I've been wondering about this for years, both as a doctor and as a trainer. Over time I've come to a few conclusions that I think could help many recreational athletes approach cardiovascular training differently.
Walk into any gym and you'll find people who have a programme. Exercises, sets, reps, progressive overload. Often with the help of a trainer. It determines which muscles they're targeting on which days, how hard to push, how much to recover. If we ask those same people about their cardiovascular training, they often will describe something they just do rather than something they've designed. They walk or sometimes run when they feel like it. Most people love a spin class because it's hard and they leave sweaty. (not that I'm against spin classes obviously, but you'll see why by the end of this article!) They lift weights until they're out of breath and count that as their cardio workout.
This doesn't mean everyone needs an elaborate endurance programme. It depends on your overall goal, time, and also — hugely important — what you enjoy. But if you enjoy endurance training, feel your approach could use an upgrade, or you're simply curious to understand it better, this article is for you.
Because I do think our cardiovascular system deserves more thought than simply doing "something".
Movement is not the same as training
This distinction sounds simple, and the definitions might be. But their implications can change the way you approach your fitness routines.
Daily movement or physical activity — walking, taking the stairs, not sitting for eight hours straight, a short walk after lunch — is a great way to improve our overall health.
Exercise is planned physical activity performed to maintain or improve health and fitness — i.e. go for a run/cycle or lift weights. But if we really want to improve not only our overall activity levels and long term adaptations in our body, we need to TRAIN.
And training is something different. Training is exercise performed as part of a longer-term system. Training deliberately plans progression and recovery. It applies a specific stimulus to the body with the intention of producing a specific physiological adaptation. Sounds complicated? It is and it isn't.
When we apply this thinking to strength training, it seems obvious to many people. Of course you need progressive overload. Of course you need recovery. Of course the exercises you choose matter.
I rarely see leisure athletes apply the same thinking to cardiovascular training.
Three things most people get wrong
Fitness trends have changed dramatically over the past few decades. The science has evolved too — but usually much more quietly. That's why I always try to come back to the underlying physiological principles rather than the latest headline.
Let's look at three misconceptions I come across again and again.
"Walking is my cardio."
Walking is genuinely one of the best things a person can do for their health. Mental health, metabolic health, cardiovascular health, longevity — the evidence is extensive and consistent. For someone who has been largely inactive, adding regular walking produces remarkable adaptations.
But if the goal is improving cardiovascular fitness — actually changing how the heart, lungs, and vascular system function under demand — that's a different conversation. Walking gets you there to a point. Beyond that point, a different, regular and targeted kind of stimulus is needed.
More on walking specifically in a dedicated post soon — it deserves one.
"If I'm out of breath, I'm doing cardio."
This one is worth unpacking carefully, because it sounds right.
Breathlessness tells you your body is working. It doesn't tell you what it's adapting to. You can be breathless after just briefly running for the bus, but wouldn't call that cardio training because it's just a short term reaction — not the sign of good, targeted training. Breathlessness can be a normal response to exercise — but it can also be a sign of illness. So it's not necessarily proof that you're training your cardiovascular system.
Cardiovascular fitness develops as a specific adaptation to training: Different training intensities produce different physiological adaptations. Some primarily develop the aerobic system. Others challenge the anaerobic threshold. Others push maximum oxygen uptake. Each has a place. Each does something different.
The experience of being out of breath doesn't tell you which adaptation you're driving. That requires understanding what you're actually doing — and why.
Zone 2 vs HIIT — which one should I do?
This question comes up constantly. The honest answer is that it's the wrong question.
Zone 2 and high-intensity interval training develop different physiological systems. One is not better than the other. A well-structured cardiovascular programme isn't built around a favourite intensity. It's built around understanding what each intensity does — and when each belongs. It's not either or — it's when and how do I create which adaptation?
That's what most cardio approaches miss entirely.
What a good cardiovascular programme actually looks like
The principles aren't complicated. But they are specific.
The same concepts that make strength training work — progressive overload, structured variation, adequate recovery, consistency over time — apply equally to cardiovascular training. The application is different. The logic is the same.
What this looks like in practice, how to build it, and how to know if it's working — that's what another post in the future will cover. But the starting point is simply this: cardiovascular training responds to structure the same way strength training does. It just rarely gets it.
Why this matters beyond the gym
Cardiovascular fitness is not primarily a performance metric. It's both a marker and a determinant of health. Cardiovascular fitness predicts healthy ageing, functional independence, disease risk, and quality of life in ways that doctors in clinics see every day. We often miss our cv health only when it's too late. Even a small cold can show us how a limited cv capacity can impact our everyday life.
VO₂ max — the measure of how efficiently the body uses oxygen during exercise — is one of the strongest predictors of all-cause mortality we have. So it is worth training specifically — more on VO₂max in a dedicated post.
So I think the importance of cv fitness is difficult to overstate. Training it properly can have a huge impact on our daily life, long term health and wellbeing. This is where exercise science and preventive medicine meet — and where I think the most important conversations are happening.
I often see that even people in the fitness industry tend to reduce cardiovascular training to calories burned, fat loss or the feeling of exhaustion. I think it's clear now that it deserves a higher place on our priority list and probably a more polished image ;)
And our fitness — including cardiovascular, strength, balance, coordination — isn't created by a handful of workouts. It's the result of giving your body a reason to adapt — again and again, over weeks, months and years.
This is the beginning of a much bigger conversation. Over the coming months I want to explore cardiovascular health, training and prevention from both a medical and coaching perspective. We'll talk about physiology, movement, performance, healthy aging and — as always — why understanding your body matters just as much as training it. My hope isn't simply that you'll exercise more. It's that you'll understand why you're training, what your body is adapting to, and start asking better questions. Because I genuinely believe that's where long-term health begins.