The first time I started looking up 50K finish times, I made the same mistake a lot of runners make.
I wanted one clean answer.
One number. One normal finish time. One simple way to know where I’d fit.
But that’s not really how a 50K works.
You’ll see one runner knock it out in 5 hours and make it look almost casual. Then you’ll see someone else out there for 8, 10, even 12 hours on the same distance, fighting through climbs, heat, stomach problems, cramps, and whatever else the trail decides to throw at them. And the strange part is… both efforts can be completely legit.
That’s what makes ultrarunning so confusing at first.
The distance stays the same, but the experience changes wildly depending on the course, the weather, the elevation, your fueling, your pacing, and how badly you mess things up in the first half without realizing it yet. A flat road 50K is one thing. A hilly trail 50K is a completely different animal. Same 31 miles on paper. Not even close in real life.
I learned that pretty quickly.
At first I thought a 50K was just a marathon with a few extra miles added on top. That sounds reasonable until you’re deep into one, holding a sticky gel, climbing something steep, and realizing your legs have stopped negotiating with you. That’s usually where the race starts teaching you what it actually is.
So if you’re here trying to figure out what a good 50K time looks like, I want to make this simple.
Yes, there are averages. Yes, there are rough benchmarks. But context matters more than almost anything else. Because in ultras, the finish time by itself tells a very incomplete story. A slower time on a harder course can be the better run. A “good” 50K time for one runner might be a complete disaster for another. And for a first-timer, the smartest goal is usually not chasing some impressive number.
It’s finishing strong enough that the whole thing doesn’t fall apart in the last stretch.
That’s the real conversation.
And once you understand that, 50K times start making a lot more sense.
The 50K Numbers You Need To Know
Most recreational runners finish a 50K somewhere in that 4 to 6 hour range if it’s on the road or a smoother trail.
But when you zoom out and look at larger datasets, the overall average lands closer to 7–8 hours, mostly because tougher courses and back-of-pack finishes pull that number up.
Elites might come through in around 3½ to 4 hours on a fast course.
On the other end, a lot of first-timers—especially on trails—are in that 6 to 8+ hour range, sometimes longer depending on how the day goes. You’ll see some runners cruise under 4 hours “no problem,” and others out there for 8, 10, even 12 hours on the exact same course.
Trail ultras change everything.
It’s common to lose 1–2 minutes per mile compared to road pace just from terrain. On smoother dirt, the difference might be small. But once you add hills, rocks, or technical sections, that gap grows quickly.
At that point, your finish time depends less on your 5K speed and more on things like terrain, elevation, weather, pacing, fueling, and how well you manage your ego over a long day.
Why 50K Times Are So Confusing
This is where most new ultrarunners get stuck.
You ask a simple question—what’s a normal 50K time—and you get answers that are all over the place. Some people say 5 hours. Others say 8. Both sound confident. Both sound right.
And somehow that makes it worse.
Terrain & Elevation (This Changes Everything)
The biggest factor is the course.
A flat 50K on the road or a smooth dirt path can feel like a long marathon. You might only be slightly slower per mile than your marathon pace.
Take that same distance into the mountains, though, and it’s a completely different experience.
Rocks, roots, mud, long climbs, technical descents—each one slows you down in ways that don’t show up on a simple pace chart.
I’ve run a flat 50K in about 5 hours, then a year later ran a hillier one in over 7 hours, even though I was fitter.
That’s how much terrain matters.
And it messes with your head, because the time alone doesn’t tell the story. A slower finish on a harder course can actually be the better performance.
That’s something you have to learn the hard way sometimes.
Pacing & Bonking (Where It Usually Goes Wrong)
The next factor is pacing.
This is where most first-timers get caught.
You feel good early on. Fresh legs, good energy, everything seems under control. So you run a bit faster than you probably should. Nothing crazy, just slightly ahead of what feels sustainable.
Then around 30K, things start to shift.
And by mile 25 or so, you’re hanging on.
I’ve lived that.
You go from thinking you’re having a great race to just trying to survive the last stretch. It’s not subtle either. It hits all at once.
There’s research showing that the runners who perform best in ultras aren’t the fastest early on. They’re the ones who slow down the least over time.
