If you’re a driven athlete, chances are you love a hard session. You want to sweat, breathe hard, feel like you’ve worked.
So when your BLOC coach puts in a Zone 2 ride or run, your first instinct might be:
“This feels too easy… am I even improving doing this?” Most of the new athletes that come to us struggle with the concept of slowing down. They've trained for years at max effort and often mumble the motto 'no pain, no gain' - sound familiar?! They also have the added pressure of PRIDE - their training data shows on Strava to all of their mates, and they're getting comments asking if they're injured, if they're ok or banter as to why they were so slow! How unfair!
But trust us: Zone 2 is not “junk miles.” In fact, it’s one of the most important parts of your training plan. Here’s why.
💡 What Is Zone 2 Training?
Zone 2 refers to a low-intensity heart rate or power zone—roughly 60–70% of your max heart rate, or around 56–75% of FTP if cycling.
It should feel comfortable, like a pace you could hold for hours. You’re breathing steadily, able to talk in full sentences. And yes—it might feel frustratingly slow!
But that’s the point.
🧠 The Science Behind Slowing Down
Here’s why training in Zone 2 is so powerful:
1. Zone 2 Training Builds Aerobic Base
Zone 2 work trains your aerobic energy system—this is the one you rely on most in long-distance triathlon. It boosts:
- Mitochondrial density (your cells’ energy factories)
- Capillary growth (more oxygen delivery to your muscles)
- Fat metabolism (teaching your body to burn fat efficiently)
A 2005 review in Sports Medicine found that aerobic base training (zone 2) improves fat oxidation, endurance capacity, and performance over time (Holloszy & Coyle, 1984).
2. Zone 2 Training Improves Recovery
Training at low intensity doesn’t just build your engine—it helps you recover better between hard sessions. It’s like active recovery with long-term gain.
In fact, mixing high and low intensities (known as “polarised training”) has been shown to be more effective than training at moderate intensities all the time.
(Seiler & Tonnessen, 2009 – Scandinavian Journal of Medicine & Science in Sports)
3. Zone 2 Training Increases Volume Without Burnout
Zone 2 lets you accumulate training hours without overstressing your system. If you tried to do all your training in Zones 3–5, you’d burn out—fast.
Consistency is king, and Zone 2 lets you train more often, for longer, and stay injury-free. Now it's starting to sound more appealing, isn't it!
4. Makes You Faster in the Long Run
Here’s the twist: slowing down now helps you go faster later.
By improving your efficiency at low intensities, you raise the ceiling for higher intensities. Your body becomes a better endurance machine—burning less fuel at any given speed. (So you do still need to mix in some hard intervals during your week, yay!)
A study by Esteve-Lanao et al. (2007) found that runners who did 80% of their training at low intensity improved race performance more than those who trained harder more often.
But Zone 2 Feels Too Easy!
That’s the hardest part for many athletes. You might think:
“But I’m barely sweating. Surely I need to push harder to make gains?”
Nope.
Going harder every session doesn’t make you stronger—it just makes you tired. High-intensity work has its place (and we use it wisely!), but it needs to be supported by a big aerobic base underneath.
Think of it like this:
Zone 2 is the foundation. Speed is the roof. Build the base, and the roof can go higher.
How to Stay in Zone 2 (and Not Cheat!)
- Use heart rate or power, not feel – especially early on
- Be prepared to slow down—maybe even walk on hills during Zone 2 runs
- Don’t be embarrassed by your pace. This is deliberate, smart training. Perhaps hide these activities on Strava if your ego doesn't like it.
- Trust the process—you’ll be glad you did when race season comes
Zone 2 training might not look glamorous on Strava. It won’t leave you gasping. But it’s the work that matters most.
At BLOC, we see time and again: the athletes who commit to Zone 2 work are the ones who:
- Stay healthier
- Recover better
- Get injured less
- Peak stronger when it counts
- Race the best
So the next time your plan says Zone 2—don’t question it. Embrace it.
Train smart, not just hard.