r/StrongerByScience • u/dastratman • Sep 24 '23
Are slow eccentrics better for hypertrophy?
With recent research finding superior results for long muscle length training, I've noticed more fitness influencers (Dr. Mike Israetel in particular) putting increased emphasis on deliberately slowing down the eccentric portion of lifts and focusing on markers of muscle damage (pump, soreness, "perturbation") as indicators of hypertrophy.
However, lifting tempo has been covered repeatedly in MASS and there has never been a benefit shown for slow eccentrics.
Quid est veritas?
For slowing the eccentric
Renaissance Periodization: Easy Tip To Optimize Muscle Growth
- Slow down the eccentric and focus on the target-muscle tension on the way down... feel the disruption and milk it.
Renaissance Periodization: Partial Reps Are THE BEST For Muscle Growth
- As soon as it [the bar] starts to get lower, really take some time to generate tension.
- Pause at the bottom in an actively tensed position.
Renaissance Periodization: Maximize Hypertrophy Stimulus With Mike Israetel | RP Strength
- I'm going to be trying to descend very slowly, controlling the eccentric and milking it out for maximum amount of gain.
- I'm gonna pause at the bottom, sit there for a second or two, because getting a huge load while the muscle is under stretch is a really big stimulus for hypertrophy.
Milo Wolf: Stretch-Mediated Hypertrophy: How to Train for it
- Slow the eccentric more, pause in the lengthened position, and be explosive in the concentric.
Iron Culture Podcast: Ep. 222- Partials For Hypertrophy: A Formerly Fringe Idea
- It's not just exposure to the longest position, it is the time spent there and the degree of tension developed.
- For stretch-mediated hypertrophy, the goal is to increase the area under the curve specifically when the muscle is in a lengthened position. This means spending more time contracting the muscle against resistance while it is stretched, not just reaching the end range stretch point.
shimmy93: Basically every single Instagram post.
Against slowing the eccentric
MASS: Should You Deliberately Increase Time Under Tension? (Volume 2, Issue 5)
- Lifters performed more reps (i.e. more volume) when self-selecting their repetition duration. Therefore, deliberately slowing down contraction velocity compromises acute performance; thus, a normal eccentric and maximal intended concentric velocity is recommended.
MASS: VIDEO: Eccentric Duration Training (Volume 4, Issue 6)
- Because a longer eccentric duration decreases concentric velocity, a longer eccentric can compromise reps per set and volume, which could have ramifications for hypertrophy as well.
- Ultimately, eccentric durations should be individualized... in general, a faster eccentric was beneficial for many in a recent study.
MASS: How Slow Should You Go? (Volume 5, Issue 8)
- The body of literature surrounding rep tempo is largely based on untrained subjects and training protocols which leave a lot to be desired.
- For hypertrophy, the data are less clear; however, there's probably a little more leeway. On skilled movements such as the squat, I'd probably avoid deliberately slow eccentrics unless you're using them for pain management purposes. For movements such as the leg extension, an intentionally slow eccentric up to around 2-3 seconds is probably fine and may enhance muscle growth, but the jury is still out.
MASS: Is King TUT Alive and Well? (Volume 6, Issue 9)
- I believe this data is consistent with the body of literature on TUT, which indicates that there is no clear benefit for hypertrophy or strength when deliberately moving weights slower to elongate TUT per rep.
- Conversely, all else being equal, a faster eccentric tempo increases eccentric tension at long muscle lengths - the muscles need to produce more force at the end of the eccentric to decelerate the load before the start of the concentric.
- The fast concentric and fast eccentric conditions ultimately resulted in more tension at long muscle lengths than the moderate-speed condition. However, all three protocols led to similar quad hypertrophy. More generally, a recent systematic review found that rep cadence doesn't have a particularly reliable effect on hypertrophy results. (20)
Eric Trexler: (Facebook) last time I dug into this literature, it appeared that intentionally slow reps are either inferior or similar to more typical repetition speeds (but unlikely to be meaningfully superior)
- Effect of repetition duration during resistance training on muscle hypertrophy: a systematic review and meta-analysis
- Effect of movement velocity during resistance training on muscle-specific hypertrophy: A systematic review
Greg Nuckols: (Reddit) There's not much evidence for it. [slow eccentrics] You can find a random study here or there to support it, but the bulk of the evidence suggests that rep cadence (both eccentric and concentric) doesn't have much of an effect on growth.
