Zone 2

[Gymbunny2025]

I’d love to hear people’s experiences of zone 2/burning fat. I know I don’t do enough zone 2 and it’s a NYR for 2026. I’d love to burn more fat too.

for reference I’m very fit, normal bmi, not looking to lose weight, run a couple of HM a year. But I’m much more heavily into hiit and cardio than endurance.

Zone 2 is about building volume without putting excessive pressure on your body.

Training your body to use fat rather than carbs as fuel takes a lot of effort and specific nutrition, and even then isn’t what makes the difference in losing body fat - that’s simply a calories in and out equation. It’s not really got anything to do with what your heart rate is while exercising.

If what you want is to be what people call toned, add weight training to your regime.

Thanks. I’m very toned. I do weight training and Pilates too.

do you train in zone 2? One of my biggest concerns is time. But I would love to hear experience of others

When training for your HMs, do you do all your runs at hard effort? Or do you do a long run at an easy pace?

Zone 2 training is literally about keeping your heart rate down. It’s not some magic thing. Studies have shown that the main benefit is in preventing injury and burnout by having some of your training volume at lower intensity. You won’t be getting any performance adaptations in Zone 2.

What I keep reading is that the majority of training should be at zone 2. I do maybe 60 mins max a week normally. Just interested to hear about others experiences of it.

I am a runner who also does weights and HIIT.
I think zone 2 training is most useful for people who do very high exercise load - so eg the guys at my running club doing 100+ miles per week need to do some lower intensity stuff to avoid injury and overtraining. For most people with limited time available i assumed you get much more bang for your buck doing more targeted intense sessions, so long as you still have scope to recover properly.

We sound similar! How much zone 2 do you do roughly per week? I’d say on average I either do a 30 plus 45 session or one 60 mins. I was thinking I could probably add a couple more hours in on a bike quite easily. No idea if that would count for anything though

and yes it’s the limited time thing isn’t it and bang for your buck. Although I’m always surprised how calories burned in Z2 isn’t far off a HIIT workout

Thinking about it I probably do another 90 mins in 2 aerobics classes I do. But I don’t think the shorter sessions will help with the fat burning during exercise 🤔

Lower intensity exercise is primarily (but not exclusively) fuelled by burning fat.
Higher intensity exercise is primarily (but not exclusively) fuelled by the body's glycogen stores.

The main benefit of zone 2 is being able to improve stamina and exercise longer while minimising over-use injuries. The exercise should be at a level where conversation is natural.
It's good to have a mix of different activity levels to cover the range of health benefits.

If aiming to lose bodyfat, then managing diet looking at calories, macros and timing is more effective than taking up a lot of zone 2 exercise

I don’t specifically target Z2. I do try to do a couple of easy paced runs per week (alongside a tempo session and an interval one) to up my running mileage so I’d guess they are z2. I guess it is reasonable that a consistent z2 isn’t too bad on calorie burn versus HIIT given the rest bits in HIIT but I find the HIIT has a much bigger impact on my fitness levels and ability to push hard which is more important to me than calorie burn

Thanks I guess that’s kind of what I do too. How long would your easy paced runs be?

just to be clear again, I’m not trying to lose weight. My bmi is 21 ish. But like today I did an interval run then a 60 mins spin class. As you say, to me it has a bigger impact on my fitness than Z2 for 2 hours. But everything I read says to progress the majority of training should be Z2. And I hate how I run out of energy after a couple of hours high intensity. I wish I could fat burn more. IMHO having to eat to fuel exercise is silly!

I work out most days for 45 mins to an hour (cardio). I would say maybe 70-80% of what I do is Z2 stuff: endurance cycling, running at an easy pace with some spells of moderate and 20-30% is high intensity (spin, interval runs, climbs). If I was exercising less, say an hour or two a week, I would shift more to high intensity work to get my heart rate up, but if you are quite a heavy exerciser, Zone 2 is kind of the foundation that everything else is built on.

OP, I’m not sure you’re reading the right things, or understanding what you’re reading (and what people are telling you here).

Zone 2 is not some silver bullet. It’s a means of increasing training volume without excessively stressing your body.

You can’t adapt your body to burn fat, and not have to eat to fuel excercise, and not lose weight!

Do you even know what your Z2 heart rate is?

Search for The Real Science of Sport podcast episode on Zone 2 from August.

A lot of fitness advice (particularly on SM) is either pitched too low (take the stairs, walk across the car park...) or a bit too hardcore and elite for most recreational runners/ exercisers. It's also often male centric and not optimal

As a runner who generally runs 2-3 HMs per year, the long run (usually 1-2 hours) is the big feature of the week. I use parkrun as a tempo/ threshold session for speed/ high intensity work and try to fit in another 30 min session of running mid-week. I also do two weights sessions; one circuit style, one heavier in the gym. What I have to bear in mind is that my job is heavy on my feet all day, plus I have a short active commute on foot/ bike which is below zone 2. The upshot of that is that my body has a lot of functional movement and that's not great for recovering from higher volumes of formal exercise at whatever intensity before adding in female middle-aged hormones.

