How I Built My Running Endurance And Became A Faster Runner

by | 14 Mar 2021 | Advanced running, Personal running journeys

Running endurance was probably the last thing on my mind when I started running. Didn’t even know what that meant. I could probably only think of ‘basic survival’ because all I could do was 90 seconds of ‘running’ followed by a minute of gasping for air.

That was my running ‘endurance’ back then when I was going through the Couch to 5K program for total beginners.

And when it comes to speed, that was a very relative term in my running formative stages. Noted for its absence.

Building endurance in order to be able to run short distances was relatively easy but once I finished the program I set my targets somewhere else – long distance running. And for that sort of target I needed to work on endurance building more seriously.

I read various programs and learned that I needed a timely and measured approach. Building running endurance could not happen overnight. I realised I needed to do regular exercises and follow a proper method in order to increase running endurance and become faster runner.

Although I was keen to increase my endurance, I also had to be mindful of strains and efforts in order to avoid injuries. And I knew that a bad injury through overtraining for a marathon could set me back right to the beginning.

With all that in mind, off I went.

Running regularly is a start to building running endurance

From the beginning I was out there running three times per week. That routine helped redevelop my leg muscles, as well as strengthen my heart and lungs. When I graduated from C25K and moved to 10K I was still running not more than three times over 7 days.

I was getting stronger and more confident. I managed to run 5km in under 30 minutes, like an average cheetah. Or so I thought. Maybe a cheetah would go faster, not sure.

I was developing my endurance but was miles away (literary) from distance running, where I wanted to be. Running three times every week where the third (weekend) run got slightly longer each time, was the next step.

I knew I wasn’t the right type for fast short runs, I hoped to run long and to run long I had to study all aspects of endurance building.

I was learning more about what my obstacles were at the moment, and what I had to do to overcome them.

Start with the right intensity

Beginners program will gently take you from 0 to 30 minutes of running and it’s not important how long a distance will be covered. The Running Injury Territory is entered when we want to reach another landmark and simply go ‘too much-too soon’. Often without guidance, thinking we know enough.

When we go from 0 to 20km per week we will notice huge changes. The body will begin to tune in well, we notice the increase in strength and psychologically some might feel immortal.

Well, sort of.

careful approach to building running endurance helps avoid injury

I followed a half marathon training program by Hal Higdon, as I felt that I needed structured guidance in terms of routines and mileage. But the running program doesn’t know your level of fitness, it doesn’t know the level of intensity you can withstand and the type of running you can endure.

And I felt I needed a structure and a careful plan for my running endurance training, and I needed it to be tailor made to my body.

It is you who will need to listen to your body, adapt and move carefully forward without exposing your bones, muscles, tendons, ligaments – and ultimately your mind, to very demanding levels of physical and mental strains, before you are ready.

I didn’t start a half marathon training until I was really comfortable running my 5K’s and until I managed to comfortably run 16km on Sundays.

The way I avoided injuries, I didn’t put myself under any time constraint. I didn’t pencil in any dates, I didn’t sign up for any races. Instead, I took my sweet time in the most relaxing way and when the moment came I knew I was ready for a half marathon training where most of the training runs I was already doing comfortably.

Remember – gradual and gentle improvements over time rather than sudden shocks based on the fact that you want to run a marathon in 6 weeks. If your friends can do it, good for them. We are all different so focus on yourself first.

Reaching the half marathon target was an important landmark but getting there wasn’t too difficult. Transition from 5K to 10K was swift and not too hard. A step towards 16K and the HM marathon program were not overly demanding, especially because I wasn’t rushing it.

In the end it took me around a year and a half from a total novice to a runner who can cover half marathon’s 21K with relative ease.

The next target was the full marathon and I was fully aware what it would take to run 42 kilometers in terms of endurance. I only needed to remind myself how tired I was getting towards the end of the half marathon – and that is just half of what needed to be done.

A lot more work and study was ahead of me and that’s where my real running endurance training had begun.

Increase running endurance without hurting your feet – find the right type of running shoes

I had very good shoes that helped me run 5-10km in comfort. But those shoes may not be the best ones to carry me through the intensity of a marathon training.

