Unlock Better Fat Loss And Fitness With Zone 2 Heart Rate Training
Zone 2 cardio is the simplest, safest way to improve fitness, energy and metabolic health in midlife - without exhausting yourself. Here’s what it is, how it works, and how to get it right.
Illustration by Hanin Abouzeid on Unsplash
Stronger, faster, harder.
Not just a line from a dodgy movie you watched in your teens, but the belief of the majority when it comes to how to approach every training session.
Sweating and breathlessness is a sign that you’re working hard, right? Yes.
And when we work hard in life we’re more likely to get results? Yes.
So the more often we push ourselves in training, the better fat loss and fitness gains we’ll get? No.
It took me a mere 20 years to sulkily accept that science was right and I was wrong about how to get the most out of my training, especially for a) running and b) fat loss.
I’d sign up for an endurance event or decide it was time to cancel the meat-pie subscription again, and then proceed to thrash myself daily, priding myself on grit and mental toughness. I’d arrive at race day with a litany of niggles, too much stomach fat and on the edge of burnout - and just survive through the event. Rarely would I secure a coveted PB (personal best), with the much more common outcomes being shattering disappointment, pain for weeks afterwards and the intention that next time I would train ‘even harder’.
So, if this cycle of boom and bust sounds familiar, here’s the good news: there’s a better way, and it starts with doing around 80% of your training at a low intensity — AKA Zone 2.
Heart Rate Zones
Physiologists divide up the beating of our hearts into different zones based on % of maximum heart rate (MHR), and understanding them is a game-changer, especially in midlife. Because when you know how to train in the right zone, you stop spinning your wheels and start building fitness that actually lasts.
For high level athletes, MHR is calculated in a lab by undertaking gaseous exchange and blood lactate tests and all manner of fancy pants stuff, but for everyone else a simple formula will do.
I use the Tanaka formula: 208 – (0.7 × your age)
So, if you’re 50: 208 – (0.7 × 50) = 173 bpm (beats per minute). Here’s what that means in practice for a 50-year-old:
| HR Zone | Range | How it feels / What it does |
|---|---|---|
| Zone 0 (<50% MHR) | <87 bpm | Sedentary or minimal movement |
| Zone 1 (50–60% MHR) | 80–103 bpm | Very light activity, recovery pace |
| Zone 2 (60–70% MHR) | 104–120 bpm | Conversational pace; builds aerobic base; primarily fat-fuelled |
| Zone 3 (70–80% MHR) | 121–137 bpm | Moderate to hard; talking in short bursts |
| Zone 4 (80–90% MHR) | 138–155 bpm | Hard effort; heavy breathing; builds speed + lactate threshold |
| Zone 5 (90–100% MHR) | 156–173 bpm | Maximal effort; sprint-level work only |
Photo by Morgane Le Breton on Unsplash
Where Most People Go Wrong
Most recreational exercisers spend too much time in Zone 3 and 4 — the ‘middle.’ Hard enough to feel worthy, but not hard enough to create real adaptation. I was a past master at this kind of session. The last marathon I ran which finally tipped me over involved haphazard training through pain for four months, including with a strapped up sprained ankle.
I discovered post-race I had run the entire 26.2 miles with an average heart rate of 174 and a peak heart rate of 202, Sprint-level cardiac effort…for a 3.5 hour event. Impressive in a stupid way — and dangerous.
Elite athletes know better: they spend 70–80% of training in Zone 2. It’s the foundation everything else sits on.
I eventually discovered I had no Zone 2 at all. When doing anything more strenuous than walking, my body sent my heart rate straight up to near Zone 4. I’d never noticed because running at an elevated heart rate had come to feel comfortable. This meant that so much time training in the painful-but-pointless zone had confused my nervous system to such an extent it had effectively shut down, leaving me in a constant state of stress, anxiety, variable mood, hunger and fatigue. This is the hidden cost of living in those middle zones, of feeling like you ought to try and max out ‘bang for buck’ on every session because of stubborn and mistaken beliefs about ‘when the going gets tough’…etc.
Where the Magic Happens
For midlife health, Zone 2 is the sweet spot. It’s steady, repeatable, joint friendly, mood-boosting, kind to your nervous system and - here’s the one many of you will likely be most interested - the most efficient for fat burning for a midlife body.
Physiologically, Zone 2 training builds bigger, more efficient mitochondria (your cells’ energy factories). It’s easier on your joints. It lowers your resting heart rate, improves your blood sugar control (critical if you’re pre-diabetic), and reduces chronic inflammation. For weight loss, it’s invaluable: consistent Zone 2 shifts your body toward fat oxidation, which means it teaches it to burn fat not just during exercise but also when at rest instead of just defaulting to carbs - especially when paired with quality sleep and nutrition.
And unlike those sexy-looking HIIT workouts on Instagram, it doesn’t fry your nervous system or leave you sore for several days. Instead of feeling wired and depleted, you finish a Zone 2 session refreshed and energised.
Illustration by Round Icons on Unsplash
The Benefits Beyond Fat Loss
Energy: More mitochondria = more stamina for life (less post-7pm sofa crashing by default)
Mood: Reduces anxiety; doesn’t spike stress hormones
Brain fog: Boosts blood flow + cognitive function (better ideas and less babbling in weekly meetings)
Longevity: Strong links to reduced disease risk and healthier ageing
Resilience: Your body learns to stay calm while doing both physical and mental work - crucial in midlife
So rather than viewing recovery zone training as easy, a copout or for weaklings/other people, see it as something tactical and evidence-based that clever people, like you, do. And for the love of God please don’t take 20 years to get there.
How to Train in Zone 2
Aim for 2–3 sessions per week, 30–45 minutes each. You can do practically any movement that raises and keeps your heart rate within the correct rnage for you. Some starters for ten:
Outdoor power walks
Incline walking on the treadmill
Cross trainer
Bike
Gentle jogging
Long dog walks
Family bike rides
Walking meetings
Tools:
If you have a heart rate monitor, use the formula above.
If not, don’t worry; here’s a decent non-techy rule of thumb: You should be able to talk. You should NOT be able to sing. Your conversation should be normal sentences and not a few snatched words here and there. Effort should feel like ‘4–5 out of 10’.
That’s literally it. Your Second Act isn’t about pushing harder, it’s about training smarter.
If you’d like help figuring out your correct Zone 2 range or building it into your weekly routine, drop me a message here and I’ll get back to you within 48 hours to arrange a free, no-obligation consultation.
