Bout Of Resistance Exercise Research Articles

The Validity of Perceived Recovery Status as a Marker of Daily Recovery Following a High-Volume Back-Squat Protocol.

The purpose of this study was to evaluate the sensitivity of PRS as a subjective marker of recovery up to 72hours after a high-volume back-squat protocol. Eleven resistance-trained men reported to the laboratory on 5 separate occasions (1 familiarization session and 4 testing sessions). The first testing session was considered the baseline session and consisted of a nonfatiguing performance assessment (ie,countermovement jumps and back squats) and a fatiguing back-squat protocol of 8 sets of 10 at 70% 1-repetition maximum separated by 2minutes of recovery. Participants returned 24, 48, and 72hours following baseline to provide a PRS rating and complete the performance assessment. Repeated-measures correlations revealed strong associations between PRS countermovement jump (r = .84) and mean bar velocity (r = .80) (both P < .001). The current findings suggest that PRS can be used as a method to effectively assess daily recovery following a fatiguing bout of resistance exercise. Practitioners are cautioned that the relationship between PRS and performance recovery is individualized, and equivalent PRS scores between individuals are not indicative of similar recovery.

T-cell counts in response to acute cardiorespiratory or resistance exercise in physically active or physically inactive older adults: a randomized crossover study.

T cells often undergo age-related changes, which may be offset by regular exercise training. However, the majority of literature is derived from cardiorespiratory exercise studies. The purpose of this study was to examine the effects of acute cardiorespiratory exercise and acute resistance exercise on the T-cell response among physically active (PA) older adults compared with physically inactive (PI) older adults. Twenty-four healthy older adults [PA n = 12; PI n = 12; means ± SD; age (years) PA 62 ± 5, PI 64 ± 5; body mass index (BMI; kg/m2) PA 23.9 ± 3.0, PI 25.6 ± 3.5] completed one bout each of matched intensity cardiorespiratory exercise and resistance exercise in a randomized order. Blood samples drawn preexercise, postexercise, and 1 h postexercise (recovery) were analyzed by flow cytometry for T cells and T-cell subsets. Resistance exercise mobilized more T-cell subsets in PI (10 of the measured types, including total T cells; CD45RA+ CD62L+, CD45RA- CD62L+, CD45RA- CD62L-, and CD45RA+ CD62L- T cells), whereas cardiorespiratory exercise mobilized more subsets in PA (CD45RA+ CD62L- and CD57+ CD45RA+ CD62L- CD4+ T cells). Both cardiorespiratory exercise and resistance exercise elicited a significant (P < 0.05) mobilization of highly differentiated (CD45RA+ CD62L-; CD57+ CD45RA+ CD62L-) CD8+ T cells into the circulation postexercise in both PA and PI groups. Furthermore, cardiorespiratory exercise resulted in a decrease in the number of circulating Th17 cells postexercise, whereas resistance exercise increased Th17 cell mobilization compared with the cardiorespiratory exercise response. There are differences between cardiorespiratory exercise and resistance exercise on the immune responses of T cells, particularly in PI individuals. This research study was registered at clinicaltrials.gov NCT03794050. NEW & NOTEWORTHY A bout of resistance exercise did not elicit the same T-cell responses as a bout of walking on a treadmill, and the response was also not the same for people who participate in regular exercise compared with those who do not. Although there were several similarities, these potential differences underscore the importance of careful selection of exercise protocol based on the population studied and the desired T-cell response to exercise outcome.

Resistance Exercise Increases Gastrointestinal Symptoms, Markers of Gut Permeability, and Damage in Resistance-Trained Adults.

