AI interviews a sports scientist.

AI: Let’s kick this off the right way. Alex, when we talk VO2 max and heart health, what’s actually going on inside the body?

Alex: You really want to understand VO2 max? Break it into two sides. “VO” is the volume of oxygen, and “max” is the maximum rate we can move that oxygen to our tissues to create energy. Strip away all the complex biochemistry and it’s basically this: we take oxygen in, we get it into the blood, we send it to the muscles, and we use it to produce energy. For VO2 max to be high, two things matter — how much oxygen we can deliver, and how much resistance that oxygen meets on the way.

Inside the lungs, the blood, and the muscle, everything has to be clean, efficient, and unobstructed. If the lungs are compromised, oxygen exchange drops. If the blood is full of plaque or LDL-heavy sludge, that oxygen hits traffic. If the muscle lacks healthy mitochondrial activity, it can’t use that oxygen properly. VO2 max is the balance between fuel and resistance — pressure in pipes, can you tell I have been a plumbing and heating engineer since I was 16, lol.

AI: Which brings us neatly into cardiovascular disease. What happens when those “pipes” stop being healthy?

Alex: That’s when atherosclerosis enters the story. Think of fatty deposits slowly lining the arteries. It’s essentially biological plumbing failure. Those restrictions increase resistance dramatically. Your heart is suddenly pumping harder and faster just to maintain not only your blood oxygen supply, but also blood pH. Blood pressure rises. The system strains. You wear the pump out faster.

And this isn’t even modern. We’ve found mummified remains from 10,000 BC with atherosclerosis...
https://www.nejm.org/doi/full/10.1056/NEJMoa0906456
So humans have clearly always been vulnerable — it’s just that today’s environment accelerates the damage. Too many calories, too little movement, too much convenience.

AI: So obesity really becomes the accelerant — the fuel that makes cardiovascular disease unavoidable?

Alex: Completely. Excess weight means excess strain. More resistance. More work for the heart. More inflammatory signalling. More plaque. That’s why people who are obese often feel breathless walking up stairs, feel chest tightness, or get joint pain. Outwardly, they laugh it off. Inwardly, they’re scared. They don’t like thinking about the damage they can’t see.

And that fear is justified. Obesity is the single largest modifiable risk factor for cardiovascular disease. Mic Drop!
British Heart Foundation: https://www.bhf.org.uk/informationsupport/risk-factors/weight

AI: So let’s say someone reads this and thinks, “That’s me. I need to fix this.” What happens next? How do you approach weight loss at Phantom Coaching?

Alex: We start with what actually works — the scientific method. Not wishful thinking. Not fads. Not extremes.

Step one is simple: track your food. Don’t change anything. I don’t care if someone is eating 1,000 calories above their recommended maintenance — we don’t change their diet for two weeks. We observe. We gather data. If you change something before understanding it, you have no baseline.

After two weeks, we reduce intake slowly — a 200-calorie drop per day, per week. That’s it. No dramatic slashing. No starvation. Just gradual descent back toward maintenance.

Because people forget this: your hormones adjust to your habits. Meals at certain times. Quantities your body expects. Cut too fast, and you crash psychologically and hormonally. Cravings explode. Mood drops. Sleep suffers. Discipline collapses.

You didn’t gain six stone in one week Karen. You won’t lose it in one week either Dave.

AI: And once they hit maintenance?

Alex: Then we introduce a deficit. 200 calories per day, then 400, and at most 500. Anything beyond 500 becomes 'unhealthy', and certainly longterm it's unsustainable. People start approaching their basal metabolic rate, and the body panics. Irritability rises. Hunger spikes. They think the answer is “eat even less,” not realising that sometimes they need a refeed. Not covering refeeds here, but will in future posts.

Because as they lose weight, their maintenance calorie target also drops — so their original deficit disappears, that's right, poof. Gone! That’s when fat loss stalls. A temporary return to maintenance resets hormones, restores metabolism, and enables progress again.

This is long-term scientific strategy. No shortcuts. No “I’ll just have one extra chocolate bar; it won’t matter.” It matters. The method only works if the discipline matches the plan.

AI: Which brings us full circle — VO2 max improves, resistance inside the system drops, weight comes down, heart strain reduces, and cardiovascular disease risk falls. It’s all connected.

Alex: Exactly. Improve the oxygen flow. Reduce the resistance. Reduce the strain. Protect the heart. Lose the weight. It’s one ecosystem. Fix one part and you uplift the rest.

Conclusion

Cardiovascular disease doesn’t start with heart attacks. It starts quietly — with resistance. With breathlessness. With low fitness. With weight gain creeping up year by year until the body reaches a breaking point. As someone wise once said about addiction (which I cannot remember where I read it) "The chains of addiction are to soft to be felt, until they are too strong to be broken". The same applies here with chronic CVD.

But acknowledging your VO2 max gives you a way back, a pathway. A measurable, trainable, scientific pathway to reduce risk, lose weight, restore health, and regain control of the system that keeps you alive.

Small steps, consistent deficits, gradual change. The scientific method, applied to real life.

Call to Action

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