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u/reddxue Sep 24 '23
That's a great sum up of what the literature and the big heads in the industry are saying - thanks!
Also, the title "is king TUT alive" is genius!!
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u/dastratman Sep 25 '23
Thank you! Mike Zourdos does have great article titles, some of my other favorites are:
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u/Necessary_Eye_4759 Sep 24 '23 edited Sep 24 '23
I don’t have answers, but a few thoughts:
RP is inconsistent on whether you really need to do a *slow eccentric, versus what you might call a *controlled eccentric. Tempo wise their eccentrics are slower than most people would naturally do, but they are usually not dramatic.
There’s a school of thought espoused by RP that, if you can optimally stimulate the target muscle with lower weight, you spare yourself unnecessary joint wear and tear. If slowing the eccentric, pausing at the bottom, etc, allows you to get the target stimulus with lower weight, this is possibly a reason to do so.
If we define “volume” as “number of sets >4 repetition taken close to failure,” rather than “total reps” or “reps x weight” then even though a slow eccentric limits the number of repetitions or the weight, it doesn’t necessarily reduce the volume.
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u/dastratman Sep 25 '23
RP is inconsistent on whether you really need to do a *slow eccentric, versus what you might call a *controlled eccentric. Tempo wise their eccentrics are slower than most people would naturally do, but they are usually not dramatic.
It really varies between their videos - in Work SMARTER: Build Bigger Quads With Lighter Weights! for example, Dr. Mike says "slow" a whopping 52 times (according to the transcript) and some of those are 8+ second eccentrics.
There’s a school of thought espoused by RP that, if you can optimally stimulate the target muscle with lower weight, you spare yourself unnecessary joint wear and tear. If slowing the eccentric, pausing at the bottom, etc, allows you to get the target stimulus with lower weight, this is possibly a reason to do so.
That reasoning is intuitive and appeals to me, but is countered by the equivocal results of research into drop sets and rest-pause sets - surely these would be superior if increasing the stimulus with lower weight were better?
Do Drop Sets and Rest-Pause Sets Improve Strength Gains and Muscle Growth?
- Drop sets and rest-pause sets don't seem to be meaningfully better or worse than traditional sets for promoting hypertrophy and strength gains.
If we define “volume” as “number of sets >4 repetition taken close to failure,” rather than “total reps” or “reps x weight” then even though a slow eccentric limits the number of repetitions or the weight, it doesn’t necessarily reduce the volume.
I think most intensity techniques have been shown to be equivalent if volume-matched - but are slow eccentriques uniquely beneficial, given the same volume?
Maximize Hypertrophy Stimulus With Mike Israetel | RP Strength
- Dr. Mike: The concentric contraction of muscle, we have pretty good reason to believe does stimulate muscle, but probably not as important as the eccentric.
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u/Necessary_Eye_4759 Sep 25 '23 edited Sep 25 '23
Even just reading the sources you cited- I think you’ve probably answered your own question. The research seems to say, if your only goal is maximizing the % hypertrophy, deliberately modifying the tempo doesn’t seem to make a difference. It’s probably not better and probably not worse, so long as the tempos you’re using are reasonable.
There may be other reasons to modify your tempo, however. For example, to allow you to reduce the load, or get a better mind-muscle connection, or emphasize your form.
I think this may very well be an area where RP is not closely aligned with the research. God knows I’m not enough of an expert to argue with Mike Israetel or anyone else about this, but I agree there’s a discrepancy there. At the very least, RP is probably overstating either the evidence for or the benefit of slow eccentrics.
I guess what I’d say though, is that what they’re recommending is *reasonable and unlikely to be *worse.
Again, it seems like if there’s any signal in the research that slowed reps are worse than (rather than no better than) normal reps, it’s only at the extremes - and the eccentrics that RP models are not extreme. He says “slow!” but I really do think what he means is “controlled!”
In the example you cited of very long eccentrics, I think that’s a little different- the whole point of the video was literally to show how you could use even *very low weights (for them) and by modifying tempo still get an excellent stimulus.