This study aimed to determine the influence of acute resistance exercise (RE) and biological sex on subjective gastrointestinal (GI) symptoms, GI epithelial damage, and GI permeability in resistance-trained males and females. Thirty resistance-trained men ( n = 15) and women ( n = 15) completed an RE bout and a nonexercise control (CON) session in a randomized counterbalanced design. The RE protocol used a load of 70% one-repetition maximum for 4 sets of 10 repetitions with a 90-s rest period length between sets and a 120-s rest period between exercises (squat, seated shoulder press, deadlift, bent-over row, and leg press). Blood samples were collected before exercise (PRE), immediately postexercise (IP), and 15-, 30-, and 60-min postexercise. Participants completed GI symptom questionnaires to assess subjective GI symptoms PRE, IP, and 60-min postexercise. Blood samples were assayed to quantify small intestine damage (I-FABP) and GI permeability (lactulose-rhamnose [L/R] ratio). Data were analyzed via separate repeated-measures ANOVA, and area under the curve (AUC) analyses were completed via one-way ANOVA. Participants reported greater GI symptoms in RE at IP compared with CON ( P < 0.001) with 70% of participants reporting at least one GI symptom with no differences between sexes. Nausea was the most reported GI symptom (63.3%), followed by vomiting (33.3%). I-FABP and L/R ratio did not exhibit differential responses between conditions. However, L/R ratio AUC was greater in males after RE than male CON ( P = 0.002) and both conditions for females ( P < 0.05). Furthermore, I-FABP AUC in the male RE condition was greater than both female conditions ( P < 0.05). Resistance-trained individuals experience GI distress after RE, with males incurring the greatest increases in markers of GI damage and permeability.

A non-invasive 13CO2 breath test detects differences in anabolic sensitivity with feeding and heavy resistance exercise in healthy young males: a randomized control trial.

There are limited tools to measure anabolic sensitivity non-invasively in response to acute physiological stimuli, which represents a challenge for research in free-living settings and vulnerable populations. We tested the ability of a stable isotope breath test to detect changes in leucine oxidation (OX) and leucine retention (intake-OX) across a range of anabolic sensitivities. Healthy males ingested a beverage containing 0.25 g·kg-1 protein and 0.75 g·kg-1 carbohydrate with the leucine content enriched to 5% with l-[1-13C]leucine at rest (FED) or after a bout of resistance exercise (EXFED), with a parallel group consuming only the tracer (FAST). Concurrent primed-constant infusions of l-[5,5,5-2H3]leucine revealed high peripheral bioavailability for FED (∼81%), EXFED (∼80%), and FAST (∼117%). After beverage ingestion, whole-body protein synthesis was greater in FED and EXFED than FAST. OX was greater in FED and EXFED than FAST, with OX lower in EXFED than FED. Leucine retention demonstrated expected physiological differences in anabolic sensitivity (EXFED>FED>FAST). We demonstrated that a non-invasive breath test based on an amino acid (leucine) that is preferentially metabolized in peripheral (muscle) tissues can detect differences in anabolic sensitivity. Future studies could examine this test within a variety of populations experiencing muscle growth or atrophy. This study was registered as a Clinical Trial at ClinicalTrials.gov (no. NCT04887727). Novelty: An oral l-[1-13C]leucine breath test can detect greater anabolic sensitivity after feeding and resistance exercise. This tool may be applied in growing (e.g., children) or wasting (e.g., aging) populations where invasive procedures are not possible.

Effects of 4-Week Tangeretin Supplementation on Cortisol Stress Response Induced by High-Intensity Resistance Exercise: A Randomized Controlled Trial.

Objective: This study aimed to investigate the effects of 4-week tangeretin supplementation on the cortisol stress response induced by high-intensity resistance exercise. Methods: A randomized controlled trial of twenty-four soccer players was conducted during the winter training season. The experimental group (EG) took the oral supplement with tangeretin (200 mg/day) and the control group (CG) took placebo for 4 weeks. Before and after the 4-week intervention, all players performed a high intensity bout of resistance exercise to stimulate their cortisol stress responses. Serum cortisol, adreno-corticotropic hormone (ACTH) and superoxide dismutase (SOD) were obtained by collecting blood samples before (PRE), immediately after (P0), and 10 (P10), 20 (P20) and 30 minutes (P30) after the exercise. Results: The serum cortisol level (PRE, p = 0.017; P10, p = 0.010; P20, p = 0.014; P30, p = 0.007) and ACTH (P10, p = 0.037; P30, p = 0.049) of experimental group significantly decreased after the 4-week intervention. Compared with control group, EG displayed a significantly lower level of the serum cortisol (PRE, p = 0.036; P10, p = 0.031) and ACTH (P30, p = 0.044). Additionally, EG presented significantly higher superoxide dismutase activity level compared with CG at P30 (p = 0.044). The white blood cell of EG decreased significantly (PRE, p = 0.037; P30, p = 0.046) and was significantly lower than CG at P20 (p = 0.01) and P30 (p = 0.003). Conclusion: Four-week tangeretin supplementation can reduce serum cortisol and ACTH, which may ameliorate the cortisol stress response in soccer players during high-intensity resistance exercise training. It can also enhance antioxidant capacity, accelerate the elimination of inflammation throughout the body, and shorten recovery time after high-intensity exercise.

