scholarly journals Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle

2009 ◽  
Vol 106 (4) ◽  
pp. 1187-1197 ◽  
Author(s):  
Vernon G. Coffey ◽  
Henriette Pilegaard ◽  
Andrew P. Garnham ◽  
Brendan J. O'Brien ◽  
John A. Hawley
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Endurance Exercise ◽  
Contractile Activity ◽  
Vastus Lateralis ◽  
Mrna Level ◽  
Molecular Profile ◽  
Hexokinase Ii ◽  
Leg Extension ◽  
Acute Responses

We examined acute molecular responses in skeletal muscle to divergent exercise stimuli by combining consecutive bouts of resistance and endurance exercise. Eight men [22.9 ± 6.3 yr, body mass of 73.2 ± 4.5 kg, peak O2 uptake (V̇o2peak) of 54.0 ± 5.7 ml·kg−1·min−1] were randomly assigned to complete trials consisting of either resistance exercise (8 × 5 leg extension, 80% 1 repetition maximum) followed by a bout of endurance exercise (30 min cycling, 70% V̇o2peak) or vice versa. Muscle biopsies were obtained from the vastus lateralis at rest, 15 min after each exercise bout, and after 3 h of passive recovery to determine early signaling and mRNA responses. Phosphorylation of Akt and Akt1Ser473 were elevated 15 min after resistance exercise compared with cycling, with the greatest increase observed when resistance exercise followed cycling (∼55%; P < 0.01). TSC2-mTOR-S6 kinase phosphorylation 15 min after each bout of exercise was similar regardless of the exercise mode. The cumulative effect of combined exercise resulted in disparate mRNA responses. IGF-I mRNA content was reduced when cycling preceded resistance exercise (−42%), whereas muscle ring finger mRNA was elevated when cycling was undertaken after resistance exercise (∼52%; P < 0.05). The hexokinase II mRNA level was higher after resistance cycling (∼45%; P < 0.05) than after cycling-resistance exercise, whereas modest increases in peroxisome proliferator-activated receptor gamma coactivator-1α mRNA did not reveal an order effect. We conclude that acute responses to diverse bouts of contractile activity are modified by the exercise order. Moreover, undertaking divergent exercise in close proximity influences the acute molecular profile and likely exacerbates acute “interference.”

Effect of consecutive repeated sprint and resistance exercise bouts on acute adaptive responses in human skeletal muscle

2009 ◽  
Vol 297 (5) ◽  
pp. R1441-R1451 ◽  
Author(s):  
Vernon G. Coffey ◽  
Bozena Jemiolo ◽  
Johann Edge ◽  
Andrew P. Garnham ◽  
Scott W. Trappe ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Acute Exercise ◽  
Vastus Lateralis ◽  
Ring Finger ◽  
Exercise Bout ◽  
Induced Response ◽  
Repeated Sprints ◽  
Leg Extension ◽  
Repeated Sprint

We examined acute molecular responses in skeletal muscle to repeated sprint and resistance exercise bouts. Six men [age, 24.7 ± 6.3 yr; body mass, 81.6 ± 7.3 kg; peak oxygen uptake, 47 ± 9.9 ml·kg−1·min−1; one repetition maximum (1-RM) leg extension 92.2 ± 12.5 kg; means ± SD] were randomly assigned to trials consisting of either resistance exercise (8 × 5 leg extension, 80% 1-RM) followed by repeated sprints (10 × 6 s, 0.75 N·m torque·kg−1) or vice-versa. Muscle biopsies from vastus lateralis were obtained at rest, 15 min after each exercise bout, and following 3-h recovery to determine early signaling and mRNA responses. There was divergent exercise order-dependent phosphorylation of p70 S6K (S6K). Specifically, initial resistance exercise increased S6K phosphorylation (∼75% P < 0.05), but there was no effect when resistance exercise was undertaken after sprints. Exercise decreased IGF-I mRNA following 3-h recovery (∼50%, P = 0.06) independent of order, while muscle RING finger mRNA was elevated with a moderate exercise order effect ( P < 0.01). When resistance exercise was followed by repeated sprints PGC-1α mRNA was increased (REX1-SPR2; P = 0.02) with a modest distinction between exercise orders. Repeated sprints may promote acute interference on resistance exercise responses by attenuating translation initiation signaling and exacerbating ubiquitin ligase expression. Indeed, repeated sprints appear to generate the overriding acute exercise-induced response when undertaking concurrent repeated sprint and resistance exercise. Accordingly, we suggest that sprint-activities are isolated from resistance training and that adequate recovery time is considered within periodized training plans that incorporate these divergent exercise modes.

