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.

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.

scholarly journals Increased net muscle protein balance in response to simultaneous and separate ingestion of carbohydrate and essential amino acids following resistance exercise

2014 ◽  
Vol 39 (3) ◽  
pp. 329-339 ◽  
Author(s):  
Oliver C. Witard ◽  
Tara L. Cocke ◽  
Arny A. Ferrando ◽  
Robert R. Wolfe ◽  
Kevin D. Tipton
Keyword(s):  
Amino Acids ◽  
Resistance Exercise ◽  
Acute Exercise ◽  
Muscle Protein ◽  
Exercise Bout ◽  
Essential Amino Acids ◽  
Delayed Response ◽  
Protein Balance ◽  
Post Exercise ◽  
Exercise Muscle

Relative to essential amino acids (EAAs), carbohydrate (CHO) ingestion stimulates a delayed response of net muscle protein balance (NBAL). We investigated if staggered ingestion of CHO and EAA would superimpose the response of NBAL following resistance exercise, thus resulting in maximal anabolic stimulation. Eight recreationally trained subjects completed 2 trials: combined (COMB — drink 1, CHO+EAA; drink 2, placebo) and separated (SEP — drink 1, CHO; drink 2, EAA) post-exercise ingestion of CHO and EAA. Drink 1 was administered 1 h following an acute exercise bout and was followed 1 h later by drink 2. A primed, continuous infusion of l-[ring-13C6]-phenylalanine was combined with femoral arteriovenous sampling and muscle biopsies for the determination of muscle protein kinetics. Arterial amino acid concentrations increased following ingestion of EAA in both conditions. No difference between conditions was observed for phenylalanine delivery to the leg (COMB: 167 ± 23 μmol·min−1·(100 mL leg vol)−1 × 6 h; SEP: 167 ± 21 μmol·min−1·(100 mL leg vol)−1 × 6 h, P > 0.05). In the first hour following ingestion of the drink containing EAA, phenylalanine uptake was 50% greater for the SEP trial than the COMB trial. However, phenylalanine uptake was similar for COMB (110 ± 19 mg) and SEP (117 ± 24 mg) over the 6 h period. These data suggest that whereas separation of CHO and EAA ingestion following exercise may have a transient physiological impact on NBAL, this response is not reflected over a longer period. Thus, separation of CHO and EAA ingestion is unnecessary to optimize post-exercise muscle protein metabolism.

Resistance-training-induced adaptations in skeletal muscle protein turnover in the fed state

2002 ◽  
Vol 80 (11) ◽  
pp. 1045-1053 ◽  
Author(s):  
S M Phillips ◽  
G Parise ◽  
B D Roy ◽  
K D Tipton ◽  
R R Wolfe ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Training ◽  
Protein Turnover ◽  
Acute Exercise ◽  
Muscle Protein ◽  
Longitudinal Design ◽  
Resistance Training Program ◽  
Fed State ◽  
Muscle Protein Turnover ◽  
Breakdown Rates

Resistance training changes the balance of muscle protein turnover, leading to gains in muscle mass. A longitudinal design was employed to assess the effect that resistance training had on muscle protein turnover in the fed state. A secondary goal was investigation of the potential interactive effects of creatine (Cr) monohydrate supple mentation on resistance-training-induced adaptations. Young (N = 19, 23.7 ± 3.2 year), untrained (UT), healthy male subjects completed an 8-week resistance-training program (6 d/week). Supplementation with Cr had no impact on any of the variables studied; hence, all subsequent data were pooled. In the UT and trained (T) state, subjects performed an acute bout of resistance exercise with a single leg (exercised, EX), while their contralateral leg acted as a nonexercised (NE) control. Following exercise, subjects were fed while receiving a primed constant infusion of [d5]- and [15N]-phenylalanine to determine the fractional synthetic and breakdown rates (FSR and FBR), respectively, of skeletal muscle proteins. Acute exercise increased FSR (UT-NE, 0.065 ± 0.025 %/h; UT-EX, 0.088 ± 0.032 %/h; P < 0.01) and FBR (UT-NE, 0.047 ± 0.023 %/h; UT-EX, 0.058 ± 0.026 %/h; P < 0.05). Net balance (BAL = FSR – FBR) was positive in both legs (P < 0.05) but was significantly greater (+65%) in the EX versus the NE leg (P < 0.05). Muscle protein FSR and FBR were greater at rest following T (FSR for T-NE vs. UT-NE, +46%, P < 0.01; FBR for T-NE vs. UT-NE, +81%, P < 0.05). Resistance training attenuated the acute exercise-induced rise in FSR (T-NE vs. T-EX, +20%, P = 0.65). The present results demonstrate that resistance training resulted in an elevated resting muscle protein turnover but an attenuation of the acute response of muscle protein turnover to a single bout of resistance exercise.Key words: myofibrillar protein, hypertrophy, protein synthesis, protein breakdown.

