Timberlake is using a barbell loaded into a landmine platform, which allows you to manoeuvre the long, heavy implement from one end, to perform eccentric emphasised presses.
What does that mean, exactly? MH fitness director Ebenezer Samuel, C.S.C.S. explains:
"This is a really smart way to beef up your overhead press," says Samuel. "First off, it's a landmine press, which is going to be safer for most people than a standard free-weight military press. It's a nice easy overhead angle that can cater to your individual shoulder mobility."
But unlike the military press, Timberlake's main focus here is not on getting the weight up.
"Truth be told Justin isn't focusing on his form on the actual pressing portion of the movement, and that's okay," Samuel continues. "The goal is to get the weight up there and then slowly lower it with one arm, getting a strong eccentric contraction and getting comfortable managing what, for Justin, is a heavy weight. Keep the reps lower if you do this because the focus is time under tension. Aim to take 2 to 3 seconds to lower the weight back to your shoulder on every rep. Aim for at least 20 seconds of time under tension. Underrated in this is keeping your core tight. It gets convenient to arch your back, but resist that temptation."
Bruno shed a little more light on how the move fit into Timberlake's routine in his own Instagram post featuring the same clip. The trainer said that his client's goal was to add 15 pounds of muscle for his role in Palmer–and getting there was no cake walk.
"Justin trains constantly year-round, but once he sets a goal, he goes after it with an intense focus and effort and does whatever it takes," Bruno wrote. "Here he’s doing an eccentric-emphasis landmine press with 120 pounds on the bar, which is seriously strong. None of the pro athletes I train have been able to beat this yet, and I haven’t either, which is actually super annoying because lifting is the one thing I thought I could do better than him. It’s really cool to see a guy in Justin’s position putting forth this type of effort and moving heavy weight because it doesn’t matter who you are, you can’t buy results in the gym. You have to work for it."
Via Men's Health