That’s a big difference.
Because it means the goal isn’t to go fast early. It’s to avoid falling apart later.
And that takes restraint.
Fueling & Hydration (The Quiet Mistake)
Fueling is another one that sneaks up on you.
In shorter races, you can sometimes get away with not eating enough. In a 50K, that doesn’t work.
If you don’t stay on top of calories, you eventually hit that low-energy state where everything slows down. Not just physically, but mentally too. It turns into this long stretch of just trying to keep moving.
I’ve had runs where I got this wrong.
Started fine, felt okay for a couple of hours, then suddenly everything dropped. Pace slowed, focus disappeared, and it became more about not stopping than actually running.
Hydration adds another layer.
Too little fluid, and things start to break down. Too much without electrolytes, and that causes its own problems. I’ve had a run where I got this wrong in the heat, and by the later miles I was lightheaded and struggling to stay steady on the trail.
Those mistakes don’t show up right away.
They show up late, when you don’t have much left to fix them.
Data Confusion (Why Everything Online Feels Off)
Then there’s the data you see online.
Strava, forums, race reports—most of it shows the good days.
You see someone’s 50K time where everything went right. What you don’t see are the races where they struggled for 8 hours or more.
So it creates this skewed picture.
You start thinking everyone is running 50Ks in 4–5 hours, and if you’re not there, something’s wrong.
But that’s not reality.
A lot of runners are finishing much later, especially on harder courses. They just don’t talk about it as much.
I remember reading discussions where people argued about what “average” meant. Some said 5–6 hours. Others said 7–8. Both were right, just talking about different kinds of races.
That’s what makes it confusing.
You’re comparing numbers without context.
The Real Issue
The problem isn’t that the times are inconsistent.
It’s that we expect them to be consistent.
A 50K isn’t a fixed experience.
It changes depending on the course, the conditions, and how you handle everything over those hours.
Once you accept that, the numbers stop feeling so confusing.
They start making sense.
The Science Behind Your 50K Effort
Let’s step away from stories for a bit and look at what’s actually happening in your body during a 50K.
Because once you understand this part, a lot of things start making sense. The slowdown, the fatigue, that feeling of being completely drained late in the race—it’s not random. It’s not you being “off.” It’s your body doing exactly what it’s supposed to do under that kind of stress.
Intensity — Why a 50K Feels Slower (But Isn’t Easier)
A 50K is not run at the same intensity as shorter races.
For most recreational runners, you’re sitting somewhere around 65–75% of your VO₂max. In simpler terms, that’s a moderate effort. You can talk a bit, you’re not sprinting, but you’re definitely working. It usually lines up with around 70–80% of your max heart rate.
That’s a big shift from something like a 10K or half marathon, where you’re pushing much closer to your limit.
In a 50K, you can’t hold that kind of intensity for hours.
So your body settles into something more sustainable.
And this is where the fuel system changes.
You rely more on fat as a fuel source. It burns slower, but there’s a lot more of it available. That’s why people talk about “fat adaptation” in ultras. But that doesn’t mean carbs don’t matter. They still do. Even at lower intensity, you’re burning a mix of fat and glycogen.
If that glycogen runs out completely, everything falls apart.
I think of it like a hybrid engine.
You’re running on both systems. If one drops too low, the whole thing struggles.
The 30K Wall (Where Everything Catches Up)
This is where things usually shift.
Around 30K, give or take, a few things tend to hit at once.
First, glycogen starts running low. Most people have roughly enough stored energy for around 20 miles. After that, you’re relying more heavily on whatever you’re taking in during the run. If you’ve been under-fueling, this is where it shows up.
It’s not gradual either.
You go from feeling okay to suddenly feeling empty.
I’ve had runs where it felt like someone flipped a switch. Same pace, same effort, and then suddenly nothing was there. Legs heavy, mind foggy, everything slowed down.
That’s not a lack of toughness.
That’s fuel.
At the same time, muscle damage is building.
Every step, especially downhill, puts stress on your muscles. Over time, that creates tiny tears. You don’t notice it early, but by the later miles, your legs start to feel stiff and unresponsive.
