Acute Bout Of Resistance Exercise Research Articles

Blunted satellite cell response is associated with dysregulated IGF-1 expression after exercise with age.

Insulin-like growth factor-1 (IGF-1) regulates protein synthesis and cell cycle kinetics. Given that aging is associated with anabolic resistance, we sought to determine if the attenuated exercise-induced satellite cell (SC) expression in older muscle is associated with a blunted IGF-1 response. SC expression (Pax7+ cells) and protein (Western blot) and mRNA (RT-PCR) expression of IGF-1 splice variants and ubiquitous (IGFBP4) and muscle-specific (IGFBP3 and -5) IGF-1 binding proteins were measured in skeletal muscle of young (Y: 22 ± 2, n = 7) and older (O: 70 ± 2, n = 7) adults up to 48h after an acute bout of resistance exercise. SC expression was greater in Y compared to O (age; P < 0.01) and increased (interaction; P < 0.05) by 24h after exercise in Y only. IGF-1Ea and IGF-1Eb mRNA tended to be greater in O (age; P < 0.06-0.09). IGF-1Eb mRNA increased at 48h (time; P < 0.05), whereas IGF-1Ec mRNA increased (interaction; P < 0.05) at 24 and 48h in O only. IGF binding protein (IGFBP)4 mRNA was greater (age; P < 0.01) in O with the increase at 24h and 48h (time; P < 0.01) primarily driven by changes in O (interaction; P < 0.01). Despite IGFBP3 mRNA being greater in O (age; P < 0.01) and increasing at 48h (time; P < 0.01), there was no effect of age or exercise on IGFBP3 protein expression. In contrast, IGFBP5 mRNA was greater (age; P < 0.01) despite IGFBP5 protein expression being lower (age; P < 0.01) in O compared to Y. The greater muscle-specific expression of IGF-1 family members with a blunted post-exercise SC expression may be a compensatory attempt to rescue age-related anabolic resistance.

Aortic stiffness, central pulse pressure and cognitive function following acute resistance exercise.

While resistance exercise (RE) is known to be beneficial for overall health, one bout of RE acutely increases aortic stiffness and pulse pressure (PP). Increases in aortic stiffness and PP in a setting of aging has been shown to detrimentally impact cognitive function. This study examined whether increased aortic stiffness and PP from an acute bout of RE is associated with cognitive function. Thirty-five participants (21 ± 2years) underwent cognitive testing before and after either an acute bout of RE or a non-exercise time-control condition. Cognitive function was assessed as reaction time and accuracy during memory recognition, attention (Flanker) and working memory (N-back) tasks. Aortic stiffness and PP were measured via pulse wave velocity (PWV) and pulse wave analysis, respectively, using a brachial oscillometric device. There were significant increases in aortic PWV and aortic PP following RE (p < 0.05) with no change in PWV or PP following the non-exercise control condition (p > 0.05). There was no change in accuracy metrics (% hits) across conditions for any cognitive task (p > 0.05). There was a condition-by-time interaction for reaction time for the memory task (p < 0.05) driven by a significant decrease in reaction times following RE (p < 0.05) with no change in reaction time following the non-exercise control (p > 0.05). Functional increases in aortic stiffness and pulse pressure following acute RE occur in the absence of detrimental changes in cognitive function in young, healthy adults.

RHEUMATOID ARTHRITIS-INCREASED GENE EXPRESSIONS IN MUSCLE ATROPHY ARE RESTORED BACK TO CONTROL AS A RESPONSE TO ACUTE RESISTANCE EXERCISE

This study had as objective to analyze the acute effects of resistance exercise (RE) on the mRNA levels of the following genes (MyoD, myogenin, IGF-1, atrogin-1, MuRF-1, and myostatin) in rheumatoid arthritis (experimental arthritis). Therefore, 26 females rats were randomly allocated into four groups, control (CT, n=7), exercise (Ex, n=6), rheumatoid arthritis (RA, n=6) and RA with exercise (RAEx, n=7). Met-BSA was injected into the tibiotarsal joint in the RA and RAEx groups. After 15 days from injection, the animals were submitted to an acute bout of RE and six hours post protocol the animals were euthanized. We evaluated the joint thickness, inflammation score, cross-sectional area (CSA) of gastrocnemius muscle fibers and mRNA expression of the IGF-1, MyoD, myogenin, myostatin, MuRF-1, atrogin-1 and GAPDH. It was observed that the joint thickness and score strongly increased in arthritic rats (p

Autonomic modulation and baroreflex sensitivity after acute resistance exercise: responses between sexes.

