How to Improve series – part 4

In part 4, we’re looking at Intensity otherwise known as “how fast to run”.


My running used to have two speeds – all-out for twenty minutes, or go very slow for ten miles. Under my system of either run all-out or run slow my race progress was limited. There was no middle ground – it was either short and fast or long and slow. The problem is when I ran all-out on a Monday and Tuesday, I wouldn’t feel like training again until Thursday and then at the weekend I’d slog through a long run.

Once in a while I looked at training plans in Runners World and they labelled their training runs as Easy runs or Hard runs or Fast runs which didn’t make any sense to me. They were just words which I couldn’t associate to what I actually needed to do on a run. Or maybe I couldn’t be bothered to think too hard about it.

I don’t think any of this is unusual among runners. If you send someone out for a thirty minute run, they subconsciously know they can handle it so they go off quickly, run fairly hard until they start to pant, ease off enough to stop panting and then hold on until they arrive home. Many of the club runners I know have a different version of this where, because they’re in a large group, they go off quickly but stop every mile or so to wait for the slower runners (thereby giving themselves regular recovery breaks). Then when they restart they put the hammer down for the next section until they pause again. While there’s nothing wrong with the occasional faster session, if it happens every time you run, you eventually stop improving.

My first attempt to train at different intensities began with a heart-rate monitor bought in the early 1990s. It came with an instruction manual stating training at 60% of maximum heart-rate would burn fat, at 80% would build aerobic fitness and over 90% would be intense, maximal exercise. If I’m honest I don’t ever recall training to those values. Any run I did, my heart-rate immediately shot up into the 160s or 170s and as my mentality was to run as hard as I could last on the treadmill, my heart-rate usually ended up somewhere around a max of 190+. If anything, I was more fascinated in seeing how high I could push my heart-rate – or how low it would go at rest.

I’ve continued to own heart-rate monitors ever since yet still rarely train by percentage. I have however often used the numbers it spews out to see whether I’m getting fitter. I doubt there’s an elite runner who trains by heart-rate other than to ensure their recovery runs are slow enough. But like myself, many do wear them to get numbers for post-run analysis.

One thing I’ve gleaned from looking at the stats of faster runners is their easy runs are done at low heart-rates. I recently ran with a 2hr35 marathoner at his sedate pace of 8:40/mile pace and his average heart-rate was 110bpm, only reaching a maximum of 129bpm when we ran up a set of steps! These sort of heart-rates don’t come naturally but as a result of many hours of training.

While I’d rarely be without mine, it’s worth remembering heart-rate monitors only became commercially available in the 1970s and runners before that were running far better times than most of us can achieve today. They’re not as useful as the manufacturers would lead you to believe.


When I eventually decided to get serious at running my first improvement came from running more often. The next improvement came from running longer on those regular runs. But to be able to do this i.e. run regularly for longer periods of time, I couldn’t just charge off down the road and hope to hang on, I had to begin with lots of easy runs.

My initial method for running easy was to set out on my typical run and slow down to a pace that felt really slow. I had to swallow my ego, not care about what people would think and just trot along with a reduced stride. It’s a method I came back to as recently as 2017 and used with great success for rebuilding my aerobic fitness. Occasionally I slotted in a fast parkrun every couple of weeks and I stuck with the very easy runs for three months. This laid the base for my first sub-20 parkrun.

When I eventually decided I was ready to introduce workouts for a layer of speed, I discovered the Pace Calculators on Greg McMillan’s website. It was enormously satisfying to find out that if I was running a 19min20 parkrun, my easy run should be between 7:42-8:12 per mile while my speedwork should be between 1min23-27 for 400m. Suddenly I had something concrete to work with.

Working to pace is a system I used very successfully for my workouts and there’s really only one drawback. It assumes you’re running in good conditions. If you live in a hilly area or where it’s windy then you have to figure out how to adapt the pace. With easy runs the pace range is usually quite wide and you don’t have to hit the pace exactly, just be in the right neighbourhood.


When I first ran to pace I didn’t own a GPS watch but I knew roughly the distance of training runs, so I could calculate what pace I’d been running. Of course once I got a GPS watch it became even easier to assure myself of that. Over time though I began to get used to the feel of an easy run and barely needed to glance at my watch to know the pace. Not all runners can do this and it’s said the biggest mistake runners make is running their easy runs too fast.

The truth is easy running is more what you’d consider “too easy”.  On a genuinely easy run, you should arrive home feeling like you haven’t done anything. I usually get back from my forty minute easy runs with a t-shirt that’s as dry as it was when I left home. Barely a drop of sweat on it. I’m doubtful many runners experience too easy because culturally we believe in hard work and the myth of no pain, no gain. It seems to make sense that to improve you have to work harder, that to run fast you have to train fast; but you really don’t (at least not too much).

It took me some years before I discovered what an easy run needed to feel like. It was no longer about holding back on pace, but ensuring I didn’t put in extra effort. These days, my focus is on my breathing to ensure it never gets too fast, too forceful or uncomfortable. Sometimes I run while breathing through my nose, always adjusting my speed to keep it feeling easy. That’s the thing – easy is a feeling, not a pace. On easy runs I never put in a big effort to get up a hill, to catch someone or finish fast. I just focus on feeling good from start to end.

“Easy is a feeling – not a pace”

Another way to keep easy runs easy is “conversational running”. You need to be able to run while holding up your end of a conversation in full sentences and without strain. There’s an obvious downside to the idea of ‘conversational running’ – it implies you need to run with someone. Of course you don’t have to, but you will look silly if you’re talking out loud to yourself! Seriously though, there’s no reason you can’t test your ability to talk in sentences when you’re out of earshot of the general public. Whether you run with someone or talk to yourself, you shouldn’t feel like you have to hang on to keep up your end of the conversation.


To summarise – getting the intensity for your runs correct is important to be able to run frequently for longer. There’s three main ways to identify intensity.

  • Using a heart-rate monitor is effective for slower runs.
  • Using pace calculators such as the ones on Greg McMillan or Jack Daniels’ website is very effective except when conditions are imperfect. But working to pace will get you at the correct speed and give you an understanding of the different intensities required and what they feel like.
  • As time goes on you can begin to run easy runs by feel using your breathing or conversation as a guide. Learning how effortless your easy runs should feel is one of the things that will help you elevate your running and make continued progress.

Whatever method you use, you’ll need a mix of intensities over the course of your training as I’ll explain in a future post. But first we’ll look at Recovery – the importance of doing nothing!

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