What's up guys? I'm Scott from muscularstrength.com
and today we're going to take a closer look at the hanging knee and
leg raise to ensure you're engaging your abs for maximum growth.
Because if done correctly,
this can be one of the best exercises to engage the entire rectus abdominis and
place a bit more emphasis on the lower abs. However, if we're being honest,
this is one of those exercises where most people perform the movement
incorrectly and end up training an entirely different set of muscles called the
hip flexes. These muscles include the rectus femoris, the iliacus,
the so as the iliocapsularis
And even though all these muscles originate in insert in slightly different
areas, they all do the same thing, which is flex the hip.
But why are we discussing hip flection in an abs video? Well,
that's because hip flection occurs when you bring your knee up towards your
chest and hip extension happens when your knee travels behind your torso.
And this movement pattern is key to understanding how to maximize the exercise.
Because when most people perform the hanging knee or leg raise,
they mostly end up recruiting the hip flexors than the abs.
So to understand why,
let's take a closer look at the anatomy of these two muscle groups.
First up is the rectus abdominis,
and although your core is comprised of many muscles,
the most prominent one you're trying to activate when training your abs is this
one or the six pack.
Now the rectus abdominis originates in the pubic area more specifically the
pubic symphesis and inserts on the xiphoid process and costal cartilages of your
ribs. So with that in mind,
imagine the rectus abdominis as a long sheet of muscles whose main function is
to flex the spine, which means to literally make your spine round,
as for the anatomy of the hip flexors,
the main hip flexor that ends up activated instead of the abs when performing a
hanging leg or knee raise is the iliopsoas
So as which originates along your lower back vertebrate then crosses the hip
joint and inserts on the femur.
Its function is to flex the hip or bring the knee up and it's involved in many
other activities such as walking, running, and even standing.
But when it comes to weightlifting,
I just want you to imagine the hip flexors as long powerful muscles that cross
the hip joint and elevate your upper leg towards your chest and just like most
other muscles in your body.
The rectus abdominis and hip flexors prefer to work together,
but what ends up happening most likely due to the name of the exercise,
is that we isolate the hip flexors with very little engagement in the abs
because instead of spinal flection occurring,
we simply raise our knees to about 90 degrees and then we stop.
If anything,
the name of the exercise should be changed to the pelvis tuck because that's
essentially what it is due to
the main purpose of your rectus abdominis is to flex the spine.
So if you've been keeping your spine straight throughout the movement,
as you lift your knees towards your chest,
all you have to do to properly activate your rectus abdominis during this
exercise is to bring your knees up a bit higher and you're good to go.
Just take a look at these two videos. On the left,
you can see me performing the exercise wrong with zero spinal flection,
and on the right you can see that my knees are traveling much higher causing
spinal flection, and most importantly, abs activation.
But make sure you're really flexing your abs throughout the movement and try to
think of your legs as the resistance, which actually brings me to my next tip.
As you become stronger,
you'll need to find ways to make this exercise more challenging,
and that can be achieved by holding a dumbbell with your feet,
even if it's just five pounds to start.
Once you're able to train with sets of 15 to 20 reps in a row using only your
body weight,
you're going to want to increase the resistance to train your abs harder and
continue to build blocky abs. But some of you might ask,
does focusing on spinal flection actually isolate the rectus abdominis from the
hip flexors? Well the answer is no.
The hip flexors will always want to help out and that's a good thing. However,
what you don't want to do is focus solely on the hip flexors and ignore the
engagement of the abs for very two good reasons. Number one,
because you want to train your abs so they become more defined obviously.
And number two,
because the hip flexors are already quite tight on most people from sitting
all day contracting and strengthening and shortening them further is an injury
just waiting to happen. Also,
since the hip flexors originated in the lumbar spine, as it becomes higher
they can even end up pulling on the vertebrae causing lower back pain and in
some cases hyperlordotic posture.
So now that you understand the exercise and how the muscles involved function
when performing it, how do you actually use the knee raise or leg lift
to train your abs? Well, first of all,
it doesn't matter if you perform this movement hanging or in a chair,
and whether you perform the knee raise version or leg lift all comes down to how
strong your abs are. In most cases,
you'll still start off with the knee raise,
then utilize the leg lift version as you get stronger. Remember,
your legs are providing the resistance. Your abs need to contract harder.
Therefore, by straightening your legs,
you're simply increasing the resistance your abs need to overcome in order to
flex the spine. Then as that becomes easier,
you'll graduate into the weighted knee raise. But if I were you,
I'd start the exercise on the captain's chair to get used to the spinal flection
portion of the movement and all you have to do is first take a moment to
stabilize your body in the air because momentum is not your friend in this
situation. Then as your spine continues to flex,
your knee should be traveling higher and higher until they reach your chest.
Then slowly control the descent as you reach a full back extension at the bottom
and then reinitiate the movement for the second repetition.
That's how you perform a leg lift properly. As for sets and reps,
when it comes to abs, it varies,
although I always usually perform four to six working sets on some workouts.
I like to go as high as 30 to 40 reps per set using just body weight where
on other days I like to train with a heavy dumbbell and keep my sets closer to
10 to 12 repetitions.
I've always found that the combination of high and low volume training has worked
best for me when trying to build abs.
So don't be afraid to switch things up throughout the week.
And if you're the kind of person who always saves abs for last,
try training abs first or on a day, that's normally a rest day. Guys,
if you want to see changes in your midsection,
you need to get into the habit of training your abs hard just like any other
muscle group. Be sure to tap that like button.
If you want to see more great content like this, and as always,
more good stuff coming soon. See ya. Hey guys, if you haven't already,
be sure to click the link below to download my free program, guaranteed gains.
All you have to do is drop your email at the top of the page and the entire
program will be sent directly to you.
It's an upper lower split that takes advantage of multiple growth periods
throughout the week with an easy to follow routine structure to keep you on
track and motivated to build the body of your dreams.