Assessing the mechanistic target of rapamycin complex-1 pathway in response to resistance exercise and feeding in human skeletal muscle by multiplex assay

2018 ◽  
Vol 43 (9) ◽  
pp. 945-949
Author(s):  
Chris McGlory ◽  
Everson A. Nunes ◽  
Sara Y. Oikawa ◽  
Evangelia Tsakiridis ◽  
Stuart M. Phillips
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Vastus Lateralis ◽  
Multiplex Assay ◽  
Target Of Rapamycin ◽  
Leg Extension ◽  
Signalling Molecules ◽  
Mechanistic Target Of Rapamycin ◽  
Phosphorylated Akt ◽  
Protein Feeding

The mechanistic target of rapamycin complex-1 (mTORC-1) is a key nutrient and contraction-sensitive protein that regulates a pathway leading to skeletal muscle growth. Utilizing a multiplex assay, we aimed to examine the phosphorylation status of key mTORC-1-related signalling molecules in response to protein feeding and resistance exercise. Eight healthy men (age, 22.5 ± 3.1 years; mass, 80 ± 9 kg; 1-repetition maximum leg extension, 87 ± 5 kg) performed 4 sets of unilateral leg extensions until volitional failure. Immediately following the final set, all participants consumed a protein-enriched beverage. A single skeletal muscle biopsy was obtained from the vastus lateralis before (Pre) with further bilateral biopsies at 1 h (1 h exercised legs (FEDEX) and 1 h nonexercised legs (FED)) and 3 h (3 h FEDEX and 3 h FED) after drink ingestion. Phosphorylated AktSer473 was significantly elevated from Pre at 1 h FEDEX. Phosphorylated p70S6K1Thr412 was significantly increased above Pre at 1 h FEDEX and 1 h FED and was still significantly elevated at 3 h FEDEX but not 3 h FED. Phosphorylated rpS6Ser235/236 was also significantly increased above Pre at 1 h FEDEX and 1 h FED with 1 h FEDEX greater than 1 h FED. Our data highlight the utility of a multiplex assay to assess anabolic signalling molecules in response to protein feeding and resistance exercise in humans. Importantly, these changes are comparable with those as previously reported using standard immunoblotting and protein activity assays.

scholarly journals Contractile activity-specific transcriptome response to acute endurance exercise and training in human skeletal muscle

2019 ◽  
Vol 316 (4) ◽  
pp. E605-E614 ◽  
Author(s):  
Daniil V. Popov ◽  
Pavel A. Makhnovskii ◽  
Elena I. Shagimardanova ◽  
Guzel R. Gazizova ◽  
Evgeny A. Lysenko ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Transcription Factors ◽  
Human Skeletal Muscle ◽  
Acute Exercise ◽  
Contractile Activity ◽  
Vastus Lateralis ◽  
Aerobic Exercise Training ◽  
Vastus Lateralis Muscle ◽  
Transcriptome Response ◽  
The One

