‘Run slow to run fast’ sounds too good to be true – but it works

Possibly, the idea that plodding along at the back of the field doesn’t seem the most likely way to improve. Surely, you ask, it’s better to hammer it all out as hard as you can and reap the rewards? Well, here’s the deal. Slow running – the kind of runs where you dawdle along and chat to your friends – are, without argument, the best way to super–boost your oxygen– carrying ability.  

The science will tell you energy is supplied by mitochondria and more of those are built by running slowly.

Plus, when you run slowly, your body substantially increases its capillary production. Capillaries are small networks of blood vessels that run through the body and bring blood – and oxygen – to the muscles and tissues. The more capillaries your body has, the more oxygen your muscles receive.  

Runners successfully use this science all the time, as we explore below.

Mike King is a mountain runner in his mid-sixties. By his own admission, most of what he does is pretty easy – but if you look at his running CV, it’s very impressive indeed and includes 50- and 100-mile races in Snowdonia and the Alps.

“Although I do a little faster running, the vast majority is relatively slow or easy. To me, the benefits are clear from a fitness point of view,” he explains. 

“With consistency – week on week, month on month and even year on year – you build a significant aerobic and endurance base. And importantly as a more mature person, I’m able to maintain my endurance and aerobic levels. I believe I’m fitter now than I was five years ago in endurance terms.”

“It’s counterintuitive, but lots of slow running actually increases your speed when you need it – both over shorter distances and over longer distances, in part because you just move faster for the same effort, and in part because you just slow down less on longer events.” 

“For me, an easy run – particularly if it’s in the hills or I’m mountain running – is rarely, if ever, hard mentally,” adds King. “There’s an absolute joy in being out in nature and travelling through the ever-changing landscape in a myriad of different weathers. Even running the same routes, the experience is never the same twice. The views change depending on the weather and sounds change as well. I love the sound of the wind in the trees, grass and rushes, running water, wildlife and even the rain. It’s always different and sometimes pleasantly surprising.”   

He describes slow running as “cleansing” and good for his mental wellbeing. “I’ll come back from a run with seemingly difficult problems resolved – often without consciously thinking about them,” King explains.

“I’ll spend long periods where I’ve not been thinking about anything, just in tune with my surroundings. At other times, the sheer concentration and focus necessary to run on rougher, technical terrain is also a great means of clearing the mind.  

“I’ll always come back from a run feeling in a better, more tranquil mood. Slow running is a fantastic stress-buster and I generally sleep really well.” 

Here’s the amazing fact: you’re probably running too fast right now. I know I have been.

I’ve realised that amazing athletes, such as Mark Allen, learned how to run slowly and then produced record-breaking runs. He dropped down from five-minute miling to outside eight minutes and reaped the benefits so dramatically that he won the Hawaii Ironman triathlon in record time.  

So how did he do it? Allen explains: “I strapped on the heart-rate monitor and kept my heart rate below 155 beats per minute. This is the number at which my body is able to take in enough oxygen to burn fat as the main source of fuel for my muscle to move. I then developed my aerobic/fat-burning system. What I discovered was a shock.

“To keep my heart rate below 155 beats per minute, I had to slow my pace down to an 8:15 mile. That’s three minutes per mile slower than I had been trying to hit in every single workout I did! My body just couldn’t use fat for fuel.

“And after nearly a year of doing mostly aerobic training – which, by the way, was much more comfortable and less taxing than the anaerobic style that I was used to – my pace at 155 beats per minute had improved to a blistering 5:20 mile.”

Use the method below to calculate your slow running target heart rate – which in turn will determine how fast you need to run.

1. Use the number 180 beats per minute as your starting point.
2. Subtract your age.
3. Correct this new number by applying the following:
   

• If you do not run, subtract another five beats. 
• If you run one or two times a week, subtract two or three beats. 
• If you run three to four times a week, keep the number where it is. 
• If you run five or six times a week, keep the number where it is. 
• If you run seven or more times a week and have done so for over a year, add five beats to the number.
• If you are over 55, add another five beats to whatever number you now have. 

Whatever figure you end up with, make this your target heart rate for your runs, adapting your pace as needed. I’m using this approach at the moment to try and boost my aerobic system and can confirm one thing: it’s very slow.

A fitness tracker or smartwatch can help you monitor your heart rate whilst out running. Saga Exceptional’s Fitness Technology Writer Steven Shaw particularly likes the Fitbit Charge 5, but take a look at our pick of the best budget fitness trackers for more options.