scholarly journals The effects of different intra-set velocity loss thresholds on lower-limb adaptations to resistance training in young adults: A systematic review and meta-analysis

2021 ◽  
Author(s):  
Petrus Gantois ◽  
Fábio Yuzo Nakamura ◽  
Julian Alcazar ◽  
Leonardo de Sousa Fortes ◽  
Fernando Pareja-Blanco ◽  
...  
Keyword(s):  
Resistance Training ◽  
Dose Response ◽  
Muscle Hypertrophy ◽  
Meta Analysis ◽  
Optimal Dose ◽  
Jump Height ◽  
Countermovement Jump ◽  
Sprint Time ◽  
Significant Difference ◽  
Bar Velocity

Abstract Background: The level of effort seems to play a key role in determining neuromuscular adaptations; however, less is known regarding the optimal dose-response for intra-set levels of effort on chronic resistance training (RT) adaptations. Objective: We aimed to synthesize the current literature on chronic RT adaptations in response to different intra-set velocity loss (VL) thresholds in the back squat exercise. We investigated changes in muscle strength, muscular endurance, sports-related physical performance, and muscle hypertrophy outcomes during resistance exercise to establish optimal dose-response relationships in physically active individuals.Methods: We conducted a literature search using PubMed (Medline), Web of Science™, Scopus, and Cochrane up to April 2021, with no restriction on year of publication. The inclusion criteria were based on the PICO strategy. A random-effect meta-analysis was performed to determine the standardized mean differences (SMD ± 95% confidence intervals) for different intra-set VL thresholds (low VL [< 15%], moderate VL [≥ 15% and < 30%], and high VL [≥ 30%]) in RT on maximum muscular strength, bar velocity against submaximal loads, endurance against a given load, countermovement jump height, running sprint time, and muscle hypertrophy. Results: A total of 4,031 articles were found and 11 studies met our eligibility criteria. Pooled results revealed improvements between pre- and post-training intervention in 1RM strength (SMD = 0.78; p < 0.001); bar velocity outputs (light-loads [SMD = 0.79; p < 0.001] and heavy-loads [SMD = 2.08; p < 0.001]); endurance against a given load (SMD = 1.21; p < 0.001); countermovement jump height (SMD = 0.50; p < 0.001); running sprint time (SMD = - 0.28; p = 0.001); and muscle hypertrophy (SMD = 0.31; p = 0.05), with no significant difference between VL thresholds (p > 0.05). However, low VL elicited greater within-group SMD for 1RM strength than moderate and high VL thresholds (SMD = 0.93; 0.72; and 0.75; for low, moderate, and high VL thresholds, respectively). Low and moderate VL thresholds resulted in greater within-group SMD than high VL thresholds for velocity against light loads (SMD for low VL = 0.89; moderate VL = 0.90; high VL = 0.59); countermovement jump height (SMD for low VL = 0.51; moderate VL = 0.58; high VL = 0.36); and running sprint time (SMD for low VL = -0.49; moderate VL = -0.32; high VL = -0.09). Moderate and high VL thresholds induced higher within-group SMD for muscle hypertrophy than low VL (SMD for low VL = 0.14; moderate VL = 0.40; high VL = 0.44). Conclusions: Low to moderate VL thresholds may provide more effective and efficient training stimuli for improving performance in strength-power tasks, due to the similar or even greater chronic adaptations achieved compared with high VL, despite the lower number of repetitions performed during the RT program. Conversely, moderate to high VL may provide more favorable training stimuli for inducing muscle hypertrophy. Strength coaches may apply these dose-response trends to design optimal RT stimuli based on their specific training goals. Protocol registration: The study protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020189321).

scholarly journals Physical Activity and Mortality in Cancer Survivors: A Systematic Review and Meta-Analysis

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Christine M Friedenreich ◽  
Chelsea R Stone ◽  
Winson Y Cheung ◽  
Sandra C Hayes
Keyword(s):  
Physical Activity ◽  
Systematic Review ◽  
Dose Response ◽  
Meta Analysis ◽  
Menopausal Status ◽  
Optimal Dose ◽  
Primary Objective ◽  
Survival Outcomes ◽  
All Cause Mortality ◽  
Pa Domain