That “concrete legs” feeling?
That’s part of it.
Then there’s the coordination side.
Your nervous system starts to fatigue too. You might notice your form slipping, your posture collapsing a bit, maybe even tripping more than usual. That’s not clumsiness. That’s your system getting tired of sending the same signals over and over.
Put all of that together, and it’s not surprising that pace drops in the final stretch.
It would actually be strange if it didn’t.
Why Small Mistakes Get Bigger Later
This is the part that catches people off guard.
Something small early on—going a bit too fast on a climb, skipping a gel, not drinking enough—doesn’t feel like a big deal at the time.
But later, it grows.
Because by the second half of the race, your margin is gone.
I’ve seen it in myself and in runners I’ve worked with. Everything feels manageable early, then suddenly it isn’t. Not because something new happened, but because everything from earlier caught up at once.
That’s why ultras feel unpredictable.
They’re not really unpredictable.
They’re just delayed.
Age & the “Ultra Prime”
This one surprised me when I first came across it.
Peak performance in ultras often shows up later than in shorter races. Late 30s, early 40s, sometimes even beyond that. There’s data showing peak speed around age 40 for 50K runners.
And when you think about it, it makes sense.
You need endurance, patience, pacing awareness, and the ability to handle long stretches of discomfort. Those things tend to improve with experience, not just raw fitness.
I’ve coached runners who didn’t start ultras until their 40s or 50s and still improved year after year.
You also see it in races.
You’ll be out there struggling late, and someone older, moving steadily, passes you without much drama. Not fast, not flashy, just consistent.
That’s experience showing up.
The Runner’s High (Not What You Think)
Before I ran ultras, I had this idea that I’d feel amazing for most of it.
Like I’d just settle into a rhythm and ride that feeling all the way through.
That’s not how it works.
You do get moments.
Early on, maybe mid-race, there are times where everything feels good. You’re moving well, maybe even smiling without realizing it. That’s real.
But it doesn’t last.
As fatigue builds, as hydration and fueling get harder to manage, that feeling fades. The body starts sending stronger signals. Discomfort, tiredness, that sense of being worn down.
I’ve had races where I felt great at mile 15 and completely done by mile 28.
Same race.
That’s normal.
The mistake is expecting the good feeling to carry you through.
It won’t.
What carries you through is having a plan for when it doesn’t.
Eating when you don’t feel like it. Slowing down when you need to. Talking yourself through the rough patches without overreacting to them.
The Bigger Picture
Once you understand what’s happening under the surface, the whole experience makes more sense.
You stop taking the slowdown personally.
You stop thinking something’s wrong just because things got hard.
Because they’re supposed to get hard.
Your body is running low on quick fuel, your muscles are taking damage, your system is getting tired. That’s the cost of going that far.
And the goal isn’t to avoid it.
It’s to manage it.
Stay steady early. Fuel consistently. Respect the distance.
Because when everything starts to stack up late in the race, that’s what keeps you moving.
How to Train & Pace for Realistic 50K Times
Now we get into the part that actually matters when you’re out there doing it.
Because understanding the science is one thing, but it doesn’t help much if you don’t know how to apply it. A 50K isn’t something you can wing. You don’t cram for it the last few weeks and hope it works out. It’s built over time, slowly, with a lot of small decisions that either help you later… or come back to bite you around mile 25.
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Train Smart (Not Just Hard)
You can’t rush this.
The biggest mistake I see, and I made it myself, is trying to jump too far too quickly. If your longest run is 15 miles, you don’t suddenly go to 25 the next week. That’s how you end up tired, injured, or both. A gradual build works better. Something like a 10% increase per week is a good ceiling, not a target.
Most solid 50K plans will bring your long runs into that 20–22 mile range. You don’t need to hit the full 31 miles in training, but you need to get close enough that race day doesn’t feel completely foreign.
What helped me more than anything was back-to-back long runs.
Something like 16 miles on Saturday, then 10–12 on Sunday. That second run feels rough at first. Legs are heavy, everything feels off, and you question why you’re doing it. But that’s the point. It teaches you how to move when you’re already tired, which is exactly what the second half of a 50K feels like.
