By David Mountford aka @DavidNFLF1


As I write, we’ve just come to the end of a cluster of 2015 autumn marathons. I ran one too, and smashed thirty-seven minutes off my PB. To achieve this, I did several things differently from the usual recommended approach during my training, one of which was a biggie: I didn’t taper.

I didn’t taper at all.

In this article I’d like to explain why, and also some of the other things I did differently. I’ll explain why I think tapering is at best unnecessary, and at worst unhelpful. It might seem an unconventional approach, but it worked for me. And despite taking issue with a few pieces of popular wisdom that pop up regularly, I hope that this will be more of a refreshing look at a valid alternative rather than being ‘controversial’. I’ll go through my layman’s understanding of the theory behind how it works, and a bit of evidence of why it works for me.

And in so doing, I think I can clear up two particular trends of #ukrunchat tweets that I’ve noticed:

  • People tweeting that they’d smashed their PBs at shorter distances immediately following their autumn marathons.
  • People tweeting how difficult resuming running is after a break.

What I Did Differently and Why

For my first marathon I followed a lot of the ‘golden rules’ that are part of running’s popular wisdom. I followed the usual sort of plan that takes the runner up to twenty-one miles on their longest run, plus a couple more long runs at eighteen miles. Every other run was shorter. Plus a three-week taper down to a ten mile run the weekend prior to the marathon.

Yet in that marathon I hit the wall badly at around mile eighteen, and had to pretty much walk the rest of it. I found that the experience of running it (and walking it) revealed how inadequate my training had actually been. So for my second marathon I was determined to do things differently. Here’s what I did.

Glycogen Depletion Training

The first of these was to use glycogen depletion training to counter hitting the wall. I could say a lot more about this but it’s not really the focus of this article. Saying that I did lots of fasted runs will suffice. The objective of these was to train my body to become much more efficient at burning bodyfat for fuel, which it needs to do once the primary energy source of liver/muscle glycogen has been used up (literally running out of energy, and hitting the wall) somewhere between sixteen to twenty miles. This requires running slowly – see my next point.

LRs, Not LSRs

Something else I could say a lot more about, but which isn’t really the focus of this article, is the speed at which I did my long runs. I use the term ‘long runs’ – and not ‘long slow runs’ (LSRs) – deliberately. I did all my long runs at marathon pace (or tried to). Not traditional LSRs at a minute-per-mile slower than marathon pace. By necessity, marathon pace is already slow; certainly slow enough to be anaerobic and achieve the aim of training the body to burn bodyfat. I’m trying to run a sub-03:45 marathon here. I need to train to be able to hold that pace.

Training Instinctively, Doing It Three Times per Week, and the ‘10% Rule’

In addition, I broke some of the other ‘golden rules’. I didn’t follow a set training plan, I ran instinctively according to how I felt each week, what I’d done the week before, what I felt I needed to work on, and what other running I needed to do. Also, I only ran three times per week, whereas a lot of plans seem to have the runner running four, five or even six times per week. And to get up to twenty-plus miles quickly enough to get several of them in, I increased my weekly mileage by more than 10%.

Training Distance

Along with not tapering, here we get to the first of the ‘biggies’; the things which deviated the most from traditional plans.

I ran full marathon distance in training (and a little bit further), twice. And when I didn’t run full distance, I ran twenty-plus miles several times – lots of them as fasted runs.

I’d already decided to run full distance in training for my next marathon before I’d finished my first, while I was still struggling. Quite simply, the most difficult thing about running 26.2 miles that first time was… well, running 26.2 miles. It is rather a long way. By only running up to twenty-one miles in training, and only doing that once, I simply hadn’t been sufficiently physically or mentally conditioned to run further.

There’s a piece of popular wisdom I do agree with: that the first twenty miles in a marathon are easy; it’s the last 6.2 that are the most difficult. So to me, the best way to prepare for those 6.2 miles is to actually run them. Or simulate them – recreating the fatigue by running twenty-plus miles while fasted.

Of course, there’s other popular wisdom that disputes this:

“You don’t need to run full marathon distance in training.”

“There’s nothing to be gained from running full marathon distance in training except injury.”

…but I strongly disagree. There are physical reasons why those last miles are the toughest miles – such as the switch from burning liver/muscle glycogen to burning bodyfat for fuel – but also psychological reasons. 26.2 miles is a long way. It seems daunting. I can tell you with absolute assurance that having run 26.2 miles in training, not only was I better physically prepared to run that distance, I was also better prepared psychologically. I knew what 23 miles felt like. I knew what to expect at 24 miles. I could measure how I felt during the race in those later miles by comparing them to how I felt during training, and was able to adjust my pace, hydration, mindset or whatever else accordingly. I had so much more confidence at the start line, as well as throughout the race, knowing what to expect from the miles ahead of me, and knowing that I was capable of running them, because I’d already done so. And in training I was also able to test different approaches to nutrition, pace, kit and other variables.

