052 - Eccentric Edge: Unlocking Upper Body Gains That Last
This 15-week study tracked how eccentric vs. concentric upper body strength training affects performance, physiology, and retention of strength gains in resistance-trained women.
Participants were split into three groups: eccentric-only training, concentric-only training, and a control group.
Training was performed twice weekly for 9 weeks, followed by 6 weeks of detraining.
What They Found:
Eccentric training led to significantly greater increases in maximal force output than concentric training after 9 weeks.
Muscle cross-sectional area (CSA) increased in both training groups, but eccentric had greater gains in biceps brachii size.
Neuromuscular activation (EMG) improved in both, but more so in the eccentric group.
Hormonal changes (testosterone, cortisol, growth hormone) remained stable—suggesting adaptations were neuromuscular and structural, not endocrine-driven.
After 6 weeks of detraining, eccentric-trained participants retained more strength and size than concentric-only athletes.
What This Means:
In tactical populations where upper body strength, load tolerance, and long-term adaptations matter, eccentric training is a force multiplier. Not only does it build more strength in less time, it also helps retain gains during periods of downtime, injury, or mission-related training gaps.
The fact that eccentric protocols created longer-lasting adaptations without hormonal disruption is especially valuable in female tactical athletes, who often train around hormonal fluctuations and unique stress profiles.
Tactical Implications:
Program Eccentric Emphasis for Upper Body Development: Target eccentric overload in push/pull variations to build maximal strength and improve neuromuscular efficiency.
Use Eccentrics to Build Resilience Against Training Gaps: Operators frequently face interruptions—travel, injury, or duty cycles. Eccentric-trained athletes retain gains longer.
Implement Strategic Detraining Phases: If time off is unavoidable, knowing eccentric work protects progress can reduce performance anxiety and overtraining.
Female Tactical Athletes May Benefit Most: Hormone-stable strength gains with minimal systemic fatigue make this protocol especially useful in female training environments.
Questions To Consider:
Are your upper body programs neglecting eccentric overload in favor of concentric-only movements?
How do you structure training to protect performance during unplanned downtime?
Could your female athletes be under-recovering from concentric overload while missing out on eccentric benefits?
What tools (tempo, eccentrics, isometrics) do you use to make gains stick beyond the training block?
Do your deloads actually preserve adaptations, or are they just a pause button?
Häkkinen K, Newton RU, Walker S, et al. Effects of Upper Body Eccentric versus Concentric Strength Training and Detraining on Maximal Force, Muscle Activation, Hypertrophy and Serum Hormones in Women. J Sports Sci Med. 2022;21(2):200-213. Published 2022 Jun 1. doi:10.52082/jssm.2022.200