There’s no need to preferentially focus on the negative portion of the lift if you’re using the same weight throughout the range of motion. If you do want to perform real eccentrics, use at least 110% of your 1RM and lower it as slowly as possible. Shoot for at least 10-seconds during the negative to maximize mechanical tension. Next time you hear someone talk about how important the negative portion of a lift is, feel free to tell them exactly how wrong they are and how they’re misinterpreting the implications of scientific studies. Actually, don’t do that. But feel free to point them here for a full discussion on the topic!
<Source: The Muscle PHD>