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Journal of Strength and Conditioning... Dec 2017Schoenfeld, BJ, Grgic, J, Ogborn, D, and Krieger, JW. Strength and hypertrophy adaptations between low- vs. high-load resistance training: a systematic review and... (Meta-Analysis)
Meta-Analysis Review
Schoenfeld, BJ, Grgic, J, Ogborn, D, and Krieger, JW. Strength and hypertrophy adaptations between low- vs. high-load resistance training: a systematic review and meta-analysis. J Strength Cond Res 31(12): 3508-3523, 2017-The purpose of this article was to conduct a systematic review of the current body of literature and a meta-analysis to compare changes in strength and hypertrophy between low- vs. high-load resistance training protocols. Searches of PubMed/MEDLINE, Cochrane Library, and Scopus were conducted for studies that met the following criteria: (a) an experimental trial involving both low-load training [≤60% 1 repetition maximum (1RM)] and high-load training (>60% 1RM); (b) with all sets in the training protocols being performed to momentary muscular failure; (c) at least one method of estimating changes in muscle mass or dynamic, isometric, or isokinetic strength was used; (d) the training protocol lasted for a minimum of 6 weeks; (e) the study involved participants with no known medical conditions or injuries impairing training capacity. A total of 21 studies were ultimately included for analysis. Gains in 1RM strength were significantly greater in favor of high- vs. low-load training, whereas no significant differences were found for isometric strength between conditions. Changes in measures of muscle hypertrophy were similar between conditions. The findings indicate that maximal strength benefits are obtained from the use of heavy loads while muscle hypertrophy can be equally achieved across a spectrum of loading ranges.
Topics: Adaptation, Physiological; Humans; Hypertrophy; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 28834797
DOI: 10.1519/JSC.0000000000002200 -
Applied Physiology, Nutrition, and... Apr 2022The purpose of this paper was to conduct a systematic review and meta-analysis of studies that compared muscle hypertrophy and strength gains between resistance training... (Meta-Analysis)
Meta-Analysis Review
The purpose of this paper was to conduct a systematic review and meta-analysis of studies that compared muscle hypertrophy and strength gains between resistance training protocols employing very low (VLL < 30% of 1-repetition maximum (RM) or >35RM), low (LL30%-59% of 1RM, or 16-35RM), moderate (ML60%-79% of 1RM, or 8-15RM), and high (HL ≥ 80% of 1RM, or ≤7RM) loads with matched volume loads (sets × repetitions × weight). A pooled analysis of the standardized mean difference for 1RM strength outcomes across the studies showed a benefit favoring HL vs. LL and vs. ML and favoring ML vs. LL. The LL and VLL results showed little difference. A pooled analysis of the standardized mean difference for hypertrophy outcomes across all studies showed no differences between training loads. Our findings indicate that when the volume load is equal between conditions, the highest loads induce superior dynamic strength gains. Alternatively, hypertrophic adaptations were similar irrespective of the load magnitude. Training with higher loads elicits greater gains in 1RM muscle strength when compared to lower loads, even when the volume load is equal between conditions. Muscle hypertrophy is similar irrespective of the magnitude of the load, even when the volume load is equal between conditions.
Topics: Adaptation, Physiological; Humans; Hypertrophy; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 35015560
DOI: 10.1139/apnm-2021-0515 -
Sports Medicine (Auckland, N.Z.) Nov 2016A number of resistance training (RT) program variables can be manipulated to maximize muscular hypertrophy. One variable of primary interest in this regard is RT... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
A number of resistance training (RT) program variables can be manipulated to maximize muscular hypertrophy. One variable of primary interest in this regard is RT frequency. Frequency can refer to the number of resistance training sessions performed in a given period of time, as well as to the number of times a specific muscle group is trained over a given period of time.
OBJECTIVE
We conducted a systematic review and meta-analysis to determine the effects of resistance training frequency on hypertrophic outcomes.
