mTOR signaling response to resistance exercise is altered by chronic resistance training and detraining in skeletal muscle

2013 ◽  
Vol 114 (7) ◽  
pp. 934-940 ◽  
Author(s):  
Riki Ogasawara ◽  
Koji Kobayashi ◽  
Arata Tsutaki ◽  
Kihyuk Lee ◽  
Takashi Abe ◽  
...  
Keyword(s):  
Resistance Training ◽  
Resistance Exercise ◽  
Intracellular Signaling ◽  
Gastrocnemius Muscle ◽  
Male Rats ◽  
Exercise Session ◽  
Signaling Proteins ◽  
Signaling Mechanisms ◽  
Exercise Induced ◽  
Training And Detraining

Resistance training-induced muscle anabolism and subsequent hypertrophy occur most rapidly during the early phase of training and become progressively slower over time. Currently, little is known about the intracellular signaling mechanisms underlying changes in the sensitivity of muscles to training stimuli. We investigated the changes in the exercise-induced phosphorylation of hypertrophic signaling proteins during chronic resistance training and subsequent detraining. Male rats were divided into four groups: 1 bout (1B), 12 bouts (12B), 18 bouts (18B), and detraining (DT). In the DT group, rats were subjected to 12 exercise sessions, detrained for 12 days, and then were subjected to 1 exercise session before being killed. Isometric training consisted of maximum isometric contraction, which was produced by percutaneous electrical stimulation of the gastrocnemius muscle every other day. Muscles were removed 24 h after the final exercise session. Levels of total and phosphorylated p70S6K, 4E-BP1, rpS6, and p90RSK levels were measured, and phosphorylation of p70S6K, rpS6, and p90RSK was elevated in the 1B group compared with control muscle (CON) after acute resistance exercise, whereas repeated bouts of exercise suppressed those phosphorylation in both 12B and 18B groups. Interestingly, these phosphorylation levels were restored after 12 days of detraining in the DT group. On the contrary, phosphorylation of 4E-BP1 was not altered with chronic training and detraining, indicating that, with chronic resistance training, anabolic signaling becomes less sensitive to resistance exercise stimuli but is restored after a short detraining period.

Effect of moderate and high-intensity endurance and resistance training on serum concentrations of MSTN and IGF-1 in old male Wistar rats

2019 ◽  
Vol 38 (2) ◽  
Author(s):  
Zohreh Shanazari ◽  
Mohammad Faramarzi ◽  
Ebrahim Banitalebi ◽  
Roohullah Hemmati
Keyword(s):  
Resistance Training ◽  
Endurance Training ◽  
High Intensity ◽  
Intracellular Signaling ◽  
Male Rats ◽  
Moderate Intensity ◽  
Exercise Session ◽  
Control Group ◽  
Significance Level ◽  
Significant Difference

Abstract Background Skeletal muscle is very sensitive to extracellular and intracellular signaling evoked by contractions from endurance and resistance exercise. The aim of this study was to compare the effects of moderate- and high-intensity endurance and resistance training on the serum myostatin (MSTN) and insulin-like growth factor (IGF-1) levels in older rats. Materials and methods Fifty old Wistar male rats (23 months old) were randomly divided into four experimental and one control groups, including moderate-endurance training (MET) (n = 10), high-intensity endurance training (EHT) (n = 10), moderate-intensity resistance training (MRT) (n = 10), high-intensity resistance training (HRT) (n = 10), and control group (C) (n = 10). Seventy-two hours after the last exercise session, euthanasia of the rats were rendered unconscious and direct blood samples were collected. Serum IGF-1 and MSTN concentration were measured using the enzyme-linked immuno sorbent assay (ELISA) method. The statistical analysis was performed using one-way analysis of variance (ANOVA) test with a significance level of p ≤ 0.05. Results There was a significant reduction in MSTN and an increase in IGF-1 concentrations was observed between IGF-I levels in high and moderate resistance and endurance training. However, no significant difference was observed in MSTN levels between groups. Discussion Therefore, it appears that resistance training, especially HRT, is effective to increase growth mediators among older rats.

scholarly journals Resistance training reduces the acute exercise-induced increase in muscle protein turnover

1999 ◽  
Vol 276 (1) ◽  
pp. E118-E124 ◽  
Author(s):  
S. M. Phillips ◽  
K. D. Tipton ◽  
A. A. Ferrando ◽  
R. R. Wolfe
Keyword(s):  
Resistance Training ◽  
Resistance Exercise ◽  
Acute Exercise ◽  
Muscle Protein ◽  
Exercise Bout ◽  
Muscle Contractions ◽  
Breakdown Rates ◽  
Single Bout ◽  
Fractional Synthesis ◽  
Exercise Induced

