Aging, especially in female, is complex, involving various factors such as reproductive sensitivity, cognitive and functional decline, and an imbalance in the redox system. This study aims to assess ...the effectiveness of long-term resistance training as a non-pharmacological strategy to mitigate the impairment of recognition memory, hippocampal redox state, and ambulation in aging female Wistar rats during the periestropause period. Thirty Wistar rats aged 17 months, in periestropause, were distributed into non-trained (NT) and resistance training (RT; stair climbing 3 times per week for 4 months) groups. Before (17 months) and after (21 months) of the RT period, the rats underwent tests for ambulation, elevated plus maze (EPM), open field, and object recognition. Biochemical and histological analyses were conducted on the hippocampus of these animals. Analysis of the results revealed that at 21 months, females in the NT group (21Mo/NT) exhibited a decreased in length (p=0.0458) and an increased in past width (p<0.0479) compared to their measurements at 17 months. However, after 4 months of RT, the female rats aged 21 months (21Mo/RT group) experienced changes in gait components, showing an increase in length (p<0.0008) and a decrease in stride width. Regarding memory, the object recognition test indicated potential cognitive improvement in 21Mo/RT animals, with significant interaction between intervention and age across all three stages of the test (total exploration time, p=0.0001; Test 1, p=0.0003; Test 2, p=0.0014). This response was notable compared to animals in the 21Mo/NT group, which showed a decline in memory capacity (p<0.01). The data showed a significant difference in relation to the age of the animals (p<0.01). The hippocampal redox state markers showed reduced lipid oxidative (p=0.028), catalase (p=0.022), and superoxide dismutase (p=0.0067) in the RT group compared to the NT group. Hippocampal cells from the 21Mo/RT group showed increased citrate synthase enzyme activity (p<0.05) and Nissl body staining (p<0.05). The results of this study demonstrate that RT performed during the periestropause phase leads to significant improvements in functional abilities, cognitive performance, and neuroplasticity in aging female rats.
•RT during the periestropause promoted cognitive health through memory conservation.•The not undergo RT during the periestropause phase showed impaired memory.•RT performed during the periestropause phase modulating the ambulation.
This study investigated the hypertrophic potential of load‐matched blood‐flow restricted resistance training (BFR) vs free‐flow traditional resistance training (low‐load TRT) performed to fatigue. ...Ten healthy young subjects performed unilateral BFR and contralateral low‐load TRT elbow flexor dumbbell curl with 40% of one repetition maximum until volitional concentric failure 3 days per week for 6 weeks. Prior to and at 3 (post‐3) and 10 (post‐10) days post‐training, magnetic resonance imaging (MRI) was used to estimate elbow flexor muscle volume and muscle water content accumulation through training. Acute changes in muscle thickness following an early vs a late exercise bout were measured with ultrasound to determine muscle swelling during the immediate 0–48 h post‐exercise. Total work was threefold lower for BFR compared with low‐load TRT (P < 0.001). Both BRF and low‐load TRT increased muscle volume by approximately 12% at post‐3 and post‐10 (P < 0.01) with no changes in MRI‐determined water content. Training increased muscle thickness during the immediate 48 h post‐exercise (P < 0.001) and to greater extent with BRF (P < 0.05) in the early training phase. In conclusion, BFR and low‐load TRT, when performed to fatigue, produce equal muscle hypertrophy, which may partly rely on transient exercise‐induced increases in muscle water content.
Background
The purpose of this systematic review update and meta-analysis was to analyze resistance exercise (RE) intervention trials in breast cancer survivors (BCS) regarding their effect on breast ...cancer-related lymphedema (BCRL) status and upper and lower extremity strength.
Methods
Systematic literature search was conducted utilizing PubMed, MEDLINE, and Embase databases. Any exercise intervention studies—both randomized controlled and uncontrolled—which assessed the effects of RE on BCRL in BCS in at least one intervention group published between 1966 and 31st January 2020 were included. Included articles were analyzed regarding their level of evidence and their methodological quality using respective tools for randomized and nonrandomized trials of the Cochrane collaboration. Meta-analysis for bioimpedance spectroscopy (BIS) values as well as upper and lower extremity strength was conducted.
Results
Altogether, 29 studies were included in the systematic review. Results of six studies with altogether twelve RE intervention groups could be pooled for meta-analysis of the BCRL. A significant reduction of BCRL after RE was seen in BIS values (95% CI − 1.10 − 2.19, − 0.01 L-Dex score). Furthermore, strength results of six studies could be pooled and meta-analysis showed significant improvements of muscular strength in the upper and lower extremities (95% CI 8.96 3.42, 14.51 kg and 95% CI 23.42 11.95, 34.88 kg, respectively).
Conclusion
RE does not have a systematic negative effect on BCRL and, on the contrary, potentially decreases it.