METHODS
Studies were deemed eligible for inclusion if they met the following criteria: (1) were an experimental trial published in an English-language refereed journal; (2) directly compared different weekly resistance training frequencies in traditional dynamic exercise using coupled concentric and eccentric actions; (3) measured morphologic changes via biopsy, imaging, circumference, and/or densitometry; (4) had a minimum duration of 4 weeks; and (5) used human participants without chronic disease or injury. A total of ten studies were identified that investigated RT frequency in accordance with the criteria outlined.
RESULTS
Analysis using binary frequency as a predictor variable revealed a significant impact of training frequency on hypertrophy effect size (P = 0.002), with higher frequency being associated with a greater effect size than lower frequency (0.49 ± 0.08 vs. 0.30 ± 0.07, respectively). Statistical analyses of studies investigating training session frequency when groups are matched for frequency of training per muscle group could not be carried out and reliable estimates could not be generated due to inadequate sample size.
CONCLUSIONS
When comparing studies that investigated training muscle groups between 1 to 3 days per week on a volume-equated basis, the current body of evidence indicates that frequencies of training twice a week promote superior hypertrophic outcomes to once a week. It can therefore be inferred that the major muscle groups should be trained at least twice a week to maximize muscle growth; whether training a muscle group three times per week is superior to a twice-per-week protocol remains to be determined.
Topics: Exercise; Humans; Hypertrophy; Muscle Fatigue; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 27102172
DOI: 10.1007/s40279-016-0543-8 -
Nutrients Feb 2022High carbohydrate intakes are commonly recommended for athletes of various sports, including strength trainees, to optimize performance. However, the effect of... (Review)
Review
High carbohydrate intakes are commonly recommended for athletes of various sports, including strength trainees, to optimize performance. However, the effect of carbohydrate intake on strength training performance has not been systematically analyzed. A systematic literature search was conducted for trials that manipulated carbohydrate intake, including supplements, and measured strength, resistance training or power either acutely or after a diet and strength training program. Studies were categorized as either (1) acute supplementation, (2) exercise-induced glycogen depletion with subsequent carbohydrate manipulation, (3) short-term (2-7 days) carbohydrate manipulation or (4) changes in performance after longer-term diet manipulation and strength training. Forty-nine studies were included: 19 acute, six glycogen depletion, seven short-term and 17 long-term studies. Participants were strength trainees or athletes (39 studies), recreationally active (six studies) or untrained (four studies). Acutely, higher carbohydrate intake did not improve performance in 13 studies and enhanced performance in six studies, primarily in those with fasted control groups and workouts with over 10 sets per muscle group. One study found that a carbohydrate meal improved performance compared to water but not in comparison to a sensory-matched placebo breakfast. There was no evidence of a dose-response effect. After glycogen depletion, carbohydrate supplementation improved performance in three studies compared to placebo, in particular during bi-daily workouts, but not in research with isocaloric controls. None of the seven short-term studies found beneficial effects of carbohydrate manipulation. Longer-term changes in performance were not influenced by carbohydrate intake in 15 studies; one study favored the higher- and one the lower-carbohydrate condition. Carbohydrate intake per se is unlikely to strength training performance in a fed state in workouts consisting of up to 10 sets per muscle group. Performance during higher volumes may benefit from carbohydrates, but more studies with isocaloric control groups, sensory-matched placebos and locally measured glycogen depletion are needed.
Topics: Athletes; Dietary Carbohydrates; Dietary Supplements; Humans; Muscle, Skeletal; Physical Endurance; Resistance Training
PubMed: 35215506
DOI: 10.3390/nu14040856 -
International Journal of Environmental... Dec 2019Effective hypertrophy-oriented resistance training (RT) should comprise a combination of mechanical tension and metabolic stress. Regarding training variables, the most...
BACKGROUND
Effective hypertrophy-oriented resistance training (RT) should comprise a combination of mechanical tension and metabolic stress. Regarding training variables, the most effective values are widely described in the literature. However, there is still a lack of consensus regarding the efficiency of advanced RT techniques and methods in comparison to traditional approaches.
METHODS
MEDLINE and SPORTDiscus databases were searched from 1996 to September 2019 for all studies investigating the effects of advanced RT techniques and methods on muscle hypertrophy and training variables. Thirty articles met the inclusion criteria and were consequently included for the quality assessment and data extraction.