The aim of this study was to evaluate autonomic modulation, blood pressure variability and baroreflex sensitivity (BRS) responses to an acute bout of free-weight resistance exercise in resistance-trained men (N.=14) and women (N.=13). Participants underwent both an acute bout of resistance exercise (RE) consisting of 3 sets of 10 repetitions at 75% 1-repetition maximum on the squat, bench press, and deadlift, and a quiet control. Autonomic modulation, blood pressure variability (LFSAP), and cardiovagal BRS were assessed at rest, 15-20 minutes (Rec1) and 25-30 minutes (Rec2) postexercise. Log transformed measures of autonomic modulation included root square of the mean ssquared differences of successive RR intervals (LnRMSSD), high-frequency power (LnHFRR) and low-frequency power (LnLFRR) and sympathovagal balance (LnLFRR/HFRR). LFSAP was used as a measurement of vasomotor tone. Cardiovagal BRS was assessed using the sequence method. There were no significant sex differences at rest and no significant sex by time by condition interactions for any variable. Compared with rest there were augmentations in LnLFRR/HFRR (P=0.002) and LFSAP (P=0.001) at Rec1 and Rec2. RMSSD and cardiovagal BRS were significantly (P=0.0001) decreased at Rec1 and Rec2 compared to rest after the acute RE. Both sexes demonstrated that acute resistance exercise using free weights has a profound impact on autonomic modulation, blood pressure variability and cardiovagal BRS.

Resistance exercise stimulates mixed muscle protein synthesis in lean and obese young adults.

Obese individuals exhibit a diminished muscle protein synthesis response to nutrient stimulation when compared with their lean counterparts. However, the effect of obesity on exercise‐stimulated muscle protein synthesis remains unknown. Nine lean (23.5 ± 0.6 kg/m2) and 8 obese (33.6 ± 1.2 kg/m2) physically active young adults participated in a study that determined muscle protein synthesis and intracellular signaling at rest and following an acute bout of resistance exercise. Mixed muscle protein synthesis was determined by combining stable isotope tracer ([13C6]phenylalanine) infusion with serial biopsies of the vastus lateralis. A unilateral leg resistance exercise model was adopted so that resting and postexercise measurements of muscle protein synthesis could be obtained simultaneously. Obesity was associated with higher basal levels of serum insulin (P < 0.05), plasma triacylglycerol (P < 0.01), plasma cholesterol (P < 0.01), and plasma CRP (P < 0.01), as well as increased insulin resistance determined by HOMA‐IR (P < 0.05). However, resting and postexercise rates of muscle protein synthesis were not significantly different between lean and obese participants (P = 0.644). Furthermore, resistance exercise stimulated muscle protein synthesis (~50% increase) in both groups (P < 0.001), with no difference between lean and obese (P = 0.809). Temporal increases in the phosphorylation of intracellular signaling proteins (AKT/4EBP1/p70S6K) were observed within the exercised leg (P < 0.05), with no differences between lean and obese. These findings suggest a normal anabolic response to muscle loading in obese young adults.

Acute Resistance Exercise Effects on Blood Flow in Resistance-Trained Versus Untrained Individuals

Data suggests that an acute bout of resistance exercise (ARE) increases forearm blood flow (FBF) and vasodilatory capacity compared to rest. However, the effects of training status on FBF and vasodilatory capacity at rest and during recovery from ARE are uncertain. PURPOSE: To compare the effects of resistance exercise training status on measures of vascular function at rest and recovery from ARE. METHODS: Fifteen resistance-trained (RT) individuals, and seven untrained (UT) individuals volunteered to participate. Measurements were taken after a 10min supine rest and 20min after ARE, or a control. Venous occlusion plethysmography was used to measure FBF and vasodilatory capacity, with 5min of occlusion (220mmHg) to induce reactive hyperemia. Area under the curve (AUC) was utilized to determine differences in blood flow. The ARE consisted of 3 sets of 10 repetitions at 75% 1-repetition maximum (1RM) on the leg press, leg curl, leg extension, lat pulldown, and chest press, with 2min of rest between sets and exercises. A 2x2x2 repeated measures ANOVA was used to evaluate group (RT, UT) across condition (ARE, control) and time (rest, recovery). If the ANOVA was significant, t-tests were used for post-hoc comparisons. RESULTS: Groups were similar (p>0.05) for age, height, and BMI, but not for weight (RT: 74.5±13.0kg; UT: 61.9±10.8kg, p=0.04). The 1RMs for chest press, leg curl, leg press, and lat pulldown were significantly different between groups (p<0.05), but not for leg extension (p=0.26). The total volume of exercise for the ARE was similar between groups (p=0.10). There were no significant (p>0.05) group differences at rest for FBF or vasodilatory capacity. There were no significant (p>0.05) 3-way interactions for FBF or vasodilatory capacity. There was a significant condition by time interaction for FBF (RT: rest: 2.9±1.1ml/100ml of tissue/min, recovery: 8.9±4.0ml/100ml of tissue/min; UT: rest: 3.1±1.1ml/100ml of tissue/min, recovery: 8.9±2.9ml/100ml of tissue/min; p<0.001) and AUC (RT: rest: 56.8±20.2units, recovery: 139.0±66.5units; UT: rest: 53.8±20.2units, recovery: 116.6±25.1units; p<0.001). CONCLUSION: These data demonstrate that acute resistance exercise significantly increases forearm blood flow and vasodilatory capacity regardless of training status.

