Leg extension help

douglasmobbs
douglasmobbs Posts: 563 Member
in Fitness and Exercise
I have just reintroduced leg extensions back into my routine.

I was trying to do 2 sets of 12 reps at 30kg (66lb) and I was struggling after 8-10 reps, however, the start was very easy. I decided to see what happened if I increased the weight. At 60kg (132lb) I was still doing 8-10 reps before I started to struggle and it felt similar to the 30kg albeit a bit more effort required to get to 8. When I upped the weight to 80kg (176lb) I only managed 6 reps.

I don't understand why my legs feel very similar doing 30kg and 60kg reps, any suggestions?

To increase power would I be better doing 8 reps @ 60kg or 6 reps @ 80kg?

Replies

  • leestanley3
    leestanley3 Posts: 37 Member
    Do the 80kgs and then weekly up the reps per set. Remember power = W / T (sorry loved physics at school.) Once you get to 12 reps, add more weight.

    You could have a large build up of lactic acid as you perform your reps (slows your ability to process muscular contraction). This is something as you get fitter you are able to buffer more and hold a faster race pace or endurance.

    The interesting thing also is when you do a drop set on the leg extension. Start by doing as many reps as you can on 80kgs, once you fail drop to 60kg until you fail, then drop to 50kgs until you fail then drop to 40 and so on.... absolute burn!!!

    Hope this helps

    Good luck...
  • douglasmobbs
    douglasmobbs Posts: 563 Member
    Thank you, did the 60's today (before I read this) and got to 10 reps before my right leg started to shake.

    I had an ACL replacement about 15 years ago and the surgeon used a bit of my hamstring to make the artificial one, wonder if this has anything to do with it. Either way something to plug away at.
  • wellbert
    wellbert Posts: 3,924 Member
    Leg extensions murder my rebuilt knee. Best thing I ever learned was that they are pretty much useless exercises (aside from aesthetic/bodybuilding reasons.) Some would argue that they can wreck your knee, too. It certainly puts a lot of strain on the joint.

    Have you tried doing barbell squats? You may find a similar result I did - knee pain greatly reduced overall, and totally comfortable in the exercise - as it strengthens the knee but primarily works the hip drive. Plus, it's very functional and directly improves other activities.
  • douglasmobbs
    douglasmobbs Posts: 563 Member
    Would a kettle bell squat do the same job. The kettle bells are free more often than the bar at the gym I go to
  • leestanley3
    leestanley3 Posts: 37 Member
    I would agree with wellbert. If you have had an ACL replacement, do more squats, lunges, leg press as these are called "closed kinetic chain exercises" Quads and hamstrings work together whereas the leg extension is all about the quads and could hurt you further. The only good way I have found to use the Leg Extension is negatives, use a 40-50% max weight lift with both legs lower with one and focus on a tempo, like 10 reps of 2-5-5, 2 seconds to lift (extend), 5 seconds to hold the contraction at the top and 5 seconds to lower... its a real killer but variety is the spice of life.

    Lunges work in this manner also with the DOMs people feel is from the eccentric (lengthening action) of the movement.

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