Tempo prescriptions come in a series of four numbers representing the times in which it should take to complete four stages of the lift. In a workout, the tempo prescription will follow the assigned number of reps, such as:
Front Squat x 2-3 reps @ 30×0

The first number refers to the lowering (eccentric) phase of the lift. Using our front squat example, the 3 will represent the amount of time (in seconds) that it should take you to descend to the bottom of the squat. (The first number always refers to the lowering/eccentric phase, even if the movement begins with the ascending/concentric phase, such as in a pull-up.)

The second number refers to the amount of time spent in the bottom position of the lift – the point in which the lift transitions from lowering to ascending. In our front squat example, the prescribed 0 means that the athlete should reach the bottom position and immediately begin their ascent. If, however, the prescription was 32×0, the athlete would be expected to pause for 2 seconds at the bottom position.

The third number refers to ascending (concentric) phase of the lift – the amount of time it takes you to get to the top of the lift. Yes, I am aware that X is not a number. The X signifies that the athlete should EXPLODE the weight up as quickly as possible. In many cases, this will not be very fast, but it is the intent that counts – try to accelerate the weight as fast as you can. If the third number is a 2, it should take the athlete 2 seconds to get the lift to the top regardless of whether they are capable of moving it faster.

The fourth number refers to how long you should pause at the top of the lift. Take, for example, a weighted pull-up prescription of 20×2, the athlete would be expected to hold his or her chin over the bar for two seconds before beginning to come down.