Comment by MichaelDickens | Hacker News Reader

Comment by MichaelDickens | Hacker News Reader

As is often the case with these sorts of studies, I'd be wary of over-extrapolating. The study specifically looked at the dumbbell curl only among untrained individuals. If you did a similar study on trained individuals, or on a compound movement like a squat or a bench press, I'd expect to see different results. (In fact, it's effectively impossible to only perform the eccentric portion of a squat or a bench press unless you're only doing a single rep.)

Another concern is that they increased intensity at the same rate for all trainees:

> The training intensity was increased progressively from 30% (1st session) to 50% (2nd and 3rd sessions), 70% (4th and 5th sessions), 80% (6th and 7th sessions), 90% (8th and 9th sessions), and 100% (10th session)

(Note: I was unclear on how they determined training intensity)

It's plausible that the trainees who are doing concentric+eccentric could tolerate a faster increase in intensity than the eccentric-only trainees, but because they didn't increase intensity as fast as they could have, they didn't show any extra strength gains.

> (In fact, it's effectively impossible to only perform the eccentric portion of a squat or a bench press unless you're only doing a single rep.)

That’s true for all movements, unless someone is resetting it for you. If you don’t move the weight to the top, you can’t lower it again.

I guess for many movements, it's possible to switch to a one-sided equivalent and use the other hand for an easier reset. Barbell press -> dumbbell press

Right, but the article says:

"you may be able to cut your weights routine in half and still see the same results."

If you do one-arm lowering and two-arm raising curls, you'll have to repeat it for the other arm. So instead of getting "less gym time" as the title says, it seems to me like it will take twice as long, though you will also be doing twice the "up" reps. Maybe that's where the extra gains come from! :-)

Yeah the article suggests doing bilateral concentric then unilateral eccentric, but that doesn't seem very practical as you point out.

Many movements have other ways to cheat the concentric using momentum though. For example with a bicep curl you can swing the weight up to the top, and then doing a controlled eccentric motion. On a pull up or dip you could jump up to the top.

That would allow you to use more weight than you could comfortably use in a concentric motion, to give you the extra loading on the eccentric portion - which may give you better strength gains - without having to do unilateral movements.

you can do eccentric overloaded training. check out flywheel machines like exerfly.

It's pretty common advice for training pull-ups to start with the eccentric movement to build strength. Easy enough to do.

Yes, but that’s just because most people have stronger legs than backs so it’s easier for them to jump up to the bar that to pull themselves up.

Could be for any reason in my mind, but whatever's lower risk seems sensible.

They used a 1 Rep Max type intensity calculation (which is very common) and to get that baseline they used an isometric contraction with a joint angle of 50deg. So basically you put someone on the machine, set the angle, tell them what to do and give them ~3 tries to do a bicep curl as hard as they can. Since the “weight” isn’t allowed to move, it’s just down to how hard each individual can pull.

I’m pretty sure they used a machine like a biodex that is basically a load cell/resistance unit that you can setup for different movements and contraction types. It works based on an arm coming off a rotational unit. So direct load cell measurements are torque. Torque can then be used to calculate other things depending on what you’re doing.

The results are interpreted and that sets the individual’s Maximum Voluntary Contraction Isometric Torque, which again is basically just 1RM on this machine.

I'd like to see a study of people who do slowed negatives on deadlifts vs just barely controlling it on the way down.

Absolutely - I understand there are some practical reasons for doing it that way but I’m always surprised to see people wasting that lowering portion simply by dropping the weight. Serious control on the way down helps too!

Another way I think about it: the weight shouldn’t bounce on the floor. If it does, slow it down.

I'd also like to see that. Might be hard though--if you're studying untrained individuals in a 6 week program, they're going to see such massive gains in their deadlift that I don't think programming will make much difference. I would rather see a study on experienced lifters over 6 months, but that's probably not going to happen.

> effectively impossible

Maybe if you are alone, but you could easily get spotted for a bench press and put low effort into raising the bar each rep.

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