The first time I did it, I hated it.
By race day, I understood why it mattered.
Terrain matters too.
If your race is on trails, train on trails. I learned that the hard way. I trained mostly on roads for a trail 50K once, and while my endurance was there, my ankles and stabilizers weren’t ready for uneven ground. I ended up rolling my ankle mid-race.
After that, I stopped guessing.
You train for the surface you’re going to run on.
The Mistake I Made (And See All the Time)
I used to treat every long run like it was a race.
I’d go out trying to hit strong splits, pushing the pace just to prove I could. It felt productive. It felt like I was getting faster.
What it actually did was wear me down.
I was always a little too tired, sometimes slightly injured, and I never really learned how to pace an ultra. So when race day came, I did exactly what I had practiced—I went out too fast.
And I paid for it later.
That’s the thing.
Training teaches you habits.
If you always push, you’ll push on race day.
If you practice patience, you’ll have it when it matters.
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Pacing Strategy (Where Most Races Are Won or Lost)
The best advice I ever got was simple.
Start slower than your ego wants to.
And honestly, slower than that.
The first part of a 50K feels easy. Almost suspiciously easy. You’ll think you’re holding back too much. That’s exactly where you want to be. If it feels even slightly hard in the first hour, you’re probably going too fast.
A rough way to think about it is adding 10–15% to your marathon pace, assuming similar terrain. So if you’re around a 4-hour marathoner, your 50K pace might sit somewhere around 10:00–10:30 per mile, before you even factor in hills or technical sections.
And if it’s hot or the course is tough, you slow down even more.
I’ve learned to treat the first half of a 50K as a setup.
If I get to halfway and feel controlled—legs okay, breathing steady—I know I did it right. If I get there already struggling, I know I made it harder than it needed to be.
Walking (The Thing That Feels Wrong Until It Doesn’t)
This one took me time to accept.
Walking felt like failure.
But in ultras, it’s just another gear.
Walking steep hills often costs you very little time compared to trying to run them, but it saves a lot of energy. That energy shows up later, when everyone else is slowing down.
The first time I leaned into this, I had a moment that stuck with me. I was hiking a climb around mile 20, moving steadily, and passed someone who was trying to run it but barely moving faster. I got to the top feeling okay, while they were completely spent.
That race ended up being one of my better ones.
Not because I ran harder.
Because I managed my effort better.
How I Break It Down Mentally
I don’t think of a 50K as one long race.
I break it into sections.
First half is just getting there feeling good.
Second half is where the work starts.
And the final 10K… that’s where you deal with whatever you’ve got left.
Most people don’t speed up at the end of a 50K.
The goal is to slow down as little as possible.
And that comes from being patient early.
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Fuel & Hydration (This Decides Your Race)
If pacing is the structure, fueling is what keeps it from collapsing.
You need to eat.
Not when you feel like it.
Before that.
A good starting point is around 200–300 calories per hour, mostly from carbs. That can be gels, chews, sports drink, or real food. It doesn’t matter what, as long as it works for you and you can keep it down.
I usually set a loose schedule.
Every 30–40 minutes, I take something.
Early on, you won’t feel like you need it.
That’s when it matters most.
Because once you feel depleted, it’s already too late to fully fix.
Hydration works the same way.
Small, steady sips. Not big swings.
In cooler conditions, maybe around 500 ml per hour. In heat, it can be double that. And electrolytes matter. I’ve learned that the hard way too. One humid run, I relied on water alone, and by the later miles I was cramping and feeling off.
Now I don’t skip electrolytes.
The Mistake You Only Make Once
I tried skipping gels once in a race.
Felt good early, thought I could get away with it.
I didn’t.
Everything fell apart later. Pace dropped, energy disappeared, and I spent the last part of the race just trying to finish.
That’s when it really sticks.
You don’t skip fueling.
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Rest & Recovery (The Part People Ignore)
Training isn’t just what you do when you run.
It’s also what you do when you don’t.
I build in easier weeks every few weeks, cutting volume by about 20–30%. It feels like you’re doing less, but that’s when your body actually catches up and adapts.
Without that, you’re just stacking fatigue.
Sleep matters more than most people want to admit.
