Wednesday, 20 July 2016

Views on Shoes (part 2!)

I posted a piece under this title (apart from the "part 2" bit) back in October 2012. The stats show that it's been the sixth most read of the roughly 200 posts I've put on this blog since I started back in 2009, so it must have stirred some interest among a few hundred people at least. Well, in the nearly 4 years since then things have moved on as it were. I've got older and slower, covered a few more miles and run a few more races, learned a bit more from a lot more mistakes. Shoe makers have progressed, proliferated, given us more choice, sometimes more help and often more confusion. And the debate and rhetoric is rising once more, so maybe time for me to throw in my two penn'orth again.

But who is this guy who dares to have a view on shoe choice you may rightly ask? An ageing pedestrian whose best years are clearly behind him, and even back whenever whose best performance was probably a not too special 35th place in the Lakeland 50, no real pedigree at all, haven't we far more accomplished practitioners to heed? You're right of course, so I'll start with a few words of defence.

1. How the top guys experience training and racing is a world away from how I do it. There are good reasons for this which we'll come to later, but it does mean that advice from them to me (and there are a lot of people down my end of the field) may not be all that relevant.

2. You'll know if you've read any of my more "technical" posts before that I like to try and get into the basic engineering of why things work, in fairly simple terms. Equipment manufacturers, either because they think we're not intelligent enough or maybe for other reasons, often don't explain this. Now you may disagree with my conclusions but if what I have to say prompts you to think things through a bit more logically that's a good enough result.

3. I enjoy doing this stuff and if you don't like reading it then you don't have to. I won't be offended.

So let's get back to shoes.

What do we actually need?

Let's start with a bit of history. I'm old enough now that some of it can come from me. When I was a schoolboy athlete I ran on the track in spiked shoes with wafer-thin leather soles, long spikes for grass tracks, shorter ones for cinders (no tartan tracks then of course). Everything else, roads, cross-country and so on was done in gym shoes (canvas tops, flat rubber soles). You slid about a bit if it was muddy but it encouraged a sense of balance to avoid too many face down excursions. When I went to university in 1967, the cool thing everyone wore around town were desert boots (and if you can remember those you're nearly as old as me). It wasn't until a few years later that the style of shoe we now know generically as "trainers" landed.

I started climbing around then, and it was the conventional thing to walk up to the crag in bendy, vibram-soled walking boots (which were also used for rock climbing in all the lower grades), but then trainers came along and we found that walk-ups could be done just as comfortably in this new style of footwear. And if you were going to walk up to Sca Fell Crag or Cloggy in trainers, then the logical next step was to use them for all hill walking unless there was any deep snow around. The term "walking" of course just meant travelling around at the best speed you could, which generally meant walking up and running down. Our climbing club had an annual outing around the Welsh 3000's, traditionally taking in Bristly Ridge on Glyder Fach and the North Ridge and Traverse of Crib Goch. The faster guys would get around in times which would be respectable even by modern standards, and we were all wearing either boots or what would nowadays be called  "road shoes".

If you want a bit of more general history, consider these two bits of information. Billy Bland set the (as yet still unbroken) record for the Bob Graham Round in 1982. Pete Bland developed the sole considered to be the forerunner of all modern fell shoes in 1985.

The point of all this of course is to stress that while the nice shoe designs we have nowadays may be helpful, people were travelling around the fells at fair speeds long before any of them were invented. So no particular shoe design is "necessary"; the only real requirements are a reasonable sense of balance, an ability to put your feet in the right places and a head that can deal with being on steep ground. If you don't have these then no shoe is going to be able to compensate. I'm personally puzzled by events that specify what type of shoe you have to wear. I can only assume that it is governed by some insurance requirement to stop the organisers being sued (well, you fell over and broke your leg but you were wearing the right shoes so that's OK).  If so, I think it's just another example of a problem (my view of course) associated with too many outdoor sports these days, where too much attention is focussed on what equipment is carried or worn, and too little on the protagonist's ability to use it. But I'll get off that hobby horse now and back to the subject.

So we've established that basically you could do any event in any footwear. Now, how does the range that we have on offer nowadays make life better, and how do you make a choice?

What are shoes designed to do?