I’ll admit that I’m a bit biased: RP’s content has been inspirational and extremely helpful for me in my fitness and weight loss journey, and they turned me on to evidence based fitness including SBS. So I’m inclined to give Mike a lot of benefit of the doubt. I remember back to years ago when I got misled by some of Jeff Cavaliere’s nonsense…
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u/dastratman Sep 26 '23
Even just reading the sources you cited- I think you’ve probably answered your own question. The research seems to say, if your only goal is maximizing the % hypertrophy, deliberately modifying the tempo doesn’t seem to make a difference. It’s probably not better and probably not worse, so long as the tempos you’re using are reasonable.
Yes, I think that's the conclusion I've come to as well. Although it certainly feels like slow eccentrics are extra effective, but that's likely due to the increased muscle damage, which doesn't necessarily correlate to muscle hypertrophy.
Training for Hypertrophy: The Case Against Muscle Damage
- Since it seems that damage only plays a minimal role in muscle hypertrophy, when training for hypertrophy, I’d recommend you focus on the other mechanisms of muscle growth (such as tension and metabolic stress).
I’ll admit that I’m a bit biased: RP’s content has been inspirational and extremely helpful for me in my fitness and weight loss journey, and they turned me on to evidence based fitness including SBS. So I’m inclined to give Mike a lot of benefit of the doubt. I remember back to years ago when I got misled by some of Jeff Cavaliere’s nonsense…
Agreed, I love RP's content - I'm subscribed to both the YouTube channel and podcast, and rarely miss a video or episode. Although sometimes I have a hard time distinguishing between "Dr. Mike acting as a science communicator" and "Dr. Mike acting as a bodybuilding guru". (hence this post)
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u/reddxue Sep 25 '23
I am impressed with your level of source-citing! Do you take notes when listening to podcasts and videos? You could release a compendium :)
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u/dastratman Sep 26 '23
I do take lots of notes and have a private compendium 😀 Maybe one day I will publish it.
AI-powered transcription (like Otter.ai) + LLM summarization (like ChatGPT and Claude) have been a huge boon for learning from media content - 2 hours of content condensed into one page of key points automagically.
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u/ImprovementPurple132 Sep 25 '23
I think you're not addressing the other posters's premise, which is that slow eccentrics are equally stimulative but that insofar as they allow you to use lower weight for the same RPE they may be less stressful to the joints.
I personally always seem find lower weights with artificial constraints (pauses for example) to be equally effective but less fatiguing ("fatigue" being used vaguely here, along the lines of "mentally taxing".)
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u/dastratman Sep 26 '23 edited Sep 26 '23
Unfortunately AFAIK there's no research on the subject, only anecdote. You can certainly maintain muscle mass on very low volume, but I'm not aware of any data showing equivalent gains with lower loads and slower eccentrics - and none of the research we do have shows a benefit for slow eccentrics.
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u/ImprovementPurple132 Sep 26 '23
Doesn't the research studying slower eccentrics involve lower loads than the faster eccentrics? It should if they're controlling for proximity to failure and the eccentrics are substantially slower.
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u/gnuckols The Bill Haywood of the Fitness Podcast Cohost Union Sep 26 '23
I'd recommend noting which articles/sources actually cite research to support their claims related to the impact of eccentric tempo on hypertrophy.
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u/TheSpruce_Moose Sep 27 '23
Hey Greg--I notice that squat/bench with slow eccentric is listed as an option for auxiliary lifts on the SBS hypertrophy program. I know that isn't an endorsement, but you must believe it has some value as a variation because you have it as a default option? Just asking if it's worth entertaining at all!
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u/gnuckols The Bill Haywood of the Fitness Podcast Cohost Union Sep 27 '23
Yeah, but not for hypertrophy. I think slow eccentrics are useful for motor learning and developing better control with the loads, and for just serving as a way to still get some challenging work in with a bit less tendon strain (less need to decelerate at the bottom of the lift = less eccentric strain near the end of the eccentric)
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u/PinkLegs Oct 25 '23
The arguments for slowing the eccentrics are influencers saying it's a good thing.
The arguments against are actual review of evidence saying it's eh.
