Plans, paces & PBs Your interval pace should depend on the length and purpose of the repetition — not simply on how hard you can run. As a practical rule, longer reps such as 1km are usually close to current 5K pace, while shorter 400m reps can be somewhat faster. The session is right when you can keep the reps controlled and consistent from start to finish.
If you currently run 25 minutes for 5K but want to run 22 minutes, jumping straight to every 22-minute pace in training is rarely the best route. Your body responds to the work you can complete now, not to the number you hope to run later.
Use a recent race, parkrun or time trial as the anchor. Then let the pace progress as your fitness catches up with the target.
The exact pace changes with the workout, but the relationship between rep length and effort is useful.
Four-hundred-metre repetitions are short enough to run faster than current 5K pace in many sessions. But they should still look like training, not a sequence of miniature races.
Eight-hundred-metre reps are long enough to make pace discipline matter. They work well around 5K effort because you accumulate meaningful time at a strong aerobic intensity without needing one continuous effort.
One-kilometre repetitions often sit close to current 5K pace. Because each rep lasts longer, forcing them substantially faster than 5K pace can change the session into something different from the work you intended.
The temptation is obvious: the watch says you ran the first repetition faster than planned, so faster must be better. Usually it is not.
A well-run interval session creates enough stress to stimulate adaptation while leaving you capable of completing the planned volume with good mechanics. If the first two reps are spectacular and the last four are survival, you have measured bravery rather than trained effectively.
Splits fade badly, form breaks down, recovery stretches longer and the session becomes a battle very early.
The reps stay close together, effort builds gradually and you finish knowing you worked hard without emptying the tank.
The entire set feels casual, pace barely changes despite short recovery and you could comfortably add many more reps.
Short recovery keeps the session aerobic and makes a moderate pace increasingly demanding. Longer recovery allows faster running and better repetition quality. Neither is automatically better — they train slightly different things.
Useful when the aim is sustained 5K-specific aerobic work. You never fully reset, so the session becomes progressively demanding.
Useful for faster repetitions where preserving speed and mechanics matters more than keeping heart rate continuously elevated.
The right recovery depends on rep length, pace, training history and the purpose of the session. Use the workout as written rather than automatically shortening recovery to make it feel tougher.
Goal pace matters because eventually your training needs to prepare you for the exact demands of race day. But that does not mean every interval from week one should be set from an ambitious future PB.
A better progression is to anchor most of the early block to current fitness, then gradually introduce more work around the target pace as the sessions become controlled.
Make the workouts repeatable and establish control.
Add volume, reduce recovery or sharpen selected repetitions.
Practise the rhythm and effort you want to hold on race day.
If you can complete every repetition close to the intended pace, with controlled recovery and without a huge fade, the session is doing its job. Over several weeks, those same sessions should begin to feel more manageable or allow a sensible progression.
If they remain impossible, your training pace or target may be too aggressive. If they become very comfortable, it may be time to progress the session or move to the next training block.
Some shorter intervals can be faster than current 5K pace, while longer repetitions are often closer to 5K pace. The correct speed depends on the repetition length, recovery and purpose of the session.
Many 5K-focused 400m sessions sit around current 5K pace to somewhat faster. The important test is whether you can keep the whole set controlled and consistent rather than producing one or two very fast repetitions.
There is no single recovery that fits every workout. Short recoveries increase the aerobic demand, while longer recoveries make faster running easier to maintain. Follow the purpose of the session rather than automatically making recovery shorter.
Base most training on current fitness and progress toward goal pace. Setting every session from a future target can make workouts unnecessarily difficult before your fitness has caught up.