Effects Of An Acute Bout Of Resistance Exercise On Cognitive Performance In Young Adults

There is overwhelming support for enhanced cognitive performance (CP) as a result of an acute bout of aerobic exercise. However, there is less research, and the research is less clear regarding the effects of an acute bout of resistance exercise (RE) on cognitive performance. PURPOSE: To investigate the effect of an acute bout of high-intensity RE on reaction time (RT), working memory (WM) & inhibition (IC) - parameters of CP. To determine if there were sex differences for RE & CP, & to examine the relationship between CP & RE-Total Load (TL). METHODS: 23 healthy males (9) & females (Age = 21.7±1.8 yrs) volunteered. Day 1: body composition (Bodpod) and VO2 max were assessed (HRmax = 189.6 +/-5.4 b/min, VO2max = 49.0+/-7.3 ml/kg/min, BF% = 18.1+/-6.5). Day 2: Ss completed an initial battery of CP tests (imPACT) & then completed 1-repitition maximums (1-RM) for 7 Res that made-up the RE routine. Days 3&4: Ss underwent either 30 minutes of semi-reclined Rest (R) or the RE routine. The RE routine consisted of 2 consecutive sets (12 reps) of each RE at 75% 1-RM, followed by 1min of R. R & RE routine order was counter-balanced. Days 2, 3&4 were separated by 1wk. Prior to (PreR & PreEx) & following R & RE routine (PostR & PostEx) Ss performed the imPACT assessment for CP. 4(Conditions) X 2(Sex) ANOVAs with Repeated Measures & a priori contrasts were used to test for significant main effects & interactions for the CP variables. RESULTS: T-Tests confirmed Males (M) exhibited higher VO2max, TL, RE-VO2 & lower BF%. PreEx-PostEx RT (526+/-60ms - 510+/-58ms) was significantly reduced (p<0.02), whereas PreR-PostR RT (525+/-53ms - 532+/-67ms) & PreR-PreEx RT (525+/-53ms - 526+/-60ms) did not differ significantly. None of the CP variables differed by Sex. RT-change (PreEx-PostEx) & TL & RE-VO2 were not significantly correlated. CONCLUSION: Following a single-bout of a high-intensity RE routine, RT was significantly reduced for M & F. However, WM & IC did not differ significantly following RE or R for M or F. M exhibited greater VO2 & VCO2 in response to greater TL, however the change in RT (PreEx-PostEx) was not related to TL the entire group or for M or F.

Predicting Energy Expenditure of an Acute Bout of Resistance Exercise in Men and Women

Predicting Energy Expenditure of an Acute Bout of Resistance Exercise in Men and Women

Human Skeletal Muscle Lipid Mediator Responses to Resistance Exercise and Anti-inflammatory Drugs