The one dispensation I did allow myself was that if I had done a twenty-plus mile run one weekend, the next weekend I would do a shorter run of around eighteen miles. And sometimes I threw in a short distance speed weekend of a fast ParkRun and Sunday half-marathon.

Not Tapering

And so to the biggie. I didn’t taper. The weekend before my marathon I ran a twenty-one mile fasted run, and three days before the marathon I ran a flat-out 10K PB. Both of these set me up beautifully, both physically and mentally, for my marathon. I was conditioned and ready to go.

Let’s go into this in more detail.

After smashing my 5K, 10K, half-marathon and marathon PBs during and immediately after marathon training, I noticed a clear trend of people tweeting that they’d done the same after their autumn marathon. This often seemed to be in surprise, as though they shouldn’t be able to do this.

But I’ve been running for eleven years and my unvarying experience is that staying in top condition requires hard, regular running. Therefore to me, tapering is at best unnecessary and at worst unhelpful. My reason for this is very, very simple: when I stop running, I get worse at it. I seem to lose fitness so damn fast. This is a phenomenon that has repeated itself time after time: if I have a rest week, or dial down the distance, intensity or frequency of my runs, I get worse at running.

Which, when I think about it, is obvious. We don’t become good at running by doing nothing. We become good at running by doing… running. Hard and fast. Or long and slow (see ‘Glycogen Depletion Training’ and ‘LRs, Not LSRs’ above). Here’s why I think it works.

A Bit of Science (Sort Of) and Theory

Before I get into the theory of why I don’t believe in tapering, I should stress that I am absolutely not trained, let alone qualified, in medical, biological or physiological science. Any errors that follow are entirely my own, and I accept all responsibility for them. I can’t provide academic references for my assertions – but I can tell you that it’s knowledge I’ve built up over many years, theories that I’ve tested myself, and conclusions that I’ve built from actual results and experience.

So, that said, my layman’s understanding has long been that ‘fitness’ is actually comprised of a combination of things:

  • The ability of our bodies to absorb oxygen with each breath. This is determined by the quantity of alveoli/capillaries within the lungs to distribute this oxygen to the bloodstream. The more there are, the more oxygen can be absorbed with each breath.
  • The ability of the blood cells to carry this oxygen.
  • The strength of the heart muscle to pump the blood, containing the oxygen, around the body, distributing it to the muscles as we run.
  • The ability of the muscles to use the oxygen to burn energy (primarily liver/muscle glycogen; bodyfat as a secondary energy source) to power movement (“fat is burned in an oxygen furnace”).

My understanding and experience is that all these things respond to what I know as ‘progressive overload’ – that is, incremental increases in the load (or ‘resistance’, or ‘challenge’, or whatever term you prefer) placed upon them. When we run, the body is aware of the stress placed upon it, and the muscle tissue which has been broken down. During periods of rest (mainly during sleep) it repairs itself, and – crucially – if enough stress has been placed upon the body, when it repairs itself it adds a tiny amount of extra muscle or capacity than it had before. So, if we’ve stressed the body sufficiently during a run, it grows extra capillaries in the lungs, the blood adapts to carry more oxygen, the heart gains strength, and the muscles gain extra tissue as well as becoming more effective at burning oxygen. This is how we gain fitness and strength.

So we can see that continuing to run is crucial to continuing to gain fitness. And not just running, but incrementally adding to the load/resistance/challenge/stress – in other words, pushing to run that bit further or faster. If we only ever run gentle 5Ks, our bodies only adapt to the point at which running that gentle 5K becomes easily achievable. But if we run a bit further, our bodies adapt to running further. If we run a bit faster, our bodies adapt to running a bit faster.

(There’s an exception to this, and it is slow running, especially when fasted, which stimulates an entirely separate biological process of adaptations to mitochondria within cells, facilitating the body’s ability to burn fat for fuel instead of readily available liver/muscle glycogen, as mentioned earlier.)

Again, I should stress that I’m not qualified in biology or physiology, but arguing that any of these things are improved by not using them seems illogical to me. Yes, the rest period is important for recovery. But without sufficiently stressing the body there’s nothing to recover from. So if we do less – as we do when we taper – our bodies adapt to doing less, and we therefore lose fitness. Which, I believe, explains another recurring trend of #ukrunchat tweets, from people wondering why resuming running after a break is so difficult.

Busting Some ‘Golden Rules’

Of course, just as with running full marathon distance in training, there’s popular wisdom that disputes this too.

“I run faster on fresh legs,” is pretty much how this goes.

