Hey guys,
can anyone explain to me why a 1RM bench press is less powerful than a rep with a lighter weight performed explosively.
cheers in advance
First define power. Here is a good article to read.
http://articles.elitefts.com/training-articles/is-there-a-difference-between-strength-and-power/
Force = mass * acceleration
Power = (Force * distance) / time = Force * velocity = mass * acceleration * velocity = mass * velocity squared / time
The amount of power that a lift has depends on 3 variables.
A 1RM lift is very slow. A look at the above equation shows velocity is squared so mathematically it is more important than mass is in the calculation of power. A faster but lighter lift would have more power.
Hypothetically let’s say your bench 1RM is 100 kg and you move it at 1 m/s. It takes you 1 second
Power = 100 kg * 1 m/s * 1 m/s / 1 s = 100 W
Let’s say you halve your weight and double your velocity. This means you halve your time.
Power = 50 kg * 2 m/s * 2 m/s / .5 s = 400 W
On a similar note, I’ve always wondered… Given that a maximal single is known to involve far less than maximal power, why do lifters insist on dynamic work and similar methods based on their power output? Is it simply for any non-specific adaptations that may occur, acknowledging the fact that this is not a valuable attribute for a powerlifter?
I believe dynamic lifting can help some PLers, but simply due to extra technique and volume in training, and the fact that many are limited by injury (though speed can cause other problems).
It just bewilders me when people start showing graphs to prove that power output is higher with lighter loads as if to say we’ve been getting it wrong - why care about power if you lift for maximal strength? Odd.
Obviously dynamic lifting can help some PLers, that is why speed work is a staple of multiple programs…
You completely missed his point. If the tangible benefit of speed work comes from the extra volume, technique practice, some sort of deloading effect, etc., and not from the increase in power production, then why do it? Just because its a staple in multiple programs? There’s a question of opportunity cost that has to be answered at some point.
I personally believe force is more important that power.
As a coach I’ve seen numerous kids push light weights fast and for easy reps. And take their percieved maxes and get pinned to the ground.
This reminds me that I’ve always thought powerlifting should really be called weightlifting, and weightlifting (Olympic lifting) should be called powerlifting!
Disclaimer: I ain’t a neuroanatomist. Nor a kinesiologist.
Speed reps train the neural system to fire at higher frequency thus getting the fast twitch, heavy mover fibers into the mix sooner.
In order, the slower twitch fibers get stimulated before the fast twitch fibers due to the size of the associated neurons: small for slow twitch with lower activation levels, and large for fast twitch with higher activation levels. During contraction the muscle fiber recruitment follows the size principle and from what I remember, the order is pretty much fixed for a given muscle.
The trick is to get the fast twitch muscles into the mix as soon as possible. Speed reps are supposed to train this response.
An indicator that you are pulling this off is that your reps at a given weight take less time. A consequence of this taking less time is the power metric since time is in the denominator of the equation.
Also, higher activation frequencies produce smoother, finer movements which imply improved skill.
So, speed reps, lots of them recruit the fast twitch fibers earlier in the lift and refine the skills.
Or so I think. Your mileage may vary. See disclaimer above.
Anecdotally, when I went to the EARLIEST training by by percents formula in the 90s as published by Simmons (my rest scheme below) I went from 550 deadlift to 630 in about 2 years, ADFPA, 181 class in my mid 30s.
Week 1: 70% x 8x3 , one set per minute
Week 2: 75% x 8x3, one set per minute
Week 3: 80% x 6x3, 1 - 1.5 minutes between sets
Week 4: 85% x 5x2, 2 - 3 minutes between sets
Week 5: (80x2, 85% x 2, 90% x2) 5 minutes between sets
Calculate new max to be 10 or 15 pounds (+ 2% or so) added to last max and start over.
Pulled every rep like I wanted to break the bar. First 2 weeks the reps were pretty damn fast. I did no assistance work.
I really think the first two weeks helped me a lot because I found that when I went heavy, like on meet day, the bar would be at my knees before I even had any “damn, this is heavy” thoughts.
[quote]csulli wrote:
This reminds me that I’ve always thought powerlifting should really be called weightlifting, and weightlifting (Olympic lifting) should be called powerlifting![/quote]
Yeah, I’ve thought the same, since powerlifting is about lifting maximum weight, and weightlifting is about generating maximum power.
[quote]csulli wrote:
This reminds me that I’ve always thought powerlifting should really be called weightlifting, and weightlifting (Olympic lifting) should be called powerlifting![/quote]
I have felt the same way about the two. Seems to make more sense that way.
[quote]csulli wrote:
This reminds me that I’ve always thought powerlifting should really be called weightlifting, and weightlifting (Olympic lifting) should be called powerlifting![/quote]
Yea, same here
There’s lots out there about dynamic work.
A friend of mine who trained at WS for a couple years comes over once in a great while to lift. When he does a dynamic day, it’s generally not based on any percentage, but more on feel. The sets also go very very fast, very little rest in between. Personally, I find dynamic day a bit harder than a ME day because of the volume and short rest periods. The focus is on moving explosively. Not everything Louie has written is done exactly as is found on the internet. There is more in listening to the body and following the three methods they employ than percentages and such. The percentage gets you in the ballpark but you take advantage or back off depending on how the weight feels.
Speed work is worth while if you know how to incorporate it - but it’s not necessary either if you are continuing to make progress. If you are at a plateau, it might be worth incorporating it for a while.
