How long should your long run actually be?

If you're training for an ultramarathon, how long does your longest training run actually need to be?

Four hours? Six hours? Eight? And if you're training for a 100-miler, do you really need to run 30, 40 or even 50 miles in training?

It's a question I get asked a lot as a coach, but I think we can become too focused on finding one magic number.

In the latest episode of my Trail Shorts podcast, I explore this in more detail, including overall training volume, diminishing returns, back-to-back runs, and why I often think in hours rather than miles when coaching trail and ultra runners.

In summary...

Your longest run is only one part of a much bigger picture.

I'm generally more interested in the overall body of training a runner can consistently complete and recover from than one enormous long run.

Terrain matters too. A six-hour mountain run covering 21 miles and 8,000ft of climbing is a very different training stimulus from 21 relatively flat miles.

And longer isn't automatically better. An extra hour may provide a useful training stimulus, but if it compromises the next few days of training, we have to ask whether the additional benefit was worth the recovery cost.

The same applies to back-to-back runs. These don't have to mean two huge long runs. A steady run followed by a long run, or a long run followed by a short easy run, can be a much smarter way of accumulating training.

Ultimately, there isn't one perfect number.

The best long run isn't necessarily the longest one you can survive. It's one you can absorb, recover from and build upon.

🎧 Want the fuller explanation? Listen to Episode 8 of Trail Shorts: How Long Should Your Long Run Actually Be?