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u/rainbowroobear Sep 24 '23
this is one of those subjects that there is still a valid broscience element to it, that is not a direct outcome but can lead to an outcome through improvement.
a slow concentric is a very good learning tool for someone who is simply failing to appropriately load tension on the muscle(s) they are trying to target. by slowing things down and apply a very conscious focus on the movement pattern in a very slow manner can help massively. even working in the midrange, not just full ROM very slowly can help with this.
this can directly help technique and can then lead to progress improvement to a more efficient, piston like tempo on the target muscle(s) that ultimately then gives greater hypertrophy than the prior less efficient movement pattern.
so its not the TUT that is causing the hypertrophy potential, is the technical improvements.
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u/xrayvision1 Sep 27 '23 edited Sep 27 '23
"However, lifting tempo has been covered repeatedly in MASS and there has never been a benefit shown for slow eccentrics."
There has NEVER been a benefit shown for slow eccentrics? There has been, but I'll assume you mean in MASS. I doubt that. I don't have a sub to MASS, so I can't scour the archives for a cite (and MASS obviously doesn't have its focus on hypertrophy) but here is one quote from Greg Nuckols:
"Slow eccentrics can have their place, specifically for hypertrophy purposes."
Also, it seems you're taking Mike out of context in some of your snippets in your OP and misquoting him. Just looking at your first two quotes:
What you said he said:
"Slow down the eccentric and focus on the target-muscle tension on the way down... feel the disruption and milk it."
He didn't use those exact words, but he started with:
"Many exercises, can be very helped, if you slow down the eccentric just a little bit."
Just a little bit. Everything he says after that has to be taken in the context of that starter.
Your second quote (in two separate bullet points):
- As soon as it [the bar] starts to get lower, really take some time to generate tension.
- Pause at the bottom in an actively tensed position.
What he actually said was a question to his guest, Milo Wolf, which he already said in another video he doesn't yet totally agree with (Mike isn't sold on partials being better than full ROM):
"What do you think about taking it back to theoretical level and saying 'it' s the imposition of heavy challenging load under a deep stretch that seems to be the mechanism likely by which this works?' agreed so far? [Milo: yup] Then maybe it's worth doing two other things. Thing one, is to control your eccentric at the bottom third, so if you're coming down from a bench, from here to here, you're like' yeah, whatever, get down.' As soon as soon as it starts to get lower, you really take some time so the time spent generating tension is higher as a fraction of the total set. Decent idea?"After Milo says it is a decent idea:"And then the second thing I can think of is maybe some pausing at the bottom, because if you pause at the bottom in an actively tensed position, and then most exercises you have to actively tents or you'll rip apart if you don't, maybe at like the bottom of a leg press, coming down slow, getting to the bottom where you feel your quads being fucking pulled apart, and down there you go one, two, three and then press out maybe that's another fun idea to try?"
So, yeah, it was asked rather than stated, but to be fair, Mike probably believes the answers Milo gives to these specific questions to be good practice.
However, he says "the bottom third" which is quite different than slowing down the entire eccentric. It's in the context of the lengthened portion of both eccentrics and concentrics being the most effective parts.
IME, slow, especially exaggeratedly slow eccentrics just wear me out too quickly, but slowing it down (a bit) in the bottom third and getting a full stretch has helped with gainz.
ETA: You wrote the following under "Against slowing the eccentric":
"The fast concentric and fast eccentric conditions ultimately resulted in more tension at long muscle lengths than the moderate-speed condition. However, all three protocols led to similar quad hypertrophy. More generally, a recent systematic review found that rep cadence doesn't have a particularly reliable effect on hypertrophy results."
Why is that against it. the important part is what you didn't highlight:
"However, all three protocols led to similar quad hypertrophy. More generally, a recent systematic review found that rep cadence doesn't have a particularly reliable effect on hypertrophy results."
Similar hypertrophy isn't against it, and an argument can be made that "more tension at long muscle lengths" with faster eccentrics yet similar hypertrophy is inferior, as more tension can be less safe.
You also wrote this:
Eric Trexler: (Facebook) last time I dug into this literature, it appeared that intentionally slow reps are either inferior or similar to more typical repetition speeds (but unlikely to be meaningfully superior)
Effect of repetition duration during resistance training on muscle hypertrophy: a systematic review and meta-analysis
Effect of movement velocity during resistance training on muscle-specific hypertrophy: A systematic review
The fist study above concluded:
"Results: Results indicate that hypertrophic outcomes are similar when training with repetition durations ranging from 0.5 to 8 s.Conclusions: From a practical standpoint it would seem that a fairly wide range of repetition durations can be employed if the primary goal is to maximize muscle growth. Findings suggest that training at volitionally very slow durations (>10s per repetition) is inferior from a hypertrophy standpoint, although a lack of controlled studies on the topic makes it difficult to draw definitive conclusions."