RESULTS
Concerning the time-efficiency of training, the use of agonist-antagonist, upper-lower body supersets, drop and cluster sets, sarcoplasma stimulating training, employment of fast, but controlled duration of eccentric contractions (~2s), and high-load RT supplemented with low-load RT under blood flow restriction may provide an additional stimulus and an advantage to traditional training protocols. With regard to the higher degree of mechanical tension, the use of accentuated eccentric loading in RT should be considered. Implementation of drop sets, sarcoplasma stimulating training, low-load RT in conjunction with low-load RT under blood flow restriction could provide time-efficient solutions to increased metabolic stress.
CONCLUSIONS
Due to insufficient evidence, it is difficult to provide specific guidelines for volume, intensity of effort, and frequency of previously mentioned RT techniques and methods. However, well-trained athletes may integrate advanced RT techniques and methods into their routines as an additional stimulus to break through plateaus and to prevent training monotony.
Topics: Humans; Hypertrophy; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 31817252
DOI: 10.3390/ijerph16244897 -
Medicine and Science in Sports and... Jun 2021This study aimed to analyze the effect of resistance training (RT) performed until volitional failure with low, moderate, and high loads on muscle hypertrophy and muscle... (Meta-Analysis)
Meta-Analysis
PURPOSE
This study aimed to analyze the effect of resistance training (RT) performed until volitional failure with low, moderate, and high loads on muscle hypertrophy and muscle strength in healthy adults and to assess the possible participant-, design-, and training-related covariates that may affect the adaptations.
METHODS
Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, MEDLINE, CINAHL, EMBASE, SPORTDiscus, and Web of Science databases were searched. Including only studies that performed sets to volitional failure, the effects of low- (>15 repetitions maximum (RM)), moderate- (9-15 RM), and high-load (≤8 RM) RTs were examined in healthy adults. Network meta-analysis was undertaken to calculate the standardized mean difference (SMD) between RT loads in overall and subgroup analyses involving studies deemed of high quality. Associations between participant-, design-, and training-related covariates with SMD were assessed by univariate and multivariate network meta-regression analyses.
RESULTS
Twenty-eight studies involving 747 healthy adults were included. Although no differences in muscle hypertrophy between RT loads were found in overall (P = 0.113-0.469) or subgroup analysis (P = 0.871-0.995), greater effects were observed in untrained participants (P = 0.033) and participants with some training background who undertook more RT sessions (P = 0.031-0.045). Muscle strength improvement was superior for both high-load and moderate-load compared with low-load RT in overall and subgroup analysis (SMD, 0.60-0.63 and 0.34-0.35, respectively; P < 0.001-0.003), with a nonsignificant but superior effect for high compared with moderate load (SMD, 0.26-0.28, P = 0.068).
CONCLUSIONS
Although muscle hypertrophy improvements seem to be load independent, increases in muscle strength are superior in high-load RT programs. Untrained participants exhibit greater muscle hypertrophy, whereas undertaking more RT sessions provides superior gains in those with previous training experience.
Topics: Adult; Female; Humans; Male; Muscle Strength; Network Meta-Analysis; Resistance Training; Skeletal Muscle Enlargement
PubMed: 33433148
DOI: 10.1249/MSS.0000000000002585 -
American Journal of Preventive Medicine Aug 2022This study aimed to systematically review and meta-analyze the relationship between resistance training and all-cause, cardiovascular disease, and cancer mortality. (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
This study aimed to systematically review and meta-analyze the relationship between resistance training and all-cause, cardiovascular disease, and cancer mortality.
METHODS
Systematic review and meta-analysis following PRISMA guidelines (International Prospective Register of Systematic Reviews Registration Number CRD42019136654) was conducted. MEDLINE (OVID), Embase, Emcare, SPORTDiscus, The Cochrane Library, and SCOPUS were searched from inception to June 6, 2021. Included studies reported resistance training as the exposure and all-cause mortality, cardiovascular disease‒specific mortality, and/or cancer-specific mortality as outcome/s. Only studies conducted among nonclinical adult populations (aged ≥18 years) and written in English were included.