We examined the effect of resistance training on the response of mixed muscle protein fractional synthesis (FSR) and breakdown rates (FBR) by use of primed constant infusions of [2H5]phenylalanine and [15N]phenylalanine, respectively, to an isolated bout of pleiometric resistance exercise. Trained subjects, who were performing regular resistance exercise (trained, T; n = 6), were compared with sedentary, untrained controls (untrained, UT; n = 6). The exercise test consisted of 10 sets (8 repetitions per set) of single-leg knee flexion (i.e., pleiometric muscle contraction during lowering) at 120% of the subjects’ predetermined single-leg 1 repetition maximum. Subjects exercised one leg while their contralateral leg acted as a nonexercised (resting) control. Exercise resulted in an increase, above resting, in mixed muscle FSR in both groups (UT: rest, 0.036 ± 0.002; exercise, 0.0802 ± 0.01; T: rest, 0.045 ± 0.004; exercise, 0.067 ± 0.01; all values in %/h; P< 0.01). In addition, exercise resulted in an increase in mixed muscle FBR of 37 ± 5% (rest, 0.076 ± 0.005; exercise, 0.105 ± 0.01; all values in %/h; P < 0.01) in the UT group but did not significantly affect FBR in the T group. The resulting muscle net balance (FSR − FBR) was negative throughout the protocol ( P < 0.05) but was increased in the exercised leg in both groups ( P < 0.05). We conclude that pleiometric muscle contractions induce an increase in mixed muscle protein synthetic rate within 4 h of completion of an exercise bout but that resistance training attenuates this increase. A single bout of pleiometric muscle contractions also increased the FBR of mixed muscle protein in UT but not in T subjects.

scholarly journals THE ROLE OF SYNAPSIN I IN INTRACELLULAR SIGNALING MECHANISMS UNDERLIES EXERCISE-INDUCED IMPROVEMENT IN SOCIAL MEMORY: A SYSTEMATIC REVIEW

2017 ◽  
Vol 10 (9) ◽  
pp. 88
Author(s):  
Ria Margiana ◽  
Akmal Primadian Suprapto
Keyword(s):  
Cell Signaling ◽  
Intracellular Signaling ◽  
Laboratory Experiments ◽  
Biological Function ◽  
Social Memory ◽  
Synapsin I ◽  
Signaling Mechanism ◽  
Signaling Mechanisms ◽  
Exercise Induced

  Objective: Intracellular signaling mechanism is an important biological function, as scholars continue to seek new ways of improving social memory. Researchers have conducted several studies on the role of synapsin I in intracellular signaling mechanism. This study assessed the empirical evidence that shows the role of synapsin I in intracellular signaling mechanism with the aim of achieving exercise-induced improvement in social memory.Methods: Nine previously conducted researches were reviewed in this paper. The included studies were controlled laboratory experiments involving mice as the subjects.Results: Although the studies included were done in different timelines, the researchers agreed in unison that synapsin I plays a crucial role in cell signaling. The outcome of the practical studies was vital in understanding function and physiology of human cells, which is fundamental in science and human anatomy.Conclusion: In particular, the findings shows how exercise can improve social memory by triggering the intracellular signaling mechanism. The limited number of studies addressing the topic of intracellular cell signaling suggests that more study is needed to provide more evidence on the issue.

scholarly journals Resistance Exercise-Induced Apelin Is Not Modulated by Higher Dietary Protein Density in Overweight Adults

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 50-50
Author(s):  
Colleen McKenna ◽  
Amadeo Salvador ◽  
Alexander Keeble ◽  
Rafael Alamilla ◽  
Susannah Scaroni ◽  
...  
Keyword(s):  
Resistance Training ◽  
Muscle Strength ◽  
Resistance Exercise ◽  
Dietary Protein ◽  
Middle Aged ◽  
Resistance Training Program ◽  
Exercise Induced ◽  
Protein Density ◽  
Middle Aged Adults ◽  
Plasma Apelin