I’ve had small issues hang around for weeks, then disappear once I backed off and slept more. It’s not complicated, but it’s easy to ignore.
Recovery work helps too.
Stretching, foam rolling, light movement. Nothing extreme, just enough to keep things from tightening up too much. After long weekends, I’ll spend some time loosening up, maybe legs up against the wall for a bit. It’s simple, but it helps.
The Bigger Point
You don’t need perfect training.
You need consistent, honest training.
Build gradually. Stay patient. Fuel properly. Rest when you need it.
Because a 50K doesn’t reward the runner who pushes the hardest early.
It rewards the one who can keep going when everything starts to stack up.
And that comes from how you train.
Not just how hard you train.
Nuance, Limits & Personal Reality
Before wrapping this up, it’s worth pulling things back a bit.
Because there’s a lot of advice out there, and not all of it applies equally to everyone. Some of it sounds clear and confident, but once you dig into it, there’s always context behind it.
The “Average Time” Trap
People love asking for the average 50K time.
And on paper, you’ll see numbers like 7 hours.
But that number doesn’t mean much on its own.
A flat road 50K with good conditions might have an average closer to 5–6 hours. A technical mountain race might average 8 hours or more.
I’ve run a 50K in 5 hours and placed mid-pack.
I’ve run another in 7 hours and placed much higher.
Same distance.
Completely different effort.
So chasing an “average” doesn’t really help.
It just creates expectations that don’t match your race.
Body, Background & Reality
Every runner shows up with a different starting point.
Body weight, injury history, training background, even things like heat tolerance or altitude exposure—they all play a role.
A heavier runner might expend more energy per step. An older runner might need more recovery. Someone with a long endurance background might handle the distance better even without speed.
And that’s fine.
You’ll see all kinds of runners in ultras.
Some built for speed, some built for endurance, some just stubborn enough to keep going.
And they all find a way to finish.
Conflicting Advice (And Why It Happens)
If you read enough, you’ll notice something.
Advice often contradicts itself.
Run by feel. Follow strict pacing.
Walk hills. Never walk.
Eat constantly. Eat only when needed.
So which one is right?
It depends.
I’ve tried strict pacing plans before. Detailed splits, heart rate targets, everything mapped out. Then the race didn’t match the plan—weather changed, terrain felt different—and I stuck to the plan anyway.
That didn’t end well.
On the other hand, I’ve also gone too far the other way and just run by feel, only to realize later that adrenaline tricked me into going too fast early.
The middle ground works best.
Have a plan, but adjust when things change.
What Actually Works
The best approach is the one that fits you.
Not what worked for someone else, not what sounds impressive, but what keeps you moving and finishing strong.
Some runners do better with structure.
Others do better with flexibility.
Some need more volume.
Others break down if they push too far.
You figure that out over time.
That’s why I always tell runners—take advice, but pay attention to your own patterns.
Because in the end, you’re the one running the race.
The Bigger Picture
There isn’t one right way to run a 50K.
There are principles that help—pace conservatively, fuel consistently, respect the terrain—but how you apply them will always be a little different.
And that’s not a problem.
That’s part of it.
Because the goal isn’t to follow a perfect plan.
It’s to find a way that works for you… and gets you to the finish.
FAQ
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What finish time should I expect for my first 50K?
It depends more than most people want it to.
If you’re coming from a marathon background—say around a 4-hour marathon—you can use that as a rough anchor. Add somewhere around 10–25% to your pace per mile, then layer in whatever the course throws at you. So if you’re running around 9:00 per mile in a marathon, you might land closer to 10:00 pace in a 50K on similar terrain, which puts you just over 5 hours.
That’s the cleaner version.
The messier, more realistic version is this.
Most first-timers, especially on trails, end up somewhere in the 6 to 8 hour range. And that’s not a sign something went wrong. That’s just what happens when you combine distance, terrain, fueling, and time on feet. Aid stations slow you down, hills slow you down, small decisions add up.
Finishing a 50K is the main thing.
The time is just a number attached to it.
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How do I pace a 50K using my marathon time?
The simplest way is to start slower than your marathon pace.
Not slightly slower. Noticeably slower.
