Why do Leg Extensions Hurt So Much?

Ok, this is going to be one of my stupid, pointless, non-applied articles that I just need to write to get something out of my head (so unless you’re really interested in minutial trivia go read something else).  It’s also a way to actually update the site as I finish up getting ready to launch the Women’s book (no foolin’ this time, the book is done and it’s just some busywork to launch in the third week of January).

Question 1: Why do leg extensions hurt so much for high reps?  I mean locally hurt, the quads are screaming and hurt more than other similar movements done for similar reps.

Question 2: What do blood flow restriction (KAAATSUUUUUU!!!), speed skating and leg extensions have in common?

Read more to find out.

Blood Flow Restriction (BFR)

Ok, for the 3 people who don’t know what BFR is, it’s a relatively new method of training where you basically use pressure to reduce blood flow to the muscle and then use relatively light loads for training.  And research has generally found that it provides similar hypertrophy gains to muscle as heavier training and does so with lighter loads with various mechanisms being involved.  Please note that the size gains are, at best, identical but not greater.  And you don’t get the strength gains you’d get from lifting real weights since you aren’t training the neural components.

Now, BFR is nice in that it does reduce joint strain which can be fantastic if you have a joint injury or deliberately need to do such.

But it has drawbacks.  One is set up since you’re having to go to the trouble to get everything tied off.  I’m not sure the average trainee can get the pressure right since it tends to be pretty specific.  Cutting off blood flow to muscles is not a good thing.  Necrosis anybody?  And while excruciatingly minor in the big scheme, there are two case studies of rhabdomyolysis occurring with BFR.  Mind you, that’s a weekly occurrence for Crossfit.