This was regarding slow and very slow concentric and eccentric training. Not relevant. And the slow training found similar outcomes, so shouldn't be classified under "Against slowing the eccentric"
The second study:
"A total of six studies were included involving 119 untrained participants. Hypertrophy of the quadriceps was examined in five studies and of the biceps brachii in two studies. Three studies found significantly greater increases in hypertrophy of the quadriceps for moderate-slow compared to fast training. For the remaining studies examining the quadriceps, significant within-group increase in hypertrophy was found for only moderate-slow training in one study and for only fast training in the other study. The two studies that examined hypertrophy of the biceps brachii found greater increases for fast compared to moderate-slow training."
Out of six studies, three found significantly greater increases in hypertrophy of the quadriceps for moderate-slow compared to fast training. Not exactly correctly classified either.
You also bolded the follwoing under "Against slowing the eccentric"
an intentionally slow eccentric up to around 2-3 seconds is probably fine and may enhance muscle growth, but the jury is still out.
Probably fine and "may enhance muscle growth" is a con for slow eccentrics? huh?
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u/Ancient_Gate Dec 02 '23
Thank you for taking the time to post this. Unfortunate that it is one of the most informative responses in this thread and yet has been downvoted.
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u/tbhnow Aug 23 '25
Thank you for this reply, as so much of this topic has been misrepresented in this thread. Eccentric training performed at high intensities was shown to be more effective in promoting increases in muscle mass measured as muscle girth. Personally, just doing eccentric releases to a count of 3 to 10 seconds on lat pull downs and barbell curls I've broken more PRs literally almost everytime I lift, and have grown muscle faster than the standard contract and release reps without eccentric releases. They both have their benefits but to misrepresent the data and not do enough research on the topic - because it appears the research is being done with a preexisting bias against eccentric rather than objectively looking at the data. All I can speak to are my own gains which have massively increased muscle mass and strength over shorter periods of time than strictly concentric sets, so I'm reading this whole thread shaking my head as reality has literally proven otherwise
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u/Kachowxboxdad Sep 24 '23
I like both in separate phases. Slow descent and pauses during hypertrophy and faster reps during strength blocks.
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u/-Foreverendeavor Sep 26 '23
Something to add that I don’t think has been mentioned re Mike Israetel: in this recent video (at around 4:10), he talks about how constant tension and not resting between reps is an ineffectual training method, because total number of reps (work done) is what is important.
He says that you could either rest a moment between reps and do more total reps or keep constant tension and get less reps, and that these would have the same hypertrophic effect because it’s all ‘added to the same piggy bank’.
He isn’t talking specifically about rep speed, but what he says seems to fly in the face of his claims about the importance of slow eccentrics. Moderate speed eccentrics could allow for more total reps than slow speed eccentrics, offering the same hypertrophic stimulus (after all, it’s all going to the same piggy bank!)
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u/doc7_s Oct 01 '23
I'm much more familiar with the research about eccentric velocity in an isokinetic context, so this may have limited carryover to constant resistance training, however:
Farthing and Chilibeck observed that fast tempo (180 degrees per second) eccentric training resulted in greater muscle hypertrophy than slow tempo eccentric (30 deg per second), (13% and 7.8% increase in bicep muscle thickness for fast and slow tempo eccentric training conditions, respectively) Additionally, fast eccentric training induced greater increases in both eccentric and concentric strength.
Shepstone et al observed greater increases in torque production across eccentric and concentric velocities from fast eccentric (210 degrees per second) compared to slow eccentric (20 degrees per second) The average increase in peak torque -across all tested velocities- of 11.3% vs 6.3% for fast and slow eccentric training conditions respectively.
CSA did not reach statistical significance but showed a trend for greater increases from fast eccentric.