Exercise has been found to induce bioactive lipid mediators which possess both pro- and anti-inflammatory activity, yet the role of these mediators in the muscle adaptive response to resistance exercise (RE) remains to be explored. PURPOSE: The present study aimed to characterize the presence of polyunsaturated fatty acid-related bioactive lipids in human skeletal muscle. Specifically, we hypothesized that high doses of anti-inflammatory drugs (NSAIDs) would hinder the action of both pro-inflammatory and pro-resolving lipid mediators in response to acute RE, thereby providing a mechanistic link to the negative effect of high (compared with low) doses of NSAIDs on the muscle hypertrophic response to RE reported by us. METHODS: Thirty-one men and women (18-35 years old) performed 8 weeks of RE with daily consumption of either a high dose of ibuprofen (IBU; 1200 mg) or a low dose of aspirin (ASA; 75 mg). Muscle biopsies were obtained before the training/treatment period and 3 h after an acute RE bout at week 4 of the intervention. We used a targeted lipidomics approach (High-Performance Liquid Chromatography with Tandem Mass Spectrometry) to compare the response of over 140 pro- and anti-inflammatory lipid mediators in IBU and ASA as well as in relation to untreated controls (CON). RESULTS: We could reliably detect 71 lipid metabolites in skeletal muscle, where 12/71 belonged to the cyclooxygenase pathway but the majority of the mediators were from the lipoxygenase and epoxygenase pathways. Overall, both the pro-inflammatory and the pro-resolving lipid mediator signature was decreased in both IBU and ASA, yet remained unchanged with exercise in CON. Pathway analysis revealed significant differences between drug treatments in the lipoxygenase pathway, specifically in mediators derived from the 5-LOX and 15-LOX enzymes, where levels after exercise were significantly lower in ASA compared with IBU. Specific metabolites driving these differences were 5-HETE, 13-OxoODE and 17-HDoHE. CONCLUSIONS: The results show that both high and low doses of NSAIDs markedly affect the skeletal muscle lipid mediator response to RE. We put forth the idea that lipid mediators from the lipoxygenase pathway may have a role in explaining the differential muscle hypertrophic response to RE noted with different doses of NSAID treatment.

Pre-workout Supplementation Does Not Augment Intramuscular MAPK Phosphorylation Immediately Following an Acute Resistance Exercise Bout

Pre-workout Supplementation Does Not Augment Intramuscular MAPK Phosphorylation Immediately Following an Acute Resistance Exercise Bout

Arachidonic acid supplementation transiently augments the acute inflammatory response to resistance exercise in trained men.

Strenuous exercise can result in skeletal muscle damage, leading to the systemic mobilization, activation, and intramuscular accumulation of blood leukocytes. Eicosanoid metabolites of arachidonic acid (ARA) are potent inflammatory mediators, but whether changes in dietary ARA intake influence exercise-induced inflammation is not known. This study investigated the effect of 4 wk of dietary supplementation with 1.5 g/day ARA ( n = 9, 24 ± 1.5 yr) or corn-soy oil placebo ( n = 10, 26 ± 1.3 yr) on systemic and intramuscular inflammatory responses to an acute bout of resistance exercise (8 sets each of leg press and extension at 80% one-repetition maximum) in previously trained men. Whole EDTA blood, serum, peripheral blood mononuclear cells (PMBCs), and skeletal muscle biopsies were collected before exercise, immediately postexercise, and at 2, 4, and 48 h of recovery. ARA supplementation resulted in higher exercise-stimulated serum creatine kinase activity [incremental area under the curve (iAUC) P = 0.046] and blood leukocyte counts (iAUC for total white cells, P < 0.001; neutrophils: P = 0.007; monocytes: P = 0.015). The exercise-induced fold change in peripheral blood mononuclear cell mRNA expression of interleukin-1β ( IL1B), CD11b ( ITGAM), and neutrophil elastase ( ELANE), as well as muscle mRNA expression of the chemokines interleukin-8 ( CXCL8) and monocyte chemoattractant protein 1 ( CCL2) was also greater in the ARA group than placebo. Despite this, ARA supplementation did not influence the histological presence of leukocytes within muscle, perceived muscle soreness, or the extent and duration of muscle force loss. These data show that ARA supplementation transiently increased the inflammatory response to acute resistance exercise but did not impair recovery. NEW & NOTEWORTHY Daily arachidonic acid supplementation for 4 wk in trained men augmented the acute systemic and intramuscular inflammatory response to a subsequent bout of resistance exercise. Greater exercise-induced inflammatory responses in men receiving arachidonic acid supplementation were not accompanied by increased symptoms of exercise-induced muscle damage. Although increased dietary arachidonic acid intake does not appear to influence basal inflammation in humans, the acute inflammatory response to exercise stress is transiently increased following arachidonic acid supplementation.

