I've found a faster descent seems to help me absorb the weight better through my legs and lats but is harder to control. When I really let it down fast, it seems like winding up for a jump, so off the chest is very explosive.
Heavy Loads with Fast Eccentric Speed
Lowering the a heavy weight quickly in a Bench Press, any lift, magnifies the bar beyond its true load.
Research by Dr Tom McLaughlin (PhD Exercise Biomechanics/ former Powerlifter) examined the differences between Elite Bench Pressers and Novice/Intermediate Bench Pressers.
McLaughlin found Elite Lifters lower the bar slower in a Heavy Bench; Novice/Intermediate Lifter lowered the bar much faster. As McLaughlin put it...
"Speed Kills"
1) Fast Eccentric: Novice/Intermediate Lifters who lowered the bar faster magnified the bar weight 149%.
300 lb Fast Eccentric Bench Press Example
That means a lifter lowing the bar too fast would encounter
447 lbs of force (300 lbs X 149%), when the bar touched the chest.
2) Slow Eccentric: Elite Lifters who lowered the bar slower increased the bar weight to a lesser degree. The bar load was magnified 112%.
300 lb Slow Eccentric Bench Press Example
That means a lifter lowing the bar slower encounter
336 lbs of force (300 lbs X 112%), when the bar touched the chest.
As someone once said, ...
Jumping Out of A 5 Story Building Won't Kill You, ...
it is the sudden stop you need to worry about!
That has to do with Newton's Second Law: Force = Mass X Acceleration.
As an example, a 10 lb medicine ball dropped 42 inches will have an impact force of 90 lbs. Source:
Plyometric bench training for 1rm increases
With that said, let's look at...
When To Employ Fast Eccentric Bench Press Training
1) Speed Bench Pressing: Speed Training involves using loads of 10 - 40% of your 1 Repetition Max.
Allowing a Fast Eccentric with Speed Training develop the Stretch Reflex.
2) Power Bench Press Training: Power involves using load of 48 - 62% of your 1 Repetition Max.
Allowing a Faster Eccentric with Power Training develops the Stretch Reflex.
The Issue of Speed and Power Bench Pressing Training
With either of these method, both Speed and Power decrease around the mid point to lockout. That because if you didn't, you'd get somewhat of a whiplash effect at the end of the movement.
Maintaining Speed and Power Through The Entire Bench Press
1) Going Ballistic: The Bench Press Bar must be launched into the air. Doing so ensures Speed and Power are maintained through the full range of the movement.
Performing Bench Press Throws in a Smith Machine with the Safety Tier ensures safety.
2) Accommodating Resistance: Attaching Bands or chains to the Bench Press Bar enables you to maintain Speed and Power.
Heavy Touch and Go Benches
There is a slight deviation when preforming Heavy Touch and Go Benches. This applies to the Squat, any other lift, as well.
1) In a Heavy Touch and Go Bench, lower the bar slowly until the bar is a couple of inches off your chest. This decreases the amount of force you will need to deal with in coming off the chest.
2) Once the bar is a couple of inches off your chest, allow eccentric bar speed to increase prior to your Touch and Go.
Doing so, triggers the Stretch Reflex; allowing you to develop the Stretch Reflex and drive more weight off the chest.
Summary
1) Heavy Fast Eccentric Benching: This is counter productive. It magnifies the bar weight beyond a lifter's capacity.
2) Lowering a Heavy Bench Press slower ensure the reversal force needed to drive the bar back up is within reason.
3) Speed and Power Fast Eccentric Training: This method is effective in developing the Stretch Reflex, providing it is performed correctly.
Kenny Croxdale