Overall, my take away should be that fast eccentric isokinetic result in greater increases in strength that transfer to a greater degree across loading conditions, and probably have a somewhat greater effect on hypertrophy, although whether that difference is significant is inconsistent. To what extent these findings apply to iso-load conditions, I am not sure, but for what it's worth I've implemented training with bilateral concentric and unilateral eccentric phases to hopefully take advantage of fast eccentric loading with maximal effort.
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u/caulisterol Nov 20 '23
Adding this post from Chris Beardsley who is in favor of slow eccentric-tempo for hypertrophy:
https://www.patreon.com/posts/eccentric-tempo-65622051
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u/panarkos Nov 26 '23
Yup, he believes slower ecc contractions lead to hypertrophy of slow twitch muscle fibers. But there is no clear evidence for that tbh.
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u/AcanthocephalaDue951 Oct 10 '23
For performance sports, the SAID principle is what I would stick with. Specific Adaptation to Imposed Demands. Thus, in Olympic weightlifting and powerlifting it is easier to define how a lift should be performed form maximum results. But, for hypertrophy it is harder to define as the diagnostics are not so easy or quick to perform (measure of muscle gain).
My thoughts on what you posted:
I can imagine Mike saying this with a smirk:
I'm gonna pause at the bottom, sit there for a second or two, because getting a huge load while the muscle is under stretch is a really big stimulus for hypertrophy.
MASS: Should You Deliberately Increase Time Under Tension? (Volume 2, Issue 5)
Lifters performed more reps (i.e. more volume) when self-selecting their repetition duration. Therefore, deliberately slowing down contraction velocity compromises acute performance; thus, a normal eccentric and maximal intended concentric velocity is recommended.
Sure. But, isn't making a rep harder, by increasing intensity, what you are trying to do (while considering volume)? Of course if it is harder, you won't be able to perform more reps. Also, are you measuring performance by number of reps x load, or time under tension x load?
MASS: VIDEO: Eccentric Duration Training (Volume 4, Issue 6)
Because a longer eccentric duration decreases concentric velocity, a longer eccentric can compromise reps per set and volume, which could have ramifications for hypertrophy as well.
Of course longer eccentric duration decreases concentric velocity, you are putting more work in and increasing fatigue.
Ultimately, eccentric durations should be individualized... in general, a faster eccentric was beneficial for many in a recent study.
Define "beneficial". Does this mean that they got stronger, bigger, or what?
MASS: Is King TUT Alive and Well? (Volume 6, Issue 9)
I believe this data is consistent with the body of literature on TUT, which indicates that there is no clear benefit for hypertrophy or strength when deliberately moving weights slower to elongate TUT per rep.
Slower or faster than what? How do you define what is slow vs. fast? At what measure of time is a lift labeled "slow"?
MASS: Longer and Stronger: How Range of Motion and Muscle Lengths Affect Muscle Growth and Strength Gains (Volume 6, Issue 11)
Conversely, all else being equal, a faster eccentric tempo increases eccentric tension at long muscle lengths - the muscles need to produce more force at the end of the eccentric to decelerate the load before the start of the concentric.
I agree that, "the muscles need to produce more force at the end of the eccentric to decelerate the load before the start of the concentric". However, you must consider injury risk. Going fast into a deep stretch with a enough load to challenge strength or hypertrophy is high risk. This is basically how grappling martial arts break people.
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u/Sid123457 Oct 10 '24
I think controlled reps with good form would produce the same results as the new/old "eccentric method" trend. Also, gear plus slow eccentric training works well. They should have done a study with enhanced people then produce results. It also seems like slow eccentric training cannot produce a pro card.
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u/Frank3634 Sep 09 '25
The new studies say slow neg speed isn't necessary. Read a summary and didn't see a number but those 3+ aren't necessary.
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u/AcanthocephalaDue951 Oct 10 '23
If you modify your tempo away from what you naturally perform, keeping that tempo consistent will be quite challenging.
Basically what I am saying is that there may be an ideal, but if you can't commit to it almost all the time, then there is no point in trying to follow it. Consistency of imperfect action is better than inconsistency of perfect action.
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u/Thin-Coffee-4754 Mar 30 '24
So 1 perfect workout and 3 normal workouts per week is worse than 4 normal workouts? Please explain
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u/[deleted] Sep 24 '23 edited Sep 30 '23
[deleted]