Effects of Acute and Chronic Resistance Exercise on the Skeletal Muscle Metabolome.

Resistance training promotes metabolic health and stimulates muscle hypertrophy, but the precise routes by which resistance exercise (RE) conveys these health benefits are largely unknown. Aim: To investigate how acute RE affects human skeletal muscle metabolism. Methods: We collected vastus lateralis biopsies from six healthy male untrained volunteers at rest, before the first of 13 RE training sessions, and 45 min after the first and last bouts of RE. Biopsies were analysed using untargeted mass spectrometry-based metabolomics. Results: We measured 617 metabolites covering a broad range of metabolic pathways. In the untrained state RE altered 33 metabolites, including increased 3-methylhistidine and N-lactoylvaline, suggesting increased protein breakdown, as well as metabolites linked to ATP (xanthosine) and NAD (N1-methyl-2-pyridone-5-carboxamide) metabolism; the bile acid chenodeoxycholate also increased in response to RE in muscle opposing previous findings in blood. Resistance training led to muscle hypertrophy, with slow type I and fast/intermediate type II muscle fibre diameter increasing by 10.7% and 10.4%, respectively. Comparison of post-exercise metabolite levels between trained and untrained state revealed alterations of 46 metabolites, including decreased N-acetylated ketogenic amino acids and increased beta-citrylglutamate which might support growth. Only five of the metabolites that changed after acute exercise in the untrained state were altered after chronic training, indicating that training induces multiple metabolic changes not directly related to the acute exercise response. Conclusion: The human skeletal muscle metabolome is sensitive towards acute RE in the trained and untrained states and reflects a broad range of adaptive processes in response to repeated stimulation.

Impact of Obesity on Exercise‐Induced Skeletal Muscle Exosomes

Exosomes are small extracellular vesicles (EVs) that can function as effective delivery vehicles through systemic circulation due to the protective effects of the phospholipid bilayer. Our previous work in mice indicated that resistance exercise induces the release of skeletal muscle EVs to promote adipose lipolysis through the action of microRNA‐1. To better understand the effect of resistance exercise on exosomes in humans, we collected blood samples as well as skeletal muscle and adipose tissue biopsies before and after a single bout of resistance exercise. Using the ExoView platform, we were able to analyze subpopulations of exosomes based on their surface tetraspanin markers (CD63, CD81, and CD9). Our preliminary findings show that serum CD81/CD9 exosome abundance is significantly lower in high BMI (&gt;30) subjects, and serum CD63/CD81 exosome abundance may be differentially affected by exercise in subjects with high BMI. Further studies are necessary to define the nucleic acid and protein contents of the exercise‐induced exosomes. To this end, we have generated a transgenic mouse with an inducible skeletal muscle specific exosome surface protein reporter, which will allow definitive tracking of exosomes released from skeletal muscle that are delivered to other organ systems.

Acute Effects of Milk vs. Carbohydrate on Bone Turnover Biomarkers Following Loading Exercise in Young Adult Females.

