Of all the leg extension machines I’ve used over the years, any time it has a weight selector/weight stack eventually I can rep the stack.
If on day 1 at a new gym you find this to be the case it could be perceived as a bummer, well don’t worry kids I’ll learn you how to do, to work around such a problem as maxing and repping that stack.
There’s many intensity multipliers :
•More reps
•Pauses at the top
•Isometric holds
•Slower reps
First stage you just do normal reps.
Since it’s leg work and a machine you want this to be high reps.
As that gets easier you pause for a count at contraction or very near it.
(You can also add reps to the set at the same time.)
Next stage is the doozy. After that final rep, (and you’re already doing high reps pausing at the top each rep) on the final rep you HOLD at the top, well slightly below it, and do a long isometric hold. Build this up to about 90 seconds.
After the set looks like over 20 reps with pauses each rep and a long (90 second or more) isometric hold thats when I’d say slow down the rep speed. Instead of normal speed you’ll slow the reps to at least a 4 or 5 count up and a 4 or 5 count down.
Of course you could also push the reps into the “century set” 100 rep per set range.
If all of the above has been milked out…use all of the above one leg at a time.
(Feel free to mix and match as you see fit.)
Some hints for knee health : isometric holds are better than reps.
For both holds and reps just shy of locking the knee out is the “top” of the movement. You stay under contraction and don’t get the absurd sheering forces this way.
Sometimes (and you’ll know when this is) you don’t want to do reps for health and longevity reasons. If isometric holds are still good then do them.
Leg extensions are one place I actually feel warm ups are necessary. I’ll usually do a bunch of sets of 5 reps adding weight in roughly equal jumps until I’m at the stack (or most of it if I’m going light) which is where the funs at.
I do believe leg extensions could cause an imbalance in leg musculature. For health and longevity reasons I’ll at the very least flex the hamstring (in a manner reminiscent of a standing leg curl) between sets. Do more than that if necessary. (This doesn’t seem to always apply with isometric holds however.)
Whatever bad is said about the movement I find done right the leg extension seriously helps my leg size and strength. The isometric holds for strength, and the high reps for size do far more for my quads than the “compound crew”™ would have you believe.
-J