You won’t recruit 400lbs worth of force into 200lbs of bar weight like you would if there was actually 400lbs on the bar. The body will not recruit more than is needed.
I’ve always been a fan of working multiple singles for all main lifts in the 75-90% range and pushing as hard/fast as possible for each rep working on technique - but that is generally closer to a meet.
You never really try to move a 1RM weight slow, however, if you train your body to move 75-90% as fast as possible w/ good technique, it will certainly help you recruit more power/force.
This isn’t scientific, this is by experience. Sorry if it’s not “politically” correct in some circles. Just trying to help you.
Dollinger: what you’re doing would be reasonable if there was no gravity, but obviously gravity is kind of an important variable here. Because you’re not simply pushing a mass in space, rather you’re pushing a mass against gravity:
Power = < Weight | Velocity >
where the inner product is the dot-product of the two vectors. This assumes that the acceleration in the plane normal to the vertical axis is negligible, which for our purposes is good enough.
Let’s throw some numbers out there. Let’s use a deadlift max of 100 kg ~ 1000 N (because I’m a physics guy and we like to use round numbers). A really fast max attempt might have a speed of 1 m/s (i.e. moving ~1 meter in ~1 second, which is optimistically fast). This means the power output is 1000 W. Now let’s use 50%, or 500 N. In order to get a power output of 1000 W, the minimum speed must be 2 m/s, or travelling that 1 meter in about half a second. For anyone with decent speed this is easily attainable and surpassable, especially considering that most people won’t be able to pull 95% + in 1 second or less.
For each person there is curve that dictates where the optimal power is achieved, a place where d[Power] / d[Intensity] = 0. Using 30% of your max will let you move the weight a certain speed, but if you increase that by 3% will your speed decrease by 3%? Probably not, in which case you are producing greater power if you increase the weight by that amount. At some point making further weight increases will decrease the speed by a factor greater than the factor by which the weight is increased, therefore decreasing the total power. This extremum is at a different intensity for everybody because of factors like leverages, form, technique, muscle output, etc. and can even change in a person from day to day from factors like fatigue and muscle-nutrient balance.
I realize my situation was simplified and I didn’t take into account the power velocity curve, but I think it was sufficient to answer the original question. The original question being “why a 1RM bench press is less powerful than a rep with a lighter weight performed explosively”. I was trying to prove that is fully possible for a lighter weight to generate greater power than a heavier weight.
I was taught to think of it this way:
Strength is a measure of the maximum force a lifter is able to apply.
Power is a measure of how long it takes a lifter to apply maximum force.
Speed work trains the body to reduce the time period between when a lifter begins the concentric portion of a movement and when maximum force is reached.
I’m certain this oversimplifies things; but when I think of it this way, it’s value seems obvious.
[quote]BlueCollarTr8n wrote:
I was taught to think of it this way:
Strength is a measure of the maximum force a lifter is able to apply.
Power is a measure of how long it takes a lifter to apply maximum force.
Speed work trains the body to reduce the time period between when a lifter begins the concentric portion of a movement and when maximum force is reached.
I’m certain this oversimplifies things; but when I think of it this way, it’s value seems obvious. [/quote]
That’s definitely what the premise is, as I’ve always understood it. I’m just not sure if there’s any reason to think its what actually occurs. Causation vs. correlation problems, etc.
Dr. Mike Zourdos recently had a presentation in Australia where he suggests that the body uses a completely different neural pattern when lifting weights under roughly 80% of 1RM. I haven’t seen the data, so I don’t know how he went about reaching this conclusion, but I certainly think its plausible. That would mean that all of the value of dynamic work is derived from the extra volume, technique work, deloading effects, etc. and not at all from the supposed increased power production. Should be interesting to see how that theory develops.
[quote]Dollinger wrote:
I realize my situation was simplified and I didn’t take into account the power velocity curve, but I think it was sufficient to answer the original question. The original question being “why a 1RM bench press is less powerful than a rep with a lighter weight performed explosively”. I was trying to prove that is fully possible for a lighter weight to generate greater power than a heavier weight.
[/quote]
Not trying to start shit, but if your model was flawed and you directly used it to draw a conclusion, then the validity of your conclusion should be questioned. Your qualitative conclusion was correct, but not so in your quantitative conclusion, which is why I posted.
Also, only the first couple sentences were really in response to you–the post as a whole was for the purposes of the thread.
Siff in Supertraining outlines that are 3 main ways to build maximum strength:
Train with a maximal weight (ME)
Train with a lighter weight at a maximal speed (DE)
Train with a lighter weight for as many reps as possible (RE)
This thread is just talking about point 2. Instead of focusing on the external factors (actual force produced) I would focus on the internal factors, what is going on with the muscle, what kind of tension is it developing? In a max effort obviously you are trying to fire the whole thing at once and there should be a lot of internal muscular tension. This same thing happens at the end of a higher rep set as you approach failure. But if you take a submax weight and lift it with normal speed, you don’t have that same tension. However if you push it fast now you are at least attempting to mimic what is happening inside the muscle when you go for a max. I would argue that dynamic effort is the least effective at improving max strength of the three options but with only 3 options it still has significant value. And I think the simple act of being able to practice the lift over and over again has very significant value - that is a lot of set-ups, a lot of “first reps”, a lot of lowering the bar in the (hopefully) proper groove, all of those things have value and the more experienced you are the more important that is (mainly because the other 2 methods are so draining you can only use them so often). I would add the slower you are (bar speed wise) and the worse your form is the more benefit you will likely get from speed work (assuming you practice good form).