ABSTRACT
Previous resistance training (RT) recommendations and position stands have addressed variables that can be manipulated when producing RT interventions. However, 1 variable that has received ...little discussion is set endpoints (i.e., the endpoint of a set of repetitions). Set endpoints in RT are often considered to be proximity to momentary failure and are thought to be a primary variable determining effort in RT. Further, there has been ambiguity in the use and definition of terminology that has created issues in interpretation of research findings. The purpose of this paper was to: (1) provide an overview of the ambiguity in historical terminology around set endpoints; (2) propose a clearer set of definitions related to set endpoints; and (3) highlight the issues created by poor terminology and definitions. It is hoped this may permit greater clarity in reporting, interpretation, and application of RT interventions for researchers and practitioners. Muscle Nerve 56: 368–374, 2017
Key points
For individuals showing suboptimal adaptations to resistance training, manipulation of training volume is a potential measure to facilitate responses. This remains unexplored.
Here, 34 ...untrained individuals performed contralateral resistance training with moderate and low volume for 12 weeks. Moderate volume led to larger increases in muscle cross‐sectional area, strength and type II fibre‐type transitions.
These changes coincided with greater activation of signalling pathways controlling muscle growth and greater induction of ribosome synthesis.
Out of 34 participants, thirteen displayed clear benefit of MOD on muscle hypertrophy and sixteen showed clear benefit of MOD on muscle strength gains. This coincided with greater total RNA accumulation in the early phase of the training period, suggesting that ribosomal biogenesis regulates the dose–response relationship between training volume and muscle hypertrophy.
These results demonstrate that there is a dose‐dependent relationship between training volume and outcomes. On the individual level, benefits of higher training volume were associated with increased ribosomal biogenesis.
Resistance‐exercise volume is a determinant of training outcomes. However not all individuals respond in a dose‐dependent fashion. In this study, 34 healthy individuals (males n = 16, 23.6 (4.1) years; females n = 18, 22.0 (1.3) years) performed moderate‐ (3 sets per exercise, MOD) and low‐volume (1 set, LOW) resistance training in a contralateral fashion for 12 weeks (2–3 sessions per week). Muscle cross‐sectional area (CSA) and strength were assessed at Weeks 0 and 12, along with biopsy sampling (m. vastus lateralis). Muscle biopsies were also sampled before and 1 h after the fifth session (Week 2). MOD resulted in larger increases in muscle CSA (5.2 (3.8)% versus 3.7 (3.7)%, P < 0.001) and strength (3.4–7.7% difference, all P < 0.05. This coincided with greater reductions in type IIX fibres from Week 0 to Week 12 (MOD, −4.6 percentage points; LOW −3.2 percentage points), greater phosphorylation of S6‐kinase 1 (p85 S6K1Thr412, 19%; p70 S6K1Thr389, 58%) and ribosomal protein S6Ser235/236 (37%), greater rested‐state total RNA (8.8%) and greater exercise‐induced c‐Myc mRNA expression (25%; Week 2, all P < 0.05). Thirteen and sixteen participants, respectively, displayed clear benefits in response to MOD on muscle hypertrophy and strength. Benefits were associated with greater accumulation of total RNA at Week 2 in the MOD leg, with every 1% difference increasing the odds of MOD benefit by 7.0% (P = 0.005) and 9.8% (P = 0.002). In conclusion, MOD led to greater functional and biological adaptations than LOW. Associations between dose‐dependent total RNA accumulation and increases in muscle mass and strength point to ribosome biogenesis as a determinant of dose‐dependent training responses.
Key points
For individuals showing suboptimal adaptations to resistance training, manipulation of training volume is a potential measure to facilitate responses. This remains unexplored.
Here, 34 untrained individuals performed contralateral resistance training with moderate and low volume for 12 weeks. Moderate volume led to larger increases in muscle cross‐sectional area, strength and type II fibre‐type transitions.
These changes coincided with greater activation of signalling pathways controlling muscle growth and greater induction of ribosome synthesis.
Out of 34 participants, thirteen displayed clear benefit of MOD on muscle hypertrophy and sixteen showed clear benefit of MOD on muscle strength gains. This coincided with greater total RNA accumulation in the early phase of the training period, suggesting that ribosomal biogenesis regulates the dose–response relationship between training volume and muscle hypertrophy.
These results demonstrate that there is a dose‐dependent relationship between training volume and outcomes. On the individual level, benefits of higher training volume were associated with increased ribosomal biogenesis.