If the volume of overall exercise is fairly low, then the ratio of high intensity can be higher. Higher levels of zone 2 are of more benefit to high volume exercisers with a good mix of intensities, and capacity for active recovery without over-doing it.

I find my watch's definition of zone 2 hard to meet. Walking is way under (unless blasting up hill with a heavy bag) and continuous running tends to bump into "zone 3" (although I can still chat, which I consider more important). It's only really run/walking that keeps it in that specific zone.

What do you mean ‘do I even know what my z2 hr is’? That sounds so patronising 😂. Yes which is why I know how much time I spend in Z2.

as pp said it’s pretty common advice that the majority of training should be in Z2. I don’t do this atm. Which is why I am wanting to increase. I posted to hear about other people’s experiences of training in Z2. One of the (many) benefits is that you burn fat as primary energy source rather than glycogen that runs out much more quickly.

Id say my exercise routine is pretty well rounded: run, spin, cycle, aerobics, weights, Pilates, yoga. What it is lacking is Z2. But as we all know it’s not as simple as just adding in more hours. So I’m at the contemplation stage. What would I drop etc. how relevant are the benefits to me. How do others incorporate it. Hence posting!

id love to hear about how much zone 2/easy pace/all day pace/whatever you want yo call it you manage?

Yes that’s what I’ve been told as well. It’s the foundation that everything else is built on. I just find it so… dull 😂

agree endurance runs I always creep above Z2 as I fatigue but that’s normal and as you say I base it on how I’m feeling plus if I’m able to carry on a conversation (and feel I could continue on comfortably at that pace).

I workout a lot during the week plus also have a very active job. It’s just that zone 2 sweet spot that I need to focus more on.

didn’t think that was a controversial thing to say in any way! Only on mumsnet apparently 😂

I was also going to recommend the Science in Sport podcast mentioned above.

What are your aims? Are you training for something in particular? You say you don’t like running out of energy after a couple of hours of hard effort… are you targeting a marathon or ultra or longer triathlon or something? Most longer distance stuff requires fuel, especially at higher intensity. Reading interviews with the UTMB winners this year they had so much focus on what they would eat and when and why.

Just always trying to improve. Not a fan of endurance (hence why I don’t do it!) so no interest in marathons etc. I enjoy 10km but do HM a couple of times a year just to keep up with the longer runs.
Even then I will run well beyond zone 2 pace.

the science of fuelling is fascinating and ever evolving I agree!

sadly I don’t have the time to be out on my bike for hours on end which I think is fantastic Z2 training. I think even aiming for 50% endurance 50% high intensity would be a big thing for me. I might try and start lower and build it up gradually. I only get endorphins from very high intensity too which I definitely miss with endurance stuff 🙈

I find cycling good for anaerobic. It's generally "easy" but the rest from downhill, and the effort bursts to go uphill are quite good for tipping into anerobic effort. I struggle to achieve that from running intervals.
My other anaerobic champion is stuff like trampoline parks and obstacle courses... not that practical for regular use though

Swimming is a good zone 2 for me.

Noooo cycling up a hill is a million times easier than running up a hill 😂. Spinning is definitely my most anaerobic activity though. Maybe that’s why I find cycling way easier in comparison!

Swimming I’m not even sure I get into Z2. I’m very slow!

I confess I haven’t read much on this in a while, but I thought the main benefits of z2 training were
a) allows adding extra volume without over training
b) adapts body to work at lower heart rate (and therefore burn more fat with less reliance on carbs) at moderate intensities

But it sounds like (a) doesn’t apply as you are comfortable at your training volume and mix it up with different training types which also helps avoid over-work, and (b) is more applicable to long distance stuff where you would otherwise need to fuel.

I just checked my race stats and for a half marathon am almost entirely in zones 4 and 5. For a full marathon predominantly 4. It isn’t until I get to a 100k+ trail race that I’m predominantly in z2.

I am not trying to say z2 isn’t of benefit, it just seems to be of more limited benefit given your aims and training programme and time available. It’s only when I’m training for a long ultra that I do more z2 stuff as I just don’t have time for it generally - and even then I’ll generally try to wing it on fitness and bloody mindedness more than low-intensity training miles!

Yes definitely HM distance isn’t Z2 unless I deliberately slow down. For me I know that when I increase endurance work it impacts positively on my VO2 max and allows me to increase my FTP etc. there are so many benefits to Z2 but this post wasn’t really to discuss them. It was more to hear about how people incorporate Z2 into their training, especially when they also prefer high intensity, and obviously we all have limited time.

I don't run much, i cycle but my DD runs at a good level

I was always of the mindset that Z2 was only of use for people with a lot of time to do volume.

But we have both found that small tweaks to training ie add in just an extra 15 or 30 extra per session (either a z2 one or a Vo2 max sess) could be a longer warm up/cool down too, increases Z2 time by 2 hours per week, thats an extra 100hours per year!

We ve been doing this for a while now and have noticed considerable benefits, perhaps more so for my DD, her Z2 mile per min time, around 7mins per mile over 90 mins.
She can also hit the track speed sessions harder and is getting PBs very often.

Thank you this is so helpful. I absolutely agree doing Z2 makes me hit more PB and makes me faster. Adding it in as a 30 mins warm up is a great idea 🙏