{"id":422696,"date":"2026-01-21T02:40:10","date_gmt":"2026-01-21T02:40:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/422696\/"},"modified":"2026-01-21T02:40:10","modified_gmt":"2026-01-21T02:40:10","slug":"i-did-zone-2-cardio-every-week-for-an-entire-year-8-things-i-learned","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/422696\/","title":{"rendered":"‘I did zone 2 cardio every week for an entire year \u2013 8 things I learned’"},"content":{"rendered":"

Slow running<\/a> has been emerging as an unexpected way to run faster over long distances. Easy, conversational-pace runs<\/a> can help you build up your aerobic base and improve your endurance without burning out. Runner Keltie O’Connor<\/a> discovered this for herself when she committed to 180 minutes of zone 2<\/a> cardio every week for a year. <\/p>\n

‘Everyone thinks running is about being in pain. Running as fast as humanly possible till the lactic acid burns your throat,’ she said. ‘But the slower I ran, the faster I got.’ Putting in the miles at a reduced pace helped her achieve fitness<\/a> and personal milestones like completing her first marathon and working through grief, while also improving key health markers. Here’s what she learned after 12 months of zone 2 runs.<\/p>\n

1. Zone 2 cardio can be the foundation of your training <\/p>\n

As a reminder, zone 2 cardio is activity done at 60 to 75% of your max heart rate. Out of the six heart rate zones, with zone 1 being very light exercise (walking) and zone 6 being extremely intense (flat-out sprint), zone 2 is done at a light-to-moderate intensity. ‘It’s the pace where you can still hold a conversation comfortably,’ says Keltie, and uses fat and oxygen as an energy source. <\/p>\n

Slow running requires you to work within zone 2, which, counterintuitively, will help you to run faster long term, as research<\/a> shows it builds mitochondria in the cells, allowing to produce more energy. ‘Instead of killing yourself and giving 100% every single workout<\/a> or every single run, you slowly build up your endurance by increasing your volume through a lot of slow-paced runs throughout the week.’ <\/p>\n

Although Keltie engaged in a wide variety of exercise styles throughout the year, zone 2 was the cornerstone of her routine. ‘I did a lot of challenges: the 30,000 step challenge<\/a>, my run streak, the Berlin Marathon, hybrid training<\/a>. But throughout that, the one constant was always getting that weekly dose of zone 2.’<\/p>\n

Her aim was to increase her general health, and she didn’t have a particular target in mind. ‘A big focus of mine was Dr Peter Attia’s<\/a> recommendations, which is 180 minutes of zone 2 cardio a week for overall longevity. No specific goals, no races, just try to get two to three runs a week or some kind of cardio where my heart was in that zone.’ <\/p>\n

2. Zone 2 is individual-specific and changes day to day<\/p>\n

While a slow running and zone 2 pace often overlap, they aren’t the same speed for a lot of people. ‘At zone 2, or 60 to 70% of your max heart rate<\/a>, normally you can do cardio and speak full sentences. Breathing feels controlled \u2013 that’s slow running. However, some people feel like they’re going easy on a run and will look down at their heart rate on their watch and it is through the roof.’ Conversely, for some very experienced athletes, even a fast run might fall within their zone 2. So heart-rate zones are very specific to the individual.<\/p>\n

A good baseline formula to use for your max heart rate is 220 minus your age, and calculate the zones from there, Keltie suggests. ‘But the only accurate way is to go get tested.’ Instead, gauge whether you’re in Zone 2 by the ‘talk test’: if you can carry out a conversation. Sometimes, she took this literally: ‘I call my fianc\u00e9 or a friend.’<\/p>\n

She also says the talk test works better than using set numbers. ‘Your heart rate will change every single day from so many factors aside from how much you’re pushing yourself in a workout. Did you just chug an energy drink with loads of caffeine right before? How much sleep did you get? Did you drink a lot last night? Hormones and other factors will also have an effect.’ <\/p>\n

Losing fat while building muscle is the goal for many fitness fans \u2013 and while it isn\u2019t easy, it is possible, says FIIT personal trainer and coach Laura Hoggins<\/a>. In this four-week plan \u2013 created exclusively for Women\u2019s Health COLLECTIVE members \u2013 you\u2019ll get the workouts and nutrition guidance needed to improve body composition in 2026.<\/p>\n

Ready to build and burn? Tap the link below to unlock 14 days of free access to the WH app, find the plan and start training today.<\/p>\n

Click here<\/a><\/p>\n

\"fitness3. Zone 2 training helps you prepare for a marathon<\/p>\n

Zone 2 training helped Keltie build up to her first marathon safely. ‘Doing relaxed runs made me want to train for a marathon because I realised, “Oh, I can run slow and long, not just short and fast.”‘ So she set herself the goal of running her first marathon<\/a> and of being fit enough to enjoy the 42km. <\/p>\n

‘My programme was five to six runs a week, which in the past I would’ve thought was one to three hours every day just lactic-acid building \u2013 that’s what I thought a run was. But then when I looked at the programme Runna gave me, it was mainly zone 2, a little zone 3: slow, comfortable, sustainable.’ While there was some speed work and one to two harder runs a week, the pace remained mostly relaxed and conversational. ‘I was kind of shocked at how you just cruised.’<\/p>\n