Summary
This study compared the time course of recovery following two resistance exercise protocols differing in the number of repetitions per set with regard to the maximum possible (to failure) ...number. Ten men performed three sets of 6 versus 12 repetitions with their 70% 1RM (3 × 6 12 versus 3 × 12 12) in the bench press (BP) and squat (SQ) exercises. Mechanical CMJ height, velocity against the 1 m s−1 load (V1‐load), biochemical testosterone, cortisol, growth hormone, prolactin, insulin‐like growth factor‐1, creatine kinase (CK) and heart rate variability (HRV) and complexity (HRC) were assessed pre‐, postexercise (Post) and at 6, 24 and 48 h‐Post. Compared with 3 × 6 12, the 3 × 12 12 protocol resulted in significantly: higher repetition velocity loss within each set (BP: 65% versus 26%; SQ: 44% versus 20%); reduced V1‐load until 24 h‐Post (BP) and 6 h‐Post (SQ); decreased CMJ height up to 48 h‐Post; greater increases in cortisol (Post), prolactin (Post, 48 h‐Post) and CK (48 h‐Post); and reductions in HRV and HRC at Post. This study shows that the mechanical, neuroendocrine and autonomic cardiovascular response is markedly different when manipulating the number of repetitions per set. Halving the number of repetitions in relation to the maximum number that can be completed serves to minimize fatigue and speed up recovery following resistance training.
This study aimed to investigate the effects of supervised and home-based exercise programs on older people with frailty or pre-frailty.
A total of 146 community-dwelling participants aged 65 and ...older who were prefrail or frail were randomly allocated into supervised exercise (N = 74) and home exercise (N = 72) groups. The 3-month supervised exercise training consisted of 3 exercise sessions per week, was performed at a hospital and supervised by a physical therapist. Home exercise participants took instructions on exercise and illustrated exercise handouts. The baseline and 3-month follow-up measurements included body composition, strength of selected upper and lower limb muscle groups, grip and leg press strengths, and five physical performance tests. Mixed-model repeated-measures analysis was applied to determine whether two groups differ in terms of changes before and after the intervention and to compare within-group improvements.
After 3 months of supervised or home-based exercise, the average number of frailty criteria met and fat percentage decreased significantly. Strength of knee extensors, knee flexors and leg press improved significantly in supervised exercise group. In home-based exercise group, the strength of all muscle groups tested improved significantly, except for leg press strength. Walking speed improved in both groups, and timed-up-and-go and timed chair rise tests improved significantly only in supervised exercise group.
Three-month supervised or home-based exercise improved walking speed and strength of the limb muscles. Supervised group showed more improvements in the physical performance tests compared with home-based exercise group.
Purpose
Cross-education (CE) of strength is a well-known phenomenon whereby exercise of one limb can induce strength gains in the contralateral untrained limb. The only available meta-analyses on CE, ...which date back to a decade ago, estimated a modest 7.8% increase in contralateral strength following unilateral training. However, in recent years new evidences have outlined larger contralateral gains, which deserve to be systematically evaluated. Therefore, the aim of this meta-analysis was to appraise current data on CE and determine its overall magnitude of effect.
Methods
Five databases were searched from inception to December 2016. All randomized controlled trials focusing on unilateral resistance training were carefully checked by two reviewers who also assessed the eligibility of the identified trials and extracted data independently. The risk of bias was assessed using the Cochrane Risk-of-Bias tool.
Results
Thirty-one studies entered the meta-analysis. Data from 785 subjects were pooled and subgroup analyses by body region (upper/lower limb) and type of training (isometric/concentric/eccentric/isotonic–dynamic) were performed. The pooled estimate of CE was a significant 11.9% contralateral increase (95% CI 9.1–14.8;
p
< 0.00001; upper limb: + 9.4%,
p
< 0.00001; lower limb: + 16.4%,
p
< 0.00001). Significant CE effects were induced by isometric (8.2%;
p
= 0.0003), concentric (11.3%;
p
< 0.00001), eccentric (17.7%;
p
= 0.003) and isotonic–dynamic training (15.9%;
p
< 0.00001), although a high risk of bias was detected across the studies.
Conclusions
Unilateral resistance training induces significant contraction type-dependent gains in the contralateral untrained limb. Methodological issues in the included studies are outlined to provide guidance for a reliable quantification of CE in future studies.
At least one-third of community-dwelling people over 65 years of age fall each year. Exercises that target balance, gait and muscle strength have been found to prevent falls in these people. An ...up-to-date synthesis of the evidence is important given the major long-term consequences associated with falls and fall-related injuries OBJECTIVES: To assess the effects (benefits and harms) of exercise interventions for preventing falls in older people living in the community.
We searched CENTRAL, MEDLINE, Embase, three other databases and two trial registers up to 2 May 2018, together with reference checking and contact with study authors to identify additional studies.
We included randomised controlled trials (RCTs) evaluating the effects of any form of exercise as a single intervention on falls in people aged 60+ years living in the community. We excluded trials focused on particular conditions, such as stroke.