My shoes were great for short to medium pavement distances but not the best shoes to cover some bad boy mileage.

careful approach to building running endurance helps avoid injury

You can’t compromise here, the shoes must be right or you will feel more strain in your joints and muscles. Find out what’s best for you through professional advice at a good running shop.

Build your aerobic base

To run long and increase endurance I had to build my aerobic base further. Aerobic basically refers to the body producing energy with the use of oxygen. Even simpler, when you inhale, the oxygen needs to move from your lungs to your muscles.

And to build a strong aerobic base you need to do it gradually, in stages, through long slow runs.

My marathon training program was making sure the runs would increase in a way that I didn’t panic when checking my schedule. Midweek runs were getting longer and would prepare me for more prolonged weekend outings.

Running long and slow is a way to develop your endurance base.

What is long? For a novice 5K is long but your body should adapt quickly to shorter distances. When marathon training, a long training run is 32km and for an ultra, a marathon is just another humble training distance.

During those runs I started using energy drinks in order to replace electrolytes lost through sweating, making sure my energy levels were maintained.

That way I also avoided dreaded cramping.

Equally, proper and regular hydration, a healthy and versatile diet and taking general supplements to support my body all become parts of my regular life. Running body needs proper loving care at all times.

What is slow? When I marathon trained I slowed down by 60-90 seconds per kilometer compared to the time that I wanted to run the actual run. If I wanted to complete a marathon in approximately 4 hours or so, I would need to run each kilometer in around 6 minutes. That is my comfortable running time.

That means my training runs would need to be 7ish to 7.30 minutes per km.

Even the marathon pros will train slow, nearly like mere mortals. And for some that will make up to 60-80% of their training. So, how do you know when you’re running slow or fast?

Simple. Your cardio zones will reflect 5 levels of running intensity based on your maximum heart rate. Hang on!? Car…dio zo……what?

KNOW YOUR Cardio Zones

You need to have a running watch or a heart monitor strap if you want to follow your cardio zones when training to increase running endurance. What we then follow is how fast the heart beats during various tempos:

careful approach to building running endurance helps avoid injury

Cardio Zone 1

(healthy), 50-60% of the maximum heart rate. This is easy, hardly sweat breaking. You can even talk in long, uninterrupted poetic sentences. Walking pace.

Cardio Zone 2

(fitness) 60-70% mhr. A bit harder but still very comfortable. You can still converse and often you feel that you could go at this tempo for a very long time. I spend 60-80% of my marathon training here. Like the pros. Off you go you calories. You can burn loads if you run like this for several hours.

Cardio Zone 3

(cardio) 70-80% mhr. This is a much harder breathing zone. No more uninterrupted poetic sentences. Spend 20-60 minutes here and your calories will do ice in the desert. This is proper running endurance training. Your heart and lung capacity is increasing, new blood vessels are building, and the circulatory system is improving.

Initially I struggled here but simply by training regularly I got quite comfortable.

Cardio Zone 4

(anaerobic) 80-90% mhr. OK, here you are gasping. Anaerobic literally means ‘without air’. Unlike aerobic, here the body is producing energy without oxygen. You may utter a word. Like……. ‘help’, for example.

This is intense, and you cannot go too long at this stage.

This will improve your VO2 max, which relates to the maximum volume of oxygen transported to your muscles. You are going to the limit and are building more endurance. Enter lactic acid which will accumulate in the bloodstream at this stage. Once we reach the threshold, we start to slow down – or stop.

Cardio Zone 5

(red line) 90-100% mhr. Runners use it during fast sprint training. Not for long though. This is a professional area. Ask your doctor if you should attempt it. Proper hardcore.

I use my running watch during training at all times, unless I will go out for a slow and relaxing run. That way I know where I am in relation to the type of run that I am aiming to complete.

The heart rate data isn’t absolutely necessary for running endurance training, many run happily without it but if your aim is to monitor your progress, it is a must.

Final stages of building running endurance: run faster

After months of regular 5 days-per-week running I reached the stage during my endurance training where I could run long but that also took a long time.

If you only train long and slow you will gain very good endurance – but you will remain very slow and will take you fairly long to complete those fairly long runs.

You can fail to train and develop all of the muscle fibers needed for faster running.

Basically, first train long and slow and once you’ve developed the slow base move on to faster training. Remember inhaling oxygen that then goes to your muscles? Well, the more oxygen in the muscles, the faster you run.

