26 September 2025
Nicklas Rossner · watch on YouTube ↗ · click any timestamp to jump the video
Machine-generated by an AI from the transcript and the top comments. Not my writing, and it may contain errors.
A sport scientist's six-lever roadmap (training, form, weight, nutrition, pacing, psychology) to a top-2% 5K time, with each lever broken down for beginner, intermediate and advanced runners. The densest stretches are the periodization breakdown (4:07–6:10) and pacing (11:20 on); the ready-made training weeks start at 13:53.
A 2022 review of world-class distance runners: ~80% of training at an easy pace, only 20% hard. Run hard all the time and you get injured or burn out; run only easy and you never get fast. Concretely: of 200 weekly minutes, 160 easy, 40 for intervals/threshold/hills.
The nuance beyond 80/20: in the base and build phases the best runners use a pyramidal split (~80% easy / 15% threshold / 5% hard), then flip to polarized (~80/20 with little in the middle) for the peak phase. Never stack hard days back to back; each phase runs 4–16 weeks.
A 2023 study: after a 5K, experienced runners kept their form efficient while beginners broke down as fatigue set in. The goal isn't perfect form when fresh but durable form when tired — e.g. 3×10 min hard with 1-min breaks used specifically to reset technique. Advanced: film yourself 5 min at goal pace and look for breakdowns in the last minute.
Losing weight while running gets addicting, and relative energy deficiency in sport (RED-S) wrecks hormones and mood. Let performance, not the scale, be the guide. Even elites only cut a few pounds going into an A-race and deliberately regain them right after.
The 2019 "Keeping Pace" review found elite 5K runners start slightly fast and hold. Beginners copying that go out guns blazing and are cooked by km 2. Until you're under 20:00, run a negative or at most even split — a positive split is for fighting positions, not chasing a time.
An analysis of 2.2 million 2024 race results found fewer than 2% of runners broke 20 minutes. His honest framing: almost anyone fully committed could get there, but age, gender, time and resources make it unrealistic for everyone.
Before any training science: cue (shoes laid out the night before), craving (remember why you run), response (make getting out the door easy), reward (endorphins, tracked miles). Straight from Atomic Habits, applied to running.
A 2023 review found recreational runners improve body composition just by running ~10 km/week. When you do get intentional, only the big three move the needle: a sustained calorie deficit, strength training alongside running, and enough protein — meal timing and fasting are fine-tuning.
No marathon-style carb loading: ~6–10 g carbs/kg in the 24 h before, a simple high-carb meal 2–3 h out, stay hydrated. The one proven free boost: rinse your mouth with sugar right before the start.
Concrete beginner, intermediate and advanced weeks. E.g. advanced (5 runs + 2 strength days): 5×3 min at 5K pace, 2×12 min threshold, 80-min easy with surges, and 8×300 m at 1500 m pace on Sunday.
The top comment (983 likes) quietly demolishes the age-and-weight excuses — though the replies note he's the exception, not the rule.
The second-most-liked take: before optimizing for sub-20 you need sub-30, which is already a huge challenge for most people. Consistency over hacks.
A sharp biomechanics observation: 4:00/km looks like a casual stroll on the long-legged host and like "a jack russell chasing a rabbit" on a stocky runner — the same pace costs different bodies very differently.
From 26:55 to sub-20 in 3.5 years by building weekly mileage to ~50 miles, keeping weekday efforts moderate, and saving race efforts for races. Process over outcome.
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0:00This is what a 30-inut 5k pace looks like.
0:02And this is what a 20inut 5k pace looks like.
0:05In this video, I'll break down the fastest way to get to that sub 25k, no matter your starting point.
0:11And then I'll give you examples of training weeks for beginners, intermediate, and advanced runners.
0:17So, you know exactly what to do starting today.
0:20My name is Nicholas. I'm a sport scientist, physiotherapist, and former professional triathlete.
0:24So, how hard is it actually to break 20 minutes in a 5k?
0:28A guy named Brian Rock analyzed over 2.2 million results in 2024 and found that less than 2% of runners ran under
0:3720 minutes. That means if you want to run a sub 20-minute 5k, you're aiming for performance in the top few%.
0:44And here's the truth. While it's my belief that almost anyone could get to that sub 20-minute mark if they committed fully,
0:51it's not realistic for everyone. Age, gender, time, and resources all play a huge role.
0:58But if you want to maximize your chances, there are six key areas that you need to master.
1:03Training, weight, nutrition, psychology, pacing, and running form.
1:07And I'm going to break each of them down for beginners, intermediates, and advanced runners.
1:12And if you want to take the guesswork out, I've built a complete 5K training plan that maps out everything week by
1:17week. It's the same system that gets results like this.