Abstract Background Recommendations for improved survival after cancer through physical activity (PA) exist, although the evidence is still emerging. Our primary objective was to conduct a systematic review and meta-analysis of the association between prediagnosis and postdiagnosis PA and survival (cancer-specific, all-cause, and cardiovascular disease mortality) for all cancers and by tumor site. Secondary objectives were to examine the associations within population subgroups, by PA domain, and to determine the optimal dose of PA related to survival. Methods PubMed, EMBASE, and SportsDiscus databases were searched from inception to November 1, 2018. DerSimonian-Laird random-effects models were used to estimate the summary hazard ratios (HRs) and 95% confidence intervals (CI) for primary and secondary analyses and to conduct dose-response analyses. Results Evidence from 136 studies showed improved survival outcomes with highest vs lowest levels of prediagnosis or postdiagnosis total or recreational PA for all-cancers combined (cancer specific mortality: HR = 0.82, 95% CI = 0.79 to 0.86, and HR = 0.63, 95% CI = 0.53 to 0.75, respectively) as well as for 11 specific cancer sites. For breast and colorectal cancers, greater reductions were observed for postdiagnosis PA (HR = 0.58–0.63) compared with prediagnosis PA (HR = 0.80–0.86) for cancer-specific and all-cause mortality. Survival benefits through PA were observed in most subgroups (within sex, body mass index, menopausal status, colorectal subtypes, and PA domain) examined. Inverse dose-response relationships between PA and breast cancer-specific and all-cause mortality were observed, with steep reductions in hazards to 10–15 metabolic equivalent hours per week. Conclusion Higher prediagnosis and postdiagnosis levels of PA were associated with improved survival outcomes for at least 11 cancer types, providing support for global promotion of PA guidelines following cancer.

Creatine supplementation elicits greater muscle hypertrophy in upper than lower limbs and trunk in resistance-trained men

2017 ◽  
Vol 23 (4) ◽  
pp. 223-229 ◽  
Author(s):  
João Pedro Nunes ◽  
Alex S Ribeiro ◽  
Brad J Schoenfeld ◽  
Crisieli M Tomeleri ◽  
Ademar Avelar ◽  
...  
Keyword(s):  
Young Adult ◽  
Resistance Training ◽  
Soft Tissue ◽  
Muscle Hypertrophy ◽  
Creatine Supplementation ◽  
Lower Limbs ◽  
Upper Limbs ◽  
Double Blind ◽  
Adult Men ◽  
Significant Difference

Background: Creatine (Cr) supplementation associated with resistance training produces greater muscular strength improvements in the upper compared with the lower body; however, no study has investigated if such region-specific results are seen with gains in muscle mass. Aim: We aimed to evaluate the effect of Cr supplementation in combination with resistance training on lean soft tissue changes in the upper and lower limbs and trunk in resistance-trained young adult men. Methods: In a randomized, double-blind and placebo-controlled design, 43 resistance-trained men (22.7 ± 3.0 years, 72.9 ± 8.7 kg, 177.9 ± 5.7 cm, 23.0 ± 2.5 kg/m2) received either creatine (Cr, n = 22) or placebo (PLA, n = 21) over an 8-week study period. The supplementation protocol included a loading phase (7 days, four doses of 0.3 g/kg per day) and a maintenance phase (7 weeks, single dose of 0.03 g/kg per day). During the same period, subjects performed resistance training four times per week using the following two-way split routine: Monday and Thursday = pectoral, shoulders, triceps, and abdomen, Tuesday and Friday = back, biceps, thighs, and calves. Lean soft tissue of the upper limbs (ULLST), lower limbs (LLLST), and trunk (TLST) was assessed by dual-energy X-ray absorptiometry before and after the intervention. Results: Both groups showed significant ( p < 0.001) improvements in ULLST, LLLST, TLST, and the Cr group achieved greater ( p < 0.001) increases in these outcomes compared with PLA. For the Cr group, improvements in ULLST (7.1 ± 2.9%) were higher than those observed in LLLST (3.2 ± 2.1%) and TLST (2.1 ± 2.2%). Otherwise, for PLA group there was no significant difference in the magnitude of segmental muscle hypertrophy (ULLST = 1.6 ± 3.0%; LLLST = 0.7 ± 2.8%; TLST = 0.7 ± 2.8%). Conclusion: Our results suggest that Cr supplementation can positively augment muscle hypertrophy in resistance-trained young adult men, particularly in the upper limbs.

