I've been working with runners since 2007.
And in that time I've lost count of the number of people
who've told me about one specific frustration they have with their running.
You might feel the same...
It usually goes a little something like this:
“So I usually run 5K and 21:30, give or take.
I've looked at various pace calculators and they suggest
that I should be able to run a 3:30 marathon.
But I'm really struggling to break the sub-4 hour marathon barrier.
What's going on with that?”
The secret to improving your running endurance is found in training
your energy systems so you can run faster for longer without getting tired.
Let me explain...
Whether you're training to run the faster mile or marathon,
the primary energy system your body uses to keep you
running is the aerobic energy system.
Simply put, on a cellular level,
your body uses oxygen to “burn” either carbohydrates in the form of glycogen
or fat as a fuel and release a substance called ATP,
which the muscles then use for energy as you exercise.
This process happens within tiny organs called mitochondria
within your muscle cells.
More about mitochondria later.
The aerobic system is fairly efficient when it comes to keeping
you running at a relatively low intensity for a long time.
So long as it has enough fuel, it'll keep you running at an easy effort
mile after mile.
While many less experienced runners assume that the only way to run
faster is to push harder in training, every session,
the Pros know that the opposite is true.
Elite runners know that to improve your running endurance it's your aerobic engine
that needs to be trained.
As you train your aerobic energy system,
and I'll show you exactly how to do that in a moment,
you'll notice the easy running pace begins
to get measurably quicker without you having to work any harder.
Now, when we want to push harder and run faster than your aerobic system,
can keep up with, your body begins to rely on the anaerobic energy system.
Here, your body is still breaking down glycogen to create ATP,
but this time without the use of oxygen in the process.
The process used in anaerobic respiration is not only less efficient,
creating lactic acid as a byproduct, but your body only has the capacity
to keep running in an anaerobic state for about 90 seconds.
After that, you're forced to slow down.
That's fine
if you want to run a fast 400 meters, but really not ideal for distance running.
So that leads me to the question from a moment ago:
Even if you can run a 21:30 5K, if you haven't sufficiently developed
your aerobic system, you won't be able to maintain the 8 minute per mile
pace needed to run a 3:30 marathon.
That's what so many runners find so difficult about stepping up distances
from 5K to 10K, and half marathon of course to marathon.
So the only way to overcome this problem is to build a bigger base
of aerobic fitness and improve your running endurance.
How do you do that?
Well, the best way to improve your endurance is a combination
of three types of training session in your running week.
Let me walk you through these sessions one by one,
Long Endurance Run
When it comes
to improving your aerobic fitness and increasing your running endurance,
the weekly long run has to be an essential part of your training plan.
Keeping the pace slow and steady firmly in your aerobic training zone
(if you're training to heart rate) and at a level of effort
where you can comfortably hold a back and forth conversation, will ensure
that your body is almost exclusively using the aerobic energy system
during the long run. Increasing the amount of time, week on week that you’re training
in your aerobic zone and using your aerobic energy system
will naturally cause your body to adapt and become more efficient
as an endurance runner.
We know that the thing that defines aerobic exercise is the use of oxygen
in the process within your cells to produce energy.
The adaptations that take place in your body as a result of aerobic training
help your muscle cells receive oxygen more efficiently and use it more effectively.
Firstly, regular aerobic exercise will increase
the density and size of the capillary system of blood vessels
that bring oxygen rich blood to the exercising muscle cells themselves.
On top of that,
your body produces more myoglobin, the substance within the muscle cells
that transports oxygen from your blood to the mitochondria,
which are the real powerhouses of the muscle cells.
It's within the mitochondria themselves,
that the process of producing energy for aerobic exercise
really takes place. As a result of frequent aerobic exercise,
your body actually increases the number of these mitochondria in your muscle cells,
literally making you a more efficient and effective aerobic exercise machine.
And that's just the physiological benefits,
not to mention the strength-endurance and resilience that you’ll build in
your legs and back as a result of that time
on your feet.
The distance of the event that you're training for will dictate
how long the longest training runs need to be.
Typically, if you're a 5K runner, I’d suggest a long run up
to about one hour in duration.
If you're training for a 10K,
then 10 miles is a good distance for your longest long run in training.
