How to Improve series – part 3

In part 3, we’re looking at Duration otherwise known as “how long to run for”.


Talk to any serious runner and the conversation eventually gets round to how many miles they’re doing out each week. One of the big misconceptions among ‘unserious’ runners is the idea you only need to run lots of miles if you’re doing a marathon. This is understandable because everybody knows a marathon is a long way. It’s the only event I see where general runners are following a training plan otherwise most are simply running a couple of times in the week and turning up to parkrun. Yet an elite 5K runner typically trains between 90-110mpw; and a low-key competitor should be aiming for at least 20-30mpw.

But miles are not the only way to measure training. I like to measure mine by time. After all a thirty minute jog is thirty minutes regardless of whether you’re Mo Farah or someone at the back of the pack.  While Mo may run double the distance, both runners are going to take about the same number of footsteps with their hearts pumping and lungs bellowing for the same time and therefore achieve the same physiological workout.

When you start to measure by time, you find the 100-mile week of an elite runner is ten hours training. They have a standard routine of running in the morning for 30-60 minutes and training again in the evening which gives them a combined total of around 1½ -2 hours.  Of course ask your average parkrunner to train for ten hours in a week and they’ll only manage 50-60 miles – if they make it through the week. That’s why mileage is misleading because how far you run depends on how quickly you can do it.

But does an amateur need to train this much? Definitely not. At least not in the beginning. Think of the unfittest person you’ve ever met. They only need to run for 15 minutes to collapse exhausted and start triggering improvement. The reason elites run so much is because the fitter they get, the harder it is to find untapped fitness. It’s like having a fresh tube of toothpaste – you can squeeze it anywhere and toothpaste comes out. When it’s almost used up, you have to squeeze from the bottom to the top to get the last drop out.


The first step for any runner turning serious is being able to run regularly for 30-45 minutes. By definition, any parkrunner should be able to do this. With this level of fitness, you can start to apply some of the general guidelines below.

Rule 1 – Warm-up takes at least ten minutes

When I was at university our physiology lecturer, Ian Parker-Dodd, used to say it takes twelve minutes for the body to reach steady-state. I had no idea what he was talking about! But I remember at my first parkruns, when I ran without warming up, it took over a mile for my breathing to settle down. After I started running gentle fifteen minute warm-ups before parkrun, I found myself feeling comfortable from the beginning. That’s all the steady-state is, the point where the body’s fully warmed up and able to run at a decent pace without strain. Some people warm-up quicker than others. I find it takes closer to twenty minutes of a training run before my body is working at its best (but I’m towards the higher end). Everybody should expect the first ten minutes of a run to be about getting into the groove.

Rule 2 – Training runs should last at least thirty minutes

If the first 10-15 minutes are spent getting warm then you want to go at least another mile or two to start improving fitness. If your run only lasts twenty minutes total then it’s barely been worth the time spent changing clothes before the session, showering after and getting your kit washed. Get into the habit of making training runs last thirty minutes – it’s good practice on the days when your legs are tired as you get used to mentally pushing yourself through – and building your mental toughness will help at the end of races.

Exceptions – when you’re coming back from injury; recovering in the days after a race; or genuinely pushed for time (“it’s better to do something than nothing”).

Rule 3 – Aim for runs to last forty minutes

One of the reasons time is a better measure than miles is because certain physiological phenomena take place that are true for everybody. How long it takes to warm-up is the first of these while another is the production of human growth hormone (HGH) peaking at the forty-minute mark. HGH helps you to build back stronger and faster and, while after forty minutes the body continues to produce it, the rate slows as time passes. If you can, extend thirty minute runs out to forty minutes to get more bang for your buck.

Rule 4 – Limit training runs to an hour

The one hour mark is another physiological limit because runners can only race at the lactate turnpoint for this long. While you’d rarely, if ever, train for an hour at this intensity; there is another reason for not training longer. The longer you run, the more you deplete your body’s fuel stores. Do that too often and you find yourself crawling along on the following days.

It’s okay to run for slightly longer, many of my runs come in between 55 mins to 1hr10. But I found when I tried training for over 1hr20 on back-to-back days it got the better of me. Good training is about getting out regularly and consistently to build on previous sessions. Don’t push the upper limit too much.

Exception – the weekly long run where you’re deliberately running for 1½ – 2½ hours to recruit more muscle, build extra aerobic fitness and adapt the body to hold more glycogen (carbs).

Rule 5 – Listen to your body

In many ways this is the most important rule but you need to have been running for a while to understand the language it talks. For beginners every run can be challenging and they may have to push through what they perceive as painful but equally it may be time to scale back. Only experience can teach which is which. Generally it’s better to err on the side of caution and stay healthy to get out again the next day. Experienced runners face a different challenge – adapting their routines to their current fitness level. Once you have a good base of miles it’s easy to ignore aches or pains or look to a physio to resolve them. But sometimes the answer is to ease off. For example, at one time I was running every day for an hour. Eventually I realised it wasn’t helping me so I dropped all my recovery runs back to forty minutes and within a few weeks found I was sleeping better, had fewer aches and pains and more energy for my key workouts.


To summarise – let your body warm up gently from the beginning of runs. Aim for runs to last thirty minutes to make them worthwhile and ideally forty minutes. Depending on your time available and where your route takes you, it’s okay to push out to an hour of running and even go a little beyond. The beauty of running by time is that as you get faster, your total mileage automatically increases with no more time taken out of your day.

I found I could hit a sub-20 parkrun time on 4-5 hours of training so that’s a good benchmark to aim for initially. In the last part of this series, I suggested aiming to run five times per week. If you run three times for forty minutes in the week, thirty minutes on Saturday at parkrun and a long run on a Sunday of 1½ hours you’ll be hitting the four hour total. It’s easy to add five minutes here and there to get a little extra training done!

In the next part of this series I’ll tell you about Intensity – how much effort to put into runs.

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