How to Run a 21 Minute 5K (Sub 20 Min. 5K How I Did IT!)

Written By: Jeremy N


No matter how fit and in shape you think you are, running an entire 5K is always a grueling experience that will shake your confidence to the core.

How to Run a 21 Minute 5K

Here’s a little math for you; to run a 5K in right at 20 minutes, you need to target a pace of about 6:30 per mile. Now, while timing is essential, that’s just the tip of the iceberg.

One note before we dig in... 

I never like to discuss anything that I have not experienced, so here is a screen shot of the first time I ran a 5K under 21 minutes.

under 21 minute 5K time


As with all other sports, it’s all about how you train your mind and body for the upcoming race. To get a great head start, it is of the utmost importance to train extensively for weeks before the actual race.

I run a tight ship, so I’ll be touching on everything you need to know about proper race training. 

All the information is already here, so I’ll just give you a quick summary.

A) Sharpen your Running Biomechanics

To run more efficiently, you have to be as smooth and streamlined like an air force fighter jet. But in this case, we’ll liken you to a mountain bike. To get the right speed, all the components have to work together seamlessly.

I’m going to take a highly educated guess and assume that you’ve never worked on your biomechanics before. So I’ll take you through the usual running checkmarks and identify which weak points need extra attention.

Give yourself a Full Running Form Assessment

While most people think that they have a great running form, the opposite is usually the case. Having a great form is the key to running efficiently and not tiring yourself out.

To assess yourself, set up a video camera and record your starting and finishing forms in your own 5K. 

After the run, here are the elements that you need to check out. I told you we were getting clinical.

  • Head: Your head needs to be perfectly still without any of that side to side motion. For those of you who did not know it, head movements tend to slow you down. Not to mention wreak havoc on your neck and spine after the run. If you notice this, try fixing your eyes on one spot and run as if you’ve got a book on your head. It helps a whole lot in the long run (pun intended).
  • Face: Don’t keep your face tight and rigid, you’ll just wear out your face muscles. Instead, keep things loose, mouth and eyes a tad open and make sure you see some cheeks flopping up and down. Kind of like that slow motion replay or sprinters crossing the line. And keep your chin down, you might stab someone with that thing.
  • Arms: It’s of the utmost importance to position your arms at the 90-degree angle. Your hands should be just under the chin and elbows going straight back. Similarly, keeping your hands loose will ensure you save energy. Throwing your hands wildly with clenched fists will definitely tire you out faster.
  • Feet: Again, keep thing loose and natural. Your feet should never land too far from your hips because it slows you down. Getting the best leverage translated to more efficient running. Also, don’t hit the ground flat-footed; it jars your body about. Instead, try to be on toes at all times.

B) Improve Your Running Speed

To run your next 5K in under 21 minutes, you actually have to be running much faster than before. Like I said, most people make the mistake of training with the aim of just making it to the finish line. You have to improve your running speed every time you train, and here’s how to do that.

Start With Interval Workouts

Also known as Fartleks, interval training simply means alternating between fast and slow running. The easiest way to achieve this is by running at 30 to 60 seconds and then slowing down to jogging for a couple of minutes. You can do this on a track or the treadmill for more accurate monitoring.

Here is the 5K training plan that I used

Sprint and Hill Workouts

Whereas distance runners will not typically sprint during a competition or race, including a ton of sprinting during training will make you a much faster 5K runner. Additionally, running on hills will give you all the intensity you need to boost speed. Uphill workouts help develop your aerobic capacity, leg strength, and endurance.

Add Weight and Resistance Training

Incorporating resistance and weight training will help runners develop stronger muscles. Use things like running parachutes, weighted vests, and other weights to help your body develop resistance.

Do Plyometrics

Think about it; isn’t running just another form of jumping? Plyometrics can help you move faster by developing stronger jump elements. Basically, squeeze in some rope jumps, lunges, butt kicks, high knees and skipping to your average workouts.

Focus on Breathing

Making the most of each breath not only helps reduce fatigue, but also increases your running speed and overall stamina. That’s because proper breathing lets in more oxygen that rejuvenates your muscles and expels the CO2 more efficiently.

While running, try to breathe into your belly rather than the chest. Also, take in as much air as you can through the mouth and expel through the nose. This lets in far more oxygen than you would otherwise get through your nostrils.

End it With a Stretch

Finishing off your training with a stretch is always recommended. This allows you to have greater flexibility that helps avoid injury and run faster. You can also incorporate stretches whenever and wherever you can.



Before we even get to the big day, it’s important to make sure that you have given your body enough time to rest. All the above training will be wasted if you do not allow at least 3 days to recover. Eat high glucose meals like pasta on the eve of the race to give your muscles as much energy as possible and go to bed early.

When the big day comes, make sure you wake up early and feel well rested. Do not do any pushups, pull ups and other strenuous activities. Just get in a couple of stretches and relax as much as possible. Eating healthy is also key, but make sure it’s a light and energy packed breakfast. The video below talks about what you need to eat to run your fastest 5K. Here are a few vital tips to consider if you’re going to be running your 5K in under 20 minutes.


Now, a lot of people think that a 5K run is just another short race that does not require plenty of hydration. For your information, 5K means 5 kilometers. I don’t know about you, but I’ve driven shorter distances than that and somehow managed to get thirsty along the way.

Start Right; Avoid Negative Splits

This is another chief mistake that I see in practically every 5K race I take part in. Starting right does not mean giving the first few Ks your all. The worst thing you could do is start too fast too early. Starting off with a ridiculous and unachievable pace will only lead to faster burnout.

Instead, settle near the front and try to find someone with a slower pace than yours to keep up with. This way, you will not run out of gas early on in the race. You can learn all about the effects of negative splits here.

Monitor the Clock

The most essential tip on how to run a 21 minute 5K is actually making it to the finish line with some time to spare. This means that you have to monitor your clock and see how much time you are are spending on each mile or kilometer.

If you notice a slag in the minutes, try to increase your pace and catch up with your training time. However, you don’t have to recover all the lost time in a single mile. You can spread out the missing minutes over each mile to maintain a less strenuous pace.

Finish Strong

If you followed all my training advice, then you were running more than the recommended distance every other day. This means that you have a couple extra gallons in your tank. The last couple of hundred meters is where you want to give it your all and empty your tank. Your sprint workouts will come in handy here as you leave your competition in the dust.

How to Run a 21 Minute 5K: Final Word

We could go to phase 3, but it basically involves a lot of gloating followed by days of pain all over your body. You will need to take care of your legs and body to help them recover from the grueling physical drain that a 5K run takes from you.

This is my training program, and it has never failed me before. Follow it carefully and you will improve your stamina, speed and running times substantially. But most importantly, remember to have fun with it.

The moment something stops being fun is when you begin to despise it. So make sure you have a great time, get is some good pictures for later and don’t be too disappointed if you don’t make your 5K in under the 20-minute mark. There’s always a next time, right?

Hi, Jeremy Here, 

I am the the guy behind Train for a 5K. On this site, I share everything that learned along my running journey. The content I create is the running training I wish I had before we started this journeyAbout Jeremy. 

I have run over 250 races including the California International Marathon, Clarksburg Country Run, and various other 5K & 10K races throughout the United States. I am a former Athletics department employee at University of the Pacific and Shoe Consultant with Dicks Sporting Goods

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