Tempo training assigns a speed to each phase of a rep, usually written as four numbers like 3-1-1-0. Read them in order: 3 seconds lowering the weight, 1 second pause at the bottom, 1 second lifting, 0 seconds pause at the top. It turns rep speed from an afterthought into a variable you program, the same way you program sets and reps.
Why it matters
Control is a skill, and tempo is how you practice it. A prescribed 3-second lowering phase makes it impossible to bounce out of the bottom of a squat or let gravity do the eccentric for you. That does three useful things. It teaches new movements faster, because slow reps expose exactly where your form breaks. It lets you train hard with lighter loads, which your joints will thank you for. And it keeps effort honest when the weights available to you are limited, like in a home gym.
How to use it in training
Pick one or two exercises per session and give them a tempo, typically the ones you're still learning or the ones that bother a cranky joint. A 3-1-1-0 or 3-0-1-0 covers most situations. Count the seconds honestly, because everyone's "3 seconds" shrinks under load.
Expect to use 20 to 30 percent less weight than normal. That's fine. The controlled reps are doing the work. Just don't apply slow tempos to everything forever: explosive strength needs fast intent too, so keep your power work fast.
Related terms
Go deeper
Does slowing reps down actually build more muscle? We dug into the evidence: Time under tension research.