Differences in Autonomic Recovery Following Maximal Resistance Exercise in Young and Older Adults

Aging is associated with negative changes in autonomic function and an increased risk of cardiovascular disease. The risk of a sudden cardiovascular event is elevated during and immediately following vigorous exercise, potentially due to increased sympathetic dominance. Because resistance exercise provides a large hypertensive stimulus and young adults show reduced cardiac vagal control during recovery, further exploration of the effects of an acute bout of resistance exercise on autonomic function and recovery in older adults is required.PurposeTo evaluate the effects of high‐intensity lower body resistance exercise on autonomic modulation in young (YA) and older adults (OA).MethodsThirty‐five YA (17 female, 26±5 years, BMI: 23.8±3.2 kg/m2) and 25 OA (14 female, 60±6 years, BMI: 29.9±5.4 kg/m2) completed 3 sets of 10 repetitions of maximal isokinetic knee flexion/extension on a force dynamometer in a semi‐recumbent position. Throughout the protocol, participants were instrumented with a 3‐lead ECG and finger‐photoplethysmography for continuous heart rate and blood pressure recordings. Time and spectral components of heart rate (HRV) and blood pressure variability (BPV), non‐invasive indices of autonomic function, were analyzed using five‐minute segments at baseline and 5‐minutes post‐resistance exercise.ResultsAt baseline, OA had higher systolic and mean blood pressure, as well as lower root mean square of successive differences (RMSSD), low‐frequency (LF) RRI, high‐frequency (HF) RRI, and baroreceptor sensitivity (BRS) (p&lt;0.05). At 5‐minutes post‐exercise, LF/HF ratio and LF systolic blood pressure increased (p&lt;0.05). RMSSD, HF RRI, and BRS, were greater at baseline for YA and all variables decreased at 5‐min, while older adults did not change over time (interactions, p&lt;0.05).ConclusionsThese results suggest YA exhibited parasympathetic withdrawal 5‐minutes post‐exercise, whereas OA either did not exhibit parasympathetic withdrawal or had already recovered at 5 min post exercise, but this cannot be distinguished from our data. Both groups appear to have elevated sympathetic modulation at 5‐min, as indicated by RRI, LF/HF and LF BPV. Further investigation of the response during exercise is required. However, there are clear differences in autonomic recovery following maximal resistance exercise in OA.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Menstrual phase and the vascular response to acute resistance exercise

Aerobic exercise has a favorable effect on systemic vascular function, reducing both central (large elastic artery) and peripheral (smaller muscular artery) stiffness. The effects of resistance exercise (RE) on arterial stiffness are more complex. Acute RE increases central artery stiffness while decreasing peripheral stiffness. To date, the majority of studies have been performed in predominantly male participants. To examine the effect of acute RE on central and peripheral arterial stiffnesses in women, a secondary purpose was to explore the influence of cyclic changes in estrogen status across the menstrual cycle on the arterial response to acute RE. 18 healthy women [28 ± 7years, body mass index (BMI) 22.6 ± 2.9kg/m2] completed an acute RE bout during the early follicular and the early luteal phase of their menstrual cycle. Salivary 17β-Estradiol concentration was measured during each phase, using a passive drool technique. Pulse-wave velocity (PWV) was obtained from the carotid-femoral and carotid-radial pulse sites to measure central and peripheral stiffness, respectively, using applanation tonometry. PWV was measured at rest, immediately, 10, 20, and 30min post-RE. 17β-Estradiol concentration was significantly lower in the early follicular vs. the early luteal phase of the menstrual cycle (1.78 ± 0.51 vs. 2.40 ± 0.26pg/ml, p = 0.01). Central PWV significantly increased (p < 0.05) and peripheral PWV significantly decreased (p < 0.05) post-RE in both the early follicular and early luteal phases. No phase-by-time interaction was detected for either vascular segment (p > 0.05). Women experience increases in central arterial stiffness and reductions in peripheral arterial stiffness following acute RE. Menstrual cycle phase may not influence changes in arterial stiffness in response to acute RE.

Cardiorespiratory Responses to Short Bouts of Resistance Training Exercises in Individuals With Chronic Obstructive Pulmonary Disease: A COMPARISON OF EXERCISE INTENSITIES.

