Acute and Chronic Effects of Accentuated Eccentric Loading vs. Constant-Load Resistance Training: A Systematic Review
Xing Zhang1, Jonathon Weakley2,3,4, Hansen Li5
1Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Granada, Spain.
Background:
Accentuated eccentric loading (AEL) is a resistance training (RT) method applying greater eccentric- than concentric-phase load to intensify the training stimulus; however, despite its common use, a comprehensive and quantitative review remains lacking.
Objective:
The aim was to compare acute responses and chronic adaptations between AEL and constant-load RT, and examine whether effects vary by AEL protocol (submaximal, maximal, supramaximal).
Methods:
PubMed, Web of Science, Embase, and EBSCO were searched from inception through July 3, 2024; eligible English-language studies were included. Pooled and subgroup meta-analyses were performed using random-effects models.
Results:
Forty-nine studies involving 773 participants were included. Although considerable variance exists in certain outcomes, our estimated effects suggest that, compared to constant-load RT, AEL results in (1) similar acute responses in loads lifted during the concentric phase (standardized mean difference [SMD] = - 0.16; p = 0.48), mechanical performance at submaximal loads during the concentric phase (SMD = - 0.07; p = 0.37), countermovement jump height both immediately (SMD = - 0.06; p = 0.86) and delayed (SMD = - 0.23; p = 0.44) post-intervention, maximal voluntary isometric force immediately post-intervention (SMD = 0.03; p = 0.89), blood lactate concentration during the intervention (SMD = - 0.06; p = 0.78), testosterone concentration immediately post-intervention (SMD = 0.68; p = 0.15), creatine kinase concentration both immediately (SMD = 0.09; p = 0.72) and delayed (SMD = 0.14; p = 0.48) post-intervention, cortisol concentration immediately post-intervention (SMD = 0.39; p = 0.05), heart rate during the intervention (SMD = 1.18; p = 0.07), acute muscle swelling immediately post-intervention (SMD = 0.26; p = 0.42), muscle electrical activity during the concentric phase (SMD = - 0.01; p = 0.90), and muscle soreness both immediately (SMD = 0.28; p = 0.30) and delayed (SMD = 0.18; p = 0.28) post-intervention; (2) greater acute responses in blood lactate concentration immediately post-intervention (SMD = 0.44; p = 0.03), growth hormone concentration immediately post-intervention (SMD = 0.50; p = 0.01), muscle electrical activity during the eccentric phase (SMD = 0.37; p = 0.01), and rating of perceived exertion immediately post-intervention (SMD = 1.72; p = 0.01); (3) similar chronic adaptations in maximal concentric strength (SMD = 0.12; p = 0.41), maximal eccentric strength (SMD = 0.19; p = 0.58), maximal isometric strength (SMD = 0.03; p = 0.93), countermovement jump height (SMD = 0.04; p = 0.87), muscle fascicle angle (SMD = - 0.10; p = 0.77), muscle fascicle length (SMD = 0.90; p = 0.17), and muscle cross-sectional area (SMD = - 0.06; p = 0.84).
Conclusion:
While AEL augments the eccentric-phase stimulus (higher eccentric load and muscle electrical activity), it also increases metabolic stress and perceived effort, implying a need for longer, more frequent inter-set rests and longer between-session recovery. Given the lack of evidence for superior chronic benefits in strength or muscle architecture over constant-load RT, practitioners should consider these factors carefully.
Protocol Registration:
The original protocol for this review was prospectively registered with the International Prospective Register of Systematic Reviews (PROSPERO) in July 2024 (CRD42024561673).
Related Concept Videos
01:27Exercise and Muscle Performance
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
01:16Eccentric Loading
01:16Eccentric Axial Loading in a Plane of Symmetry
01:21Design of Columns under an Eccentric Load
01:12General Case of Eccentric Axial Loading
Consider a member subjected to equal and opposite forces that are applied along a line that does not coincide with the member's neutral axis. In unsymmetrical...
01:20Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...