapeutic strategies have been studied to help recovery after exercise. Jakyakgamcho-tang (JGT) is a widely prescribed herbal medicine to treat muscle pain and cramps in traditional Eastern medicine. The aim of this study is to evaluate the effect of JGT for reducing pain and improving muscle damage after exercise. METHODS This study is a randomized, double-blind, placebo-controlled, crossover design clinical trial. A total of 30 healthy male adults will be recruited. Subjects who voluntarily wish to participate in this study will be hospitalized for 4 days. On the first day, the subjects will perform a standardized treadmill exercise for 1 h to induce DOMS. After the exercise, the subjects will take either JGT or a placebo for 3 days. After a more than 1 week wash-out period, the subjects will repeat the same process with the other drug. Pain intensity, calf circumference, and pain threshold will be measured as outcome measures. Blood tests and blood pressure will be measured as safety assessments. In addition, blood tests for muscle damage and inflammation markers, such as creatine kinase, interleukin-6, and C-reactive protein, will be analyzed. DISCUSSION This will be the first trial to assess the effect of JGT on exercise-induced muscle soreness. Our findings will provide valuable data to determine the clinical effects of JGT on DOMS. TRIAL REGISTRATION Clinical Research Information Sevice, KCT0003457. Registered on 29 January 2019.
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The relationships between sarcopenic skeletal muscle loss during ageing and macronutrient metabolism, obesity and onset of diabetes.
Welch, AA, Hayhoe, RPG, Cameron, D
The Proceedings of the Nutrition Society. 2020;(1):158-169
Abstract
Skeletal muscle is integral to the metabolism and utilisation of macronutrients; however, substantial muscle loss and morphological changes occur with ageing. These are associated with loss of muscle function and accelerate rapidly from the age of 60 years, leading to the conditions of sarcopenia and frailty. As the relationship between muscle ageing and macronutrient metabolism and utilisation has seen limited research to date, this review focuses on the interactions between skeletal muscle changes during ageing, metabolism and utilisation of fat, carbohydrates and overall energy expenditure.Skeletal muscle contributes less to resting energy expenditure during ageing, potentially contributing to onset of obesity from middle age. Age-related changes to skeletal muscle lead to glucose dysregulation, with consequent reduction in glycaemic control, increased insulin resistance and ultimately onset of type-2 diabetes. Recent studies indicate that high total fat and SFA intake are detrimental to skeletal muscle, while higher intakes of PUFA are protective. Age-associated changes in skeletal muscle may also reduce total fatty acid utilisation.In conclusion, further research is needed to understand the relationships between macronutrient metabolism and utilisation and age-related changes to skeletal muscle. No dietary recommendations exist specifically for skeletal muscle health during ageing, but we advise individuals to follow healthy eating guidelines, by consuming sufficient protein, fruit and vegetables, and limited SFA and to maintain physically active lifestyles. Clinicians responsible for managing type-2 diabetes need to be aware of growing evidence relating age-related skeletal muscle changes to diabetes onset and progression.
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Effects of dapagliflozin on the serum levels of fibroblast growth factor 21 and myokines and muscle mass in Japanese patients with type 2 diabetes: A randomized, controlled trial.
Yamakage, H, Tanaka, M, Inoue, T, Odori, S, Kusakabe, T, Satoh-Asahara, N
Journal of diabetes investigation. 2020;(3):653-661
Abstract
AIMS/INTRODUCTION Our aims were to examine the add-on effects of a sodium-glucose cotransporter 2 inhibitor, dapagliflozin, compared with existing antidiabetes treatments, on anthropometric/metabolic parameters, the levels of an endocrine regulator, fibroblast growth factor 21 (FGF21); a skeletal muscle mass (SMM) negative regulator, myostatin; and a metabolic regulator, irisin, in patients with type 2 diabetes. MATERIALS AND METHODS A total of 54 patients with type 2 diabetes were randomly divided into dapagliflozin and control groups. The dapagliflozin group received dapagliflozin 5 mg/day in addition to conventional therapy for 24 weeks. The primary outcome was the change in the level of serum FGF21 from baseline. The secondary outcomes included changes from baseline in anthropometric/metabolic parameters and serum levels of myostatin and irisin. RESULTS Bodyweight decreased in the dapagliflozin group compared with the control group (P < 0.001), but the changes in SMM were not significant between the groups (P = 0.611), thereby elevating the ratio of SMM-to-bodyweight in the dapagliflozin group (P = 0.028). Myostatin levels were significantly decreased (P = 0.010), and irisin levels showed a nearly significant reduction (P = 0.052) in the dapagliflozin group compared with the control group, whereas FGF21 levels did not change significantly from baseline to the end of the intervention in both the dapagliflozin (P = 0.673) and the control (P = 0.823) groups. CONCLUSIONS Dapagliflozin add-on therapy in patients with type 2 diabetes reduced myostatin levels significantly and maintained SMM, without significant changes in FGF21 levels.