Resistance training is recommended in pulmonary rehabilitation for people with chronic obstructive pulmonary disease (COPD); however, the acute cardiorespiratory responses to different intensities of resistance training are not known. We compared acute cardiorespiratory responses with high-intensity versus low-intensity resistance exercises in persons with COPD and healthy, matched controls. This research may assist in developing training parameters in COPD. Participants (n = 10 per group) performed 1 set of 10 repetitions of leg extension and arm elevation at 2 intensities: 40% (low) and 80% (high) of 1-repetition maximum. Minute ventilation ((Equation is included in full-text article.)E), oxygen uptake ((Equation is included in full-text article.)O2), and heart rate (HR) data were collected continuously and expressed as absolute values and relative to values at (Equation is included in full-text article.)O2peak derived from a cardiopulmonary exercise test. Blood pressure, oxygen saturation, and rating of perceived exertion (RPE) were monitored before and after each set of exercises. Individuals with COPD showed similar (Equation is included in full-text article.)E, (Equation is included in full-text article.)O2, and HR with high- versus low-intensity exercises. RPE was higher after high- vs low-intensity leg extension (4 ± 1.4 vs 2 ± 1, P < .005) and arm elevation (3 ± 2 vs 1 ± 1.4, P < .005). Compared with healthy participants, relative (Equation is included in full-text article.)O2, (Equation is included in full-text article.)E, and HR were higher in COPD (≅40% vs 20% of the (Equation is included in full-text article.)O2peak; ≅60% vs 20% of (Equation is included in full-text article.)Epeak; and ≅80% vs 20% of HRpeak; all Ps ≤ .004). Absolute responses and RPE were similar between groups, irrespective of intensity and exercise. Immediate cardiorespiratory responses to an acute bout of resistance exercise appear to be independent of the exercise intensity in COPD. Although people with COPD are working closer to their (Equation is included in full-text article.)O2peak, their responses and RPE are comparable with healthy controls.

The Effect of Resistance Exercise on Inflammatory and Myogenic Markers in Patients with Chronic Kidney Disease.

Background: Muscle wasting is a common complication of Chronic Kidney Disease (CKD) and is clinically important given its strong association with morbidity and mortality in many other chronic conditions. Exercise provides physiological benefits for CKD patients, however the molecular response to exercise remains to be fully determined. We investigated the inflammatory and molecular response to resistance exercise before and after training in these patients.Methods: This is a secondary analysis of a randomized trial that investigated the effect of 8 week progressive resistance training on muscle mass and strength compared to non-exercising controls. A sub-set of the cohort consented to vastus lateralis skeletal muscle biopsies (n = 10 exercise, n = 7 control) in which the inflammatory response (IL-6, IL-15, MCP-1 TNF-α), myogenic (MyoD, myogenin, myostatin), anabolic (P-Akt, P-eEf2) and catabolic events (MuRF-1, MAFbx, 14 kDa, ubiquitin conjugates) and overall levels of oxidative stress have been studied.Results: A large inflammatory response to unaccustomed exercise was seen with IL-6, MCP-1, and TNF-α all significantly elevated from baseline by 53-fold (P < 0.001), 25-fold (P < 0.001), and 4-fold (P < 0.001), respectively. This response was reduced following training with IL-6, MCP-1, and TNF-α elevated non-significantly by 2-fold (P = 0.46), 2.4-fold (P = 0.19), and 2.5-fold (P = 0.06), respectively. In the untrained condition, an acute bout of resistance exercise did not result in increased phosphorylation of Akt (P = 0.84), but this was restored following training (P = 0.01). Neither unaccustomed nor accustomed exercise resulted in a change in myogenin or MyoD mRNA expression (P = 0.88, P = 0.90, respectively). There was no evidence that resistance exercise training created a prolonged oxidative stress response within the muscle, or increased catabolism.Conclusions: Unaccustomed exercise creates a large inflammatory response within the muscle, which is no longer present following a period of training. This indicates that resistance exercise does not provoke a detrimental on-going inflammatory response within the muscle.

Whey Protein Supplementation Enhances Whole Body Protein Metabolism and Performance Recovery after Resistance Exercise: A Double-Blind Crossover Study.

No study has concurrently measured changes in free-living whole body protein metabolism and exercise performance during recovery from an acute bout of resistance exercise. We aimed to determine if whey protein ingestion enhances whole body net protein balance and recovery of exercise performance during overnight (10 h) and 24 h recovery after whole body resistance exercise in trained men. In a double-blind crossover design, 12 trained men (76 ± 8 kg, 24 ± 4 years old, 14% ± 5% body fat; means ± standard deviation (SD)) performed resistance exercise in the evening prior to consuming either 25 g of whey protein (PRO; MuscleTech 100% Whey) or an energy-matched placebo (CHO) immediately post-exercise (0 h), and again the following morning (~10 h of recovery). A third randomized trial, completed by the same participants, involving no exercise and no supplement served as a rested control trial (Rest). Participants ingested [15N]glycine to determine whole body protein kinetics and net protein balance over 10 and 24 h of recovery. Performance was assessed pre-exercise and at 0, 10, and 24 h of recovery using a battery of tests. Net protein balance tended to improve in PRO (P = 0.064; effect size (ES) = 0.61, PRO vs. CHO) during overnight recovery. Over 24 h, net balance was enhanced in PRO (P = 0.036) but not in CHO (P = 0.84; ES = 0.69, PRO vs. CHO), which was mediated primarily by a reduction in protein breakdown (PRO < CHO; P < 0.01. Exercise decreased repetitions to failure (REP), maximal strength (MVC), peak and mean power, and countermovement jump performance (CMJ) at 0 h (all P < 0.05 vs. Pre). At 10 h, there were small-to-moderate effects for enhanced recovery of the MVC (ES = 0.56), mean power (ES = 0.49), and CMJ variables (ES: 0.27–0.49) in PRO. At 24 h, protein supplementation improved MVC (ES = 0.76), REP (ES = 0.44), and peak power (ES = 0.55). In conclusion, whey protein supplementation enhances whole body anabolism, and may improve acute recovery of exercise performance after a strenuous bout of resistance exercise.