Dairy products and impact exercise have previously been identified to be independently beneficial for bone mineral properties, however, it is unknown how the combination of these two osteogenic interventions may alter acute bone turnover. Using a randomized crossover design, we compared the acute effects of consuming milk vs. an isoenergetic carbohydrate control beverage on bone biomarkers following loading exercise. Thirteen healthy female participants (Age = 20.3 ± 2.3y; BMI = 21.0 ± 1.1 kg/m2) consumed either 550 mL of 0% skim white milk (MILK) or 52.7 g of maltodextrin in 550 mL of water (CHO), both 5 min and 1 h following completion of a combined plyometric (198 impacts) and resistance exercise (3–4 sets/exercise, 8–12 reps/set, ∼75% 1-RM) bout. Venous blood samples were obtained pre-exercise, and 15 min, 75 min, 24 h and 48 h post-exercise to assess serum concentrations of bone resorption biomarkers, specifically carboxyl-terminal crosslinking telopeptide of type I collagen (CTX), receptor activator nuclear factor kappa-β ligand (RANKL), and sclerostin (SOST), as well as bone formation biomarkers, specifically osteoprotegerin (OPG) and osteocalcin (OC). When absolute biomarker concentrations were examined, there were no interaction or group effects for any biomarker, however, there were main time effects (p < 0.05) for RANKL, SOST, and OC, which were lower, and the OPG: OPG/RANKL ratio, which was higher at 75 min post-exercise compared with baseline in both conditions. In addition to assessing absolute biomarker concentrations at specific timepoints, we also evaluated the relative (% change) cumulative post-exercise response (75 min to 48 h) using an area under the curve (AUC) analysis. This analysis showed that the relative post-exercise CTX response was significantly lower in the MILK compared to the CHO condition (p = 0.03), with no differences observed in the other biomarkers. These results show that while milk does not appear to alter absolute concentrations of bone biomarkers compared to CHO, it may attenuate relative post-exercise bone resorption (i.e., blunt the usual catabolic response to exercise).

Enhancement of anaerobic glycolysis \u2013 a role of PGC-1\u03b14 in resistance exercise

Resistance exercise training (RET) is an effective countermeasure to sarcopenia, related frailty and metabolic disorders. Here, we show that an RET-induced increase in PGC-1α4 (an isoform of the transcriptional co-activator PGC-1α) expression not only promotes muscle hypertrophy but also enhances glycolysis, providing a rapid supply of ATP for muscle contractions. In human skeletal muscle, PGC-1α4 binds to the nuclear receptor PPARβ following RET, resulting in downstream effects on the expressions of key glycolytic genes. In myotubes, we show that PGC-1α4 overexpression increases anaerobic glycolysis in a PPARβ-dependent manner and promotes muscle glucose uptake and fat oxidation. In contrast, we found that an acute resistance exercise bout activates glycolysis in an AMPK-dependent manner. These results provide a mechanistic link between RET and improved glucose metabolism, offering an important therapeutic target to counteract aging and inactivity-induced metabolic diseases benefitting those who cannot exercise due to many reasons.

Acute Left Atrial Response to Different Eccentric Resistance Exercise Loads in Patients with Heart Failure with Middle Range Ejection Fraction: A Pilot Study.

In this study, we aimed to assess acute changes occurring on atrial function following single bouts of eccentric resistance exercise (ECC-RE) performed at two different loads. Twenty-five patients with chronic heart failure with middle range ejection fraction (HFmrEF) participated in three experimental sessions in a randomized order and on separate days: two sessions of ECC RE at 20% (ECC-20) of one-repetition maximum (1-RM) and 50% (ECC-50) 1-RM, and one session of control, without exercise. Each session lasted three minutes. Before and immediately after the sessions, patients underwent echocardiography and blood pressure and heart rate measurement. Peak atrial longitudinal strain (PALS) and peak atrial contractile strain (PACS) significantly increased after both ECC-20 (+16.3%) and ECC-50 (+18.1%) compared to control (between sessions p = 0.022). Peak atrial contractile strain (PACS) significantly increased after ECC-50 (+28.4%) compared to ECC-20 (+17.0%) and control (between sessions p = 0.034). The ratio of transmitral and annular velocities (E/E’) increased significantly after ECC-20 (+10.4%) and ECC-50 (+19.0%) compared to control (between groups p = 0.003). EF, left ventricular longitudinal strain, and stroke volume did not change after ECC-RE sessions compared to control. Cardiac output increased significantly after ECC-20 and ECC-50 compared to control, (between groups p = 0.025). In conclusion, both ECC-RE sessions were well tolerated, and LA functional reserve was properly mobilized in response to ECC-RE in patients with HFmrEF. Cardiac output increased at the cost of an increased LV filling pressure, but no detrimental changes of LV function occurred.

