With more fuel being added to the footwear fire, AW’s running shoe guru explains why the debate may not be quite as straightforward as it seems

It’s now a well-worn routine. An athlete breaks a record or achieves a headline-grabbing time and the first question asked is “what shoes were they wearing?”

Barely a week now seems to go past without one performance or another adding more fuel to the footwear fire and usually irritating the athlete in question at the same time.

But both sides are right. On one hand, those who seek to protect the integrity and history of the sport have every right to raise the question, while the athlete is also correct to point out that it’s not just the tools of their trade which are doing the work.

A recent example is Beth Potter’s astonishing 14:41 5km which was two seconds faster than Beatrice Chepkoech’s world record and sliced 43 seconds from the Scot’s PB.

All fingers pointed at the ASICS Metaspeed Sky shoes she was wearing, but Potter told AW: “At the end of the day you still have to do the training. You still have to get up early in the morning and train hard, year on year, session on session. It’s not just the shoes.”

Asked if she was insulted by the suggestion she only ran fast because of her footwear, she added: “Yes I do when they don’t know anything about my training and they are people who are just speculating. I train really hard and I have a great group of people around me in Leeds who help me and who believe in me.

“These people are picking on my Power of 10 which is from four years ago and taking data which is out of context. So, yes, I do find it a bit insulting. They don’t see what I do day in, day out.”

READ MORE: Beth Potter beats world record time at Podium 5km

It’s also true that, while we’ve seen a large upward trend in performance, wearing a pair of “super shoes” does not automatically guarantee success. Indeed, while some athletes seem to take a seismic leap forward, others may only see the slightest marginal gain or in fact no benefit at all.

We are all individuals with many variables and the shoes have many variables, too. Here’s why it’s not necessarily a ‘one shoe fits all’ situation.

During Potter’s run, many things such as weather conditions and fellow competitors fell into place perfectly, but there is an interesting point to note about her shoe sponsor, too.

ASICS have two versions of their new Metaspeed shoe – the Sky and the Edge – and it highlights one of the reasons why some respond differently to shoes than others.

The Sky is aimed at runners who increase their stride length when increasing speed, while the Edge is for those who increase cadence (number of strides per minute). The unique shape of the midsole of each shoe has a slightly different interaction with the ground and complements the runner’s biomechanics.

READ MORE: ASICS Metaspeed Sky review

But what else within a shoe could have a possible effect? Its size could make a difference, especially when you consider the slight differences in foot shape. One runner with a size nine foot could have longer toes than another with the same size foot. This would mean that their feet bend in slightly different places. If the carbon plate within a shoe has a curve, this flex point will of course work optimally with a specific foot size.

The “drop” of a shoe is another variable. This is the height of the heel cushioning compared to that under the forefoot. The new ASICS is a 5mm drop with the Nike Next% an 8mm drop. But have you considered how important, or indeed accurate, this drop is?

In a larger shoe, men’s size 11, compared to a much smaller women’s size four in the same shoe the drop is actually much steeper in the smaller shoe.

Personally, I believe that the higher drop seen in the latest super shoes helps with recovery when compared to older models which were often known as “racing flats”. The foot sitting flatter to the ground encourages a more mid to forefoot gait, but also leads to tighter calf muscles after a hard race.

We should also consider where the carbon plate is situated within the shoe. In some models it is sandwiched between two layers of foam cushioning whilst in others it sits between the cushioning and the sole. This will have an effect on its flexibility and the amount of “rebound” it can offer.

In their Carbon X shoe, HOKA said the plate was there simply to retain the rocker shape of the foam rather than to offer any “springboard” effect.

Also consider the thickness of the carbon plate, its relative stiffness and how this will be affected in different sizes, while the weight of a runner, of course, will have a direct effect on the stiffness of the shoe and the force going through it.

So, we have some who will respond fantastically well to these shoes and others who won’t.

A recent example is Kenenisa Bekele quoted as saying he wasn’t happy with the updated Nike Alphafly (the shoe Eliud Kipchoge wore in the INEOS 1:59 event) prior to the planned clash at last year’s elite London Marathon.

On the track, the new super spikes have also claimed records. Again, carbon plates have been added, but spike plates have always been very rigid. Personally, particularly in the longer distances, I feel it’s the greater stack heights of cushioning that have helped to reduce excess strain and make running faster for longer more comfortable.

It’s not just on race-day, it’s the long-term benefit from training harder, with better recovery, that the shoes and spikes afford which leads to the improved performances.

And, of course, it goes without saying that before questioning the possible response of these shoes, one should consider the possible response of your own training. After all, if you aren’t putting in the miles, nothing is going to make up for that deficit!