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Muscle Damage and Metabolic Responses to Repeated-Sprint Running With and Without Deceleration.
Minahan, CL, Poke, DP, Morrison, J, Bellinger, PM
Journal of strength and conditioning research. 2020;(12):3423-3430
Abstract
Minahan, CL, Poke, DP, Morrison, J, and Bellinger, PM. Muscle damage and metabolic responses to repeated-sprint running with and without deceleration. J Strength Cond Res 34(12): 3423-3430, 2020-This study aimed to determine whether repeated-sprint running with deceleration aggravates markers of muscle damage or delays the recovery of performance compared with repeated-sprint running without deceleration. Fourteen male team-sport athletes performed 2 randomly ordered testing sessions on a nonmotorized treadmill with one session requiring subjects to decelerate (TMd) within 4 seconds before stopping or immediately step to the side of the treadmill belt at the completion of each sprint (TMa). Peak and mean velocities, speed decrement, blood lactate concentrations, and oxygen uptake were monitored during the repeated-sprint running protocols. Countermovement vertical jump (CMJ) performance, perceived muscle soreness, sit-and-reach flexibility, plasma creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin (Mb) concentrations were quantified immediately before and after and 45 minutes, 24 and 48 hours after repeated-sprint running protocols. Although muscle damage was indicated by increases in CK, LDH, and Mb (p ≤ 0.05) in both groups, there was no significant effect of condition (TMa vs. TMd) on any of the measured performance or physiological variables (p > 0.05). The present study indicated that the removal of deceleration from repeated-sprint running on a nonmotorized treadmill has no effect on metabolism or performance during or after repeated-sprint running or markers of muscle damage.
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The Role of Protein Intake and its Timing on Body Composition and Muscle Function in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Wirth, J, Hillesheim, E, Brennan, L
The Journal of nutrition. 2020;(6):1443-1460
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Abstract
BACKGROUND Increased protein intake has been suggested to improve gains in muscle mass and strength in adults. Furthermore, the timing of protein intake has been discussed as a margin of opportunity for improved prevention measures. OBJECTIVE This systematic review investigated the effect of protein supplementation on body composition and muscle function (strength and synthesis) in healthy adults, with an emphasis on the timing of protein intake. METHODS Randomized controlled trials were identified using PubMed, Web of Science, CINAHL, and Embase, up to March 2019. For meta-analyses, data on lean body mass (LBM), handgrip strength, and leg press strength were pooled by age group (mean age 18-55 or >55 y) and timing of protein intake. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach. RESULTS Data from 65 studies with 2907 participants (1514 men and 1380 women, 13 unknown sex) were included in the review. Twenty-six, 8, and 24 studies were used for meta-analysis on LBM, handgrip strength, and leg press strength, respectively. The protein supplementation was effective in improving (mean difference; 95% CI) LBM in adults (0.62 kg; 0.36, 0.88) and older adults (0.46 kg; 0.23, 0.70), but not handgrip strength (older adults: 0.26 kg; -0.51, 1.04) and leg press strength (adults: 5.80 kg; -0.33, 11.93; older adults: 1.97 kg; -2.78, 6.72). Sensitivity analyses removing studies without exercise training had no impact on the outcomes. Data regarding muscle synthesis were scarce and inconclusive. Subgroup analyses showed no beneficial effect of a specific timing of protein intake on LBM, handgrip strength, and leg press strength. CONCLUSION Overall, the results support the positive impact of protein supplementation on LBM of adults and older adults, independently of intake timing. Effects on muscle strength and synthesis are less clear and need further investigation. This systematic review was registered on PROSPERO as CRD42019126742.
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Partial-body cryotherapy (-135°C) and cold-water immersion (10°C) after muscle damage in females.
