RunPackGuides · 5 min read
How long should your long run be? A simple guide by goal
How long your weekly long run should be for 5K, 10K, half marathon and marathon training, how fast to run it, how to build up safely, and why it’s best with friends.
The long run is the backbone of most training plans: one run a week that’s noticeably longer than the others, at an easy pace. It builds endurance, gets your legs used to time on feet, and for many runners it’s the social highlight of the week.
How long, by goal
| Training for | Typical longest long run |
|---|---|
| 5K | 6–8 km, or 45–60 minutes |
| 10K | 10–14 km, or 60–90 minutes |
| Half marathon | 16–20 km, or up to about 2 hours |
| Marathon | 28–35 km, or up to about 3 hours |
These are the peaks, reached a few weeks before race day. Most weeks the long run is shorter.
A rule of thumb for weekly balance
Many coaches keep the long run to about 25–35% of your weekly distance. If you run 30 km a week, a 10 km long run is about right. If the long run is half your week, build up your other runs first.
Building up
- Add 1–2 km, or 10 minutes, every week or two.
- Every third or fourth week, cut back for a recovery week.
- Cap marathon long runs by time: past about 3 hours, the extra fatigue usually outweighs the benefit.
How fast?
Easy: conversational pace or zone 2, typically 60–90 seconds per kilometre slower than 5K pace. For half and marathon training, some plans add a few kilometres at goal pace near the end of some long runs. Work out that pace with the pace calculator or the marathon pace chart.
Why the long run is better together
Ninety minutes alone is a long time. With friends, it’s a catch-up. Run at the slowest person’s pace, plan a loop with a coffee stop at the end, and use an out-and-back so mixed paces meet up (more in running with someone faster or slower). On the weeks you can’t meet, a shared feed keeps the long run social: RunPack puts everyone’s runs, from any watch or just an iPhone, in a private feed for your crew, and its weekly challenge rotates through longest run, weekly distance, number of runs and pace.