When you're finishing the last rep of the set, and things are getting pretty intense, have your legs ever just started shaking like crazy.

It's happened to me thrice, twice when i was doing leg extensions and once when i was doing standing barbel bicep curls.

In the leg extensions my right leg just started shaking like crazy! And i didn't even notice it until my friend saw it and laughed.

And i'm talking about like quick shaking back and forth, and today when i was doing the curls that leg just started shaking as i was finishing the last rep.

Is this something i should be worried about?

When you're finishing the last rep of the set, and things are getting pretty intense, have your legs ever just started shaking like crazy.

It's happened to me thrice, twice when i was doing leg extensions and once when i was doing standing barbel bicep curls.

In the leg extensions my right leg just started shaking like crazy! And i didn't even notice it until my friend saw it and laughed.

And i'm talking about like quick shaking back and forth, and today when i was doing the curls that leg just started shaking as i was finishing the last rep.

Is this something i should be worried about?


I wouldn't worry about it. More than likely you're hitting the muscle hard causing it to spasm.

Pretty common I think. I bet they shake on seated calf raises too.

Mine shake all the time. After particularly hard workouts, my entire body quakes. Sometimes I can't hold the pen to write down final stats or have to use two hands for the water bottle. It's mostly a sign that your nervous system has had it and needs to rest.

Though, if you are new at lifting, you'll also shake because your nervous system and muscles doesn't know how to properly handle the new movement you're using. This is a bit different.

Yup, CNS adaptation.......ideally it's learning to get all the fibers to fire properly to handle the load, it will diminish as you continue to lift....until you up the weight or change the angle and confuse the CNS again.

However....like chicanerous mentioned....it sounds like the old CNS was fried for the day.

Yup, CNS adaptation.......ideally it's learning to get all the fibers to fire properly to handle the load, it will diminish as you continue to lift....until you up the weight or change the angle and confuse the CNS again.

However....like chicanerous mentioned....it sounds like the old CNS was fried for the day.


Either way, I love that feeling.:tucool:

Well during the leg extensions it was pretty comical, :lol:
my face was red , my eyes were half closed then suddenly my right leg starts jingling back and forth beyond my control.

Well during the leg extensions it was pretty comical, :lol:
my face was red , my eyes were half closed then suddenly my right leg starts jingling back and forth beyond my control.


Dude, make sure you exhale on the extension. You don't wanna pop a spring.:eek:

Well during the leg extensions it was pretty comical, :lol:
my face was red , my eyes were half closed then suddenly my right leg starts jingling back and forth beyond my control.

"Sewing machine leg" as it is sometimes called, is not a problem.

But check your breathing - you want to try and avoid the red face as much as possible.