Well, that may be true. We’re certainly less likely to run well on tired legs. But we’re equally as unlikely to run well on legs that have been neglected. We’re back to the principle of progressive overload again. When we taper we reduce the stimulus for the body to respond, therefore it begins retreating back to a state which matches the reduced load placed upon it. In other words, losing fitness, because we’re not running as much.

“You can’t gain any more fitness in the last two or three weeks before a marathon.”

What rot. Of course we can. Why would the process of gaining fitness – progressive overload – stop just because of some arbitrary date on a calendar?

“You won’t lose fitness by taking things easy in the two or three weeks before a marathon.”

Again, what rot. The idea of progressive overload shows us this. Let’s counter one overused cliché with another: “If you don’t use it, you lose it.” There.

A Bit of Evidence

As I’ve said, losing fitness after taking things even just a little easier is such a well-established pattern for me that, after eleven years of running, I automatically factor it into my expectations after rest weeks.

But I do have a relatively recent equivalent of tapering that I can offer as a case study. This summer (August 2015) I did some running while on holiday in Cornwall. Not as many miles as I would normally run, and at a reduced intensity – sounds pretty close to a taper. Let’s have a look at Strava to see what happened before, during and after this (another good point: always keep a training diary).

In addition to an intervals session and a Saturday long run, every week I do a midweek 10K. We’ll use that as a measure because I usually do it on the same route (it’s a reliable benchmark of my progress). A few weeks prior to the holiday, I’d changed to a new route. Here are my times:

Date Time Comments
9th July 44:52 Slow; getting used to the new route
16th July 43:35 PB
23rd July N/A Ran 8.5 miles as had missed a run earlier in the week.
30th July 43:16 PB

(It’s worth nothing that at the end of the third week, on Saturday 25th July, I ran a full marathon distance at marathon pace in training – or tried to; I was seven seconds per mile off. Note that a 10K PB followed five days later.)

Apart from the week I missed, there’s a clear improvement week on week in my times. That’s fairly typical for me: gradually, incrementally improving my times by pushing to beat them each week –progressive overload, in other words. (And because of that, these times are a little embarrassing as by now I’m a bit faster!)

However, the following week – 1st August to 8th August – I was on holiday. I did three runs that week: a steady/tempo 10K in 44:39, a six-mile run/walk alongside the family who had hired bikes, and a nine mile trail run including a 1-in-4 gradient hill and some of the South West Coast Path. So, not smashing myself to pieces, but not exactly inactive either. Roughly equivalent to a taper. I also did some press-ups, pull-ups and crunches throughout the week, for strength and conditioning. Should have been enough to keep me ticking over.

But after returning home, I could only run my next midweek 10K on 13th August in 46:13. And my Strava notes read as follows: “Very slow, very tough, really struggled, felt very out of condition, despite running while on holiday last week. Struggled to keep form too.”

I hadn’t run sufficient distance or intensity while I was away.

The week after that, 20th August, I ran my 10K in 44:40, noting: “Slow. Still not back to full fitness.”

The week after that, 27th August, I ran 43:39, with: “That’s more like it! Getting closer to full speed.”

And finally, the week after that, 3rd September, I ran 43:20, which we can say is back on the pace I was running before the holiday. So I took four weeks to get back up to speed after having an easier week.

The week after that, 10th September, having now been pushing myself for over a month, I ran 43:15 – a one second PB. This followed my second full distance (well, twenty-seven miles) training run the preceding weekend.

Two things jump out at me from this:

  1. Losing fitness after an easier week.
  2. PBs the week after full marathon distance runs – just as people have tweeted.

To me this validates the idea of not tapering, of running full distance in training, and of continually pushing (progressive overload). So that’s what I did. As I said, the weekend prior to my autumn marathon I did a twenty-one mile fasted run at marathon pace, and was able to hit and hold that pace precisely – I’d targeted 08:20 minute miles and that’s exactly what I ran. This was the longest fasted run I’d ever done. Midweek, three days before the marathon, I ran my 10K as hard as I could for another PB at 42:36, my first ever sub-43.

And then, on the Sunday I ran my marathon and took thirty-seven minutes off my PB.

So, no – I won’t be tapering for my next marathon either.


Not tapering might seem an unconventional approach, given the ubiquity of the popular wisdom that says we must taper, and must not run full distance, in training. But my experience is my experience, and it works.

So after all this, I’m not surprised that people began tweeting that they’d smashed their PBs at other distances following their autumn marathons. They’d just run an ideal ‘training’ run – full marathon distance at race pace – as massive progressive overload stimulus. I’m equally unsurprised that people tweet that they find resuming running difficult after a break, or after taking it easy for a while – their bodies have adapted to the reduced workload.

And that’s why I don’t taper for marathons.