scholarly journals Accuracy in predicting repetitions to task failure in resistance exercise: a scoping review and exploratory meta-analysis

2021 ◽  
Author(s):  
Israel Halperin ◽  
Tomer Malleron ◽  
Itai Har-Nir ◽  
Patroklos Androulakis-Korakakis ◽  
Milo Wolf ◽  
...  
Keyword(s):  
Scoping Review ◽  
Prediction Accuracy ◽  
Meta Analysis ◽  
Upper Body ◽  
Lower Body ◽  
Analysis Model ◽  
Task Failure ◽  
Resistance Exercises ◽  
The Difference ◽  
Training Background

Background: Prescribing repetitions relative to task-failure (TF) is an emerging approach to resistance training. Under this approach, participants terminate the set based on their prediction of the remaining repetitions left to TF. While this approach holds promise, an important step in its development is to deter-mine how accurate participants are in their predictions. That is, what is the difference between the predicted and actual number of repetitions remaining to TF, which ideally should be as small as possible. Objective: Examine the accuracy in predicting repetitions to TF in resistance exercises. Design: Scoping review and exploratory meta-analysis. Search and Inclusion: A systematic literature search was conducted with PubMed, SPORTDiscus, and Google Scholar in January 2021. Inclusion criteria included studies with healthy participants who predicted the number of repetitions they can complete to TF in various resistance exercises, before or during an ongoing set, which was performed to TF. Sixteen publications were eligible for inclusion, of which 13 publications that cover 12 studies were included in our meta-analysis with a total of 414 participants. Results: The main multilevel meta-analysis model including all effects sizes (262 across 12 clusters) revealed that participants tended to under predict the number of repetitions to TF by 0.95 repetitions (95% CIs= 0.17 to 1.73), but with considerable heterogeneity (Q(261)= 3060, p< 0.0001; I2 = 97.9%). Me-ta-regressions showed that prediction accuracy slightly improved when the predictions were made closer to set failure (β= -0.025 [95% CIs= -0.05 to 0.0014]) and when the number of performed to TF was lower (<12 repetitions, β= 0.06 [95% CIs= 0.04 to 0.09]; >12 repetitions, β= 0.47 [95%CIs= 0.44 to 0.49]). Set number trivially influenced prediction accuracy with slightly increased accuracy in later sets (β= -0.07 repetitions [95% CIs= -0.14 to -0.005]). In contrast, participants training status did not seem to influence prediction accuracy (β= -0.006 repetitions [95% CIs= -0.02 to 0.007]) and neither did the implementation of upper or lower body exercises (Upper body – Lower body= -0.58 repetitions [95% CIs -2.32 to 1.16]). Conclusions: Participants were imperfect in their ability to predict proximity to TF independent of their training background. It re-mains to be determined whether the observed degree of inaccuracy should be considered acceptable. De-spite this, prediction accuracies can be improved if they are provided closer to TF, when using heavier loads, or in later sets. To reduce the heterogeneity between studies, future studies should include a clear and detailed account of how TF was explained to participants and how it was confirmed.

scholarly journals Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis

2021 ◽  
pp. 1-9
Author(s):  
Fredrik Tonstad Vårvik ◽  
Thomas Bjørnsen ◽  
Adam M. Gonzalez
Keyword(s):  
Strength Training ◽  
Meta Analysis ◽  
Random Effect ◽  
Random Effect Model ◽  
Acute Effect ◽  
Upper Body ◽  
Lower Body ◽  
Inclusion Criteria ◽  
Double Blind ◽  
Citrulline Malate

Citrulline malate (CitMal) is a dietary supplement that is suggested to enhance strength training performance. However, there is conflicting evidence on this matter. Thus, the purpose of this meta-analysis was to determine whether supplementing with CitMal prior to strength training could increase the total number of repetitions performed before reaching voluntary muscular failure. A systematic search was conducted wherein the inclusion criteria were double-blind, placebo-controlled studies in healthy participants that examined the effect of CitMal on repetitions to failure during upper body and lower body resistance exercises. The Hedges’s g standardized mean differences (SMD) between the placebo and CitMal trials were calculated and used in a random effect model. Two separate subanalyses were performed for upper body and lower body exercises. Eight studies, including 137 participants who consisted of strength-trained men (n = 101) and women (n = 26) in addition to untrained men (n = 9), fulfilled the inclusion criteria. Across the studies, 14 single-joint and multijoint exercises were performed with an average of 51 ± 23 total repetitions during 5 ± 3 sets per exercise at ∼70% of one-repetition maximum. Supplementing with 6–8 g of CitMal 40–60 min before exercise increased repetitions by 3 ± 5 (6.4 ± 7.9%) compared with placebo (p = .022) with a small SMD (0.196). The subanalysis for the lower body resulted in a tendency for an effect of the supplement (8.1 ± 8.4%, SMD: 0.27, p = .051) with no significant effect for the upper body (5.7 ± 8.4%, SMD: 0.16, p = .131). The current analysis observed a small ergogenic effect of CitMal compared with placebo. Acute CitMal supplementation may, therefore, delay fatigue and enhance muscle endurance during high-intensity strength training.