Potato Protein Ingestion Increases Muscle Protein Synthesis Rates at Rest and during Recovery from Exercise in Humans.

ABSTRACTIntroductionPlant-derived proteins have received considerable attention as an alternative to animal-based proteins and are now frequently used in both plant-based diets and sports nutrition products. However, little information is available on the anabolic properties of potato-derived protein. This study compares muscle protein synthesis rates after the ingestion of 30 g potato protein versus 30 g milk protein at rest and during recovery from a single bout of resistance exercise in healthy, young males.MethodsIn a randomized, double-blind, parallel-group design, 24 healthy young males (24 ± 4 yr) received primed continuous l-[ring-13C6]-phenylalanine infusions while ingesting 30 g potato-derived protein or 30 g milk protein after a single bout of unilateral resistance exercise. Blood and muscle biopsies were collected for 5 h after protein ingestion to assess postprandial plasma amino acid profiles and mixed muscle protein synthesis rates at rest and during recovery from exercise.ResultsIngestion of both potato and milk protein increased mixed muscle protein synthesis rates when compared with basal postabsorptive values (from 0.020% ± 0.011% to 0.053% ± 0.017%·h−1 and from 0.021% ± 0.014% to 0.050% ± 0.012%·h−1, respectively; P < 0.001), with no differences between treatments (P = 0.54). In the exercised leg, mixed muscle protein synthesis rates increased to 0.069% ± 0.019% and 0.064% ± 0.015%·h−1 after ingesting potato and milk protein, respectively (P < 0.001), with no differences between treatments (P = 0.52). The muscle protein synthetic response was greater in the exercised compared with the resting leg (P < 0.05).ConclusionsIngestion of 30 g potato protein concentrate increases muscle protein synthesis rates at rest and during recovery from exercise in healthy, young males. Muscle protein synthesis rates after the ingestion of 30 g potato protein do not differ from rates observed after ingesting an equivalent amount of milk protein.

Effects of Hypoxia-Hyperoxia Preconditioning on Indicators of Muscle Damage After Acute Resistance Exercise in Male Athletes.

PurposeThe purpose of this study was to investigate the effects of acute repeated hypoxia–hyperoxia preconditioning on resistance exercise (RE)-induced muscle damage in male athletes.MethodsEleven young male athletes participated in this randomized double-blind counter-balanced crossover study, and were divided into Normoxia (N) and Hypoxia–Hyperoxia (HH) trials. Subjects of the respective trials were supplied with normoxic (FiO2 = 0.21), or alternating hypoxic/hyperoxic air (FiO2 = 0.10/0.99, 5 min each) for 60 min. Thirty minutes after preconditioning, subjects performed acute bouts of RE consisting of bench press, deadlift, and squats. Each exercise included 6 sets of 10 repetitions at 75% one-repetition maximum (1RM) with 2 min rest between sets. After a 2-week washout period, subjects changed trials and completed the same study procedure after the alternate preconditioning. Muscle soreness, maximal voluntary contraction (MVC), and circulating biochemical markers were tested before preconditioning (baseline) and during recovery at 0, 24, and 48 h after exercise.ResultsAcute RE significantly increased levels of muscle soreness, creatine kinase (CK) and myoglobin (Mb), and decreased levels of peak knee extension torque in the N trial. Muscle soreness, CK, and Mb levels of the HH trial were significantly lower than that of the N trial after exercise. Interestingly, interleukin-6 (IL-6) levels of the HH trial increased significantly 0 h after exercise compared to baseline and were significantly higher than that of the N trial 0 and 24 h after exercise. However, no significant differences of thiobarbituric acid reactive substances (TBARS), cortisol, testosterone, peak torque, and average power levels were found between N and HH trials during recovery.ConclusionOur data suggest that pre-exercise treatment of alternating hypoxic/hyperoxic air could attenuate muscle damage and pain after acute RE, but has no effect on muscle strength recovery in young male athletes.

