The Metrics That ACTUALLY Matter (And the Ones That Don’t)

By  Fergus Crawley 

Metrics overwhelm us. Full stop.

We’re all walking around with a VO2 max estimate, a readiness score, a Strava heatmap, a calorie count, and a sleep score all competing for our attention before we’ve even had breakfast. And most of us are reacting to every single wobble in every single number like it means something.

It usually doesn’t.

So here’s a rundown of the metrics we think are actually worth your attention – and how to use them without letting them own you.

Calories (and macros)

View them like your current account balance.

Track your intake, be aware of it, use it to make informed decisions. That’s it. Don’t build your entire relationship with food around a number on an app.

Amount matters more than almost anything else for performance and body composition. Layer in quality – micronutrition, whole foods, sensible carb timing around training – on top of that foundation. But don’t confuse the foundation for the whole house. We went through the whole “IIFYM, live off Pop-Tarts and whey protein” phase collectively as an industry. Yes, you can stay lean eating rubbish. No, you won’t feel or perform your best doing it.

Track it for a period to build awareness. Then either keep tracking if you’ve got a healthy relationship with it, or use what you’ve learned to make better intuitive decisions from there.

The notes section of your training diary

This is the one people skip, and it’s the one that gives everything else context.

Numbers are objective – they go up, they go down. But they don’t tell you why. Maybe your lifts went up because work was quiet and you were sleeping brilliantly. Maybe they went up despite a chaotic month, and that’s actually more impressive. You won’t know unless you write it down.

If you look back at “six weeks that went really well” and try to repeat the training without accounting for the fact that life looks completely different now, you’re going to get a completely different outcome. Metrics without context are just lines on a graph.

Smiles per mile

Not on your watch. Not in any app. But arguably the most important metric on this list.

Some sessions are just turning up and getting it done. Others make you smile – properly, uncontrollably, mid-session or after. That’s worth noticing. It’s worth actively choosing sometimes, too – running twenty-five seconds per K slower than prescribed because you’re running with a group of mates and having a genuinely great time is not a wasted session.

Training is repetitive by design. Same places, same sessions, small progressive overload, week after week. So when you catch yourself grinning – after a big lift, on a solo run somewhere new, wherever – that’s a signal worth paying attention to. It’s also a good way of fighting back against a life spent staring at screens: your body telling you that you’re having a good time is a very different kind of feedback to a like on a photo.

Your actual training data

Sets, reps, loads, times – written down, tracked properly, over time.

The value here isn’t any single number. It’s the story those numbers tell across weeks and months. People are quick to overreact to one or two data points when really they need a much bigger sample to draw any real conclusion. Some people respond to a block of training in a nice steady line upward. Others plateau for weeks, then jump. Some don’t seem to move at all until week six, then suddenly do. If you only ever look at this week versus last week, you’ll misread what’s actually going on.

The algorithmic stuff – VO2 max, race predictors, threshold pacing

Useful. Also, largely proxies.

Your watch’s VO2 max estimate isn’t measuring your VO2 max directly – it’s inferring it from heart rate data, which is itself influenced by a dozen other variables. That doesn’t make it useless. If it trends up over six months of training, you can be fairly confident your actual fitness has improved, even if the specific number isn’t gospel.

Same principle as scale weight on a diet. Not the full picture on its own, but if it’s trending the right way and you’re not falling apart in the process, it’s telling you something real. The trap is fixating on the single number and ignoring everything else going on around it.

Hours of sleep – and when you’re getting them

One of the single biggest performance levers available to any of us, and one of the most ignored.

It’s not just about hitting eight hours. It’s about consistency – a steady circadian rhythm, similar bed and wake times, and an honest awareness of how disrupted sleep is actually affecting you. Five broken hours across three wake-ups is a very different thing to five uninterrupted hours, even though the number on the app looks the same.

The real skill isn’t perfect sleep. It’s not stacking bad nights. If you know last night was rough, that’s the signal to protect tonight -not to just push through and hope for the best two nights running.

And if life genuinely doesn’t allow for enough sleep right now – new baby, demanding period at work, whatever it is — the honest move is to adjust your training expectations accordingly, not to pretend the deficit doesn’t exist.

Progressive overload – properly understood

Most people think progressive overload means the numbers on the sheet go up. Weight increases, pace increases, done.

That’s not quite it. Real progressive overload is doing the same session again and finding it easier – lower heart rate, lower perceived effort, same output. The ability to add more load or intensity next time is a consequence of that adaptation, not the definition of it.

This matters enormously in hybrid training specifically, because fatigue masks fitness. You can be eight weeks into a block, strength numbers feeling flat or even dropping, and conclude the whole approach isn’t working – when actually you’re just carrying cumulative fatigue from increasing volume across multiple disciplines at once. Deload, let that fatigue dissipate, and your actual fitness often reveals itself. This is exactly the point in a hybrid block where people quit, convinced it’s not working, when really they just haven’t given the adaptation time to show up.

Don’t rush the early weeks of a block just because you feel fresh, either. Move at the pace the programming intends. Trying to make every session maximally hard while you’ve still got fresh legs just pulls forward fatigue you’ll need later.

The bottom line

None of these numbers mean much in isolation. Context is everything – and half of that context has to come from you, not your watch.

Track what’s useful. Notice what actually matters – including the stuff with no dashboard, like whether you’re still smiling. And don’t mistake a proxy for the real thing, or a bad week of data for the full story.

Want coaching that looks at the whole picture, not just the numbers on your watch? Get in touch with the OMNIA coaching team.