Abstract Objectives Apelin is a putative exercise-sensitive myokine that has been shown to be associated with physical independence during aging. Physical performance is highly dependent on muscle strength, with a clear role of dietary protein (i.e., &gt; Recommended Dietary Allowance) for the maintenance of age-related muscle strength. However, the influence of dietary protein density on exercise-induced apelin remains unknown. Therefore, our aim was to evaluate plasma apelin concentrations and its relationship with muscle strength in middle-aged adults consuming differential amounts of animal-based protein during progressive resistance training. Methods 41 overweight middle-aged adults (50 ± 2 y, BMI 28 ± 1 kg · m−2, M = 19, F = 22) were stratified and randomized to consume either high protein (1.68 ± 0.06 g · kg−1·d−1) or moderate amounts of animal-based protein (1.16 ± 0.04 g · kg−1·d−1) during a 10-week weight-maintenance nutrition counseling-controlled resistance training program. Body composition was assessed by dual-energy x-ray absorptiometry. Muscle strength was assessed by one-repetition maximum (1RM) and isometric maximal voluntary contraction (MVC) at 60° knee angle. Oral glucose tolerance tests were performed at baseline and post-intervention. Results Main effects of time were observed for increases in lean body mass (P = 0.003), upper and lower body 1RM (all P ≤ 0.001), isometric MVC (P = 0.013), and plasma apelin concentrations (P = 0.007). There were no changes in body adiposity or glucose-insulin regulation (e.g., HOMA-IR, Matsuda) with the intervention (all P ≥ 0.152). Apelin was positively and significantly associated with isometric MVC (extension: r = 0.233, P = 0.047; flexion: r = 0.308, P = 0.008), but not 1RM. Conclusions Our results show that resistance training increases circulating apelin concentrations which is related to isometric strength gain. However, higher consumption of animal-based protein foods does not potentiate these resistance-exercise induced adaptations in overweight middle-aged adults. Funding Sources Funded in part by the Beef Checkoff. CFM funded by JBT Fellowship, UIUC.

Chronic resistance training in women potentiates growth hormone in vivo bioactivity: characterization of molecular mass variants

2006 ◽  
Vol 291 (6) ◽  
pp. E1177-E1187 ◽  
Author(s):  
William J. Kraemer ◽  
Bradley C. Nindl ◽  
James O. Marx ◽  
Lincoln A. Gotshalk ◽  
Jill A. Bush ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Resistance Training ◽  
Resistance Exercise ◽  
Molecular Mass ◽  
Acute Exercise ◽  
Control Group ◽  
Detection Systems ◽  
Molecular Variants ◽  
Exercise Induced

This investigation determined the influence of acute and chronic resistance exercise on responses of growth hormone (GH) molecular variants in women. Seventy-four healthy young women (23 ± 3 yr, 167 ± 7 cm, 63.8 ± 9.3 kg, 26.3 ± 4.0% body fat) performed an acute bout of resistance exercise (6 sets of 10 repetition maximum squat). Blood samples were obtained pre- and postexercise. Resulting plasma was fractionated by molecular mass ( fraction A, >60 kDa; fraction B, 30–60 kDa; and fraction C, <30 kDa) using chromatography. Fractionated and unfractionated (UF) plasma was then assayed for GH using three different detection systems (monoclonal immunoassay, polyclonal immunoassay, and rat tibial line in vivo bioassay). Subjects were then matched and randomly placed into one of four resistance exercise training groups or a control group for 24 wk. All experimental procedures were repeated on completion of the 24-wk resistance training programs. After acute exercise, immunoassays showed consistent increases in UF GH samples and fractions B and C; increases in fraction A using immunoassay were seen only in the monoclonal assay. No consistent changes in bioactive GH were found following acute exercise. Conversely, chronic exercise induced no consistent changes in immunoassayable GH of various molecular masses, whereas, in general, bioassayable GH increased. In summary, although acute exercise increased only immunoactive GH, chronic physical training increased the biological activity of circulating GH molecular variants. Increased bioactive GH was observed across all fractions and training regimens, suggesting that chronic resistance exercise increased a spectrum of GH molecules that may be necessary for the multitude of somatogenic and metabolic actions of GH.

Ursolic acid stimulates mTORC1 signaling after resistance exercise in rat skeletal muscle

2013 ◽  
Vol 305 (6) ◽  
pp. E760-E765 ◽  
Author(s):  
Riki Ogasawara ◽  
Koji Sato ◽  
Kazuhiko Higashida ◽  
Koichi Nakazato ◽  
Satoshi Fujita
Keyword(s):  
Resistance Exercise ◽  
Ursolic Acid ◽  
Gastrocnemius Muscle ◽  
Corn Oil ◽  
Muscle Protein ◽  
Akt Signaling ◽  
Sprague Dawley ◽  
Mtorc1 Signaling ◽  
Exercise Induced ◽  
Mtorc1 Activation