Mixed muscle protein synthesis and breakdown after resistance exercise in humans

1997 ◽  
Vol 273 (1) ◽  
pp. E99-E107 ◽  
Author(s):  
S. M. Phillips ◽  
K. D. Tipton ◽  
A. Aarsland ◽  
S. E. Wolf ◽  
R. R. Wolfe
Keyword(s):  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Exercise Bout ◽  
Synthesis Rate ◽  
Breakdown Rate ◽  
Time Points ◽  
Significant Difference ◽  
Fractional Synthesis ◽  
Exercise In Humans

Mixed muscle protein fractional synthesis rate (FSR) and fractional breakdown rate (FBR) were examined after an isolated bout of either concentric or eccentric resistance exercise. Subjects were eight untrained volunteers (4 males, 4 females). Mixed muscle protein FSR and FBR were determined using primed constant infusions of [2H5]phenylalanine and 15N-phenylalanine, respectively. Subjects were studied in the fasted state on four occasions: at rest and 3, 24, and 48 h after a resistance exercise bout. Exercise was eight sets of eight concentric or eccentric repetitions at 80% of each subject's concentric 1 repetition maximum. There was no significant difference between contraction types for either FSR, FBR, or net balance (FSR minus FBR). Exercise resulted in significant increases above rest in muscle FSR at all times: 3 h = 112%, 24 h = 65%, 48 h = 34% (P < 0.01). Muscle FBR was also increased by exercise at 3 h (31%; P < 0.05) and 24 h (18%; P < 0.05) postexercise but returned to resting levels by 48 h. Muscle net balance was significantly increased after exercise at all time points [(in %/h) rest = -0.0573 +/- 0.003 (SE), 3 h = -0.0298 +/- 0.003, 24 h = -0.0413 +/- 0.004, and 48 h = -0.0440 +/- 0.005], and was significantly different from zero at all time points (P < 0.05). There was also a significant correlation between FSR and FBR (r = 0.88, P < 0.001). We conclude that exercise resulted in an increase in muscle net protein balance that persisted for up to 48 h after the exercise bout and was unrelated to the type of muscle contraction performed.

scholarly journals A comparison of 2H2O and phenylalanine flooding dose to investigate muscle protein synthesis with acute exercise in rats

2009 ◽  
Vol 297 (1) ◽  
pp. E252-E259 ◽  
Author(s):  
Heath G. Gasier ◽  
Steven E. Riechman ◽  
Michael P. Wiggs ◽  
Stephen F. Previs ◽  
James D. Fluckey
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
High Intensity ◽  
Acute Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Primary Objective ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Single Bout

The primary objective of this investigation was to determine whether 2H2O and phenylalanine (Phe) flooding dose methods yield comparable fractional rates of protein synthesis (FSR) in skeletal muscle following a single bout of high-intensity resistance exercise (RE). Sprague-Dawley rats were assigned by body mass to either 4-h control (CON 4 h; n = 6), 4-h resistance exercise (RE 4 h; n = 6), 24-h control (CON 24 h; n = 6), or 24-h resistance exercise (RE 24 h; n = 6). The RE groups were operantly conditioned to engage in a single bout of high-intensity, “squat-like” RE. All rats were given an intraperitoneal injection of 99.9% 2H2O and provided 4.0% 2H2O drinking water for either 24 ( n = 12) or 4 h ( n = 12) prior to receiving a flooding dose of l-[2,3,4,5,6-3H]Phe 16 h post-RE. Neither method detected an effect of RE on FSR in the mixed gastrocnemius, plantaris, or soleus muscle. Aside from the qualitative similarities between methods, the 4-h 2H2O FSR measurements, when expressed in percent per hour, were quantitatively greater than the 24-h 2H2O and Phe flooding in all muscles ( P < 0.001), and the 24-h 2H2O was greater than the Phe flooding dose in the mixed gastrocnemius and plantaris ( P < 0.05). In contrast, the actual percentage of newly synthesized protein was significantly higher in the 24- vs. 4-h 2H2O and Phe flooding dose groups ( P < 0.001). These results suggest that the methodologies provide “qualitatively” similar results when a perturbation such as RE is studied. However, due to potential quantitative differences between methods, the experimental question should determine what approach should be used.

scholarly journals Resistance exercise maintains skeletal muscle protein synthesis during bed rest

1997 ◽  
Vol 82 (3) ◽  
pp. 807-810 ◽  
Author(s):  
Arny A. Ferrando ◽  
Kevin D. Tipton ◽  
Marcas M. Bamman ◽  
Robert R. Wolfe
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Resistance Training ◽  
Resistance Exercise ◽  
Lean Body Mass ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Bed Rest ◽  
Skeletal Muscle Protein ◽  
Skeletal Muscle Protein Synthesis

Ferrando, Arny A., Kevin D. Tipton, Marcas M. Bamman, and Robert R. Wolfe. Resistance exercise maintains skeletal muscle protein synthesis during bed rest. J. Appl. Physiol. 82(3): 807–810, 1997.—Spaceflight results in a loss of lean body mass and muscular strength. A ground-based model for microgravity, bed rest, results in a loss of lean body mass due to a decrease in muscle protein synthesis (MPS). Resistance training is suggested as a proposed countermeasure for spaceflight-induced atrophy because it is known to increase both MPS and skeletal muscle strength. We therefore hypothesized that scheduled resistance training throughout bed rest would ameliorate the decrease in MPS. Two groups of healthy volunteers were studied during 14 days of simulated microgravity. One group adhered to strict bed rest (BR; n = 5), whereas a second group engaged in leg resistance exercise every other day throughout bed rest (BREx; n = 6). MPS was determined directly by the incorporation of infusedl-[ ring-13C6]phenylalanine into vastus lateralis protein. After 14 days of bed rest, MPS in the BREx group did not change and was significantly greater than in the BR group. Thus moderate-resistance exercise can counteract the decrease in MPS during bed rest.