Reduction in daily activity leads to dramatic metabolic disorders, while regular aerobic exercise training is effective for preventing this problem. The purpose of this study was to identify genes that are directly related to contractile activity in human skeletal muscle, regardless of the level of fitness. Transcriptome changes after the one-legged knee extension exercise in exercised and contralateral nonexercised vastus lateralis muscle of seven men were evaluated by RNA-seq. Transcriptome change at baseline after 2 mo of aerobic training (5/wk, 1 h/day) was evaluated as well. Postexercise changes in the transcriptome of exercised muscle were associated with different factors, including circadian oscillations. To reveal transcriptome response specific for endurance-like contractile activity, differentially expressed genes between exercised and nonexercised muscle were evaluated at 1 and 4 h after the one-legged exercise. The contractile activity-specific transcriptome responses were associated only with an increase in gene expression and were regulated mainly by CREB/ATF/AP1-, MYC/MAX-, and E2F-related transcription factors. Endurance training-induced changes (an increase or decrease) in the transcriptome at baseline were more pronounced than transcriptome responses specific for acute contractile activity. Changes after training were associated with widely different biological processes than those after acute exercise and were regulated by different transcription factors (IRF- and STAT-related factors). In conclusion, adaptation to regular exercise is associated not only with a transient (over several hours) increase in expression of many contractile activity-specific genes, but also with a pronounced change (an increase or decrease) in expression of a large number of genes under baseline conditions.

Mammalian target of rapamycin pathway is up-regulated by both acute endurance exercise and chronic muscle contraction in rat skeletal muscle

2013 ◽  
Vol 38 (8) ◽  
pp. 862-869 ◽  
Author(s):  
Brittany A. Edgett ◽  
Melanie L. Fortner ◽  
Arend Bonen ◽  
Brendon J. Gurd
Keyword(s):  
Skeletal Muscle ◽  
Endurance Exercise ◽  
Gastrocnemius Muscle ◽  
Contractile Activity ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Pathway ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Sprague Dawley ◽  
Sprague Dawley Rats

This study examined changes in the expression of translation initiation regulatory proteins and mRNA following both an acute bout of endurance exercise and chronic muscle contractile activity. Female Sprague Dawley rats ran for 2 h at 15 m·min−1 followed by an increase in speed of 5 m·min−1 every 5 min until volitional fatigue. The red gastrocnemius muscle was harvested from nonexercised animals (control; n = 6) and from animals that exercised either immediately after exercise (n = 6) or following 3 h of recovery from exercise (n = 6). Compared with control, ribosomal protein S6 (rpS6) mRNA was elevated (p < 0.05) at both 0 h (+32%) and 3 h (+47%). Both a catalytic subunit of eukaryotic initiation factor 2B (eIF2Bε) (+127%) and mammalian target of rapamycin (mTOR) mRNA (+44%) were increased at 3 h, compared with control. Phosphorylation of mTOR (+40%) and S6 kinase 1 (S6K1) (+266%) were increased immediately after exercise (p < 0.05). Female Sprague Dawley rats also underwent chronic stimulation of the peroneal nerve continuously for 7 days. The red gastrocnemius muscle was removed 24 h after cessation of the stimulation. Chronic muscle stimulation increased (p < 0.05) mTOR protein (+74%), rpS6 (+31%), and eukaryotic initiation factor 2α (+44%, p = 0.069), and this was accompanied by an increase in cytochrome c (+31%). Increased resting phosphorylation was observed for rpS6 (+51%) (p < 0.05) but not for mTOR or eukaryotic initiation factor 4E binding protein 1. These experiments demonstrate that both acute and chronic contractile activity up-regulate the mTOR pathway and mitochondrial content in murine skeletal muscle. This up-regulation of the mTOR pathway may increase translation efficiency and may also represent an important control point in exercise-mediated mitochondrial biogenesis.

scholarly journals Nutritional modulation of training-induced skeletal muscle adaptations

2011 ◽  
Vol 110 (3) ◽  
pp. 834-845 ◽  
Author(s):  
John A. Hawley ◽  
Louise M. Burke ◽  
Stuart M. Phillips ◽  
Lawrence L. Spriet
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Nutrient Availability ◽  
Training Stimulus ◽  
Energy Status ◽  
Metabolic Potential ◽  
Training Adaptation ◽  
Regulatory Processes ◽  
Acute Responses ◽  
External Stimuli

