Hey, Adidas, stop it, ok?

Adidas Springblade

Adidas has come out with the second shoe that aims to absorb and rebound energy like nothing before with the new Springblade.  The first is their Energy Boost shoe. Both are super innovative, and I'm sure are the result of an incredible amount of R&D (both time and money). I applaud all of that effort, but I fundamentally can't agree with what these shoes try to do. Going a step beyond not agreeing, I'm actually very concerned with what these shoes will actually do to the body despite their attempts to protect joints and increase performance for a given level of energy expenditure.

Aside from selling the things, Adidas has a noble goal of decreasing joint pain and increasing endurance by cushioning impact and deploying more kinetic energy per stride. I'll also add that I love to see that they're using their Techfit upper in the Springblade, which I've found to be comfortable and compliant with different foot shapes (though the toe cap seems to negate the real benefit of the upper since it will restrict the toes from splaying and naturally providing stability).

My issue starts with how the body will react to these two models. Several reviews of the Energy Boost have raised concerns with the unpredictable nature of the energy return, like running on a trampoline. This screws with your body's ability to sense angles, balance and forces, and fire muscles appropriately (aka proprioception). There are arguments for training in proprioceptively rich (aka unstable) environments as it strengthens the minor support muscles around your joints and builds the primary movers in a wider range than overly-controlled exercise. That said, these aren't positioned as proprioceptive trainers (like a Bosu or balance disc is). They're positioned as running shoes you could run a race in.

For the Springblades, I'm even more concerned because they really force you down one path - heel striking, and they look to snap you ahead a bit as the plastic blades spring back. That can't be good for the knees - knees that have just taken a jolt from the heel strike you can't avoid in these things. I'm sure you could mid-foot strike in them, but I would imagine you'll get an odd jolt from the heel blades when they touch and spring back which would put an odd strain on a knee that isn't expecting return forces from heel striking to come when it isn't heel striking.

The Energy Boost are also so thick in the back and rigidly constructed under the forefoot that I can't these being forefoot strikable.  I'm sure you can mid-foot strike in them, though.

Adidas Energy Boost

Am I basing this off looking at the shoes rather than running in them?  Yes. I've read a lot of reviews of the Energy Boost, and my thoughts are pretty well validated by the reviewers who have run in them. And we're not talking about average Joe reviewers, but highly educated and respected reviewers like Pete Larson of runblogger.com and author of Tread Lightly. Adidas talks a lot about the energy return of the shoe, but it's not clear that this is actually useful or good in a running shoe. They have no evidence to show this to be the case. The same is clear in the marketing of the Springblade.

The shoes look really cool (especially the Springblades), and I'm sure will sell fine. However, they're both very expensive ($180 for Springblades (!) and $150 for Energy Boost), so I really think the burden of proof of the true benefit of the technology needs to be there. Cushioning or energy return may be good, but before you ask me to spend more than any other competitor shoe I've seen on the market, perhaps you could really show me why and how it's good.

This all reminds me of a similar situation in the opposite direction. Vibram FiveFingers came out with a lot of claims of being better without a lot of proof of this being true. Those claims as taken by the average consumer imparted a sense of health benefit or at least benefit to running and injury reduction. No proof has emerged, and injuries have still been experienced by VFF wearers. The result was a class action lawsuit that Vibram lost.  Notice the analogs here - claims that the tech is better for you and will help your body, yet a lack of proof. For some reason, the media was all over Vibram for its claims, but no one in the mainstream sports media seems to be pointing out what Adidas is doing here.

I'm not trying to be a conspiracy theorist or anything, but I'm saying people need to be mindful of claims without proof, and the trend of the big sports companies to generally isolate the body from the sport with excessive cushioning and technology to do the work for us (like blades from Adidas or shocks from Nike that spring us forward so we don't have to).

Removing yourself from your exercise isn't a great way to be healthy. Get closer to it, let your body do what it's made to do, smile and enlighten.your.body.