RESULTS
A total of 10 studies were included in the meta-analyses. Compared with undertaking no resistance training, undertaking any amount of resistance training reduced the risk of all-cause mortality by 15% (RR of 6 studies=0.85; 95% CI=0.77, 0.93), cardiovascular disease mortality by 19% (RR of 4 studies=0.81; 95% CI=0.66, 1.00), and cancer mortality by 14% (RR of 5 studies=0.86; 95% CI=0.78, 0.95). A dose-response meta-analysis of 4 studies suggested a nonlinear relationship between resistance training and the risk of all-cause mortality. A maximum risk reduction of 27% was observed at around 60 minutes per week of resistance training (RR=0.74; 95% CI=0.64, 0.86). Mortality risk reductions diminished at higher volumes.
DISCUSSION
This systematic review and meta-analysis provides the strongest evidence to date that resistance training is associated with reduced risk of all-cause, cardiovascular disease, and cancer-specific mortality. More research is needed to determine whether any potential mortality benefits gained from resistance training diminish at higher volumes.
Topics: Adolescent; Adult; Cardiovascular Diseases; Humans; Neoplasms; Resistance Training
PubMed: 35599175
DOI: 10.1016/j.amepre.2022.03.020 -
Asian Journal of Surgery Oct 2021Progressive resistance training (PRT) is one of the most commonly used exercise methods after joint replacement, while its effectiveness and safety are still... (Meta-Analysis)
Meta-Analysis Review
Progressive resistance training (PRT) is one of the most commonly used exercise methods after joint replacement, while its effectiveness and safety are still controversial. Therefore, it's vital to investigate the effect of PRT on muscle strength and functional capacity early postoperative total hip arthroplasty (THA) or total knee arthroplasty (TKA). Relevant studies were identified via a search of Medline, Web of science and Cochrane Library from 2002 to 12 May 2020. Fifteen of 704 studies which comprised 6 THAs and 8 TKAs, involving 1021 adult patients were eligible for inclusion in the meta-analysis. There were no significant differences between the two groups after TKA in the 6-min walk test (6-WMT) within 1 month (95% CI = -0.41, 1.53), within 3 months (95% CI = -0.27, 0.76), within 12 months (95% CI = -0.29, 0.66); climb performance in seconds (s) (SCP), leg extension power, timed up and go test in seconds (s) (TUG) within 1 month (95% CI = -1.75, 0.77), within 3 months (95% CI = -0.48, 0.33), within 12 months (95% CI = -0.44, 0.35), sit to stand, number of repetitions in 30s (ST). There was no difference in the incidence of adverse events (95% CI = -0.01, 0.10). Similarly, two groups were also no obvious distinction after THA in the 6-WMT, SCP, Leg extension power, ST. PRT early after THA or TKA did not differ significantly from SR in terms of functional capacity, muscle strength recovery and incidence of adverse events. PRT is one of the options for rapid rehabilitation after joint replacement.
Topics: Adult; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Humans; Postural Balance; Resistance Training; Time and Motion Studies
PubMed: 33715964
DOI: 10.1016/j.asjsur.2021.02.007 -
Sports Medicine (Auckland, N.Z.) Jul 2022In resistance training, periodization is often used in an attempt to promote development of strength and muscle hypertrophy. However, it remains unclear how resistance... (Meta-Analysis)
Meta-Analysis
BACKGROUND
In resistance training, periodization is often used in an attempt to promote development of strength and muscle hypertrophy. However, it remains unclear how resistance training variables are most effectively periodized to maximize gains in strength and muscle hypertrophy.
OBJECTIVE
The aims of this study were to examine the current body of literature to determine whether there is an effect of periodization of training volume and intensity on maximal strength and muscle hypertrophy, and, if so, to determine how these variables are more effectively periodized to promote increases in strength and muscle hypertrophy, when volume is equated between conditions from pre to post intervention.