Morphological diversity of larval skeletons in the sea urchin family Echinometridae (Echinoidea: Echinodermata)

2006 ◽  
Vol 86 (4) ◽  
pp. 799-816 ◽  
Author(s):  
Sonoko Kinjo ◽  
Tsuyoshi Uehara ◽  
Ikuko Yazaki ◽  
Yoshihisa Shirayama ◽  
Hiroshi Wada
Keyword(s):  
Body Length ◽  
Morphological Diversity ◽  
The Body ◽  
Upper Body ◽  
Tropical Species ◽  
Lower Body ◽  
Morphological Comparison ◽  
The Family ◽  
Bottom Width ◽  
The Difference

To clarify the morphological variety of larval skeletons, a detailed morphological comparison among the species of the family Echinometridae was performed. Through conspecific comparison of larval skeletons among different ages, we found five skeletal characters of the body skeleton that are stable in the four-armed pluteus and thus useful in homologous comparison among the species. The morphological variation was summarized as the difference in the number of spines and posteroventral transverse rods, and differences in the shape of the body skeleton. Significant correlations were found between some skeletal characters, such as between upper body length and bottom width of body skeleton and between lower body length and the number of spines. We found that the larval skeletons of tropical species tend to have fewer spines and rods than those of temperate species, which is consistent with the hypothesis that a reduction in skeletal elements decreases the specific gravity of larvae as an adaptation to tropical waters.

scholarly journals Do multi-ingredient protein supplements augment resistance training-induced gains in skeletal muscle mass and strength? A systematic review and meta-analysis of 35 trials

2019 ◽  
Vol 54 (10) ◽  
pp. 573-581 ◽  
Author(s):  
Kerry R O’Bryan ◽  
Thomas M Doering ◽  
Robert W Morton ◽  
Vernon G Coffey ◽  
Stuart M Phillips ◽  
...  
Keyword(s):  
Exercise Training ◽  
Resistance Exercise ◽  
Muscle Mass ◽  
Meta Analysis ◽  
Fat Free Mass ◽  
Upper Body ◽  
Lower Body ◽  
Resistance Exercise Training ◽  
Eligibility Criteria ◽  
Subgroup Analyses

ObjectiveTo determine the effects of multi-ingredient protein (MIP) supplements on resistance exercise training (RT)-induced gains in muscle mass and strength compared with protein-only (PRO) or placebo supplementation.Data sourcesSystematic search of MEDLINE, Embase, CINAHL and SPORTDiscus.Eligibility criteriaRandomised controlled trials with interventions including RT ≥6 weeks in duration and a MIP supplement.DesignRandom effects meta-analyses were conducted to determine the effect of supplementation on fat-free mass (FFM), fat mass, one-repetition maximum (1RM) upper body and 1RM lower body muscular strength. Subgroup analyses compared the efficacy of MIP supplementation relative to training status and chronological age.ResultsThe most common MIP supplements included protein with creatine (n=17) or vitamin D (n=10). Data from 35 trials with 1387 participants showed significant (p<0.05) increases in FFM (0.80 kg (95% CI 0.44 to 1.15)), 1RM lower body (4.22 kg (95% CI 0.79 to 7.64)) and 1RM upper body (2.56 kg (95% CI 0.79 to 4.33)) where a supplement was compared with all non-MIP supplemented conditions (means (95% CI)). Subgroup analyses indicated a greater effect of MIP supplements compared with all non-MIP supplements on FFM in untrained (0.95 kg (95% CI 0.51 to 1.39), p<0.0001) and older participants (0.77 kg (95% CI 0.11 to 1.43), p=0.02); taking MIP supplements was also associated with gains in 1RM upper body (1.56 kg (95% CI 0.80 to 2.33), p=0.01) in older adults.Summary/conclusionsWhen MIP supplements were combined with resistance exercise training, there were greater gains in FFM and strength in healthy adults than in counterparts who were supplemented with non-MIP. MIP supplements were not superior when directly compared with PRO supplements. The magnitude of effect of MIP supplements was greater (in absolute values) in untrained and elderly individuals undertaking RT than it was in trained individuals and in younger people.Trial registration numberCRD42017081970.

scholarly journals Accuracy in Predicting Repetitions to Task Failure in Resistance Exercise: A Scoping Review and Exploratory Meta-analysis

2021 ◽  
Author(s):  
Israel Halperin ◽  
Tomer Malleron ◽  
Itai Har-Nir ◽  
Patroklos Androulakis-Korakakis ◽  
Milo Wolf ◽  
...  
Keyword(s):  
Resistance Exercise ◽  
Scoping Review ◽  
Meta Analysis ◽  
Task Failure

scholarly journals Effects of Testosterone on Serum Concentrations, Fat-free Mass, and Physical Performance by Population: A Meta-analysis