The effect of active vs passive recovery and use of compression garments following a single bout of muscle-damaging exercise

BACKGROUND: Some recovery strategies are needed to reduce or eliminate the effect of negative symptoms caused by exercise. OBJECTIVE: The aim of this study was to determine the effect of different types of recovery after single-bout strength exercises on biomarkers of muscle damage, cytokine release and lactate elimination. METHODS: Following familiarization, 10 male volunteers performed four randomized recovery protocols (passive or active recovery with or without compression garments) following a single bout of resistance exercise (squat and deadlift exercises). The blood creatine kinase (CK), lactate dehydrogenase (LDH), interleukine-6 (IL-6), and tumor necrosis factor-alfa (TNF-α) values were measured before and after exercise, and after 24, 48, 72 hours. RESULTS: The CK analysis showed that all protocols significantly increased (p&lt; 0.05) CK activity compared to the pre and 24 h post time points. Interestingly, protocol 3 and 4 significantly decreased (p&lt; 0.05) CK activity compared 24 and 72 h post-exercise. LDH, IL-6, and TNF values did not show significant difference (p&gt; 0.05) at the time points tested. CONCLUSIONS: Active recovery is an effective method for reducing the severity and duration of muscle damage and for accelerating the clearance of blood lactate (BLa) following a single bout of strength training. There is no added benefit of using compression garments.

Pre-sleep protein supplementation after an acute bout of evening resistance exercise does not improve next day performance or recovery in resistance trained men.

ABSTRACTBackgroundTo evaluate the effect of pre-sleep protein supplementation after an acute bout of evening resistance training on next day performance and recovery the following day in physically active men.MethodsEighteen resistance trained men performed a single bout of resistance exercise then received either a pre-sleep protein (PRO) supplement containing 40 g of casein protein (PRO; n = 10; mean ± SD; age = 24 ± 4 yrs; height = 1.81 ± 0.08 m; weight = 84.9 ± 9.5 kg) or a non-caloric, flavor matched placebo (PLA; n = 8; age = 28 ± 10 yrs; height = 1.81 ± 0.07 m; weight = 86.7 ± 11.0 kg) 30 min before sleep (1 h after a standard recovery drink). Blood samples were obtained pre-exercise and the following morning (+12-h) to measure creatine kinase and C-reactive protein. Visual analog scales were utilized to assess perceived pain, hunger, and recovery. One-repetition maximum (1RM) tests for barbell bench press and squat were performed pre-exercise and the following morning (+12-h). Statistical analysis was performed using SPSS (V.23) and p ≤ 0.05 was considered statistically significant.ResultsThere were no significant differences between the groups in next morning performance or muscle damage biomarkers. However, pre-sleep PRO resulted in a lower perception of hunger that approached significance the following morning when compared to PLA (PRO:43.6 ± 31.2, PLA: 69.4 ± 2.22; 95% C.I. = −53.6, 2.0; p = 0.07; d = 0.95).ConclusionsFollowing an evening bout of exercise, pre-sleep PRO did not further improve next morning muscle damage biomarkers or maximal strength performance in resistance trained men compared to a non-caloric PLA. However, there may be implications for lower perceived hunger the next morning with pre-sleep PRO consumption compared to PLA.