We used standard methodological procedures expected by Cochrane. Our primary outcome was rate of falls.
We included 108 RCTs with 23,407 participants living in the community in 25 countries. There were nine cluster-RCTs. On average, participants were 76 years old and 77% were women. Most trials had unclear or high risk of bias for one or more items. Results from four trials focusing on people who had been recently discharged from hospital and from comparisons of different exercises are not described here.Exercise (all types) versus control Eighty-one trials (19,684 participants) compared exercise (all types) with control intervention (one not thought to reduce falls). Exercise reduces the rate of falls by 23% (rate ratio (RaR) 0.77, 95% confidence interval (CI) 0.71 to 0.83; 12,981 participants, 59 studies; high-certainty evidence). Based on an illustrative risk of 850 falls in 1000 people followed over one year (data based on control group risk data from the 59 studies), this equates to 195 (95% CI 144 to 246) fewer falls in the exercise group. Exercise also reduces the number of people experiencing one or more falls by 15% (risk ratio (RR) 0.85, 95% CI 0.81 to 0.89; 13,518 participants, 63 studies; high-certainty evidence). Based on an illustrative risk of 480 fallers in 1000 people followed over one year (data based on control group risk data from the 63 studies), this equates to 72 (95% CI 52 to 91) fewer fallers in the exercise group. Subgroup analyses showed no evidence of a difference in effect on both falls outcomes according to whether trials selected participants at increased risk of falling or not.The findings for other outcomes are less certain, reflecting in part the relatively low number of studies and participants. Exercise may reduce the number of people experiencing one or more fall-related fractures (RR 0.73, 95% CI 0.56 to 0.95; 4047 participants, 10 studies; low-certainty evidence) and the number of people experiencing one or more falls requiring medical attention (RR 0.61, 95% CI 0.47 to 0.79; 1019 participants, 5 studies; low-certainty evidence). The effect of exercise on the number of people who experience one or more falls requiring hospital admission is unclear (RR 0.78, 95% CI 0.51 to 1.18; 1705 participants, 2 studies, very low-certainty evidence). Exercise may make little important difference to health-related quality of life: conversion of the pooled result (standardised mean difference (SMD) -0.03, 95% CI -0.10 to 0.04; 3172 participants, 15 studies; low-certainty evidence) to the EQ-5D and SF-36 scores showed the respective 95% CIs were much smaller than minimally important differences for both scales.Adverse events were reported to some degree in 27 trials (6019 participants) but were monitored closely in both exercise and control groups in only one trial. Fourteen trials reported no adverse events. Aside from two serious adverse events (one pelvic stress fracture and one inguinal hernia surgery) reported in one trial, the remainder were non-serious adverse events, primarily of a musculoskeletal nature. There was a median of three events (range 1 to 26) in the exercise groups.Different exercise types versus controlDifferent forms of exercise had different impacts on falls (test for subgroup differences, rate of falls: P = 0.004, I² = 71%). Compared with control, balance and functional exercises reduce the rate of falls by 24% (RaR 0.76, 95% CI 0.70 to 0.81; 7920 participants, 39 studies; high-certainty evidence) and the number of people experiencing one or more falls by 13% (RR 0.87, 95% CI 0.82 to 0.91; 8288 participants, 37 studies; high-certainty evidence). Multiple types of exercise (most commonly balance and functional exercises plus resistance exercises) probably reduce the rate of falls by 34% (RaR 0.66, 95% CI 0.50 to 0.88; 1374 participants, 11 studies; moderate-certainty evidence) and the number of people experiencing one or more falls by 22% (RR 0.78, 95% CI 0.64 to 0.96; 1623 participants, 17 studies; moderate-certainty evidence). Tai Chi may reduce the rate of falls by 19% (RaR 0.81, 95% CI 0.67 to 0.99; 2655 participants, 7 studies; low-certainty evidence) as well as reducing the number of people who experience falls by 20% (RR 0.80, 95% CI 0.70 to 0.91; 2677 participants, 8 studies; high-certainty evidence). We are uncertain of the effects of programmes that are primarily resistance training, or dance or walking programmes on the rate of falls and the number of people who experience falls. No trials compared flexibility or endurance exercise versus control.
Exercise programmes reduce the rate of falls and the number of people experiencing falls in older people living in the community (high-certainty evidence). The effects of such exercise programmes are uncertain for other non-falls outcomes. Where reported, adverse events were predominantly non-serious.Exercise programmes that reduce falls primarily involve balance and functional exercises, while programmes that probably reduce falls include multiple exercise categories (typically balance and functional exercises plus resistance exercises). Tai Chi may also prevent falls but we are uncertain of the effect of resistance exercise (without balance and functional exercises), dance, or walking on the rate of falls.
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