Marathon training isn’t just about how fast you can run on a good day, it’s about building an engine that lasts. Here’s why running slower might be the smartest way to get faster, and how I learned to trust the process.
You’d think that after running a few marathons, I’d have the whole thing down to a fine art. Five years ago, I probably would have said I did. Back then, I could plough through a long run, wreck myself, and somehow be fine again the next day. Those days are gone.
The reality is, as you get older, you have to change how you train. Recovery is now as important as the miles themselves, and that took me a while to accept. For a couple of years I kept trying to train like I used to. My body kept reminding me I wasn’t 25 anymore. Eventually, I had to admit I needed to run smarter.
The biggest change for me has been building consistency and finding a routine I can stick to. Joining my local club, Artane Beaumont RC, and my old running group at Clongriffen Runners have been a massive help. Having people to train with keeps me accountable, and it’s given my running a rhythm again.
Your Body is an Engine
When it comes to running, especially marathons, your body works like an engine. There are two main parts you need to train:
- The aerobic system – This is your endurance engine. It keeps you going for hours, burning fuel efficiently without breaking down.
- The anaerobic system – This is your short-term power boost. It’s for hills, surges, and the sprint to the line, but it burns through energy quickly.
Most runners love working on the anaerobic side. It feels exciting and fast. But without a big, efficient aerobic base, that speed doesn’t last. In a marathon, the lack of endurance will catch you out every time.
Slow is Steady, and Steady is Fast
We all like heading out the door or joining a group and immediately running at tempo pace. It feels good in the moment, but it’s not doing you any favours when you hit the wall in a race. You need a fall-back pace — the kind of pace you can hold without thinking, even when you’re tired.
Let’s say you’re training for a sub-4 marathon. Your race pace might be 5:40 per kilometre, but your long runs should sometimes be closer to 6:10 or 6:15. That might feel painfully slow and frustrating, but it’s where the magic happens. Running slower builds the aerobic system, improves efficiency, and means you can cover the distance without breaking down. Over time, you’ll find your “slow” pace naturally gets faster without extra effort.
Why It Works
By keeping the pace easy on some runs, you’re able to train more often without battering your legs. You recover quicker, which means you can fit in the harder sessions that improve your anaerobic system without feeling wiped out for days afterwards. It’s the balance between the two that makes you a stronger, faster runner.
Switching to this way of training was frustrating for me, I won't lie. It meant slowing down, ignoring the ego and want to go at a pace I felt I should be going at, and trusting that the steady work would pay off. And it has. I’m stronger now than I’ve been in years, and I can sustain paces that used to feel like a stretch.
If you’re training for a marathon, build your engine first. Keep some of your runs slow, stay consistent, and give yourself the best chance of not just finishing strong, but actually enjoying the race.
