WHAT DOES IT MEAN?
The speed at which you do your reps. This is often unnaturally slowly, in order to maximise muscular growth. Tempo is often recorded in a four-digit format – for instance, 4021. The numbers refer, in order, to the time in seconds taken for the eccentric (lowering) part of the move, the pause in the bottom position, the concentric (lifting) part and the pause at the top. Occasionally you’ll see an X, symbolising explosiveness, which simply means “as fast as possible”.
WHY SHOULD YOU WORRY ABOUT IT?
There’s some evidence that time under tension (TUT), or how long your muscles are working during your sets, is more important than how many sets or reps you do for hypertrophy. So doing a ten-rep set that lasts for a solid 60 seconds might be more effective than grinding out 12-15 reps with the same weight but faster. Bear in mind, though, that total TUT for each body part seems to be the defining factor – so if it’s chest day, include your dips as well as flyes and bench presses. Conversely, other studies suggest that lifting explosively can recruit otherwise hard-to-hit muscle fibres, so the odd fast concentric isn’t a bad idea.
Superset a slow set of bench presses with chin-ups, using a weight that allows you to do six reps of each, with a 4021 tempo. Rest for 90 seconds, and repeat a total of four times. If you’ve never done it before, enjoy the all-day pump.