I’ve often heard runners say that they buy shoes that are slightly too big to allow for their feet to swell whilst running.
This idea of “sizing up” and buying a shoe that is half or maybe even a full size bigger than you would normally wear doesn’t quite make sense to me. Here’s why:
Firstly I’d question if your feet do actually swell during running. Whilst there is some evidence that over hydrating can cause feet swelling (link) and that oedema can occur during prolonged exercise such as ultra distance events, it isn’t guaranteed to happen to everyone. Secondly, even if they do swell, your feet will tend to get fatter rather than longer so to accommodate that what you actually need is a wider shoe rather than a larger one.
there’s a wide pair here somewhere!
Lets take a hypothetical situation: A runner who normally wears a size 9 shoe decides to wear a size 10 for a long race. They hope that this will prevent painful feet by allowing their feet to swell. So, what happens during the first 4 or so hours of the race before their feet swell? They are running in a pair of shoes that is a size too big for them!
As humans we develop a complex sense called proprioception or kinesthesia which allows us to perceive movement and body position and is hugely important in controlling motor skills, such as running. Imagine if we have done all our training in a pair of size 9 shoes and our brain has sensed how if feels to run in these shoes, how to react to the myriad of stimuli and sensations of running in them. Then we go and try to race in a larger shoe. That hard wiring of the brain to know just how high to lift the foot to avoid tripping suddenly needs to be re learnt. For a while we are clumsy and have to think about how we are placing our feet rather than it being instinctive.
Have you ever noticed that you are much more likely to to trip, stumble or stub your toe towards the end of a long run when you are fatigued? It’s more likely to happen late into an ultra than it is on a 10k, even though you are running much more slowly. Fatigue, such as experienced towards the end of a long race affects both muscle function and proprioception, increasing the likelihood of tripping. Now add in running in shoes that are too big, it’s a perfect storm!
If you do experience foot swelling whilst running do you actually need a bigger shoe size or could you just loosen the laces? Maybe you just need a shoe that has a bit more room in the toe box? Or you could use a removable insole and take it out when your feet feel uncomfortable in order to give the shoe more volume.
or you could remove the insoles
We are individuals and it is important to find what works for you, but don’t just assume that you need to size up your shoes for your long runs. I did the Paddy Buckley Round on a very warm day. I wore the same pair of Inov-8 Roclites that I had worn both on long hill days and short, fast training runs. Once laced up I didn’t touch the laces again until I’d finished, not even to change my socks!
Boa® Fit – a new lacing system for trail running shoes?
There have been numerous design changes to running shoes over recent years; lighter materials, sticky rubber, Graphene infused outsoles etc etc but the method of keeping them on your feet has pretty much been the same – laces. You pull them as tight as feels comfortable, tie them in a knot that won’t come undone (you hope) and forget about them. Simple. So is there any scope for changing to a different system? Is there room for improvement or if it ain’t broke should we not try to fix it?
Boa® Fit System on the Adidas Terrex Two
I hadn’t really given the topic much thought so I was interested when given the chance to test a pair of shoes with the Boa® Fit system. Basically this is a dial on the shoe which can be turned to tension the laces and pulled to release or undo them. The system isn’t new, it was developed almost 20 years ago as a method of fastening snowboard boots and has since been used on sports footwear such as cycling shoes, but I hadn’t come across it used for off road running shoes. The shoes I tested are the Adidas Terrex Two (GTX) and whilst I was interested in the shoe I was most keen to see how the Boa® Fit System performed.
quick release Boa® Fit System
I wore the shoes for over two months, clocking up over 150 miles in a range of conditions from the hot and dry September to the more recent wet weather. As these are a trail running rather than fell shoe most of the runs were on harder or rockier trails and short grass. They aren’t designed to tackle rugged, boggy fell type terrain. I wore them for different types of run ranging from long, fairly easy runs of up to 90 minutes to for more intense training such as hill repeats on rough ground and 1 kilometre fast intervals on hard packed trails. I used the Goretex version of the shoe, a non Goretex version is also available.
hill reps with the Adidas Terrex Two Boa® Fit System
To be honest I was rather skeptical at first with a couple of concerns; one that the system was a bit “overkill” and that laces are perfectly fine, and two that the system might fail by getting mud and grit into the mechanism. After a couple of months of testing I have changed my mind slightly. Yes the system is more than you “need” and an ordinary lacing system is fine but the Boa® Fit System does have it’s advantages.
Getting them on and off is really quick! Ok, but you might say that if you can’t afford to spend an extra minute at the start and finish of a run then you’ve got other things to worry about!