Skeletal muscle displays remarkable plasticity, enabling substantial adaptive modifications in its metabolic potential and functional characteristics in response to external stimuli such as mechanical loading and nutrient availability. Contraction-induced adaptations are determined largely by the mode of exercise and the volume, intensity, and frequency of the training stimulus. However, evidence is accumulating that nutrient availability serves as a potent modulator of many acute responses and chronic adaptations to both endurance and resistance exercise. Changes in macronutrient intake rapidly alter the concentration of blood-borne substrates and hormones, causing marked perturbations in the storage profile of skeletal muscle and other insulin-sensitive tissues. In turn, muscle energy status exerts profound effects on resting fuel metabolism and patterns of fuel utilization during exercise as well as acute regulatory processes underlying gene expression and cell signaling. As such, these nutrient-exercise interactions have the potential to activate or inhibit many biochemical pathways with putative roles in training adaptation. This review provides a contemporary perspective of our understanding of the molecular and cellular events that take place in skeletal muscle in response to both endurance and resistance exercise commenced after acute and/or chronic alterations in nutrient availability (carbohydrate, fat, protein, and several antioxidants). Emphasis is on the results of human studies and how nutrient provision (or lack thereof) interacts with specific contractile stimulus to modulate many of the acute responses to exercise, thereby potentially promoting or inhibiting subsequent training adaptation.

scholarly journals Myosin heavy chain expression in rodent skeletal muscle: effects of exposure to zero gravity

1993 ◽  
Vol 75 (6) ◽  
pp. 2471-2477 ◽  
Author(s):  
F. Haddad ◽  
R. E. Herrick ◽  
G. R. Adams ◽  
K. M. Baldwin
Keyword(s):  
Skeletal Muscle ◽  
Muscle Protein ◽  
Vastus Lateralis ◽  
Mrna Level ◽  
Relative Content ◽  
Type I ◽  
Zero Gravity ◽  
Mrna Levels ◽  
Heavy Chains ◽  
Vastus Intermedius

This study ascertained the effects of 9 days of zero gravity on the relative (percentage of total) and calculated absolute (mg/muscle) content of isomyosin expressed in both antigravity and locomotor skeletal muscle of ground control (CON) and flight-exposed (FL) rats. Results showed that although there were no differences in body weight between FL and CON animals, a significant reduction in muscle mass occurred in the vastus intermedius (VI) (P < 0.05) but not in the vastus lateralis (VL) or the tibialis anterior. Both total muscle protein and myofibril protein content were not different between the muscle regions examined in the FL and CON groups. In the VI, there were trends for reductions in the relative content of type I and IIa myosin heavy chains (MHCs) that were offset by increases in the relative content of both type IIb and possibly type IIx MHC protein (P > 0.05). mRNA levels were consistent with this pattern (P < 0.05). The same pattern held true for the red region of the VL as examined at both the protein and mRNA level (P < 0.05). When the atrophy process was examined, there were net reductions in the absolute content of both type I and IIa MHCs that were offset by calculated increases in type IIb MHC in both VI and red VL. Collectively, these findings suggest that there are both absolute and relative changes occurring in MHC expression in the "red" regions of antigravity skeletal muscle during exposure to zero gravity that could affect muscle function.

scholarly journals Sex-specific alterations in mRNA level of key lipid metabolism enzymes in skeletal muscle of overweight and obese subjects following endurance exercise

2009 ◽  
Vol 36 (3) ◽  
pp. 149-157 ◽  
Author(s):  
Ira J. Smith ◽  
Kim M. Huffman ◽  
Michael T. Durheim ◽  
Brian D. Duscha ◽  
William E. Kraus
Keyword(s):  
Skeletal Muscle ◽  
Lipid Metabolism ◽  
Endurance Exercise ◽  
Regulatory Element ◽  
Mrna Level ◽  
Mrna Abundance ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Middle Aged ◽  
Metabolism Enzymes

