Swimrun is a new sport and a sport that puts new and quite extreme demands on a sport shoe. The shoe should protect, support and promote good running technique during long distance running in extremely varied terrain, (tarmac, gravel, trail, rock and grass to name a few), under wet, muddy and dry conditions and everything in between. It should at the same time minimize the impact on the athlete’s technique and endurance while swimming. It is therefore quite understandable that the sports shoe industry did not have a product up their sleeve that could answer all these demands. In recent years there have been shoes that have been marketed as good for Swimrun (for example Icebug Zeal), but they still do not appear to have been developed for this purpose. For example they may be made out of non-absorbing material, but drainage is still limited or they have normal shoelaces that many athletes change to rubber laces that do not need to be tied but can be adjusted using a quick lock system. However, our hope is that as the sport grows so should the industries incitement to come up with tailored Swimrun products.
In the meantime, before the industry realize the potential of the sport, Swimrunners, inventive as always have tried and adapted the existing types and brands. So far orienteering shoes in particular some models of Inov8, have become a popular choice, but brand and model variation among athletes in a
race is big. In tests where different types of shoes have been compared the more
popular brands have not always come up on top when it comes to impact on pulse of the athlete while swimming and weight after swimming. To us this signals that there is still potential to improve key structures in the shoes and that the perfect Swimrun shoe is yet to be developed.
So what is it we want from a Swimrun shoe?
In general we want a shoe that enable us to run in varied terrain with good technique and without the risk of injuries due to lack of protection and at the same time does not limiting or perhaps even better improve our swimming. Let us therefore look in more detail at the different parts of the shoe and what features can be improved. Some things we bring up are quite obvious and uncontroversial while we realize that others may cause some debate. Variation in products is good so that different preferences can be satisfied, but no matter what the show looks like it must have been constructed in order to suit the above mentioned demands.
Upper Material – It seems quite obvious that a material that does not retain water is ideal. However, drainage is equally important, as is keeping sand and grit out.
Lacing – lacing retains water and knots risk to come undone therefore none absorbing laces that do not need to be tied, but that still can be tightened and released are probably ideal. One example of this is found on many Salomon shoes.
Midsole – the dimensions of the midsole is more of a question mark. To support good running technique and minimize impact on swimming perhaps the thinner the better. However there is a balance when it comes to the need of protection to avoiding pain from sharp rocks and from the impact of running long distances. A thick midsole offer better protection but may intuitively hinder the swimming due to more weight and resistance in the water. However this might not be the case. If you consider that most midsoles are made out of EVA-material which is the same material that is found in floatation devices, i.e. it is extremely buoyant. Perhaps therefore a thicker midsole with more EVA actually counteracts the legs from sinking? We have not tried this experimentally but would like to know.
Outsole – Good traction on both wet and dry surfaces is a must. However if spikes is a benefit or not is more questionable. Better traction in mud and on uneven wet surfaces may favor spikes, but risk of instability in landing and loss of grip on smooth surfaces may be a disadvantage. In addition spikes makes the shoes bulky and less ideal if you would like to remove the shoes completely
during long swims and store them under the wetsuit. Some triathlon shoes on the market have drainage holes straight through the sole into the shoe and some swimrunners have been known to drill their own holes. Perhaps this is feature that should be part of the optimal shoe.
In our opinion the best balance between the different features may be the following. A shoe made out of none absorbing material with a mesh-like structure for drainage and drainage holes through the soles. A pre-tied, quick lock, non-absorbing lacing system. EVA-midsole that compensates for the weight of the shoe and a relatively flat outer sole made out of sticky rubber that gives some extra grip without being bulky.
Will this type of shoe be on the market for the next Swimrun season?
We sure hope so!
/The Ultraswimrun Team