Tempos are great for building your speed stamina. They are ran at a lactate threshold pace- which is roughly 25-30 seconds per mile slower than 5k pace, or a pace you can sustain for an hour in a road race.
Tempos vary in lengh, ammount of reps, and recoveries, depending on what you're training for. For instance longer tempo work - 2 x 25 minutes with 10 minute jog in between is more suited for longer endurance events like marathons.
These sessions differ to interval sessions as intervals are used more to refine raw speed. These are ran in and around 5k pace and the reps themselves are more frequent and/or shorter. Recoveries tend to be static and you're looking for more natural pacing progression for most of the session, as opposed to tempos which are ran at even and consistent splits.
Terrain, conditions and how the body is feeling will always determine effort, so listen to it. But a good rule of thumb to know you've paced tempos right is that when you finish the session, if you were to run the last rep again, you could do so at a similar level of intensity. You should be well worked after the session, but not exhausted. Think 'comfortably quick'
Tempo work can take a short while to get into the swing of things, but once you've found your pace for the sessions they are really satisfying. It's so important to let the body do the talking and not to force a pace or surge into each rep.
Tempo work is fundamental for endurance runners, and raising the level in which you accumulate lactate in the body will mean the ability to run faster paces for longer, and more comfortably.
When it comes to running tempos think relaxed, long sustained effort that's both moderately quick yet comfortable. It's also really beneficial to use the first third of a tempo to ease in and go at a pace that feels very comfortable, to then progress into the session at a rate that your body choses. You'll get much more of a satisfying session, a stronger finish, and also the you won't be as tired, therefore recovering better. It's much better training a bit slower than needed instead of quicker.
Cameron Harris- Head Coach
This latter point is so crucial as what makes tempo work so good for our training (on top of all the known benefits) is the ability for it to train our body to run at that comfortable 70-80% level effort. This means we can roll out speedwork on a weekly basis without it wearing us out, therefore making progressive performance gains over a longer term without getting injured or risking being overtrained.