Well, different shoes are designed to meet the needs of different runners, participating in different styles of running, over different ground. Let's start with the ground. Depending on what style of training and events is your particular bag, you might over the course of a running year have to deal with:

Smooth gravel trails (wheelchair and road bike friendly)
Stonier roads and jeep tracks (think Old Coach Road or Lairig Mor)
Typical UK "mountain" paths (stones, odd boulders, bits of mud and grass, etc)
Boulder fields (think top of the Scafell Pikes, Glyder Fach, etc)
Simple rocky scrambling (Sca Fell, Tryfan, Crib Goch)
Sloping mud and steep grass
Tussocks, heather and other similar nasties
Wet ground (ankle deep)
Boggy ground (knee deep or worse)
Beach sand
Dune sand

Shall I go on? I'm sure you could think of more, but the point is that all these are different, and the "hard" surfaces are different again whether they are wet or dry. No one shoe is going to perform well on all of these, so what we see now is that the shoes we have available have become more specialised to deal with a small selection of these conditions. 

I could ramble on now about there being equally lengthy lists covering the variety in types of event and type of runner, all having a different impact on shoe design, but I think you probably get the picture. It's complicated. So what we need is a set of criteria against which we can judge what our needs are for a particular project, or for our running in general. There are again many to choose from but I'll ignore some (like do you need a shoe colour to match your overall style palette..) and go for the ones that make sense to me.

Criteria for shoe design

1. Grip

Staying upright, making progress over the ground, staying in control down hills are essential parts of the game so grip is important. But no one sole will give you good grip everywhere, Studs are great on ground where they can dig in, grass, mud, etc (particularly when it's wet) but when you're going to be landing on a hard surface (rocks and stones) grip comes from friction, and here the more rubber you can get down the better (think of the F1 guys). This is why "trail shoes" have evolved with a larger contact area than fell shoes - most trails, particularly in continental Europe and North America (markets that many shoe designers are aiming for) are hard packed and usually dry. Bog, heather and near vertical grass are rather more British specialities.

2. Stability

By stability I mean what does the shoe do when you put it down on a surface that isn't horizontal (either in the direction of travel, across it, or most likely at some sort of diagonal angle). Does it hold your foot solid relative to the footprint, or does your foot lurch off in the direction of the slope, banging your toes into the front of the shoe or threatening to turn your ankle. Two main things contribute to stability, the closeness of the fit and the distance between the underside of your foot and the ground. The former depends on whether you can find a shoe of your chosen design to fit your foot, but the second depends on the depth of the shoe base  - the combined thickness of insole, midsole and tread. The deeper the base, the bigger the rotational force your foot will experience; this is regardless of grip, it's just about geometry and mechanics. Thin soled shoes are much more stable than deep soled ones.

3. Cushioning

There has been mountains of debate in recent years about minimal shoes, deeply cushioned shoes and everything in between. Every style has its evangelists but I'm clear that there is no one right answer. What the engineering tells you however is that every time you put your foot down it has to dissipate an amount energy which will be determined  by your speed, weight, cadence, and so on. You can't get away from this, this amount of energy is fixed and has to be absorbed somewhere. What you can do though is to change the time over which it is absorbed  -  energy is a force applied over a time, so if you can increase the time then you decrease the force transmitted back up through your foot and leg, and it is these forces that wear us out over the long term. You increase the time by putting some suspension (springs) into the system so the force has to work against the springs and operates more slowly. Again, think of the car analogy.

Minimal shoe runners adjust their gait to achieve a light, progressive footfall, so the springs are provided entirely by the leg muscles. The rest of us do this to certain extent but less expertly, so we either get battered feet or help ourselves a bit by using a spring in the sole of our shoes  -  cushioning. As we land the cushioning in the sole compresses, absorbing energy, then as we take off it expands again, giving us a bit back (don't be fooled, you never get anywhere near all the energy back either from your muscles or your shoe  -  life's cruel that way).

4. Water absorption

This may seem a fringe issue (well, all shoes get wet, don't they?) but I've observed that a major factor in runners not being able to complete longer races, particularly in our UK conditions, is foot problems initiated and/or exascerbated by continually wet feet. Wet feet for twelve or fifteen hours don't normally hurt anyone, but take that on into two or three days or more and blisters, trenchfoot and so on become real problems. The key design feature here is how much water a shoe retains once it has got wet, Unless you're very unlucky, periods of rain or wet sections on the course are transient and then you get to a dryer section. If your shoes retain relatively little water you can just change into dry socks and away you go; but if your shoes hold water they immediately wet out any dry socks and you're back to square one.

Some modern shoe designs are extremely comfortable because of all the padding on the uppers, but these are the very designs that hold the most water. Try some experiments weighing various shoes dry and fully wet and you'll see what I mean.  