1:20I'll leave a link to that in the description if you want to grab it.
1:23Now, let's look at exactly how to train to get under that magic 20inut mark.
1:28If you're new to running or running less than 20 km per week, then you don't need to worry about fancy training
1:34strategies just yet. Your number one focus should be consistency and gradual progression.
1:40But the real question is, how do you become a consistent runner?
1:44None of all the science and smart training strategies will work if you're not consistent.
1:48So, we need to make running a habit.
1:50Now, there's a bunch of science about habit building.
1:53And if you're having a hard time staying consistent, then I will highly recommend the book Atomic Habits by James Clear.
2:01But if you don't have the time to read that, here's a quick TLDDR for you.
2:05Basically, every habit follows a four-step loop.
2:07Q, craving, response, and reward. The Q is what triggers the habit.
2:12For running, that could be laying out your shoes the day before.
2:14The craving is the desire. Maybe it's feeling fitter.
2:18Maybe it's relief or maybe it's running a sub 20-minute 5K.
2:22Remind yourself of why you run.
2:24The response is the action itself.
2:26So, lacing up your shoes and going out the door.
2:28And the reward is what reinforces it.
2:31That could be the endorphin rush you get after a run or even something simple like tracking your miles in an app.
2:37So, if you want to stay consistent, make the cue obvious, the craving attractive, the response easy, and the rewards satisfying.
2:44That way, running becomes less of a struggle and more a natural part of your week.
2:48Once you're running two, three, or more times per week consistently for months, it's time to train specifically for that sub 20inut
2:565k. And to make your training most effective, we have to look at something called training intensity distribution.
3:02Now, stick with me here. It's actually pretty simple.
3:05A scientific review from 2022 that looked at the characteristics of the best runners in the world found they don't just train
3:13hard all the time. In fact, about 80% of their training is done at an easy pace and only 20% is hard.
3:20This is called the 8020 rule or polarized training.
3:23So why does it matter? Because if you run hard all the time, you risk injuries or you risk burning out.
3:29But if you only run easy, you'll never get fast.
3:32A polarized approach gives you the best of both worlds, building endurance while still improving speed.
3:39So, what does this look like in practice?
3:41If you run a total of 200 minutes per week, 160 of those should be easy and only 40 should be allocated
3:48to harder sessions like interval training.
3:51But you need both if you're going to run a sub20minut 5k.
3:55This is the framework that turns consistency into progress.
3:58Now, the hottest sessions could be V2 max intervals or threshold runs or hill sprints.
4:03And I'll show you an example of how to put all of this together into a weekly schedule by the end of
4:07this video. But if you really want to kick it up a notch, then there's still one thing missing, and that thing
4:12is called periodization. Now, if you're already consistent and running a lot, and you have experience with structured workouts, it's time to
4:20look at periodization. This is when you look beyond just what workouts to do and look at when to do them.
4:26Periodization means breaking down your training into different blocks that each serve a specific purpose.
4:32Most coaches use three different blocks when preparing for a race.
4:35The base phase where you build aerobic capacity with mostly easy mileage and some steady runs.
4:41The build phase where you introduce some more intensity like threshold runs, V2 max intervals, and race specific sessions.
4:47And the peak phase where you sharpen your fitness, reduce volume, and focus on quality so you hit your best performance on
4:54race day. The power of periodization is that it layers in fitness progressively.
4:59Endurance first, then strength and speed, and then specificity.
5:02Instead of trying to do everything at once, you train in cycles that build upon each other.
5:07And that's what allows advanced runners to break through plateaus.
5:10It's also what separates you from just being fit to being in race shape.
5:14You're not just running, you're timing your training so that you peak when it matters.
5:19So, how do we actually periodize our training like this?
5:22Or put another way, what does this look like in practice?
5:25A systematic review from 2022 looked at what the best runners in the world are doing.
5:30And here's the simple takeaway. First, think hard day, easy day.
5:34You don't stack hard days back to back.
5:36Instead, you follow up every challenging day with something easy to allow your body to adapt.
5:41Second, in the base and build phase, for most people, the best approach is what's called a pyramidal model.
5:48That means about 80% of your training should be easy.
5:51about 15% should be that medium pace or threshold pace and then about 5% should be hard.
5:57Then when you hit the peak phase, we flip the script slightly.
6:00Now we do a polarized approach with about 80% easy and then 20% hard and very little in the middle.
6:07And each phase usually lasts somewhere around 4 to 16 weeks depending on how long you have to train for your event.
6:15But here's the truth. You can have the best training plan in the world and still miss sub 20 if your form
6:21breaks down. Form is the silent killer of 5k performance.