Resistance exercise initiates mechanistic target of rapamycin (mTOR) translocation and protein complex co-localisation in human skeletal muscle

The mechanistic target of rapamycin (mTOR) is a central mediator of protein synthesis in skeletal muscle. We utilized immunofluorescence approaches to study mTOR cellular distribution and protein-protein co-localisation in human skeletal muscle in the basal state as well as immediately, 1 and 3 h after an acute bout of resistance exercise in a fed (FED; 20 g Protein/40 g carbohydrate/1 g fat) or energy-free control (CON) state. mTOR and the lysosomal protein LAMP2 were highly co-localised in basal samples. Resistance exercise resulted in rapid translocation of mTOR/LAMP2 towards the cell membrane. Concurrently, resistance exercise led to the dissociation of TSC2 from Rheb and increased in the co-localisation of mTOR and Rheb post exercise in both FED and CON. In addition, mTOR co-localised with Eukaryotic translation initiation factor 3 subunit F (eIF3F) at the cell membrane post-exercise in both groups, with the response significantly greater at 1 h of recovery in the FED compared to CON. Collectively our data demonstrate that cellular trafficking of mTOR occurs in human muscle in response to an anabolic stimulus, events that appear to be primarily influenced by muscle contraction. The translocation and association of mTOR with positive regulators (i.e. Rheb and eIF3F) is consistent with an enhanced mRNA translational capacity after resistance exercise.

Free-weight resistance exercise on pulse wave reflection and arterial stiffness between sexes in young, resistance-trained adults

We sought to determine the sex-specific effects of an acute bout of free-weight resistance exercise (RE) on pulse wave reflection (aortic blood pressures, augmentation index (AIx), AIx at 75 bpm (AIx@75), augmentation pressure (AP), time of the reflected wave (Tr), subendocardial viability ratio (SEVR)), and aortic arterial stiffness in resistance-trained individuals. Resistance-trained men (n = 14) and women (n = 12) volunteered to participate in the study. Measurements were taken in the supine position at rest, and 10 minutes after 3 sets of 10 repetitions at 75% 1-repetition maximum on the squat, bench press, and deadlift. A 2 × 2 × 2 ANOVA was used to analyse the effects of sex (men, women) across condition (RE, control) and time (rest, recovery). There were no differences between sexes across conditions and time. There was no effect of the RE on brachial or aortic blood pressures. There were significant condition × time interactions for AIx (rest: 12.1 ± 7.9%; recovery: 19.9 ± 10.5%, p = .003), AIx@75 (rest: 5.3 ± 7.9%; recovery: 24.5 ± 14.3%, p = .0001), AP (rest: 4.9 ± 2.8 mmHg; recovery: 8.3 ± 6.0 mmHg, p = .004), and aortic arterial stiffness (rest: 5.3 ± 0.6 ms; recovery: 5.9 ± 0.7 ms, p = .02) with significant increases during recovery from the acute RE. There was also a significant condition × time for time of the reflected wave (rest: 150 ± 7 ms; recovery: 147 ± 9 ms, p = .02) and SEVR (rest: 147 ± 17%; recovery: 83 ± 24%, p = .0001) such that they were reduced during recovery from the acute RE compared to the control. These data suggest that an acute bout of RE increases AIx, AIx@75, and aortic arterial stiffness similarly between men and women without significantly altering aortic blood pressures.