Endurance exercise (EE) leads to beneficial alterations in skeletal muscle lipid metabolism in overweight and obese individuals; however, the mechanisms of these improvements are poorly understood. The primary goal of the current investigation was to test the hypothesis that long-term EE training (6 mo) leads to alterations in the mRNA abundance of key lipid metabolism enzymes in skeletal muscle of overweight and obese middle-aged women and men. A secondary aim of this study was to investigate the hypothesis that exercise-mediated adaptations in mRNA levels differ between women and men. The mRNA abundance of representative lipogenic and lipolytic genes from major lipid metabolism pathways, as well as representative lipogenic and lipolytic transcription factors, were determined by real-time PCR from skeletal muscle biopsies collected before and ∼24 h after the final bout of 6 mo of EE. Six months of EE led to increases in muscle lipoprotein lipase, peroxisome proliferator-activated receptor-γ coactivator-1α, carnitine palmitoyltransferase-1 β, diacylglycerol acyltransferase-1, and acid ceramidase mRNA in women, but not men. In contrast, in men, EE led to reductions in the mRNA content of the lipogenic factors sterol regulatory element binding protein-1c and serine palmitoyl transferase. These data suggest that EE-mediated alterations in the abundance of the lipid metabolism genes studied here are fundamentally different between overweight and obese middle-aged women and men. Future studies should determine whether these adaptations in mRNA levels translate into changes in protein function.

Influence of muscle glycogen availability on ERK1/2 and Akt signaling after resistance exercise in human skeletal muscle

2005 ◽  
Vol 99 (3) ◽  
pp. 950-956 ◽  
Author(s):  
Andrew Creer ◽  
Philip Gallagher ◽  
Dustin Slivka ◽  
Bozena Jemiolo ◽  
William Fink ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Muscle Glycogen ◽  
Human Skeletal Muscle ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Akt Signaling ◽  
Cellular Growth ◽  
Muscle Glycogen Content ◽  
Ribosomal S6 Kinase

Two pathways that have been implicated for cellular growth and development in response to muscle contraction are the extracellular signal-regulated kinase (ERK1/2) and Akt signaling pathways. Although these pathways are readily stimulated after exercise, little is known about how nutritional status may affect stimulation of these pathways in response to resistance exercise in human skeletal muscle. To investigate this, experienced cyclists performed 30 repetitions of knee extension exercise at 70% of one repetition maximum after a low (2%) or high (77%) carbohydrate (LCHO or HCHO) diet, which resulted in low or high (∼174 or ∼591 mmol/kg dry wt) preexercise muscle glycogen content. Muscle biopsies were taken from the vastus lateralis before, ∼20 s after, and 10 min after exercise. ERK1/2 and p90 ribosomal S6 kinase phosphorylation increased ( P ≤ 0.05) 10 min after exercise, regardless of muscle glycogen availability. Akt phosphorylation was elevated ( P < 0.05) 10 min after exercise in the HCHO trial but was unaffected after exercise in the LCHO trial. Mammalian target of rapamycin phosphorylation was similar to that of Akt during each trial; however, change or lack of change was not significant. In conclusion, the ERK1/2 pathway appears to be unaffected by muscle glycogen content. However, muscle glycogen availability appears to contribute to regulation of the Akt pathway, which may influence cellular growth and adaptation in response to resistance exercise in a low-glycogen state.

Expression of titin-linked putative mechanosensing proteins in skeletal muscle after power resistance exercise in resistance-trained men

2020 ◽  
Author(s):  
Stefan G. Wette ◽  
Nigel P. Birch ◽  
Matthias Soop ◽  
Martina Zügel ◽  
Robyn M. Murphy ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Creatine Kinase ◽  
Resistance Exercise ◽  
Vastus Lateralis ◽  
Cytoskeletal Proteins ◽  
Muscle Sample ◽  
Post Exercise ◽  
Protein Levels ◽  
Ankyrin Repeat Proteins ◽  
Muscle Remodeling

