Many lifters wonder about the utility of eccentric training. Since the concentric phase is where you should fail the rep, is the eccentric phase really that useful? Isn’t it under-loaded relative to the concentric phase? That logic leads to the concept of accentuated eccentrics, or eccentric overload training. That tidy logic has been floating around the lifting zeitgeist for decades. But tidy logic isn’t data, and when you line up the research, the story is messier than the sales pitch.

A recent study by ​Yue et al​ is the newest addition to this body of research.

Before we dive in, a quick primer on one way to accentuate the eccentric: weight releasers. Weight releasers are detachable hooks that hold extra plates on a barbell for the eccentric, then automatically drop off at the bottom so you lift a lighter concentric rep.

In the present study by Yue and colleagues, participants performed 4 sets of 6 reps on squats. One group of subjects performed traditional squats, one group used weight releasers on 2 reps per set, and one group used weight releasers on all 6 reps. When using the weight releasers, the eccentric was loaded at 120% of 1RM, whereas the concentric was loaded with 75% of 1RM. Essentially, this design allowed the researchers to compare varying degrees of eccentric overload. Oddly enough, the researchers measured rectus femoris cross-sectional area, which likely wasn’t the best choice given the biarticular nature of the muscle. However, in spite of the strange choice of measurement site, eccentric overload training led to greater growth.

Previous research, however, was much less convincing. Two of the strongest studies to date tell a consistent story. In a study by ​Douglas et al​, trained rugby players completed 12 weeks of squats, with one group performing accentuated eccentrics about 20% heavier than the concentric load using a Smith machine. The eccentric group showed early gains in strength and sprint speed, but quadriceps muscle thickness did not increase in either group.

Likewise, other longitudinal research supports the same pattern; similar hypertrophy with traditional versus accentuated eccentric-loading on a set-per-set comparison (​1​, ​2​, ​3​).

Mechanistically, this makes sense once you look beyond the eccentric loading alone. After all, increasing load for the eccentric phase will fatigue you more and reduce how many repetitions you can perform in total across the set. As a very rough heuristic, “total tension” across the set may end up being similar enough that hypertrophic outcomes will be similar.

Even if accentuated eccentrics did yield a small hypertrophy edge, the practicality problem remains. Performing them safely for free-weight movements requires weight releasers – detachable hooks that hold extra plates on the barbell during the eccentric, then drop off at the bottom so you lift a lighter concentric rep – and ideally one or two partners to reattach them between reps. That’s cumbersome enough in a powerlifting gym, let alone a commercial one. Newer devices like the Voltra are starting to make eccentric overload more accessible by dynamically adjusting resistance through motorized control, but they’re still niche, expensive, and far from widespread adoption. Until tools like that become commonplace, accentuated eccentrics will remain difficult to implement for most free-weight exercises.

So, from a hypertrophy perspective, accentuated eccentric loading is a solution in search of a problem. The available research suggests that normal, traditional training already exposes the muscle to sufficient eccentric stimulus.

That said, if you plan on trying accentuated eccentric loading, the most practical options are using devices like the Voltra – which automatically adjusts resistance to overload the eccentric phase – or simply using a bit of “body English” to assist with the concentric portion after a slow, deliberate lowering. Both methods capture the essence of eccentric overload without needing weight releasers or extra spotters, making them far more manageable in regular gym settings. You can also overload the eccentric on many machine exercises by performing eccentrics unilaterally and concentrics with a bit of assistance from your other arm or leg.

If nothing else, this line of research highlights the danger of embracing a compelling theoretical rationale without weighing it against actual evidence. The idea that greater eccentric force must yield greater growth sounds persuasive in isolation, but when tested, it simply doesn’t hold up. A reminder that logic ≠ evidence.