Hohenauer, E, Costello, JT, Deliens, T, Clarys, P, Stoop, R, Clijsen, R
Scandinavian journal of medicine & science in sports. 2020;(3):485-495
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Abstract
This randomized controlled trial examined the effects of cold-water immersion (CWI), partial-body cryotherapy (PBC), or a passive control (CON) on physiological and recovery variables following exercise-induced muscle damage (EIMD, 5 × 20 drop jumps) in females. Twenty-eight females were allocated to PBC (30 seconds at -60°C, 2 minutes at -135°C), CWI (10 minutes at 10°C), or CON (10 minutes resting). Muscle oxygen saturation (SmO2 ), cutaneous vascular conductance (CVC), mean arterial pressure (MAP), and local skin temperature were assessed at baseline and through 60 minutes (10-minute intervals), while delayed onset of muscle soreness (DOMS), muscle swelling, maximum voluntary isometric contraction (MVIC), and vertical jump performance (VJP) were assessed up to 72 hours (24-hour intervals) following treatments. SmO2 was lower in PBC (Δ-2.77 ± 13.08%) and CWI (Δ-5.91 ± 11.80%) compared with CON (Δ18.96 ± 1.46%) throughout the 60-minute follow-up period (P < .001). CVC was lower from PBC (92.7 ± 25.0%, 90.5 ± 23.4%) and CWI (90.3 ± 23.5%, 88.1 ± 22.9%) compared with CON (119.0 ± 5.1 and 116.1 ± 6.6%, respectively) between 20 and 30 minutes (P < .05). Mean skin temperature was lower from CWI vs PBC (between 10 and 40 minutes, P < .05). Mean skin temperature was higher in CON compared with CWI up to 60 minutes and compared with PBC up to 30 minutes (P < .05). DOMS was lower following both PBC and CWI compared with CON through 72-hour (P < .05), with no difference between groups. No main group differences for swelling, MVIC, and VJP were observed. In conclusion, CWI elicited generally greater physiological effects compared with PBC while both interventions were more effective than CON in reducing DOMS in females, but had no effect on functional measures or swelling.
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Assessing skeletal muscle radiodensity by computed tomography: An integrative review of the applied methodologies.
Poltronieri, TS, de Paula, NS, Chaves, GV
Clinical physiology and functional imaging. 2020;(4):207-223
Abstract
Low-radiodensity skeletal muscle has been related to the degree of muscle fat infiltration and seems to be associated with worse outcomes. The aim of this study was to summarize the methodologies used to appraise skeletal muscle radiodensity by computed tomography, to describe the terms used in the literature to define muscle radiodensity and to give recommendations for its measurement standardization. An integrative bibliographic review in four databases included studies published until August 2019 in Portuguese, English or Spanish and performed in humans, adults and/or the elderly, of both sex, which investigated skeletal muscle radiodensity through computed tomography (CT) of the region between the third and fifth lumbar vertebrae and evaluated at least two muscular groups. One hundred and seventeen studies were selected. We observed a trend towards selecting all abdominal region muscle. A significant methodological variation in terms of contrast use, selection of skeletal muscle areas, radiodensity ranges delimitation and their cut-off points, as well as the terminologies used, was also found. The methodological differences detected are probably due to the lack of more precise information about the correlation between skeletal muscle radiodensity by CT and its molecular composition, among others. Therefore, until the gaps are addressed in future studies, authors should avoid arbitrary approaches when reporting skeletal muscle radiodensity, especially when it comes to prognosis inference. Studies using both CT and direct methods of muscle composition evaluation are encouraged, to enable the definition and validation of the best approach to classify fat-infiltrated muscle tissue, which will favour the nomenclature uniformization.
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Effect of a load distribution system on mobility and performance during simulated and field hiking while under load.
Sessoms, PH, Gobrecht, M, Niederberger, BA, Sturdy, JT, Collins, JD, Dominguez, JA, Jaworski, RL, Kelly, KR
Ergonomics. 2020;(2):133-144
Abstract
This study was conducted to test a modular scalable vest-load distribution system (MSV-LDS) against the plate carrier system (PC) currently used by the United States Marine Corps. Ten Marines engaged in 1.6 km load carriage trials in seven experimental conditions in a laboratory study. Kinematic, kinetic, and spatiotemporal gait parameters, muscle activity (electromyography), heart rate, caloric expenditure, shooting reaction times, and subjective responses were recorded. There was lower mean trapezius recruitment for the PC compared with the MSV-LDS for all conditions, and muscle activity was similar to baseline for the MSV-LDS. Twenty-seven Marines carrying the highest load were evaluated in the field, which measured an increase in energy expenditure with MSV-LDS; however, back discomfort was reduced. The field evaluation showed significantly reduced estimated ground reaction force on flat-ground segments with the MSV-LDS, and the data suggest both systems were comparable with respect to mobility and energy cost. Practitioner summary: This study found that a novel load distribution system appears to redistribute load for improved comfort as well as reduce estimated ground reaction force when engaged in hiking activities. Further, hiking with a load distribution system enables more neutral walking posture. Implications of load differences in loads carried are examined. Abbreviations: AGRF anterior-posterior ground reaction forces; CAREN Computer Assisted Rehabilitation Environment; GRF: ground reaction forces; HR: heart rate; ML-GRF: mediolateral ground reaction forces; MOLLE Modular Lightweight Load-carrying Equipment; MSV-LDS: modular scalable vest-load distribution system; NHRC Naval Health Research Center; PC: plate carrier; PPE: personal protective equipment; RPE: rating of perceived exertion; SAPI small arms protective insert; sEMG: surface electromyography; USMC United States Marine Corps; VGRF Ground reaction forces in the vertical.