2020 ◽  
Vol 4 (9) ◽  
Author(s):  
Alyssa N Varanoske ◽  
Lee M Margolis ◽  
Stefan M Pasiakos
Keyword(s):  
Physical Performance ◽  
Performance Metrics ◽  
Functional Performance ◽  
Meta Analysis ◽  
Fat Free Mass ◽  
Upper Body ◽  
Lower Body ◽  
Double Blind ◽  
Young Males ◽  
And Performance

Abstract Testosterone (T) administration (TA) increases serum T and fat-free mass (FFM). Although TA-mediated increases in FFM may enhance physical performance, the data are largely equivocal, which may be due to differences in study populations, the magnitude of change in serum T and FFM, or the performance metrics. This meta-analysis explored effects of TA on serum T, FFM, and performance. Associations between increases in serum T and FFM were assessed, and whether changes in serum T or FFM, study population, or the performance metrics affected performance was determined. A systematic review of double-blind randomized trials comparing TA versus placebo on serum T, FFM, and performance was performed. Data were extracted from 20 manuscripts. Effect sizes (ESs) were assessed using Hedge’s g and a random effects model. Data are presented as ES (95% confidence interval). No significant correlation between changes in serum T and FFM was observed (P = .167). Greater increases in serum T, but not FFM, resulted in larger effects on performance. Larger increases in testosterone (7.26 [0.76-13.75]) and FFM (0.80 [0.20-1.41]) were observed in young males, but performance only improved in diseased (0.16 [0.05-0.28]) and older males (0.19 [0.10-0.29]). TA increased lower body (0.12 [0.07-0.18]), upper body (0.26 [0.11-0.40]), and handgrip (0.13 [0.04-0.22]) strength, lower body muscular endurance (0.38 [0.09-0.68]), and functional performance (0.20 [0.00-0.41]), but not lower body power or aerobic endurance. TA elicits increases in serum T and FFM in younger, older, and diseased males; however, the performance-enhancing effects of TA across studies were small, observed mostly in muscular strength and endurance, and only in older and diseased males.

The Optimal Load for Maximal Power Production During Lower-Body Resistance Exercises: A Meta-Analysis

2015 ◽  
Vol 45 (8) ◽  
pp. 1191-1205 ◽  
Author(s):  
Marco A. Soriano ◽  
Pedro Jiménez-Reyes ◽  
Matthew R. Rhea ◽  
Pedro J. Marín
Keyword(s):  
Meta Analysis ◽  
Power Production ◽  
Lower Body ◽  
Maximal Power ◽  
Optimal Load ◽  
Resistance Exercises ◽  
Body Resistance

The Optimal Load for Maximal Power Production During Upper-Body Resistance Exercises: A Meta-Analysis

2016 ◽  
Vol 47 (4) ◽  
pp. 757-768 ◽  
Author(s):  
Marco Antonio Soriano ◽  
Timothy J. Suchomel ◽  
Pedro J. Marín
Keyword(s):  
Meta Analysis ◽  
Power Production ◽  
Upper Body ◽  
Maximal Power ◽  
Optimal Load ◽  
Resistance Exercises ◽  
Body Resistance

scholarly journals Ergogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-Analysis

2021 ◽  
Vol 18 (11) ◽  
pp. 5773
Author(s):  
Jozo Grgic ◽  
Juan Del Coso
Keyword(s):  
Subgroup Analysis ◽  
Muscular Strength ◽  
Meta Analysis ◽  
Ergogenic Effect ◽  
Upper Body ◽  
Caffeine Intake ◽  
Muscular Endurance ◽  
Lower Body ◽  
Caffeine Ingestion ◽  
Significant Difference

This meta-analysis aimed to explore the effects of caffeine ingestion on muscular endurance and muscular strength in women. Five databases were searched to find relevant studies. A random-effects meta-analysis of standardized mean differences (SMD) was performed for data analysis. Subgroup meta-analyses explored the effects of caffeine on upper-body and lower-body muscular endurance and muscular strength. Eight crossover placebo-controlled studies were included in the review. In the main meta-analysis that considered data from all included studies, there was a significant ergogenic effect of caffeine on muscular endurance (SMD = 0.25; p = 0.027) and muscular strength (SMD = 0.18; p < 0.001). In a subgroup analysis that considered only upper-body exercises, there was a significant ergogenic effect of caffeine on muscular endurance (SMD = 0.20; p = 0.007) and muscular strength (SMD = 0.17; p < 0.001). In a subgroup analysis that considered only lower-body exercises, there was no significant difference between caffeine and placebo for muscular endurance (SMD = 0.43; p = 0.092) or muscular strength (SMD = 0.16; p = 0.109). The main finding of this meta-analysis is that caffeine ingestion has a significant ergogenic effect on muscular endurance and muscular strength in women. The effects reported in this analysis are similar to those previously observed in men and suggest that women may use caffeine supplementation as an ergogenic aid for muscular performance. Future research is needed to explore the effects of caffeine on lower-body muscular endurance and muscular strength in this population.

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