Senolytic treatment rescues blunted muscle hypertrophy in old mice

With aging, skeletal muscle plasticity is attenuated in response to exercise. Here, we report that senescent cells, identified using senescence-associated β-galactosidase (SA β-Gal) activity and p21 immunohistochemistry, are very infrequent in resting muscle, but emerge approximately 2 weeks after a bout of resistance exercise in humans. We hypothesized that these cells contribute to blunted hypertrophic potential in old age. Using synergist ablation-induced mechanical overload (MOV) of the plantaris muscle to model resistance training in adult (5–6-month) and old (23–24-month) male C57BL/6 J mice, we found increased senescent cells in both age groups during hypertrophy. Consistent with the human data, there were negligible senescent cells in plantaris muscle from adult and old sham controls, but old mice had significantly more senescent cells 7 and 14 days following MOV relative to young. Old mice had blunted whole-muscle hypertrophy when compared to adult mice, along with smaller muscle fibers, specifically glycolytic type 2x + 2b fibers. To ablate senescent cells using a hit-and-run approach, old mice were treated with vehicle or a senolytic cocktail consisting of 5 mg/kg dasatinib and 50 mg/kg quercetin (D + Q) on days 7 and 10 during 14 days of MOV; control mice underwent sham surgery with or without senolytic treatment. Old mice given D + Q had larger muscles and muscle fibers after 14 days of MOV, fewer senescent cells when compared to vehicle-treated old mice, and changes in the expression of genes (i.e., Igf1, Ddit4, Mmp14) that are associated with hypertrophic growth. Our data collectively show that senescent cells emerge in human and mouse skeletal muscle following a hypertrophic stimulus and that D + Q improves muscle growth in old mice.

Increased cortisol levels caused by acute resistance physical exercise impair memory and learning ability.

Acute physical exercise works as an activator of the responses of the human organism to stress. This is based on the activation of the hypothalamic–pituitary–adrenal (HPA) axis, affecting physical, physiological and psychological levels. This study aimed to analyse the effects of a single bout of high-intensity resistance exercise on cognitive-behavioural responses: visuo-spatial path learning and memory, as well as physiological responses (salivary cortisol levels). Nineteen healthy male military-trained powerlifting subjects were tested in a within-subject design on two experimental days with an interval of 48 h. The stress and cognitive variables were measured by cortisol levels and Ruff–Light trail-learning test (RULIT) test scores, respectively. The results showed the immediate influence of acute exercise on cortisol, with significantly higher cortisol levels found in subjects after completion of the acute resistance exercise. In addition, this study found a significant deterioration of memory and learning ability after a dose of intense resistance exercise. In conclusion, the study highlights the relative effects of resistance exercise on cortisol and cognitive performance depending on the intensity and type of the exercise, the moment of measurement and the cerebral areas implicated.

The Effect of a Single Bout of Resistance Exercise with Blood Flow Restriction on Arterial Stiffness in Older People with Slow Gait Speed: A Pilot Randomized Study.

Purpose: Low-intensity resistance exercise with moderate blood-flow restriction (LIRE-BFR) is a new trending form of exercises worldwide. The purpose of this study was to compare the acute effect of a single bout of traditional resistance exercise (TRE) and LIRE-BFR on arterial stiffness in older people with slow gait speeds. Methods: This was a randomized, controlled clinical study. Seventeen older adults (3 men; 14 women; 82 ± 5 years old) completed a session of TRE (n = 7) or LIRE-BFR (n = 10). At baseline and after 60 min post-exercise, participants were subject to blood pressure measurement, heart rate measurements and a determination of arterial stiffness parameters. Results: There was no significant difference between the TRE and LIRE-BFR group at baseline. Pulse-wave velocity increased in both groups (p < 0.05) post-exercise with no between-group differences. Both exercise modalities did not produce any adverse events. The increase in systolic blood pressure, pulse pressure, augmentation pressure and pulse wave velocity (all p > 0.05) were similar after both TRE and LIRE-BFR. Conclusion: TRE and LIRE-BFR had similar responses regarding hemodynamic parameters and pulse-wave velocity in older people with slow gait speed. Long-term studies should assess the cardiovascular risk and safety of LIRE-BFR training in this population.

Bone-Regulating MicroRNAs and Resistance Exercise: A Mini-Review

MicroRNAs (miRNA) are a class of short noncoding RNA that play important roles in controlling gene expression. Many miRNAs have been identified as being important regulators of bone cell function, thus affecting the bone remodeling processes. In addition to being expressed in specific tissues and exerting intracellular effects, miRNAs can enter the blood where they can be taken up by other tissues. These circulating miRNAs (c-miRNA) also have clinical significance as biomarkers of musculoskeletal diseases as they are tissue-specific, are stable and easily detectable, and require minimally invasive procedures. This mini-review discusses miRNAs with regulatory roles in bone metabolism and c-miRNA responses to acute bouts of resistance exercise. MiRNA responses (e.g., upregulation/downregulation of expression) vary depending on the resistance exercise protocol characteristics and the age of the participants. There are gaps in the literature that need to be addressed as most of the resistance exercise studies focused on miRNAs that regulate skeletal muscle in male participants.

