Article 3 - Resistance Training Efficacy

Brief Review on Resistance Training Efficacy

Introduction

A systematic review by Ramos-Campo et al. investigates the efficacy of split versus full-body resistance training on strength and muscle growth. The objective was to compare the effects of these training routines using a meta-analysis of previous studies and following PRISMA guidelines.

Study Overview

  • Authors: Domingo J. Ramos-Campo, Pedro J. Benito-Peinado, Luis Andreu-Caravaca, Miguel A. Rojo-Tirado, Jacobo A. Rubio-Arias

  • Affiliations:

    1. LFE Research Group, Department of Health and Human Performance, Universidad Politécnica de Madrid, Madrid, Spain

    2. Sports Physiology Department, UCAM Universidad Católica San Antonio de Murcia, Murcia, Spain

    3. Health Research Center, University of Almería, Almería, Spain

Background

The need to understand the impact of different resistance training routines is crucial for optimizing hypertrophy and strength effectively. The systematic review included 14 studies with a total of 392 subjects, comparing the two most prevalent methods of resistance training: full-body (FB) routines and split routines (Sp).

Key Findings

Strength Gains and Muscle Growth Comparisons

  • Bench Press Strength:

    • Mean Difference (MD): 1.19

    • Confidence Interval (CI): [−1.28, 3.65]

    • P-value: 0.34

  • Lower Limb Strength:

    • MD: 2.47

    • CI: [−2.11, 7.05]

    • P-value: 0.29

  • Muscle growth comparisons included elbow extensors, elbow flexors, vastus lateralis, and lean body mass, with similar results across both types of routines indicating no significant impact on strength or muscle hypertrophy when volume equated.

Discussion on Resistance Training Frequency

  • Importance of Frequency:

    • Training Frequency Definition: Number of training sessions per week or the frequency of targeting specific muscle groups.

    • Evidence suggests frequency does not significantly affect muscle hypertrophy when training volume is controlled.

Research Findings:

  • Higher frequency resistance training may enhance muscle synthesis but does not provide significant strength gains compared to lower frequencies if volume is equated.

  • Volume has a direct correlation with strength gains, indicating a dose-response relationship between training volume and muscle adaptations.

Common Practices in Resistance Training

  • Bodybuilders typically utilize split routines, training each muscle group once a week, while weightlifters and powerlifters engage in higher frequency training through full-body routines.

  • Split vs. Full-Body Routines:

    • Split routines often involve exercises targeting specific muscle groups leading to increased metabolic stress and possibly greater hypertrophic responses.

    • Full-body routines stimulate major muscle groups in each session, potentially providing different adaptations.

Methodology of Review

Search Strategy

  • Databases: Web of Science (WOS), PubMed-Medline, searches included articles up to June 23, 2023.

  • Keywords: Split training, full-body training, resistance training frequency, and hypertrophy.

Selection Criteria

  • Requirement for studies to compare split and full-body routines for strength or muscle mass, incorporating participants aged 18-40, presented in English.

  • Exclusions included editorials, studies focused solely on acute effects, and those including subjects with specific pathologies or drug interactions.

Data Extraction and Analysis

  • Two researchers independently reviewed studies, focusing on strength performance via one repetition maximum (1RM) for bench press and lower-limb swings, as well as muscle cross-sectional areas.

  • Statistical Analysis: Meta-analysis performed using Review Manager software, calculating MD and 95 % CI as measures of effect size. Heterogeneity was evaluated using I² statistic and Cochrane’s chi-square test.

Outcome Characteristics

Overall Outcomes

  • Strength Performance:

    • Findings show that both training modalities yield similar strength adaptations, confirming that training volume carries a more substantial influence than the choice of routine.

  • Hypertrophy Effects:

    • Both routines elicited comparable muscle size increases, emphasizing that equalizing training volume negates the impact of training distribution on muscle growth.

Risk of Bias Assessment

  • Conducted using the Cochrane’s RoB2 tool revealed the majority of studies had low risk levels, although some concerns were identified.

  • No significant publication bias was detected across analyzed performance metrics.

Practical Implications

  • Individuals can choose between split and full-body routines based on personal preference without concern for significantly differing strength or hypertrophic outcomes as both can be effective.

  • It is recommended that experienced practitioners may benefit from higher training fluctuations to enhance adaptation further.

Conclusion

The systematic review and meta-analysis provide robust evidence that, when volume is equated, the differences between split and full-body resistance training routines in terms of strength and muscle hypertrophy are negligible. This suggests that the choice of training regimen may hinge more on personal preference rather than inherent effectiveness in achieving training goals.