A recent study identified ursolic acid (UA) as a potent stimulator of muscle protein anabolism via PI3K/Akt signaling, thereby suggesting that UA can increase Akt-independent mTOR complex 1 (mTORC1) activation induced by resistance exercise via Akt signaling. The purpose of the present study was to investigate the effect of UA on resistance exercise-induced mTORC1 activation. The right gastrocnemius muscle of male Sprague-Dawley rats aged 11 wk was isometrically exercised via percutaneous electrical stimulation (stimulating ten 3-s contractions per set for 5 sets), while the left gastrocnemius muscle served as the control. UA or placebo (PLA; corn oil only) was injected intraperitoneally immediately after exercise. The rats were killed 1 or 6 h after the completion of exercise and the target tissues removed immediately. With placebo injection, the phosphorylation of p70S6K at Thr389 increased 1 h after resistance exercise but attenuated to the control levels 6 h after the exercise. On the other hand, the augmented phosphorylation of p70S6K was maintained even 6 h after exercise when UA was injected immediately after exercise. A similar trend of prolonged phosphorylation was observed in PRAS40 Thr246, whereas UA alone or resistance exercise alone did not alter its phosphorylation level at 6 h after intervention. These results indicate that UA is able to sustain resistance exercise-induced mTORC1 activity.

scholarly journals Chronic capsiate supplementation increases fat-free mass and upper body strength but not the inflammatory response to resistance exercise in young untrained men: a randomized, placebo-controlled and double-blind study

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Vilton Emanoel Lopes de Moura e Silva ◽  
Jason Michael Cholewa ◽  
Ralf Jäger ◽  
Nelo Eidy Zanchi ◽  
Marcelo Conrado de Freitas ◽  
...  
Keyword(s):  
Resistance Training ◽  
Inflammatory Response ◽  
Resistance Exercise ◽  
Fat Free Mass ◽  
Upper Body ◽  
Exercise Session ◽  
Double Blind ◽  
Body Strength ◽  
Upper Body Strength ◽  
And Performance

Abstract Background Acute capsaicinoid and capsinoid supplementation has endurance and resistance exercise benefits; however, if these short-term performance benefits translate into chronic benefits when combined with resistance training is currently unknown. This study investigated changes of chronic Capsiate supplementation on muscular adaptations, inflammatory response and performance in untrained men. Methods Twenty untrained men were randomized to ingest 12 mg Capsiate (CAP) or placebo in a parallel, double-blind design. Body composition and performance were measured at pre-training and after 6 weeks of resistance training. An acute resistance exercise session test was performed pre and post-intervention. Blood samples were collected at rest and post-resistance exercise to analyze Tumor necrosis factor- (TNF-), Soluble TNF- receptor (sTNF-r), Interleukin-6 (IL-6) and Interleukin-10 (IL-10). Results Exercise and CAP supplementation increased fat-free mass in comparison to baseline by 1.5 kg (P < 0.001), however, the majority of the increase (1.0 kg) resulted from an increase in total body water. The CAP change scores for fat-free mass were significantly greater in comparison to the placebo (CAP ∆%= 2.1 ± 1.8 %, PLA ∆%= 0.7 ± 1.3 %, P = 0.043) and there was a significant difference between groups in the bench press exercise (P = 0.034) with greater upper body strength change score for CAP (∆%= 13.4 ± 9.1 %) compared to placebo (∆%= 5.8 ± 5.2 %), P = 0.041. CAP had no effect on lower body strength and no supplementation interactions were observed for all cytokines in response to acute resistance exercise (P > 0.05). Conclusion Chronic Capsiate supplementation combined with resistance training during short period (6 weeks) increased fat-free mass and upper body strength but not inflammatory response and performance in young untrained men.

Repeated resistance exercise training induces different changes in mRNA expression of MAFbx and MuRF-1 in human skeletal muscle

2008 ◽  
Vol 294 (1) ◽  
pp. E43-E51 ◽  
Author(s):  
Henrik Mascher ◽  
Jörgen Tannerstedt ◽  
Thibault Brink-Elfegoun ◽  
Björn Ekblom ◽  
Thomas Gustafsson ◽  
...  
Keyword(s):  
Resistance Training ◽  
Resistance Exercise ◽  
Mrna Expression ◽  
Vastus Lateralis ◽  
Statistical Significance ◽  
Exercise Session ◽  
Ribosomal Protein S6 ◽  
Expression Of Genes ◽  
Repeated Exercise ◽  
The Difference