RPS6 phosphorylation occurs to a greater extent in the periphery of human skeletal muscle fibers, near focal adhesions, after anabolic stimuli.

Following anabolic stimuli (mechanical loading and/or amino acid provision), the mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of protein synthesis, translocates toward the cell periphery. However, it is unknown if mTORC1-mediated phosphorylation events occur in these peripheral regions or before translocation (i.e., in central regions). We therefore aimed to determine the cellular location of a mTORC1-mediated phosphorylation event, RPS6Ser240/244, in human skeletal muscle following anabolic stimuli. Fourteen young, healthy males either ingested a protein-carbohydrate beverage (0.25 g/kg protein and 0.75 g/kg carbohydrate) alone [n = 7; 23 ± 5 yr; 76.8 ± 3.6 kg; and 13.6 ± 3.8% body fat (BF), FED] or following a whole body resistance exercise bout (n = 7; 22 ± 2 yr; 78.1 ± 3.6 kg; and 12.2 ± 4.9%BF, EXFED). Vastus lateralis muscle biopsies were obtained at rest (PRE) and 120 and 300 min following anabolic stimuli. RPS6Ser240/244 phosphorylation measured by immunofluorescent staining or immunoblot was positively correlated (r = 0.76, P < 0.001). Peripheral staining intensity of p-RPS6Ser240/244 increased above PRE in both FED and EXFED at 120 min (∼54% and ∼138%, respectively, P < 0.05) but was greater in EXFED at both poststimuli time points (P < 0.05). The peripheral-to-central ratio of p-RPS6240/244 staining displayed a similar pattern, even when corrected for total RPS6 distribution, suggesting RPS6 phosphorylation occurs to a greater extent in the periphery of fibers. Moreover, p-RPS6Ser240/244 intensity within paxillin-positive regions, a marker of focal adhesion complexes, was elevated at 120 min irrespective of stimulus (P = 0.006) before returning to PRE at 300 min. These data confirm that RPS6Ser240/244 phosphorylation occurs in the region of human muscle fibers to which mTOR translocates following anabolic stimuli and identifies focal adhesion complexes as a potential site of mTORC1 regulation in vivo.

The effects of acute resistance exercise among young adults: A randomized controlled trial

Background The effects of a single bout of resistance exercise (RE) on state anxiety and worry symptoms are understudied. Further, how resistance exercise training (RET) changes response to acute RE is unknown.Methods Sixty-two untrained young adults (mean age (y):26.6; RET n = 27, Wait-list (WL): n = 35, 62.9% female) were randomized to an eight-week, ecologically-valid, guidelines-based RET condition, or eight-week WL control condition. Two acute RE trials were nested within the design at week one and eight, to determine RE response, and change in RE response following RET. The RET condition completed a twice-weekly RET intervention. The WL condition completed 30-minute bouts of quiet-rest at week one and eight. Two-condition (RE/quiet-rest) x two-time (pre/post) x two-session (weeks one/eight) RM-ANCOVAs examined differences between acute RE and quiet-rest pre-post and between acute sessions. Sub-analyses were conducted among young adults with analogue-Generalized Anxiety Disorder (AGAD). Primary outcomes were anxiety and worry symptoms.Results Compliance was 99% (Rate of perceived exertion (6–20) = 14±1, Muscle soreness (1–10)=4 ± 2), with no adverse events. There were no significant three-way interactions for anxiety symptoms or worry symptoms (all p ≥ 0.51) among the total sample or AGAD sample. The magnitude of change in outcomes at each session for both samples were small and non-significant (Hedges’ d = -0.26 to 0.23).Limitations Post-condition assessment of primary outcomes was only conducted at a single time point.Conclusion RE did not elicit significant reductions in state anxiety or worry symptoms ten minutes post-RE. RET did not change response to acute RE. Clinicians should encourage RET for maximum anxiolytic benefits.