Did you know you build more strength during the eccentric (lowering) phase of a movement?
Before we dive into this, let's talk about about the 3 different stages of a movement.
Eccentric - The lowering or downwards phase, where the agonist (primary mover) is being lengthened under tension.
Isometric/amortization - The pause, between an eccentric and concentric contraction. Where the muscle is overcoming the pre-stretch, getting ready to generate force.
Concentric - The upwards phase, which involves the muscles shortening to generate force production.
Example: During a squat, the eccentric phase is when your bending at the knees, and going down into the squat. The isometric phase would be the pause at the bottom, and the concentric phase would be standing back up, extending through your knees.
Eccentric contractions and strength improvements
Lowering an external weight generates greater force production capabilities, compared to a concentric action. This makes the eccentric phase great for overloading the body, as the body can handle more weight eccentrically than concentrically. To put it this way, if you can't lower a weight under control, you certainly aren't going to be able to press it. With the controlled lowering of the external force, your body will evolve, by increasing strength gains.
It's not just strength within the muscle were talking about either. Connective tissue responds far greater in eccentric loads. Tendons become hardened and help generate more force between bones and muscles.
Did you know physiotherapists commonly use slow eccentrics to rehabilitate an injury to build back the strength?
How to apply this information
There's two ways we can directly apply this information into your training.
1) Negative/eccentric training - Most popular within training partners, so you have a spotter for help. With this style of training, you would put more weight on than you can generally lift concentrically, e.g. 105% of you max. You would slowly lower the weight for at least 5 seconds, then have your training partner help you lift the weight back up. This is great, but does have it's disadvantages, such as an increase in injury risk, most commonly seen in people who haven't warmed up properly, or have poor form.
2) Secondly, just slowing the eccentric phase on your exercises that you do now, in your strength training. So instead of doing 3 sets of 8 reps, going 1 seconds down, 1 second up. Now concentrate on lowering the weight for 4-6 seconds, prior to lifting the weight back up on the concentric phase.