Eccentric vs. Concentric Training: A Systematic Review and Meta-Analysis of Randomized Controlled Trials on Performance and Health Benefits Across Diverse Populations

Eccentric (ECC) and concentric (CON) muscle training produce distinct physiological responses, with potential implications for musculoskeletal, metabolic, and cardiovascular health. Therefore, our objective is to synthesize evidence from randomized controlled trials comparing the effects of ECC and CON training on strength, hypertrophy, metabolic function, and cardiovascular health across diverse adult populations. A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines and registered in PROSPERO (ID: CRD42024627600). The review included eight randomized controlled trials, pooling data from a total of 441 participants. For strength-related outcomes, six studies (n = 322) were included; for hypertrophy, four studies (n = 210); and for cardiovascular measures, three studies (n = 154). Studies were assessed using the TESTEX scale. Standardized mean differences and random-effects models were applied (p ≤ 0.05). Results indicated that ECC training consistently produced moderate to large improvements in muscle strength (pooled ES = 0.95; I2 = 78.6%) and hypertrophy (pooled ES = 0.60; I2 = 62.3%), particularly in populations with chronic obstructive pulmonary disease (COPD) and older adults. The rate of force development (RFD) showed large effect sizes for ECC (RFD50: ES = 0.97; RFD100: ES = 0.95) but minimal change for CON (RFD50: ES = 0.04; RFD100: ES = 0.10). Both ECC and CON showed minimal effects on cardiovascular outcomes (heart rate and blood pressure: pooled ES range = −0.16 to 0.00; I2 = 41.8%) and limited tendon remodeling (ES = −0.18). In conclusion, ECC exercise demonstrates superior benefits for improving muscular strength, hypertrophy, and power across varied populations, particularly those with clinical conditions such as COPD. Its impact on cardiovascular health and tendon properties, however, appears limited. These findings support the integration of ECC modalities into targeted rehabilitation and performance programs.