Zone 2 Training Benefits: Why Pro Athletes Run Slower to Get Faster

I've been reading up on the 'Norwegian Method' and this whole Zone 2 obsession that seems to be taking over the endurance world. For the longest time, I thought if I wasn't huffing and puffing, I wasn't working hard enough.

It turns out I might have been spending too much time in 'No Man's Land'—that middle ground where you're too tired to recover but not fast enough to get the top-end benefits. I've started keeping my heart rate under 140 bpm, which feels incredibly slow, almost like a 'mosey' rather than a run.

Has anyone else seen real results from slowing down? My pace per mile is rubbish right now, but the science says my mitochondrial density should be improving. I'm hoping this translates to a better 5k time in the summer.

Also, for those in the UK, what are you using to track? My Garmin seems a bit optimistic with the wrist-based HR, so I’m thinking about picking up a chest strap for more accuracy.

It definitely feels counterintuitive at first. I tried my first "slow" run yesterday and felt like I was barely moving. My neighbors probably thought I was power walking! But the science behind mitochondrial density seems solid.

The hardest part is the ego hit, isn't it? Seeing your pace drop on Strava is gutting. But I've been doing 80/20 for six months now in the peaks and my recovery has never been better. No more 'niggling' injuries.

Spot on @NorthernLass. In Canada we get a lot of treadmill time in the winter, and Zone 2 is the only thing that keeps me from burning out before the snow melts. It builds that massive aerobic base so when you do turn on the jets for HIIT, you actually have the engine to support it.

How are y'all measuring your zones? I'm just using the 220-age formula on my Garmin but I feel like it puts my Zone 2 way too low. I'm practically walking at 130bpm.

@TXguy99 Throw that formula in the bin! It's notoriously rubbish. You're better off doing a talk test—if you can't hold a full conversation without gasping, you're too high. Or go get a proper lactate threshold test if you've got the spare quid.

Exactly. The formula is just a statistical average. I use the Karvonen method which factors in resting heart rate. Much more accurate for me.

So if I'm training for a half-marathon, should I really be doing 80% of my miles this slow? It feels like I won't be ready for race pace.

Yes! That's the 'magic' of it. By not smashing yourself every run, you have the actual energy to go 100% on your speed days. Most people run their easy days too fast and their fast days too slow. It's called the 'black hole' of training.

Preach! The 'black hole' is where progress goes to die.

I've seen my 5k time drop by nearly 90 seconds since I slowed down my Monday/Wednesday runs. It sounds like a load of bollocks until you actually see the data on your own wrist.

Okay, I'm sold. Going to try the talk test on my next loop around the park. If I'm chatting to myself like a crazy person, blame LondonLad!

What about fat burning? I've heard Zone 2 is the 'fat burning zone' but HIIT burns more calories per minute. Which one wins for weight loss?

HIIT burns more per minute, but you can only sustain it for 20 mins. I can do Zone 2 for two hours. Total caloric burn usually ends up higher with the long steady stuff, plus it doesn't spike your cortisol as much.

Spot on. Plus, Zone 2 trains your body to prioritize fats as fuel over glycogen. It's about metabolic flexibility. Essential for not 'bonking' during a marathon.

Does anyone else find it incredibly boring though? I have to load up on podcasts or I just start counting paving stones.

Haha, yeah. I usually listen to audiobooks. It's a great time to 'check out'. It's almost meditative once you stop obsessing over the pace clock.

Just finished a 45 min Z2 session. Had to walk the hills to keep the heart rate down. That was humbling as hell.

Walking the hills is exactly what you should be doing at first. Stick with it for a month and you'll be running those same hills at the same heart rate. That's the progress you're looking for!

Thanks for the encouragement guys. I'm going to stick to the plan for my spring training cycle and see what happens.