Effects of acute exercise on the gluconeogenic capacity of periportal and perivenous hepatocytes

2001 ◽  
Vol 91 (3) ◽  
pp. 1099-1104 ◽  
Author(s):  
François Désy ◽  
Yan Burelle ◽  
Patrice Bélanger ◽  
Marielle Gascon-Barré ◽  
Jean-Marc Lavoie
Keyword(s):  
Incubation Medium ◽  
Acute Exercise ◽  
Metabolic Response ◽  
Liver Perfusion ◽  
Glucose Production ◽  
Selective Destruction ◽  
Single Bout ◽  
Lactate And Pyruvate ◽  
The Difference ◽  
Exercise Induced

The present study was conducted to examine the effect of a single bout of exercise (rodent treadmill, 60 min at 26 m/min, 0% grade) on the gluconeogenic activity of periportal hepatocytes (PP-H) and perivenous hepatocytes (PV-H) in fasted (18 h) rats. Isolated PP-H and PV-H, obtained by selective destruction following liver perfusion with digitonin and collagenase, were incubated with saturating concentrations of alanine (Ala; 20 mM) or a mixture of lactate and pyruvate (Lac+Pyr; 20:2 mM) to determine the glucose production flux ( J glucose) in the incubation medium. Results show that, in the resting conditions, J glucose from all exogenous substrates was significantly higher ( P < 0.01) in PP-H than in PV-H. Exercise, compared with rest, resulted in a higher J glucose ( P < 0.01) from Lac+Pyr substrate in the PV-H but not in the PP-H, resulting in the disappearance of the difference in J glucosebetween PP-H and PV-H. Exercise, compared with rest, led to a higher J glucose ( P < 0.01) from Ala substrate in both PP-H and PV-H. However, the exercise-induced increase in J glucose (gluconeogenic activity) from Ala substrate was higher in PV-H than in PP-H, resulting, as from Lac+Pyr substrate, in the disappearance ( P > 0.05) of the difference of J glucose between PP-H and PV-H. It is concluded that exercise differentially stimulates the gluconeogenic activity of PV-H to a larger extent than PP-H, indicative of a heterogenous metabolic response of hepatocytes to exercise.

scholarly journals Stimuli and sensors that initiate skeletal muscle hypertrophy following resistance exercise

2019 ◽  
Vol 126 (1) ◽  
pp. 30-43 ◽  
Author(s):  
Henning Wackerhage ◽  
Brad J. Schoenfeld ◽  
D. Lee Hamilton ◽  
Maarit Lehti ◽  
Juha J. Hulmi
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Muscle Damage ◽  
Muscle Hypertrophy ◽  
Muscle Protein ◽  
Large Body ◽  
Focal Adhesions ◽  
Indirect Evidence ◽  
Skeletal Muscle Hypertrophy ◽  
Exercise Induced

One of the most striking adaptations to exercise is the skeletal muscle hypertrophy that occurs in response to resistance exercise. A large body of work shows that a mammalian target of rapamycin complex 1 (mTORC1)-mediated increase of muscle protein synthesis is the key, but not sole, mechanism by which resistance exercise causes muscle hypertrophy. While much of the hypertrophy signaling cascade has been identified, the initiating, resistance exercise-induced and hypertrophy-stimulating stimuli have remained elusive. For the purpose of this review, we define an initiating, resistance exercise-induced and hypertrophy-stimulating signal as “hypertrophy stimulus,” and the sensor of such a signal as “hypertrophy sensor.” In this review we discuss our current knowledge of specific mechanical stimuli, damage/injury-associated and metabolic stress-associated triggers, as potential hypertrophy stimuli. Mechanical signals are the prime hypertrophy stimuli candidates, and a filamin-C-BAG3-dependent regulation of mTORC1, Hippo, and autophagy signaling is a plausible albeit still incompletely characterized hypertrophy sensor. Other candidate mechanosensing mechanisms are nuclear deformation-initiated signaling or several mechanisms related to costameres, which are the functional equivalents of focal adhesions in other cells. While exercise-induced muscle damage is probably not essential for hypertrophy, it is still unclear whether and how such muscle damage could augment a hypertrophic response. Interventions that combine blood flow restriction and especially low load resistance exercise suggest that resistance exercise-regulated metabolites could be hypertrophy stimuli, but this is based on indirect evidence and metabolite candidates are poorly characterized.

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