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Combined protein and calcium β-hydroxy-β-methylbutyrate induced gains in leg fat free mass: a double-blinded, placebo-controlled study.
Stahn, AC, Maggioni, MA, Gunga, HC, Terblanche, E
Journal of the International Society of Sports Nutrition. 2020;(1):16
Abstract
BACKGROUND The leucine metabolite β-hydroxy-β-methylbutyrate (HMB) is widely used as an ergogenic supplement to increase resistance-training induced gains in fat free mass (FFM) and strength in healthy adults. Recent studies have questioned the effectiveness of HMB, particularly when a high protein diet is habitually consumed. To investigate the additive resistance-training induced effects of HMB and protein in untrained individuals, we conducted a randomized double-blind, placebo-controlled study that compared the effects of combined protein and HMB supplementation to protein supplementation alone on FFM and muscle strength after 12-week resistance training. METHODS Sixteen healthy men (22 ± 2 yrs) performed a periodized resistance-training program for twelve weeks (four sessions per week). The program comprised two mesocycles, characterized by a linear periodization and non-linear periodization, respectively, and separated by a 1-week tapering period. All participants received 60 g of whey protein on training days and 30 g of whey protein (WP) on non-training days. Participants were randomly assigned to additionally receive 3 g of calcium HMB (WP + HMB) or a placebo (WP + PLA). Body composition and physical fitness were tested before and after the 12-week training program. Whole-body and arm and leg fat free mass (FFM) were assessed by bioimpedance spectroscopy; upper arm and leg fat free cross sectional areas were also quantified using magnetic resonance imaging (MRI); upper and lower body strength were measured by One-repetition maximum (1-RM) bench press and leg press. RESULTS Whole-body and segmental FFM increased in both groups (P < 0.001). However, gains in leg FFM were higher in WP + HMB vs. WP + PLA (arm FFM: + 6.1% vs. + 9.2%, P = 0.2; leg FFM: + 14.2% vs. + 7.0%, P < 0.01). No change in fat mass was observed (P = 0.59). 1-RM increased in both groups (P < 0.001). CONCLUSIONS Combined protein and HMB supplementation resulted in segmental, but not whole-body increases in FFM compared to protein supplementation alone. These findings could explain some of the controversial effects of HMB reported in previous studies and have practical implications for maximizing training-induced gains in FFM and clinical conditions associated with skeletal muscle deconditioning such as aging, sedentary lifestyles, bed rest and spaceflight.
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Protein intake in older people : Why, how much and how?
Kiesswetter, E, Sieber, CC, Volkert, D
Zeitschrift fur Gerontologie und Geriatrie. 2020;(4):285-289
Abstract
The protein intake of older people has gained increasing scientific interest as a potential factor to delay the age-associated decline in muscle mass and consequently to counteract the development of sarcopenia. The skeletal muscle of older people seems less responsive to the anabolic stimulus of protein intake. Therefore, higher protein needs are discussed to overcome this anabolic resistance and to maintain muscle mass as far as possible. Besides the total amount of protein consumed, the distribution, quality and timing in relation to physical exercise are considered relevant; however, deriving clear recommendations for clinical practice is still difficult as positive results of protein intake on muscle metabolism found in experimental trials cannot simply be transferred to everyday conditions and randomized controlled trials often failed to show improvements in muscular outcomes related to protein supplementation. The effectiveness of protein supplementation may depend on functional resources of the older persons and the habitual protein intake. There is still a need for studies with well-defined protocols and populations to further elucidate the role of protein in the prevention and treatment of sarcopenia.