(Events in which you can guarantee to meet wet ground almost continuously for days  on end (such as the Pennine Way) need a bit of specialist thinking so I'm excluding them here. There are experts around and I'm certainly not one of them)

So these are my significant criteria. It's just a question of choosing a shoe using these and we're sorted? Well actually no, because you will have seen already that there are some pretty big incompatibilities here, and as with anything, design is always a question of finding the best compromises for the job. Let's look first at the trade-offs.


There are a lot, but I think it's really only worth  concentrating on the three bigs ones, which are

1. You can't have a perfect grip on all surfaces. As we covered earlier grip on grass needs studs and grip on rock needs rubber. 

2. You can't have good cushioning and good stability. Cushioning increases the sole depth, which directly decreases stability.

3. If it's wet, you can't have upper shoe comfort and dry feet.

The runner

So far we've only talked  about the shoe in isolation, but equally important is the runner's shape, ability and ambitions.

Foot Shape

I posted another piece back in November 2013 entitled "Bad News and Blisters" which is another one that has has a lot of views (in fact it's my third most read ever) in which I claimed that the most important thing about any shoe choice is that they fit your foot. I have a slight reservation on this nowadays which I'll explain later but it's still a good base to work from. If you are recommended, or pre-select, a design which on try-out you find is too wide, too narrow, too tight or loose on the instep, etc for you, then probably the best thing to do is try something else.

Ability and Ambition

If you look at the results of most major ultras, the difference in finish time between the leading finishers and the back of the pack is normally a factor of around two, sometimes even more. If the winner of the Lakeland 50 gets home in 8 hours and another competitor takes 15, then it's not just that the winner is a better runner, he(or she) is playing a completely different game. It's the difference between running a 9 and a half minute mile average (and by inference a lot faster than this on the downs and flats) and a long walk. I would be really surprised if the same shoes were equally suitable for both competitors to get the most out of their day. Stability and grip become paramount when you're flying down rocky ground, comfort is probably far more important after a longish but fairly pedestrian day on your feet.

So choose your weapon.

As I said in my earlier post back in 2012, I'm not going to translate this thinking into a recommended brand of shoes, because it should be clear even from getting this far that there is no "one size fits all" answer. It used to annoy me when I saw runners making specific recommendations, even for individual races; "shoe X is definitely the best. shoe Y is unbeatable, and so on". Now I see it so often that I just let it pass. But if runners do seek recommendations from others who have experience of a particular shoe "in the field" I think it would be far more helpful to them  to ask specific questions rather than just "how good is it?" "What's the grip like on wet/dry rock,? how stable on technical ground?" etc might be better questions.

So all I'm going to do here is to put up a few scenarios about how I now go about choosing shoes. Everyone will be different from me and will reach different conclusions, but there's no reason why the thought process shouldn't work for everyone.

As an aside, this will lead to an assumption that most runners will have a range of shoes available for different races (depending on the range of events that interest you). If you're not at that point already I think you should consider it; the long term cost is no different (think about that one for a moment if you initially don't agree).

To illustrate my thinking I'll try to refer to well known events that many runners will have some experience of; my natural preference is for hilly events these days but that's just because I can't run very fast, still there should be enough for you to get the idea. Unless the event has specific difficulties with for example a lot of wet ground, the two most important factors for me are how long is the event and how much technical ground it has. 

Something like the Scafell Pike marathon is a no-brainer; only twenty six miles but getting on for twenty of that is technical ground (It's difficult to define "technical", it tends to mean different things to different people, but let me have a shot and say that it means ground where you have to make an individual decision about each footfall, and most footfalls will impose some sort of lateral force on your foot). So for this race I would choose a shoe with good wet/dry rock grip and good stability. I wouldn't be too bothered about cushioning because (a) it's not all that useful on this type of ground, and (b) I'm only going to be out for 6 hours or so, so quite happy to put up with a bit of battering. Last time I did it I wore Speedcross which I'm still using now, but I'm considering a move back to one of the Innovates which seem to have come on a bit recently (I tried Rocklites about 6-7 years ago and found that I enjoyed them but couldn't last more than 20 miles without their hurting my feet, but both my running style and shoe designs have changed quite a bit since them). I'm also looking around for a stable shoe that gets a bit more rubber down for events that feature a lot more rock and scrambling sections. The pleasure that you get from moving over rocky ground in stable, grippy shoes makes using anything else to seem like driving a truck after a sports car. But for those of us a long way from the top of this particular game, the problem is that we can't keep it up for long  -  for me, the daylight hours of a long summer's day is about all I can do, any more and my feet are wrecked.