There are very good head-spinning scientific articles on the subject but when I was making my own personal journey I aimed at basic simplicity:


  1. To run long I need an aerobic base
  2. To get a good base I need to increase my long weekend runs
  3. And to make those long runs a bit faster I need to practice some speedwork. Simple.

Use interval & tempo running as part of your running endurance training

What is an interval? That is literally the rest period that happens between fast running.

For example, you aim to run 6 x 200m interval runs. You will run each 200m in a fast and controlled way, but not going your own superfast, all out running. Then you will slow down, jog or even walk those interval periods of 200 meters in between. Rinse and repeat 6 times.

There are many examples of interval running, you will find them in your chosen running program. I trained 6-10 x 200m and 5-8 x 400m.

Interval training is dating back to the late 1930s and is recognised as one of the most effective single training systems ever devised. Some even reckon that it can develop speed in a runner more quickly than any other form of training.

I followed Hal Higdon’s 5K program aiming to improve my time and in 8 weeks my 5K time went from around 29 minutes to just over 24mins. I run intervals in Zone 4 and the strength that I gained helped me improve my distance running.

Everything is linked.

Tempo runs gained popularity in the early 1990s. Another great training system aimed at improving your lactate threshold.

Here is what I do. I train 30, 35, 40 and 45 minute runs. First third of the run is warming up in cardio Zone 2. The second third I would accelerate and reach the point of running hard and steady, but not too fast, Zone 4 pushing to Zone 5.

The last third I would ease back, slow down to a more comfortable level again.. During fast running I was reaching the point of discomfort, gasping for air, pushing my lactate threshold.

I normally commit a day per week each to interval and tempo runs.

Mind your running ‘efficiency’. Plus exercises to become faster runner

This is what many place in the so-called ‘genes’ category. Efficiency relates to the economy of your motion and your biomechanics.

Basically, some guys are naturally smoother runners than others. The lower the oxygen consumption and the lower the amount of stress on your heart & lungs, the further you will run.

Still, this can be improved within our own limits.

There are many exercises to become faster runner, and many types of strength training suitable for runners.

Start by getting stronger and do strength exercises from planks to push ups, from squats and lunges to weight training. You don’t need to venture into the body building category but you should work a bit harder on your body to gain more overall strength.

careful approach to building running endurance helps avoid injury

Photo by Zach Lucero on Unsplash

Try and improve your cadence (or stride rate) as well. That’s the number of steps per minute.

Optimal cadence is considered to be around 180 per minute but there is no such thing as ideal. Some runners are really fast with a lower cadence number.

But if you constantly run too slow you will be likely to create more vertical energy, project more upward than forward motion and by doing so you are employing breaking forces and simply wasting energy.

The idea is the same as with increasing your distance – patience over time and practice.

Better stride rate and you are spending less time on the ground, going further and faster.

And finally…

Try Fartlek! Very useful when developing speed, stamina, endurance and running economy. Contrary to what you may think, fartlek is a Swedish word roughly translated as ‘speed play’.

Fartlek is very similar to interval training. The main difference is that the intervals in Fartlek are flexible and not set in stone, as is the case with the classic interval training. Instead you yourself, or whoever are running with, decide when to push and speed up, and how to measure your intervals. It is a great way to increase running endurance by being spontaneous and having fun, alone or with friends.

And don’t forget hill runs either!

I never specifically went out to work just on them simply because my local area is very hilly anyway. Your legs will get stronger, your stride will improve, you will become a healthier as well as stronger runner.

Running endurance training requires time and commitment. It will yield great benefits and will make you a much better overall runner. Exercises to become faster runner need to be done regularly and steadily. There are different methods and ways to increase running endurance, but they all take time. Because all of that is time consuming you won’t notice some of the improvements straight away.

I recently ran a half marathon in much more comfort, less fatigue and faster than ever before. My marathon training runs have become easier in every way and psychologically that is an important boost. It helps me advance to another target with confidence and assurance.

Remember to take your time, don’t compare yourself to others and be realistic. Some of us can develop quicker, some will take longer.

Believe that you can extend your abilities, work harder and you’ll get there. And, as always, enjoy what you do!

Cover photo by Brian Erickson on Unsplash


  1. Great article

    • Thank you, Ronald!


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