Little is known about the molecular responses to power resistance exercise that lead to skeletal muscle remodeling and enhanced athletic performance. We assessed the expression of titin-linked putative mechanosensing proteins implicated in muscle remodeling: muscle ankyrin repeat proteins (Ankrd1, Ankrd2 and Ankrd23), muscle-LIM proteins (MLP), muscle RING-finger protein-1 (MuRF-1), and associated myogenic proteins (MyoD1, myogenin, and myostatin) in skeletal muscle in response to power resistance exercise with or without a post-exercise meal, in fed, resistance-trained men. A muscle sample was obtained from the vastus lateralis of seven healthy men on separate days, 3h after 90 min of rest (Rest) or power resistance exercise with (Ex+Meal) or without (Ex) a post-exercise meal, to quantify mRNA and protein levels. The levels of phosphorylated HSP27 (pHSP27-Ser15) and cytoskeletal proteins in muscle and creatine kinase activity in serum were also assessed. The exercise increased (P≤0.05) pHSP27-Ser15 (~6-fold) and creatine kinase (~50%), whereas cytoskeletal protein levels were unchanged (P>0.05). Ankrd1 (~15-fold) and MLP (~2-fold) mRNA increased, whereas Ankrd2, Ankrd23, MuRF-1, MyoD1, and myostatin mRNA were unchanged. Ankrd1 (~3-fold, Ex) and MLPb (~20-fold, Ex+Meal) protein increased, but MLPa, Ankrd2, Ankrd23, and the myogenic proteins were unchanged. The post-exercise meal did not affect the responses observed. Power resistance exercise, as performed in practice, induced subtle early responses in the expression of MLP and Ankrd1, yet had little effect on the other proteins investigated. These findings suggest possible roles for MLP and Ankrd1 in the remodeling of skeletal muscle in individuals who regularly perform this type of exercise.

scholarly journals Acute and chronic resistance training downregulates select LINE-1 retrotransposon activity markers in human skeletal muscle

2018 ◽  
Vol 314 (3) ◽  
pp. C379-C388 ◽  
Author(s):  
Matthew A. Romero ◽  
C. Brooks Mobley ◽  
Petey W. Mumford ◽  
Paul A. Roberson ◽  
Cody T. Haun ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Training ◽  
Resistance Exercise ◽  
Satellite Cell ◽  
Vastus Lateralis ◽  
Future Research ◽  
Resistance Training Program ◽  
Myoblast Proliferation ◽  
Retrotransposon Activity

Herein, we examined if acute or chronic resistance exercise affected markers of skeletal muscle long interspersed nuclear element-1 (LINE-1) retrotransposon activity. In study 1, 10 resistance-trained college-aged men performed three consecutive daily back squat sessions, and vastus lateralis biopsies were taken before (Pre), 2 h following session 1 (Post1), and 3 days following session 3 (Post2). In study 2, 13 untrained college-aged men performed a full-body resistance training program (3 days/wk), and vastus lateralis biopsies were taken before ( week 0) and ~72 h following training cessation ( week 12). In study 1, LINE-1 mRNA decreased 42–48% at Post1 and 2 ( P < 0.05), and reverse transcriptase (RT) activity trended downward at Post2 (−37%, P = 0.067). In study 2, LINE-1 mRNA trended downward at week 12 (−17%, P = 0.056) while LINE-1 promoter methylation increased (+142%, P = 0.041). Open reading frame (ORF)2p protein expression (−24%, P = 0.059) and RT activity (−26%, P = 0.063) also trended downward by week 12. Additionally, changes in RT activity versus satellite cell number were inversely associated ( r = −0.725, P = 0.008). Follow-up in vitro experiments demonstrated that 48-h treatments with lower doses (1 μM and 10 μM) of efavirenz and nevirapine (non-nucleoside RT inhibitors) increased myoblast proliferation ( P < 0.05). However, we observed a paradoxical decrease in myoblast proliferation with higher doses (50 μM) of efavirenz and delavirdine. This is the first report suggesting that resistance exercise downregulates markers of skeletal muscle LINE-1 activity. Given our discordant in vitro findings, future research is needed to thoroughly assess whether LINE-1-mediated RT activity enhances or blunts myoblast, or primary satellite cell, proliferative capacity.

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