6:25You can have the fitness, but if your technique breaks down when you get tired, then you're going to slow down.
6:31A study from 2023 compared beginner and experienced runners after a 5k and found that experienced runners kept their form efficient while
6:40beginners started to break down once fatigue set in.
6:43So, the real key is not just having perfect form when you're fresh.
6:47It's having a perfect form when you get tired.
6:49Now, if you're a beginner, your main job is just to become aware of your running form.
6:53Don't overthink your biomechanics. Just focus on a few simple cues.
6:57Run tall with your chest open.
6:59Try to up your cadence by about 10%.
7:02And let your arms drive the rhythm.
7:04Once you're consistent, the next step is training your form under fatigue.
7:08Remember, fatigue exaggerates any weakness. So, here's a couple of things you can focus on.
7:13Add some form drills once or twice per week.
7:15Use strength training for your legs and your core to keep you stable.
7:19And do workouts that force you to reset your form on the fatigue.
7:23Things like a 3x 10 minutes hard with a 1 minute break in between works wonders here.
7:28Then during your 1 minute break, refocus, focus on your technique, and then start up again.
7:34This helps your form become more durable and not just doable.
7:37If you're already close to sub20, then your form can be the difference between running 2005 and 1959.
7:45At this level, it's all about refinement.
7:48Here's a few things you can try.
7:50First, film yourself running at your goal race pace.
7:53So, 359 per km or 4 minutes per kilometer for at least 5 minutes.
7:58Then, look for subtle breakdowns in that last minute.
8:01Do you drop your cadence or do you do some overstriding?
8:04Then use strength training and plyometrics to reinforce your efficiency and your spring.
8:08The margin of error gets smaller the faster you get.
8:11So keeping your form sharp when it matters can be the breakthrough.
8:15But form is only half of the equation.
8:17There's another factor that quietly makes or breaks your 5K and that's weight and nutrition.
8:23Get it wrong and no amount of training or great running form can save your race.
8:27You see, weight is a crucial part of running and in general the lighter you are, the faster you get.
8:33But before you go starving yourself, there's one very important note to make.
8:38And that is that losing weight while running can become very addicting.
8:42And unfortunately, especially in running, there's a real issue called relative energy deficiency in sports or red S.
8:50This means you get all sorts of problems with your hormones and your mood by training too much and eating too little.
8:56So, make sure to eat enough to fuel your performance and don't let your weight determine whether you're going in the right
9:02direction or not. Your performance should always be your guiding line.
9:07Also, make sure that you feel good.
9:09If you're in doubt whether or not this affects you, I highly recommend seeing a professional.
9:15But if you are healthy and looking to lose some weight, here's what the science say to do.
9:18A review from 2023 found that most recreational runners naturally improved body composition just by running 10 kilometers per week.
9:27So, when you're a beginner, you don't necessarily have to micromanage your diet.
9:31Just moving more and keeping things simple will usually move things in the right direction.
9:36Once you're running consistently, we need to be a bit more intentional if we want to keep losing weight.
9:42And here's the thing, when we talk about running and weight loss, the rules don't change.
9:46The same three things always matter most.
9:48I've broken this down more in another video, but here's the short version.
9:52A meta analysis from 2025 found that the big three that actually move the needle the most are a sustained calorie deficit,
10:00strength training alongside your running, and enough protein.
10:03Everything else, meal timing, fasting, you name it, are fine-tuning.
10:07The big three are what matters the most.
10:09When you're an advanced runner, you're probably already lean.
10:13And now it's all about that finetuning.
10:15With some of the best athletes in the world, we do weight cycles.
10:19This means they might lose a few pounds going into their A- race, that could be a world championships or an Olympics,
10:25and then just straight after that race, we try to regain those pounds.
10:30We do this to avoid that relative energy deficiency.
10:32And to be honest, that's probably the biggest problem if you're running a lot.
10:37Don't get addicted to the scale.
10:39Measure your performance and how you're feeling.
10:42That's all that matters. Now, what about race day?
10:44Should we eat something special? For short events like a 5K, you don't need to take in massive amounts of carbohydrates like
10:51you do in a marathon. According to a review from 2025, you should just aim for about 6 to 10 g of
10:56carbs per kilogram of body weight in the 24 hours before your race.
11:00Then have a simple high carb meal 2 to 3 hours before your race.
11:04It could be something like toast or rice or a bagel.
11:07And make sure to stay hydrated.
11:09If you want a small boost that has been scientifically proven to work, then rinse your mouth with some sugar just before
11:16the race starts. That's really all it takes to make sure nutrition isn't the thing holding you back during your 5K.