METHODS
Systematic searches were conducted in PubMed, Scopus and SPORTDiscus databases. Data from the individual studies were extracted and coded. Meta-analyses using the inverse-variance random effects model were performed to compare 1-repetition maximum (1RM) and muscle hypertrophy outcomes in (a) non-periodized (NP) versus periodized training and (b) in linear periodization (LP) versus undulating periodization (UP). Subgroup analyses examining whether results were affected by training status were performed. Meta-analyses of other periodization model comparisons were not performed, due to a low number of studies.
RESULTS
Thirty-five studies met the inclusion criteria. Results of the meta-analyses comparing NP and periodized training demonstrated an overall effect on 1RM strength favoring periodized training (ES 0.31, 95% confidence interval (CI) [0.04, 0.57]; Z = 2.28, P = 0.02). In contrast, muscle hypertrophy did not differ between NP and periodized training (ES 0.13, 95% CI [-0.10, 0.36]; Z = 1.10, P = 0.27). Results of the meta-analyses comparing LP and UP indicated an overall effect on 1RM favoring UP (ES 0.31, 95% CI [0.02, 0.61]; Z = 2.06, P = 0.04). Subgroup analyses indicated an effect on 1RM favoring UP in trained participants (ES 0.61, 95% CI [0.00, 1.22]; Z = 1.97 (P = 0.05)), whereas changes in 1RM did not differ between LP and UP in untrained participants (ES 0.06, 95% CI [-0.20, 0.31]; Z = 0.43 (P = 0.67)). The meta-analyses showed that muscle hypertrophy did not differ between LP and UP (ES 0.05, 95% CI [-0.20, 0.29]; Z = 0.36 (P = 0.72)).
CONCLUSION
The results suggest that when volume is equated between conditions, periodized resistance training has a greater effect on 1RM strength compared to NP resistance training. Also, UP resulted in greater increases in 1RM compared to LP. However, subgroup analyses revealed that this was only the case for trained and not previously untrained individuals, indicating that trained individuals benefit from daily or weekly undulations in volume and intensity, when the aim is maximal strength. Periodization of volume and intensity does not seem to affect muscle hypertrophy in volume-equated pre-post designs. Based on this, we propose that the effects of periodization on maximal strength may instead be related to the neurophysiological adaptations accompanying resistance training.
Topics: Adaptation, Physiological; Humans; Hypertrophy; Muscle Strength; Muscle, Skeletal; Resistance Training
PubMed: 35044672
DOI: 10.1007/s40279-021-01636-1 -
Heart Failure Reviews Sep 2022Aerobic training (AT) has been the primary mode of exercise training in cardiac rehabilitation. Historically, the reason for the prescription of AT was that it was... (Meta-Analysis)
Meta-Analysis Review
Aerobic training (AT) has been the primary mode of exercise training in cardiac rehabilitation. Historically, the reason for the prescription of AT was that it was speculated that although RT may be beneficial for some clinical outcomes, it may have an adverse effect on ventricular structure and function. However, RT has now made its way into current cardiac rehabilitation guidelines, including those directed towards patients with HF, albeit differences exist across institutions and guidelines. A systematic search of PubMed, EMBASE and Cochrane Trials Register on April 30, 2021, was conducted for exercise-based rehabilitation trials in HF. Randomised and controlled trials that reported on resistance training versus usual care or trials that directly compared RT to an AT intervention were included. Resistance training versus controls improves parameters of lower (SMD 0.76 (95%CI 0.26, 1.25, p = 0.003] and upper extremity muscle strength (SMD 0.85 (95%CI 0.35, 1.35), p = 0.0009], both key parameters of physical function throughout the lifespan. Importantly, RT in isolation, versus control, improves VO2peak [MD: 2.64 ml/kg/min (95%CI 1.67, 3.60), p < 0.00001] and 6MWD [MD: 49.94 m (95%CI 34.59, 65.29), p < 0.00001], without any detrimental effect on left ventricular parameters. Resistance training in HF patients is safe and improves parameters of physical function and quality of life. Where people with HF are unable to, or are not inclined to, partake in aerobic activity, RT alone is appropriate to elicit meaningful benefit.
Topics: Exercise Therapy; Exercise Tolerance; Heart Failure; Humans; Quality of Life; Resistance Training
PubMed: 34542742
DOI: 10.1007/s10741-021-10169-8