Engage leg drive.

Drive your feet down and away from you HARD, without allowing your hips to rise or your body to move. This force will transfer through your chest, helping to drive the bar off your chest and back toward its top position over your shoulders.
Feet down and away
PUSH YOUR BODY UP THE BENCH
PUSH YOUR BODY UP THE BENCH
Neversate
PUSH YOURSELF UP THE BENCH
PUSH YOURSELF UP THE BENCH
Reactive Training Systems
Instead of trying to push through your toes, try to push your heels down like you're in mud - like you're pushing your feet into mud. Then try to push the mud forward... So push down hard and then forward as hard as you can.
Elite FTS
EXTERNAL FORCE + DRIVE BACK
EXTERNAL FORCE + DRIVE BACK
Kabuki Strength
Think about doing a leg extension and push yourself... across the bench. If your chest is high, you will feel your legs reinforcing your arch by driving your traps further into the bench. Keep this tension in your legs throughout the entire set.
Alan Thrall
Imagine she's driving her toes into the end of the shoes... Driving down with the heels makes it more likely for the butt to come off the bench.
Juggernaut
LEGDRIVE DEMO
LEGDRIVE DEMO
Alan Thrall
I want you to think of a fighter throwing a punch. You can throw a punch with just your arm, just like you can bench press with just your arms, but... a STRONG punch starts from the floor just like a strong bench press starts from the floor... When you initiate that leg drive, instead of trying to drive your butt upward like it's trying to go straight to the ceiling, I want you to try to push towards your head like you would literally slide backwards towards the uprights.
Neversate
For the timing of your leg drive once you're set up... your legs are going to be engaged pushing your body northward, and it's going to increasingly go up as that bar comes down. So as that bar is lowering I'm putting 60% pressure on my legs, then 70%, 80%, 90%, until I touch my chest. Once I touch my chest, I reverse all of that. My legs drive as hard as possible: 100% pushing my head towards the top of the bench and that bar will start going up.
Neversate
Leg drive arguably one of the most important things in bench pressing... What people think that means is "push your butt up off the bench" and that is the absolute opposite of what you want to do... you want to push yourself north on the bench so your head is sliding towards the barbell, creating kinetic energy traveling all the way up your body into your arms into that bar.
Neversate
LEG DRIVE TUTORIAL
LEG DRIVE TUTORIAL
try to push yourself backwards on the bench...the leg drive is performed during the entirety of the rep...we're trying to push ourselves backwards on the bench and not up
Barbell Medicine
In an effort to create a bar path back over the face, some lifters will try and manipulate their arm angle to create this action but in doing so will lose their stacked joint position. Instead, your leg drive needs to create the energy that pushes the bar towards your face. Push your feet down and away from you, driving your toes into the ends of your shoes and creating energy coming back towards your head that the bar will follow.
Putting pressure into the floor is the first step to creating effective leg drive during the Bench Press. Good leg drive will push their lifter towards their own head and to create this effect, you need to push down and away. Pushing your toes into the ends of your shoes will help to make sure you’re pushing at the right angle, rather than just pushing straight down.
Imagine that the bottom portion of the bench (where your hips lay) is cut off, and execute your setup and press in the exact same manner...Your hips are in contact with the pad, but they are not bearing your bodyweight. This is active hips at its finest. You should have material contact with the pad but you’re using your legs to drive your body onto your traps.
Imagine sitting in a wheeled desk chair and pushing off HARD backwards down the nearest hallway by pushing off both your feet at once and think about what you’re doing with your quads and feet.
MPS Training
Drive your feet into the ground and forward. Try to crush your toes into the front of your shoes... You should feel the pressure in your quads. If you do this correctly and you have a solid arch set up you will feel yourself being pushed back into the bench.
Alan Thrall
Drive the bar off your chest
WHY USE LEG DRIVE
WHY USE LEG DRIVE
Proper leg drive must initiate force backward toward the bar, not up toward the ceiling. This keeps your butt on the bench while applying force toward the bar, nicely complementing the desired J-curve bar path that naturally places the bar over the appropriate joints for each phase of the lift...Good leg drive accelerates the bar through the most common sticking point, which is a few inches off the chest. If you can blast through the point, it becomes much easier to flare the elbows and get the bar aligned over the triceps and shoulders.
I try to maintain consistent leg drive pushing me this way towards my head up the bench to keep me on my traps to keep me in position to keep my chest up.
Calgary Barbell
If you push your head towards the direction of the bar, there's no way that your butt should pop up off the bench. When you take the the bar out, tighten your quads and bring it down to your chest... Take [the bar] down with tight quads, but then when you're ready to throw it up - that's when you're going to really fire your legs to push yourself back towards the bar. That's going to help... raise your chest towards the bar and... apply all the force of your legs towards the bar.
Omar Isuf
You wanna think about having 99% leg tension on the unrack and descent... and then that extra 1% to drive the bar off your chest.
As you start the press, squeeze your glutes hard and try to drive your heels through the floor. This pushes your chest slightly higher, and back into the bar. The force of your chest pushing back into the bar helps you drive the bar back off your chest toward your throat, putting it in the proper position to finish the press.
Stronger By Science
SPRING MOTION
SPRING MOTION
Alan Thrall
If you have a good arch and your glutes are engaged it's gonna be much harder for your butt to leave that bench... Also while you're pushing your knees out, you want to be engaging your quads. As soon as I'm rack the bar, I'm probably at about 20-30% legs engaged. As I lower the bar, I go to 40%, 50%, 60%, 70%, all the way up. As soon as the bar touches my chest and I reverse it, my legs are 100% engaged trying to slide me backwards on the bench. But since my traps are set and I'm pinned, my arch is going to hold and all that kinetic energy is going to go from my feet through my legs, into my torso, up my arms, and out the middle of my hand just like a punch.
Neversate
A lot of your power from the bench press comes from your feet...being able to stay in that tight position all starts with your connection to the ground.
Mind Pump
We want to get the bar into that [mechanically advantageous] position as quickly as possible. We have to achieve that with leg drive because if Marissa was just to come down and touch... and with only her arms tries to drive it back over her shoulder it would either happen late... or if she were to get there early, she would... lose that relationship of bar over wrist, wrist over elbow that we're trying to achieve. So leg drive is gonna help you achieve a more optimal bar path.
Juggernaut
...your feet and legs create an abutment, providing horizontal resistance against the tendency for your butt to move away from your shoulders... Your feet should be actively pushing to create a line of force parallel to the bench pushing you toward the head side of the bench.
Barbell Logic
Get your leg drive on throughout the entirety of the lift... push yourself up and back the whole time to avoid your butt lifting up.
Calgary Barbell