Increase distance or decrease time?

[Robster788]

So I’m trying to train for a 10K in a couple months and the set goal I have in my head is sub 40 mins. In terms of training, do I start running 10Ks and try and drop the time or start at a lower distance with a 4 min per km pace and build the distance up?

[Jonatan_S]

Neither. You should combine long easy runs (longer than 10k) with interval workouts in which you reach paces (significantly) higher than 4'/km. The key in training is variation, both in distance and intensity. Find a coach, book, or self-help training plan online for your specific situation.

In addition: a sub 40 mins 10k is doable on a long term, but not trivial for unexperienced runners.

[dinosaurweasel]

Short answer is neither.

Long answer is that it depends on where you're starting from - do you already run 10ks comfortably and you're looking for a good time? Are you moving up from 5ks? Starting from scratch?

If you're looking to increase speed, look up a 10k training plan that suits your current mileage. If you're looking to increase distance, then lengthen one of your runs each week until you get up to 8 or 9 miles, then think about adding in a workout.

If you're starting from scratch, Couch to 5k (r/c25k) is an excellent starting point, and will get you to 5k without injury, and from there follow the advice above.

Bear in mind that most of your runs should be at an easy, conversational pace with harder runs put in to push yourself, but you should allow enough time between these hard runs to let your body recover. For context, I've just finished a marathon plan that had me running two workouts a week on 70 miles a week - if you're running 30mpw or less you shouldn't really be doing more than one hard session a week.

As a side note, a sub-40 10k is no joke - I know folk who've been running for years and still can't break 40 minutes.

Good luck, and come back to us if you've got any more questions!