Effect of Repetition Duration During Resistance Training on Muscle Hypertrophy: A Systematic Review and Meta-Analysis

2015 ◽  
Vol 45 (4) ◽  
pp. 577-585 ◽  
Author(s):  
Brad J. Schoenfeld ◽  
Dan I. Ogborn ◽  
James W. Krieger
Keyword(s):  
Systematic Review ◽  
Resistance Training ◽  
Muscle Hypertrophy ◽  
Meta Analysis

scholarly journals Efficacy and safety of bevacizumab in the treatment of adult gliomas: a systematic review and meta-analysis

BMJ Open ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. e048975
Author(s):  
Huan Wang ◽  
Jianxin Guo ◽  
Tianze Wang ◽  
Kai Wang ◽  
Zhuojun Wu ◽  
...  
Keyword(s):  
Systematic Review ◽  
Large Scale ◽  
Meta Analysis ◽  
Progression Free Survival ◽  
Optimal Dose ◽  
Secondary Outcome ◽  
Efficacy And Safety ◽  
Free Survival ◽  
Significant Difference ◽  
Clinical Centre

ObjectiveTo assess the efficacy and safety of bevacizumab (BEV) in patients with glioma.DesignSystematic review and meta-analysis.ParticipantsAdults aged 18 years and above, whose histology was confirmed to be malignant glioma.Primary and secondary outcome measuresThe main indicators included progression-free survival (PFS) rate and overall survival (OS) rate, and the secondary indicators were adverse reactions.ResultsA total of 11 clinical centre trials were included in this study for meta-analysis, including 2392 patients. The results of the meta-analysis showed that the median PFS rate of the BEV group was significantly higher than that of the non-BEV group (p<0.00001). When comparing PFS between two groups, we found that the PFS in the BEV group was higher than that in the non-BEV group at 6 months (OR 3.31, 95% CI 2.74 to 4.00, p<0.00001), 12 months (OR 2.05, 95% CI 1.70 to 2.49, p<0.00001) and 18 months (OR 1.31, 95% CI 1.02 to 1.69, p=0.03). But at 24 months (OR 0.83, 95% CI 0.50 to 1.37, p=0.47), there was no significant difference between the two groups. At 30 months (OR 0.62, 95% CI 0.39 to 0.97, p=0.04), the PFS of the BEV group was lower than that of the non-BEV group. Moreover, The results showed that BEV had no significant effect on improving OS, but the adverse reaction in BEV group was significantly higher than that in non-BEV group.ConclusionThe evidence suggests that BEV can significantly prolong the PFS of patients with glioma within 18 months and shorten the PFS of patients after 30 months. This limitation may be related to the subgroup of patients, the change of recurrence mode, the optimal dose of drug, the increase of hypoxia, the enhancement of invasiveness and so on. Therefore, it is necessary to carry out more samples and higher quality large-scale research in the future.

scholarly journals Changes in UPR-PERK pathway and muscle hypertrophy following resistance training and creatine supplementation in rats

2021 ◽  
Author(s):  
Hersh Nouri ◽  
Dariush Sheikholeslami-Vatani ◽  
Mohammad Raman Moloudi
Keyword(s):  
Resistance Training ◽  
Exercise Training ◽  
Muscle Hypertrophy ◽  
Training Session ◽  
Creatine Supplementation ◽  
Physiological Adaptation ◽  
Flexor Hallucis Longus ◽  
Protein Kinase R ◽  
Significant Difference ◽  
Total Ratio

