its well documented that more large motor units are recruited when lifts are heavy or lifted quickly.
A "motor unit" in the body is a particular muscle fibre combined with the nerve which ennervates it (makes it go). Motor units don't vary in size.
I think what you read more likely said "large
amounts of motor units must fire to lift heavy weights" or something like that. In other words, if you do compound exercises and bust your foofer, you hit your body harder than if you do isolation exercises and take it easy.
I find that things are easier when we use everyday words like "muscle" and "bust your foofer." When we get fancy we fck it up, I know I certainly do.
haz said:
i still think he will gain some benefit from doing the same weight he did last session. he will complete the reps quicker, isn't that something different? and he will gain confidence.
In my experience, no. This is because as Markos notes, how does the guy time his reps? Should he get one of those metronome thingies they put on pianos?
Rep tempo is something which appears in many textbooks as a variable in training. In practice, trainees don't time themselves because they're too busy getting the weight up. So varying tempo is something which works with a trainer there, "up, two, three, four, pause, down, two, three, four, up..."
Try to do that on your own you'll get nowhere.
This sort of overly-complex thing doesn't build people's confidence, because it just confuses them. "Yesterday I lifted 75kg, today I lifted 77.5kg" or "yesterday I did 6 reps with 10kg, today I did 7 reps with 10kg," this builds people's confidence because it's a simple and obvious sign of progress. "Yesterday I did 8 reps but 2 of them were slowish, today I think the last 2 were a bit faster..." is just too vague.
haz said:
tho truth be told i read a study that said that in beginners there was no difference in strength gained from people doing 4reps and 10 rep training programs.
... in the first 4 to 8 weeks, for formerly sedentary people. For the first 4-8 weeks, whether a person does 5 reps, 12, single sets or triples, splits or full-body - if they were doing nothing before and are doing something now, their body will adapt.
If they were formerly active in some other sport it's not such a shock to their body and the kind of routine they do matters - they're not
complete beginners. If it's past the first 4-8 weeks, then their body has got over the shock of actually doing anything at all, and the kind of routine they do matters.
What's most important in the first 4-8 weeks is getting into the
habit of exercise. Habits are most easily formed when there's a routine to them. This is the reason that so many different routines, people try them and they work - they have a piece of paper to follow, on Monday they know what they'll be doing in the gym on Friday, so many reps with so much weight.
So though it may make no difference to them in the first 4-8 weeks whether they do 5 reps or 12, single sets or triples, supersets or whatever, because it makes a difference afterwards it's best to get them into a rhythm of doing a particular routine. Telling them, "whatever you do you'll grow, so don't worry about it," encourages them to chop and change their workout according to whim - which leads to not creating the
habit of exercise, and they drop out like too many others.
So we just tell beginners a target rep range, give them 3-6 exercises to do, and tell them, "more, more and more, go bust your arse." Keep it simple, no fancy words or obscure science or But Chad Says, simple. Then they get into the habit - the best workout is the one you stick to.