Over time, she increased her mileage. ‘I didn’t just start cranking out 200 km weeks. I started at 12km in a week and then it moved up to 14. Then my long runs went from 10 km to 12 km. Zone 2 gave my body space to adapt while still getting the volume in to allow my body to run 42 km injury-free.’ <\/p>\n

Concentrating on zone 2 paid off, as Keltie successfully completed her first continuous marathon. ‘I never had to stop. I finished it dancing and smiling on my face \u2013 it felt easy. I left the marathon in a good enough mood that two days afterwards I went to Oktoberfest.’ <\/p>\n

4. Walking counts as zone 2<\/p>\n

When a medical procedure meant that Keltie couldn’t train for two months during marathon preparation \u2013 ‘No running, no jumping<\/a>, no lifting’ \u2013 she had to switch up her approach. ‘I thought, “There’s a different way to do zone 2. Rather than just running, you can also do it walking<\/a>.’ <\/p>\n

Things got easier once she’d properly recovered. ‘Once I was cleared from the doctor, I slowly got back into running. I would run 500m, walk 500m, then do a slow 5km, then a slow 10km, then a slow 20. Instead of forcing it, which I know makes me hate something, I slowly rebuilt my foundation and then signed up for a half and full marathon.’ <\/p>\n

5. You’ll see clear health improvements as your body adapts<\/p>\n

Keltie showed improvements in several key health indicators. Her blood work results after the medical procedure ‘came back great’ despite worries that the marathon would wreck her hormones.<\/p>\n

Her resting heart rate also dropped by six beats per minute. ‘It was about 60 beats per minute in January. By the peak of my zone 2 training, it was averaging about 54 beats per minute. <\/p>\n

Her heart-rate variability<\/a> (HRV) also improved by 10 points. ‘This is the craziest stat for me because HRV [measures] your stress,’ Keltie reflected. ‘If your HRV is lower than your average, you’re probably under-recovering \u2013 so you’re stressed, not sleeping, or you’re overtraining.’ <\/p>\n

But even though Keltie was running more, her HRV improved due to sleeping enough, recovering<\/a> properly, and not overreaching with her training by slowly adding in volume. ‘It’s cool to see how my body was able to adapt to more stress because I was doing it at at slow rate versus the opposite \u2013 overtraining and overreaching \u2013 which would’ve caused my average HRV to plummet.<\/p>\n

‘Aside from some tweaks and sore muscles<\/a>, I never got injured once during my marathon training or on marathon day,’ she continued. Keltie also decreased her body’s age by 9 years, according to Whoop’s algorithm, which, though not 100% accurate, took into account factors like zone 2, VO2 max, sleep and recovery. <\/p>\n

\"runner<\/p>\n

YouTube<\/p>\n

6. You can’t optimise for everything at once<\/p>\n

Keltie admitted that her zone 5 and strength training<\/a> suffered that year while she concentrated on zone 2. ‘I focused less on strength training and mobility. I pretty much only lifted enough to avoid injury. The main reason? That’s life. We only all have so many hours in a day and you cannot optimise every single second, especially when a lot of us have desk jobs and our job isn’t being a marathon runner.’ <\/p>\n

However, she planned to restore more balance in 2026. ‘Instead of more miles, I’m thinking of reducing my volume and refocusing back on the five pillars of my health span: Zone 2 cardio, VO2 max, strength training, mobility, and social and fun.’<\/p>\n

7. It’s effective for longevity<\/p>\n

At the end of March, Keltie’s dad passed away from heart disease, which changed how she viewed the runs. ‘Suddenly, this wasn’t just a fun little fitness challenge anymore. My grandfather on my dad’s side had died of a heart attack. My dad died from a combination of cardiovascular disease and a stroke. And my own blood work had shown not great Apo B (Apolipoprotein B) and Lipoprotein(a) (Lp(a)) [key indicators of heart disease] and cholesterol.’<\/p>\n

She saw that zone 2 work could help her reduce her risk of heart disease. ‘In that moment, I realised even though I’m fit, I’m genetically cursed when it comes to heart disease, which [incidentally] is the number-one killer on Earth. I realised slow running wasn’t a trendy thing that I saw online [but a way to] train for longevity. I don’t think the concept really…clicks until you experience something like this.’ Research has long supported her thoughts, with a study<\/a> finding that moderate-intensity cardio for 150 minutes a week led to blood pressure drops that cut coronary heart disease mortality by 4-9%.<\/p>\n

8. Consistent, small steps make a big difference <\/p>\n

Understandably, Keltie found it hard to stay active initially. ‘When my dad passed, I stopped training for a little while.’ But then running became her solace, a way to remind herself that life was still moving in the right direction. ‘I started something tiny. Even it was just for a few minutes or a 1 km run, I needed a small victory every day in that moment of grief. It wasn’t perfect, but every day I was able to show up and that built momentum. Sometimes a run is all you need.’<\/p>\n

Related Stories\"Headshot