Abstract The unfolded protein response (UPR) plays a pivotal role in some exercise training induced-physiological adaptation. Our aim was to evaluate the changes in the protein kinase R-like endoplasmic reticulum kinase (PERK) arm of the UPR and hypertrophy signaling pathway following 8 weeks of resistance training and creatine (Cr) supplementation in rats. Thirty-two adult male Wistar rats (8 weeks old) were randomly divided into 4 groups of 8: untrained + placebo (UN + P), resistance training + placebo (RT + P), untrained + Cr (UN + Cr) and resistance training + Cr (RT + Cr). Trained animals were submitted to the ladder-climbing exercise training 5 days per week for a total of 8 weeks. Cr supplementation groups received creatine diluted with 1.5 ml of 5% dextrose orally. The flexor hallucis longus (FHL) muscle was extracted 48 hours after the last training session and used for western blotting. After training period, the RT + Cr and RT + P groups presented a significant increase in phosphorylated and phosphorylated /total ratio hypertrophy indices, phosphorylated and phosphorylated/total ratio PERK pathway proteins and other downstream proteins of the PERK cascade compared with their untrained counterparts (P < 0.05). The increase in hypertrophy indices were higher but PERK pathway proteins were lower in the RT-Cr group than in the RT + P group (P < 0.05). There was no significant difference between the untrained groups (P > 0.05). Our study suggests that resistance training in addition to Cr supplementation modifies PERK pathway response and improves skeletal muscle hypertrophy.

scholarly journals Effects of plyometric and pull training on performance and selected strength characteristics of junior male weightlifter

2019 ◽  
Vol 23 (3) ◽  
pp. 120-128 ◽  
Author(s):  
İ. İnce ◽  
A. Şentürk
Keyword(s):  
Training Program ◽  
Analysis Of Variance ◽  
Group Interaction ◽  
Strength Characteristics ◽  
Control Group ◽  
Jump Height ◽  
Plyometric Training ◽  
Countermovement Jump ◽  
Significant Difference ◽  
Main Effects

Purpose: The aim of this study was to investigate the effect of plyometric and pull training added an Olympic weightlifting training program (twice a week for 8 wk) on performance and selected strength characteristics in junior male weightlifter. Material: The participants [n = 34; age: 16.03 ± 0.9 y; mass: 74.78 ± 14.86 kg; height: 170.53 ± 6.81 cm] were randomized into a pull (n = 11), a plyometric (n = 12), and a control (n= 11) groups. The groups trained 6 days a week during the 8-week study period. The pull group performed four pull exercises and the plyometric group performed four plyometric exercises added to Olympic weightlifting program for 2 days a week, and the control group performed an Olympic weightlifting program alone. Analysis of variance and Magnitude-based inferences used to determine whether a significant difference existed among groups on snatch clean and jerk total (SCT), squat (SQ), back strength (BS), countermovement jump (CMJ), 30 sec. repeated jump height (RJH) and peak barbell velocity (PV). Results: The ANOVA showed a time × group interaction for SCT, BS and RJH. The MBI indicated positive changes for SCT in control group, for BS in pull group and for RJH in plyometric group. The results for the PV decrease in plyometric and pull group indicated no significant time × group interaction, but there was a significant main effects. ASK "Inserisci l'aim" \* MERGEFORMAT ASK \* MERGEFORMAT Conclusions: The results of this study showed that the addition of pull or plyometric training to an Olympic weightlifting program interfered with weightlifting performances.

The effects of vertically oriented resistance training on golf drive performance in collegiate golfers

2017 ◽  
Vol 13 (4) ◽  
pp. 598-606 ◽  
Author(s):  
Austin R Driggers ◽  
Kimitake Sato
Keyword(s):  
Resistance Training ◽  
Peak Power ◽  
Driving Performance ◽  
Peak Force ◽  
Division I ◽  
Jump Height ◽  
Countermovement Jump ◽  
Ball Speed ◽  
Force Development ◽  
Vertical Jumps

The purpose of this study was to examine the effects of vertically oriented resistance training on golf driving performance. Ten Division-I collegiate golfers completed two resistance training sessions per week for 10 weeks during the fall tournament season. Pre- and post-training assessments of strength-power and golf performance were compared. To assess strength-power, jump height, peak force, and peak power were measured from static and countermovement vertical jumps; peak force and rate of force development from 0 to 250 ms were measured from an isometric mid-thigh pull. Golf performance was assessed in terms of ball launch speed, spin rate, carry yardage, and total yardage, averaged from five shots using a driver. Following training, all measures of strength-power improved, with countermovement jump peak power improving significantly ( p < 0.00625). The golf performance assessment indicated significant increases ( p < 0.0125) in ball speed, carry yardage, and total yardage. These results suggest that vertically oriented resistance training can improve golf driving performance.

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