Something like 10–15% slower per mile is a good starting point. If your marathon pace is 8:00, you’re probably better off starting closer to 9:00 pace in a 50K, then adjusting for hills and terrain as you go.
But here’s where it gets different.
Pacing in a 50K isn’t steady the way a marathon is. It moves around. You might be running 9-minute miles on flats, hiking hills at 13-minute pace, then moving faster again on descents. That’s normal.
The goal isn’t even pace.
It’s effort.
If the effort stays controlled early, you give yourself a chance later. And if you get to the last 10K feeling okay, that’s when you can decide if you want to push a bit more.
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Should I be worried if I’m walking a lot?
No.
And honestly, this is one of the biggest mental shifts.
Walking in ultras isn’t something that happens when things go wrong. It’s part of how the race is run. Even strong runners walk at times—steep climbs, technical sections, while eating or drinking.
I’ve seen people power-hike hills at almost the same speed as someone trying to run them, but using less energy. Then they get to the top and keep moving while the other runner needs to recover.
That’s the difference.
If you’re walking, do it with intent. Keep moving, stay engaged. It’s not a break, it’s just a different gear.
And once you accept that, the whole race feels more manageable.
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How much should I eat and drink during a 50K?
You need to eat more than you think.
A good starting point is around 200–300 calories per hour, mostly from carbohydrates. That could be gels, chews, sports drink, or even real food if your stomach handles it well. The exact source doesn’t matter as much as consistency.
Start early.
Within the first 30–45 minutes, even if you don’t feel like you need it yet. Because once you feel depleted, you’re already behind.
Hydration works the same way.
Small, steady sips instead of big swings. In cooler weather, maybe around 500 mL per hour. In heat, it can be closer to a liter or more. Electrolytes matter too, especially if you’re sweating a lot.
And this part matters more than anything.
Practice in training.
You don’t want race day to be the first time you try something new.
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Will I lose weight during a 50K?
Not in the way most people think.
You might lose a bit of weight during the race, but it’s mostly water and glycogen, not actual fat. And sometimes, the opposite happens. You finish, and the next day you weigh more.
That’s inflammation.
Your body holding onto fluid to repair itself.
I’ve seen it happen, and it throws people off.
The bigger point is this.
A 50K isn’t a weight-loss tool.
If anything, your body needs more fuel during this kind of effort, not less. Trying to restrict calories during a race is a fast way to end up struggling late.
Focus on finishing.
The rest takes care of itself.
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How long should I train before running a 50K?
Longer is usually better.
If you already have a solid base, something like 3 to 6 months of focused training works for most people. Closer to 6 months gives you more room to build gradually and adjust when things don’t go perfectly.
Shorter builds—10 to 12 weeks—can work if you’re already in good shape, but there’s less margin for error.
Key parts of training stay pretty consistent.
You build your long runs into that 20–22 mile range. You might include back-to-back long days to simulate fatigue. And if your race is on trails, you spend time on trails.
You also practice the small things.
Carrying gear, fueling, maybe running in the dark if your race might stretch that far.
All of that takes time to figure out.
So if you’re unsure, give yourself more time.
It usually makes the whole experience smoother.
Final Coaching Takeaway
The real win in a 50K isn’t the number on your watch.
It’s getting to the finish line at all.
When you cross it, you’re not thinking about pace charts or averages.
You’re thinking about everything it took to get there.
The early mornings. The long runs where things didn’t go well. The moments during the race where you weren’t sure you could keep going, and then somehow you did.
You’ll be tired. Probably sore in places you didn’t expect. Maybe a little sunburned. Maybe holding back tears or not bothering to hold them back at all.
And it feels… worth it.
Not because of the time.
Because you did something that, at some point, felt out of reach.
I remember finishing one of my ultras and not even looking at my watch right away. I just stood there, trying to process it. All the training, all the doubt, everything that led up to that moment.
That’s what stays with you.
The time is just the record.
The experience is the part that changes you.
And once you go through it, something shifts.
You stop thinking in terms of “can I do this?”
You start thinking, “what’s next?”
Because whether it took you 5 hours or 9, you still covered the same 50K.
And that counts for everything.