I first got to test this shoe on a Formula 1 racing track, yup, you read that right. We got to run around in them on a soon to reopen Formula 1 racing track to see how fast these shoes could go. Spoiler, obviously not as fast as a Formula 1 car. 

There are a lot of running shoes on the market that claim to be fast. Some are, some are not and some are only suitable for runners that are already fast. The Adidas SL20 however, claims to be for everyone. No matter what type of runner you are, you can go fast in this shoe, whatever fast means for you. I found that really interesting, because fast shoes these days are often marketed towards a certain type of runner that is already fast and it’s often also linked to a certain type of pace or marathon time. I’m not a fast runner and I don’t come anywhere near the times that faster runners reach on a marathon. I liked that the marketing behind this shoe didn’t only focus on the really fast runners and acknowledged that what is fast, is personal. Because let’s face it, about 10% of runners are really or pretty fast, but what are the other 90% supposed to do for their speed and tempo workouts?

I’m a heel striking (because that’s what happens when you run slower), back of the pack kind of runner. Faster shoes, especially those with carbon plates, aren’t designed for runners like me. But the SL20 does not have a carbon plate. There is also a carbon fibre plate kind of version of the SL20, the Adizero Pro, which comes with the same Lightstrike midsole as the SL20, a new midsole material, but has ultraboost in the heel and obviously a carbon fibre plate in the midsole. 

The SL in SL20 stands for super light and this shoe definitely lives up to its name, it only weighs about 200 grams in the women’s model. It is a neutral running shoe and it has a 10 mm drop with a 24 mm heel stack and a 14 mm forefoot stack. 

Upper

The detached tongue is pretty thin, but still comfortable. I normally don’t like a thin tongue since I lace my shoes pretty tight to prevent heel slippage, and that’s more comfortable with some padding. But in this case it hasn’t bothered me. There is some more padding in the heel, and since this is more of a shorter distance shoe the padding is enough. 

The upper is made out of a thin engineered mesh, which seems to fit the lightweight theme of the shoe. It’s snug enough for a good fit and there are extra eyelets so you can lace the shoes properly. 

Midsole

As mentioned before, the SL20 has the new Lightstrike midsole, although it isn’t entirely new since it’s been used in basketball shoes before, but it is new for running shoes. It is lighter than boost, but also less plush than boost. The interesting thing is, is that the Lightstrike doesn’t feel remarkably springy or like it has a huge energy return and yet you do go faster in these shoes. 

Outsole

The outsole is Continental rubber which gives you good traction and there is a y-shaped torsion plate underneath the midfoot to give some added support.The shoe is quite stiff, but that’s what helps you go faster.  

Performance

I always have to get used to these shoes when I’ve just put them on. For some reason it isn’t that comfortable for the first mile or so, it always feels a bit awkward, but after that it’s actually quite comfortable. Not super plush, but that is to be expected, considering this being a fast and light shoe. 

I’ve done shorter and longer runs in this shoe. I also did some interval and tempo runs in them. I had no trouble reaching the interval paces that my training plan required in these shoes, I easily managed those. It is a good shoe for faster runs. 

Conclusion

So, as a slower runner can you reach a fast pace in these shoes? Yes. The first time I ran in them on the racing track I came quite close to my 5K PB time. Not bad considering I was trying to go fast, but I wasn’t trying for a PB and the racing track isn’t really meant for runners either, there are some really steep and sharp bends and there was a lot of wind that day.

Is this shoe better for people who are midfoot or forefoot strikers rather than heel strikers? Probably, it is likely that you could go even faster in them if you are not a heel striker, but they aren’t bad for heel strikers either, which is definitely something for a fast racing shoe. It does become a bit of an issue when you are trying to go longer distances. The heel to toe transition isn’t optimal when you are a heel striker. When you are trying to go fast for a shorter distance, this isn’t too much of an issue, but when you are going longer and thus slower it becomes more noticeable. I wouldn’t go much further than a 10k in these, because at that point the heel to toe transition seems to take more energy than the shoe can return to you and it’s just costing you energy at that point. Plus, this shoe isn’t super plush and that becomes more of an issue if you go longer.  

It is a good, well thought out shoe that comes at a good price, it retails for only $100. It’s a good fast shoe to have in your rotation. It’s not a super plush ride, but it does the job for shorter, faster runs and it is suitable for different types of runners. It will be interesting to see future Adidas shoes with Lightstrike and I think the Adizero Boston 9 has a combination of Lightstrike and Boost.