At the other end of the scale perhaps is the West Highland Way race, 95 miles of dry, hard-packed trail with maybe 7 or 8 miles of technical ground in total, the remainder very easy underfoot. I would never go with anything other than well-cushioned shoes on here, my favourite these days are Skechers Gorun Ultra. These shoes are actually too wide for me across the front but fit well everywhere else, so I'm happy to compromise and place my feet a bit more carefully where it's rocky. 

I think it's important to make some sort of objective assessment of the ground in any race before making a shoe choice. For example both the UTMB and the Tor des Geants have reputations for being nearly as hard as they come, but this is due to the length, climbing and altitudes involved. Underfoot they are both on well constructed, easy paths, so cushioned shoes are a no-brainer for me. 

The Lakeland 100 is a hard one to judge. It has a reputation for being a big, gnarly 100-miler, maybe the toughest in the UK. This is possibly justified, but if you look at the ground underfoot it has some short sections of  technical trail, maybe amounting to 10 miles in total, otherwise the predominating feature is long, stony but straightforward paths and jeep-tracks, the sort of terrain where for me cushioning really pays off, particularly in the second half. If a drop bag was available at Braithwaite, 30 miles in with most of the technical stuff done, I would be tempted to go for stable shoes at the start and change to cushioned there, but as it is I'm happy to go with cushioned from the start. 

The compromise you make is to be a bit more careful (ie slower) on ground where you might turn an ankle, but at my pace this doesn't cost a lot of time in the overall scheme of things. 

I've completed the race in road shoes (Asics Nimbus) and Hoka Stinsons in the past. This year I'll probably go with the Skechers. The real payback comes on all the easy stony paths and road sections (all of leg 1, nearly all of Braithwaite to Dalemain, Gatescarth, Garburn, most of Troutbeck to Chapel Stile, etc) where you can cruise along in comfort without having to concentrate too hard. But then I'm never completing this event at more than a 3mph average -  if I had ambitions in the 25-30 hour range I might choose different shoes.

Events with both lots of technical ground and lots of "grass and track" are harder to call, but some of them have retrievable dropbag options that allow you to change shoes, usually into cushioned ones later in the event. This works well on the Lakes 10 Peaks (change at Honister) and Lakes in a Day (change at Ambleside).

In 2012 I had converted to Hokas for a cushioned option but they were really still in their infancy. They've come on a lot since then with many different designs, generally trading cushion for a bit more stability. I still keep one pair on the go (last ones Rapa Nui, now moved on to Speedgoats), because although they always feel a bit heavier and less manoeverable than the Skechers (and nearly twice the price!) they've gradually grown to cope with wet ground a bit better, with more resistant uppers just above the sole area and less padding - Hoka are obviously learning from European feedback where Skechers are clearly designed for the dusty dry trails of North America. The only problem with Hokas (within this "cushioned" category) is that they have never overcome the poor grip problem, get them on steep wet grass and it's never a completely certain experience. I found the Rapa Nuis to be a good choice on Day 3 of the Dragon's Back, keeping dry and comfortable feet without too much performance compromise.

I seem to have banged on a lot about cushioned shoes, but I guess that's because I wear them a lot. I'm not trying to convert anyone, just explaining why I do what I do. I see quite a few runners wearing cushioned shoes at events these days, but also many (probably the majority) who do not. But I also read a lot on forums of runners who have finished events in various degrees of foot pain and believed that's just the way it has to be. I don't think it is; remember, we do this for fun.

So that's it then. No magic answers, just I hope a few ideas that may prompt a bit more logical thought on shoe choice. I'm happy to be shot at as always.


Dave T said...

Interesting, as ever. Most varied course I've done was the High Terrain Events Kielder 80k earlier this year. Needed to change shoes every 20 minutes: cycle track, road, forest tracks, single track, open fell, marsh and snow. I'm going to design a shoe with interchangable soles - just need an engineer with a bit of time on their hands and an interest in ultra running. Do you know anyone?

Richard said...

Great post again Andy,

As I've aged I've prioritised cushioning over almost anything else. This, and a modification in running style (through a change to low-drop shoes) has seen my lower limb chronic injuries disappear. I'm using the Hoka Cliftons at the moment (mainly road running) and apart from their alarming wear rate they seem to work.
One observation I would agree with you on is that the term "trail" has radically different meanings in the British Isles and North America. For us it generally means wet and slippery and for them dry and hard packed. As your feet disappear from under you on a muddy trail you learn this pretty quickly.