Adjustable on the go. Occasionally I will go for a run and after a few minutes realise that I’ve either tied my laces too tight or too loose and need to adjust them. Again in the grand scheme of things it’s no big deal but in a race situation it could make a difference. With this system it takes seconds to adjust the tension.
Your laces don’t come undone. This is a big plus. Yes it is possible to tie your laces so that they don’t come undone but that often means that when you do want to undo them it is a bit of a struggle – especially with gloves on or with cold fingers. With the Boa® Fit System one pull on the dial releases all the tension and you’re out.
Easy to undo. As above, the quick release mechanism makes taking them off very quick and easy. No fumbling around with cold fingers trying to undo those double knots that you tied.
On the issue of the mechanism failing I never had any issues despite deliberately running through muddy puddles. The fact that the system is used on mountain bike shoes indicates that it can stand up to much worse conditions than found during trail running. The dial does stand proud of the shoe so it would be possible to catch it on a rock if running on very technical trails but I didn’t experience any problems.
testing the shoes in wet conditions
The Adidas Terrex Two with Boa® Fit System does cost £30 more than the same shoe with standard laces. Comparison here and here.
If the lacing system did fail the solution wouldn’t be as simple as replacing the laces.
Despite my initial skepticism I really got to like the Boa® Fit System. Admittedly it is more expensive than the same shoe with a standard lacing system but that isn’t being forced upon you, those on a tighter budget still have the choice. The ease at putting them on and off was probably their biggest attraction. I found myself slipping them on as I left the house to drive out to the Peak District then tightening them up whilst sat at traffic lights (out of gear and with the handbrake on obviously!) The fact that they can be undone in seconds, even whilst wearing gloves or with cold fingers will be very useful as winter approaches – remember tying that knot that you didn’t want to come undone?! As the shoes were designed for trail running rather than fell running it wasn’t possible to test whether or not the Boa® Fit System would stand up to the more rugged conditions of say the upland fells in winter conditions. However the fact that the system is successfully used in both mountain biking and ski / snowboarding suggests there is no reason why not.
This video shows just how easy it is to tighten and undo the shoes:
Adidas Terrex Two (GTX) Boa – Review
As for the shoes themselves they are a reasonably lightweight trail running shoe, my pair of the Goretex version size 7 weighing 625g. Given the choice I would opt for the standard over the Goretex version – Goretex works well for short durations but if you are out for any length of time or in heavy rain I find that your socks get wet and water soaks down into the shoes. Also any deep puddles that create splashes have the same effect with water getting in through the foot hole rather than soaking through the fabric. Once water gets in, because the Goretex doesn’t allow the shoes to drain freely, you end up running around with water sloshing in your shoes!
The fit is fairly wide and obviously suits that particular foot shape, it might not suit those with narrower feet particularly for example when descending technical trails. The outsole with Continental rubber gave a good grip on hard packed and rocky ground even in wet conditions but the lugs aren’t deep enough to cope with muddy conditions. These are a trail running rather than fell running shoe.
good grip from the Continental rubber
The Terrex Two have a 5 mm drop (heel 24.5 mm / forefoot 19.5 mm) which feels quite responsive and good for moving quickly on rough ground yet with enough cushioning to make faster paced running comfortable. I have found them to be a good choice for faster paced interval training on hard packed trail terrain.
Not the cheapest shoe on the market (the standard lacing system is £30 cheaper) but in line with the likes of rival brands such as Salomon and Inov-8.
Inov-8 Roclite have been my shoe of choice this year.
I’ve used them for working, training and racing. Unfortunately the rough gritstone, coarse heather and acidic peat of the Peak District have taken their toll and after 878 kilometres (I know thanks to SportTracks training software which calculated it!) the uppers have given up the ghost!
Interestingly, compared to the uppers the sole has fared pretty well with quite a lot of tread remaining.
there’s miles left in them lad!
The shoes have done me well and have had some great adventures:
Roclites doing what they were designed for
And have seen some stunning running conditions:
blue sky running
struggling on Ennerdale fell race – me, not the shoes!
So I reckon that I’ve had my moneys worth out of them and whilst I’m always reluctant to throw my favourite bits of kit away, the good news is….
I’ve got a shiny new pair!
ooh – new shoes!
For out and out bog and mud I wear Inov-8 Mudclaws but for mixed fell and trail running I don’t think you can beat Inov-8 Roclites. So I’m off to hit the fells with my new shoes – it will be a shame to get them dirty!