11:22So, your training is dialed in, your form is on point, and your nutrition and weight is on point.
11:26But none of it matters if you blow up on race day.
11:29And that's why pacing is key, and it's where most runners miss their shots at a sub 20minut 5k.
11:35A 5K is short enough to feel like you can just go out sprinting, but it's long enough that you can burn
11:42out completely and lose minutes in the last 2K.
11:46A scientific review from 2019, literally called keeping pace, analyzed pacing strategies from 800 m all the way to the marathon.
11:54When it came to the 5K, they found that elite runners actually use a slightly positive split, meaning they start a bit
12:01faster, then they hold steady until that final sprint at the end.
12:04But here's the problem. When beginner runners try to copy that, they don't just start out a bit faster.
12:11They go out guns blazing and then by the second kilometer, they're already cooked.
12:16That's called overpacing. And it's one of the most common reasons that people blow up in the 5k.
12:22So, if you're a beginner, your number one goal is to avoid blowing up.
12:26Most beginners go out way too fast.
12:29So, for the first 2 km, go out a bit slower than you'd like to.
12:34Then in the middle, hold steady.
12:35And for the final kilometer, just leave it all out there on the track.
12:39That's the safest way to pace your 5k without blowing up.
12:43If you're closer to sub 20, then you might try to do a slight negative split.
12:48It gives you some control in the beginning and that mental edge to finally pick it up by the end.
12:54So, here are my suggestions. For the first half, run just a touch slower than your goal pace.
12:59Then when you hit the halfway point, accelerate slowly so that you run faster for the last half of the race.
13:06And for the final 800 m, just go all out.
13:10This pacing strategy builds confidence and teaches you how to close strong.
13:15Think of it like saving your nitro for the last lap in a video game.
13:18Use it too early and you're empty before the race even starts.
13:22Save it for the end and you'll be passing by people who are falling apart.
13:26And that's what sub 20-minute 5ks are made of.
13:28Now, if you're in the low 20s and just looking for that breakthrough, then the advice is the same as for the
13:34intermediate runner, negative split or at most an even split.
13:38And it's because until you're under 20 minutes on a 5k, going out with a slight positive split, so going out slightly
13:45too fast is still too risky.
13:47It's what elites do when they're fighting for positions, but not what you should be doing if you're fighting for a time.
13:54So, the best practice is still a controlled start and a faster finish.
13:57Okay, so we've covered the principles, but how do you actually pull all of this together into a training plan?
14:03This is where most people get stuck.
14:05They know the theory, but they don't know how to put it into practice.
14:08So, let me give you an example of exactly what a week could actually look like.
14:12Let's start with a beginner week.
14:14At this stage, the goal isn't to smash workouts.
14:17It's laying the foundation and staying consistent.
14:20So, basically, you could just go out for two or three or four easy runs.
14:23But here's another way to go about it.
14:25On Monday, we do three times five minutes form focused intervals with a one minute rest in between.
14:31On Wednesday, we do 20 minute easy, finishing with four by 20 seconds short sprints.
14:36On Thursday, we rest and on Friday, we do 4x3 minutes V2 max intervals.
14:40Saturday and Sunday, we also rest.
14:42Once you're training regularly, we can mix things up.
14:45Now, the goal is to add some structured intensity while keeping 70 to 80% of our training easy.
14:51We also start adding some strength training.
14:53We could also do that with a beginner, but I always feel like it's better to start with less and then we
14:59can always add on more from there.
15:01Here's what a week could look like.
15:03On Monday, we do 6x2 minutes at 3k to 5k pace.
15:06On Tuesday, we rest. On Wednesday, we do an easy run with some running drills and some strides.
15:12On Thursday, we add some heavy strength training.
15:14Then on Friday, we do a 35minut progression run, starting slow and building to our 5k pace for the final 5 minutes.
15:21On Saturday, we rest. And on Sunday, we do an easy run of 65 minutes.
15:26Finally, if you're already running five times per week, this is how it could be structured.
15:31On Monday, we do 5* 3 minutes at 5k pace with a 90 second rest.
15:35On Tuesday, we do an easy run with some running drills and some strides.
15:39On Wednesday, we do 2 by 12 minutes at threshold pace.
15:42On Thursday, we do some heavy strength training.
15:44On Friday, we do 80minute easy with surges every 15 minutes.
15:48On Saturday, we do some more heavy strength training.
15:50And on Sunday, we add some intensity with 8 by 300 meters at 1500 meter pace.
15:55But what about that strength training?
15:57What should it actually look like if we want to run faster for longer?
16:01I'll show you exactly how strength training can make you faster and less likely to get injured in this video right