Effect of free-weight vs. machine-based strength training on maximal strength, hypertrophy and jump performance - a systematic review and meta-analysis

Markus E Haugen; Fredrik T Vårvik; Stian Larsen; Arvid S Haugen; Roland van den Tillaar; Thomas Bjørnsen

doi:10.1186/s13102-023-00713-4

Effect of free-weight vs. machine-based strength training on maximal strength, hypertrophy and jump performance - a systematic review and meta-analysis

BMC Sports Sci Med Rehabil. 2023 Aug 15;15(1):103. doi: 10.1186/s13102-023-00713-4.

Authors

Markus E Haugen¹, Fredrik T Vårvik^{2

3

4}, Stian Larsen⁵, Arvid S Haugen^{6

7}, Roland van den Tillaar⁵, Thomas Bjørnsen^{2

3

4}

Affiliations

¹ Department of Sport Sciences and Physical Education, Nord University, Levanger, Norway. haugen@helseogprestasjon.no.
² Department of Sport Science and Physical Education, Faculty of Health and Sport Sciences, University of Agder, Kristiansand, Norway.
³ Strength and Power consultant at the Norwegian Olympic and Paralympic Committee and Confederation of Sports, Oslo, Norway.
⁴ Norwegian Olympic and Paralympic Committee and Confederation of Sports, Oslo, Norway.
⁵ Department of Sport Sciences and Physical Education, Nord University, Levanger, Norway.
⁶ Department of Anaesthesia and Intensive Care, Haukeland University Hospital, Bergen, Norway.
⁷ Department of Nursing and Health Promotion Acute and Critical Illness, Faculty of Health Sciences, OsloMet - Oslo Metropolitan University, Oslo, Norway.

Abstract

Background: The effectiveness of strength training with free-weight vs. machine equipment is heavily debated. Thus, the purpose of this meta-analysis was to summarize the data on the effect of free-weight versus machine-based strength training on maximal strength, jump height and hypertrophy.

Methods: The review was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, and the systematic search of literature was conducted up to January 1^st, 2023. Studies that directly compared free-weight vs. machine-based strength training for a minimum of 6 weeks in adults (18-60 yrs.) were included.

Results: Thirteen studies (outcomes: maximal strength [n = 12], jump performance [n = 5], muscle hypertrophy [n = 5]) with a total sample of 1016 participants (789 men, 219 women) were included. Strength in free-weight tests increased significantly more with free-weight training than with machines (SMD: -0.210, CI: -0.391, -0.029, p = 0.023), while strength in machine-based tests tended to increase more with machine training than with free-weights (SMD: 0.291, CI: -0.017, 0.600, p = 0.064). However, no differences were found between modalities in direct comparison (free-weight strength vs. machine strength) for dynamic strength (SMD: 0.084, CI: -0.106, 0.273, p = 0.387), isometric strength (SMD: -0.079, CI: -0.432, 0.273, p = 0.660), countermovement jump (SMD: -0.209, CI: -0.597, 0.179, p = 0.290) and hypertrophy (SMD: -0.055, CI: -0.397, 0.287, p = 0.751).

Conclusion: No differences were detected in the direct comparison of strength, jump performance and muscle hypertrophy. Current body of evidence indicates that strength changes are specific to the training modality, and the choice between free-weights and machines are down to individual preferences and goals.

Keywords: Equipment; Exercise; Force production; Modalities; Muscle size; Resistance training; Stability.