Sex-specific Differences In Pulse Wave Reflection And Arterial Stiffness After Resistance Exercise

Resistance exercise is recommended to improve fitness and to reduce the risk and severity of chronic diseases. Currently, no studies have evaluated sex differences in resistance-trained individuals in response to an acute bout of resistance exercise on pulse wave reflection and arterial stiffness. PURPOSE: We sought to determine sex-specific differences after an acute bout of free-weight resistance exercise on pulse wave reflection and arterial stiffness in resistance-trained individuals. METHODS: Resistance-trained men (n=14) and women (n=12) volunteered for the study. Aortic hemodynamics, pulse wave reflection and arterial stiffness were assessed in the supine position at rest and 10 minutes after an acute bout of free-weight exercise utilizing 3 sets of 10 repetitions at 75% 1-repetition maximum on the squat, bench press, and deadlift. Two minutes of rest was given between sets and exercises. An ANOVA was used to analyze the effects of sex across condition (acute resistance exercise or control) and time (rest and recovery). Paired t-tests were used for all post-hoc comparisons. RESULTS: The sexes had similar values at rest and after the acute resistance exercise such that there were no significant 3-way interactions. There were also no main effects of resistance exercise on brachial or aortic blood pressure. There were significant time by condition interactions for heart rate (rest: 61±9bpm; recovery: 89±13bpm, p=0.0001), augmentation index (rest: 12.1±7.9%; recovery:19.9±10.5%, p=0.003), augmentation index at 75bpm (rest: 5.3±7.9%; recovery: 24.5±14.3%, p=0.0001), augmentation pressure (rest: 4.9±2.8mmHg; recovery: 8.3±6.0mmHg, p=0.004), and pulse wave velocity (rest: 5.3±0.6ms; recovery: 5.9±0.7ms, p=0.02) such that they significantly increased after the acute resistance exercise. There were also significant time by condition interactions for time of the reflected wave (rest: 150±7ms; recovery: 147±9ms, p=0.02) and the subendocardial variability ratio (rest: 147±17%; recovery: 83±24%, p=0.0001) such that there were reduced after the acute resistance exercise. CONCLUSION: These data suggest that an acute bout of resistance exercise alters pulse wave reflection and arterial stiffness similarly between the sexes without significantly altering aortic hemodynamics.

Acute Resistance Exercise Effects on Autonomic Modulation Between Resistance-Trained Men and Women

While it has been reported that women have greater vagal withdrawal during aerobic exercise and supramaximal exercise compared to men, the sex-specific responses to an acute bout of resistance exercise are unknown. PURPOSE: To determine the effects of an acute bout of free-weight resistance exercise consisting of the squat, bench press, and deadlift on heart rate variability (HRV) and heart rate complexity (HRC) between the sexes. METHODS: Twenty-three resistance-trained (aged 23±3 yrs; mean±SD) men (n=13) and women (n=10) with a minimum of 1 year of resistance training volunteered for the study. Autonomic modulation was assessed at rest as well as 15-20 minutes (Rec1) and 25-30 minutes (Rec2) after an acute bout of resistance exercise utilizing 3 sets of 10 repetitions at 75% 1-repetition maximum on the squat, bench press and deadlift. Two minutes of rest was given between sets and exercises. A quiet control condition of the same duration was also utilized for each participant. Measures of HRV were analyzed in the frequency domain and included measures of vagal modulation (normalized high frequency (HFnu)), sympathetic modulation (normalized low frequency (LFnu)), and sympathovagal balance (LF/HF ratio). Sample Entropy (SampEn), indicative of vagal modulation, was used as a measure of HRC. A repeated measures ANOVA was used to compare the effects of sex (men and women) across the two conditions (resistance exercise and control) and time (rest, Rec1 and Rec2). T-tests were used for post-hoc testing if the ANOVA was significant with a Benjamini-Hochberg correction factor. RESULTS: There were no significant sex differences at rest for any of the variables. Furthermore, there were no significant sex x condition x time interactions for any variable. Compared with Rest LFnu (Rest: 35.5±15.3%; Rec1: 73.0±18.0; Rec2: 66.0±25.1%, p=0.0001), LnLF/HF (Rest: 4.0±0.9%; Rec1: 5.1±1.1%; Rec2: 5.2±1.1%, p=0.002) were augmented at Rec1 and Rec2. HFnu (Rest: 61.2±17.1%; Rec1: 40.3±22.3%; Rec2: 38.4±21.8%, p=0.0001) and SampEn (Rest: 1.5±0.3units; Rec1: 1.2±0.3units; Rec2: 1.3±0.5units, p=0.0001) were decreased at Rec1 and Rec2 compared to Rest after the acute resistance exercise. CONCLUSIONS: These data suggest that acute RE using free-weights has a profound impact on autonomic modulation that is similar between the sexes.