I did read the article......and I'm not wrong at all.
The fact is, most discussions of tempo I've read couch it in terms of the timing of various aspects of a rep - i.e seconds. Tempo is expressed as seconds - as in 3/0/1, 4/0/2 etc. etc. In any event, if timing of tempo protocols in seconds was irrelevant - then tempo wouldn't be expressed in terms of seconds.
And in that context, the longer it takes to push a weight, the slower a tempo it is associated with - that is all I was pointing out. Start with whatever you care to define as " as fast as you can " - call that fast tempo - pare it back by a half, full second etc, and comparatively speaking - then you can call that a moderate tempo.
Well you are wrong if you are trying to suggest that time matters at all when it comes to the proven science that "moving the weight as fast as you can shows greater gains".
I see your point though, you're saying if person A can move the weight at 2 seconds but chooses to move it at 2.5 seconds, is there any research that shows this will get less gains. On that point I'm not quite sure if 0.5 or even 1 second would create a difference.
But back to what I was talking about before and time not mattering, well I'm afraid you are wrong if you say that it does matter purely because people measure the movement in seconds. They do that to set benchmarks for themselves nothing else. The idea behind explosive training is that you move the weight as fast as you can, like I said at the beginning of a set it might take 2 seconds going as fast as you can, and by the end of the set it might take you 4 seconds, but you are still trying to explode and get the weight up as fast as possible.
If we go by your theory, then there is a change in tempo here, however it's not through choice it's just due to the muscle tiring. However, the person is still attempting to lift the weight as fast as possible and putting in as much stimulation to do so. If anything, the person will receive a benefit from this drop in "tempo" as it shows the muscle is tiring and they are causing more and more tears and damage.
And thats why I quoted several articles which describe why tempo is not important because it is all about how fast you intend and are trying to move it.
So I suggest we simply move away from the time issue. The only advice we can scientifically and safely give is "move the weight as fast as you possibly can on the concentric stage without sacrificing form is proven to give large gains". That has been proven in all the articles I have listed above.
As for you asking whether there would be a different in 0.5 or 1 seconds decrease in tempo, well, the only thing I can suggest is that the articles never bothered to measure a difference that small, and no one probably has.
My best guess is since they have proved that moving the weights faster is better than slower, that logically we can come to the conclusion that a "fast tempo" is better than a "moderate tempo", but they haven't been able to prove this as a 1/2 a second time difference would be quite hard to measure against gains.
Sure, 1/2 a second or a whole second might not make much change, but I would rather stick with the proven knowledge that moving the weight as fast as possible produces the biggest gains when compared to a slower speed, rather than chance my gains on the fact that going 1 second slow MIGHT produce the same gains.
So I definitely recognize your argument that gains might not be altered, so why should we strive for 100% effort at 2 seconds when we could get away with 3 seconds and see the same gains? You're right there, maybe it is a waste of effort for the same gains, maybe we are all pushing ourselves harder than we need to.
So unless you can quote some research that suggests a fast tempo is better than a moderate tempo, all we can establish with proof is that a fast tempo on the concentric stage is better than a slow tempo. So in the case of fast vs slow, faster comes out on top, in the case of fast vs moderate I can only guess that Fast would also come out on top but as far as I know there is no research anywhere to prove this.
Therefore with lack of research to prove either side of the argument it's case closed and again all we can safely prove is that moving the weight as fast as possible compared to a slow pace shows an increase in strength and muscle mass.
So I guess that answers the question the initial poster asks, slow reps or fast reps. Definitely fast on concentric stage, but you MAY be able to get away with a "moderate tempo".