I tend to get first time, half marathon runners running slightly over
distance to 14 miles in their training, depending on the person
and their running experience,
and if they need the confidence boost of achieving
the 13.1 mile half marathon distance in training.
Marathon training, however, is different.
absolutely no need
to run the full 26.2 mile
distance in any single long training run.
The longest I get most of my runners to run
is 20 miles or three and a half hours, depending on their pace,
and which marks they hit first.
There's a point of diminishing
return around about the three and a half hour mark of a long run.
After this point, the increased risk of injury outweighs
any aerobic benefits you might gain from running longer.
That's where scheduling additional shorter aerobic runs in your training week
will help you further boost your aerobic development.
In fact, let's dive into that a little deeper.
Midweek Aerobic Runs
So one of the biggest misconceptions around aerobic training
is that some runners seem to believe that the weekly long run
is the be all and end all of endurance training.
The reason why most Pro runners run such high mileage
is that in terms of adaptation to aerobic training, the human body responds
most effectively to a relatively high weekly volume of aerobic mileage.
Simply put, your aerobic fitness will improve quicker
if you focus on weekly mileage or duration of running in your aerobic zone,
rather than simply focusing on one weekly long
endurance run. Each week alongside your long run,
you can also run two or three shorter,
easy efforts aerobic zone runs.
Aim for around 60 to 90 minutes in duration for each.
For many runners, over time
this will allow you to build towards
around about 6 hours of total aerobic running per week.
If you're not there with your running quite yet and 6 hours sounds like a lot,
that's just fine.
Just look at what you're doing at the moment and ask where
you might be able to squeeze some more easy miles into your plan.
The point I'm making is that weekly volume of aerobic running is the key,
not only the long run.
Incorporating shorter, easy runs in the week
is how you accumulate more weekly mileage
without placing undue stress on your body and increasing injury risk.
As an example, if you're currently running three times per week,
a long run, a threshold workout and a shorter easy run,
you're more likely to see improvements in your running from adding
another relatively short, easy aerobic
mid-week run, rather than by adding another high intensity
sessions such as regular track intervals or hill reps.
Okay, I mentioned tempo workouts a second ago,
let's talk about them as they're a third piece of this tried
and tested method for running faster, for longer.
Tempo Workouts
So you might have heard tempo workouts also referred to as threshold runs.
They're the same thing and involve you running at your lactate threshold,
sustaining an effort
which is right at the point where your aerobic system is topping out
and your anaerobic system is beginning to kick in and produce lactic acid.
These sessions feel hard, productive,
and afterwards I actually usually find them quite satisfying...
Not so much during though!
The best way to describe the level of effort
during a tempo run is
“sustainably uncomfortable”.
Some coaches loosely
define it as the hardest effort you could maintain for 60 minutes.
Obviously, that equates to different things for different runners,
but as a start point, for a lot of people
your tempo pace and your 10K race pace are roughly the same.
Because you're running at the point
where your anaerobic system is beginning to take over from your aerobic system,
the lactate (the byproduct of anaerobic respiration)
is beginning to accumulate in your bloodstream.
The body has to work hard while you're running to clear that lactate.
While your body is able to process and clear the lactate at a rate
that it’s being produced,
you can keep on pushing at this hard but sustainable level of effort.
But as soon as it can't keep up and the accumulation of lactate
in the blood hits a certain concentration, that's when those heavy
burning legs start to kick in and you're forced to back-off the pace.
The good news is that with regular tempo workouts, you'll be able to run
at a faster pace before your body reaches its lactate threshold.
And once it does, your body will also be more efficient
at processing this lactate out of your blood stream as you exercise,
meaning that you can push harder and run faster for longer.
There are so many different ways to structure a tempo running workout,
but a basic example would be something like: a two mile easy warmup,
followed by three miles at your tempo, pace (think 10K race effort),
and then a one mile easy cool down.
In terms of frequency,
Aim to do one tempo session per week at the most,
but make it a quality workout.
If there's one thing that elite runners do incredibly well compared
to normal runners, it's that they run the majority
of their weekly mileage super easy so that when it's time to turn on the pace
and do a hard tempo workout, their legs are ready to go.