The gain in muscle mass as a result of resistance training is dependent on changes in both anabolic and catabolic reactions. A frequency of two to three exercise sessions per week is considered optimal for muscle gain in untrained individuals. Our hypothesis was that a second exercise session would enlarge the anabolic response and/or decrease the catabolic response. Eight male subjects performed resistance exercise on two occasions separated by 2 days. Muscle biopsies were taken from the vastus lateralis before and 15 min, 1 h, and 2 h after exercise. Exercise led to severalfold increases in phosphorylation of mTOR at Ser2448, p70 S6 kinase (p70S6k) at Ser424/Thr421 and Thr389, and ribosomal protein S6, which persisted for up to 2 h of recovery on both occasions. There was a tendency toward a larger effect of the second exercise on p70S6k and S6, but the difference did not reach statistical significance. The mRNA expression of MuRF-1, which increased after exercise, was 30% lower after the second exercise session than after the first one. MAFbx expression was not altered after exercise but downregulated 30% 48 h later, whereas myostatin expression was reduced by 45% after the first exercise and remained low until after the second exercise session. The results indicate that 1) changes in expression of genes involved in protein degradation are attenuated as a response to repetitive resistance training with minor additional increases in enzymes regulating protein synthesis and 2) the two ubiquitin ligases, MuRF-1 and MAFbx, are differently affected by the exercise as well as by repeated exercise.

Effect of resistance exercise training on cortical and cancellous bone in mature male rats

1998 ◽  
Vol 84 (2) ◽  
pp. 459-464 ◽  
Author(s):  
Kim C. Westerlind ◽  
James D. Fluckey ◽  
Scott E. Gordon ◽  
William J. Kraemer ◽  
Peter A. Farrell ◽  
...  
Keyword(s):  
Resistance Training ◽  
Exercise Training ◽  
Resistance Exercise ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Mature Male ◽  
Male Rats ◽  
Northern Analysis ◽  
Bone Area ◽  
Resistance Exercise Training

Westerlind, Kim C., James D. Fluckey, Scott E. Gordon, William J. Kraemer, Peter A. Farrell, and Russell T. Turner.Effect of resistance exercise training on cortical and cancellous bone in mature male rats. J. Appl. Physiol. 84(2): 459–464, 1998.—The effect of resistance training on tibial cancellous and cortical bone was evaluated in rats by using static histomorphometry and Northern analysis. Five-month-old male Sprague-Dawley rats were randomly assigned to exercise (Ex; n = 8) or control (Con; n = 4) groups. Animals were operantly conditioned to press two levers, facilitating full extension and flexion of the hindlimbs (“squats”), while wearing an unweighted vest. After an 8-wk familiarization period, Ex animals performed 3 sessions/wk for 17–19 sessions with progressively increased amounts of weight applied to the vest. Con rats completed the same exercise protocol without applied resistance. No difference in cross-sectional, medullary, or cortical bone area was observed between Ex and Con rats in the tibial diaphysis. In contrast, the cancellous bone area in the proximal tibial metaphysis was significantly larger in trained rats. Trabecular number, trabecular thickness, and the percentage of cancellous bone covered by osteoid were significantly greater in the Ex animals compared with Con animals. In addition, steady-state mRNA levels for osteocalcin for the Ex group were 456% those expressed in the Con group. The data demonstrate that resistance training increases cancellous bone area in sexually mature male rats and suggest that it does so, in part, by stimulating bone formation.

scholarly journals Use of Session Rating of Perceived Exertion for Monitoring Resistance Exercise in Children Who Are Overweight or Obese

2008 ◽  
Vol 20 (3) ◽  
pp. 333-341 ◽  
Author(s):  
Michael R. McGuigan ◽  
Abdulaziz Al Dayel ◽  
David Tod ◽  
Carl Foster ◽  
Robert U. Newton ◽  
...  
Keyword(s):  
Resistance Training ◽  
Resistance Exercise ◽  
Correlation Coefficient ◽  
Perceived Exertion ◽  
Training Session ◽  
Rating Of Perceived Exertion ◽  
Exercise Session ◽  
Significant Difference ◽  
Resistance Exercises ◽  
Single Set

The purpose of this study was to investigate the use of the OMNI Resistance Exercise scale (OMNI-RES) for monitoring the intensity of different modes of resistance training in children who are overweight or obese. Sixty-one children (mean age = 9.7 ± 1.4 years) performed three resistance training sessions every week for 4 weeks. Each session consisted of three sets of 3–15 repetitions of eight different resistance exercises. OMNI-RES RPE measures (0–10) were obtained following each set and following the end of the exercise session. There was a significant difference between average RPE (1.68 ± 0.61) and Session RPE (3.10 ± 1.18) during the 4 weeks of training (p < .05). There was no significant change in session RPE over the 4 weeks of training. The correlation coefficient between average and session RPE values was significant (r = .88, p < .05). The findings of the current study indicate that the RPE values are higher when OMNI-RES measures are obtained following the whole training session than when obtained following every single set of exercise. This suggests that in children the session RPE provides different information to the average RPE across the entire session.

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