Olympic athletes, coaches and brands, have a long history of generating new, exciting technology. For instance, the first Nike running shoes were popularized by legendary track and field athlete Steve Prefontaine and his coach Bill Bowerman. The 2016 Rio Olympics were no different. They were full of cool, clever, inspiring, and ridiculous innovations that did more than just capture the imaginations of us mere mortals—they definitely expanded them.

Not all of these have been proven, and some of the all-time greatest Olympians have eschewed excess technology to adopt a more minimalist approach. But whether it’s a cooling helmet, aerodynamic tape, AI martial arts coaches, or a ring that handles transactions, the engine of innovation continues to churn and companies large and small are cashing in. Here were our 6 favorite technologies from the 2016 Rio Olympics…

The 3D-Printed Running Shoes

In the years leading up to the Rio Olympics, Jamaican Shelly-Ann Fraser-Pryce helped Nike design the perfect spikes based on data captured while testing her sprints. 3D printing was then used to make hundreds of prototypes, allowing Nike to experiment with different amounts of stiffness in the foot plates. As they say, no one shoe fits all, and 3D printing allows for more flexibility without the need to create new molds each time (there are startups also getting into the 3D printed custom footwear game). Nike also developed a honeycomb design of fixed pins that don’t screw in or out, allowing runners to sit closer to the track. The technology was vindicated during the games, with the United States dominating track and field events more than they have since the Los Angeles Games in 1984, with a combined 32 medals.

Usain Bolt, on the other hand, who has helped Jamaica earn a disproportionate number of medals in the last three Olympics, went with a more minimalist approach by Puma. His shoes are the same that can be bought on their website for $135. The big difference is that they’re gold, paying homage to Michael Johnson, one of the greatest and most charismatic Olympic athletes in history. Meaningful design can be its own form of technology.

The Cooling Head Gear

The great thing about being an Olympic athlete is that you can wear almost anything, no matter how ridiculous, and nobody is going to try to kick your ass. This cooling hood by Nike, for instance, which looks like a packing peanut stretched into an imperial helmet, would not have flown on my high school’s track team. But for athletes like gold medalist Ashton Eaton, it’s cool—literally. The cooling hood reduces an athlete’s core temperature without resorting to sweating or getting wet. That can be important for the decathlon, which requires strength and speed, but also visual acuity and concentration. If you’ve ever sweated in your eyes during a casual jog, imagine throwing a javelin under those conditions.

The inner layer of the device contains cool water that targets the head, neck, and areas around the eyes—all of which retain extra body heat. Perhaps they also have the unintended consequence of mitigating an athlete’s ego. You just can’t take yourself too seriously or worry what others think with one of these on. That’s the sort of attitude that earns gold.

The Visa Payment Ring

Lest you think Olympic technology only applies to sports that market in milliseconds, take a look at the Visa ring that allowed visitors and athletes to make mobile payments without exchanging currency. For a group of people who are often wearing spandex, not having to carry a wallet was a big plus, and the ring itself requires no battery source; instead it used the native power of the payment terminal to create the transaction. It’s similar to the way the magnetic strip on a credit card works. Bracelets and other wearable transaction devices have already taken off in Europe, where over 3 billion contactless transactions have been recorded.

The Visa rings that were unveiled during the Rio Olympics are now for sale by pre-order in the UK. They’re light, water proof, and fairly affordable at €39. But will they fly in America, the country that takes years to transition from swipe-and-a-signature to a chip? As it always does in the Olympics, time will tell.

The Aerodynamic Tape (Aeroswift Tape)

Athletic hobbyists are always looking for an excuse to throw money at things like expensive tape, tiny water bottles, and bionic knee/ankle/elbow contraptions. It may seem like the equivalent of putting spoilers on your car when you never intend to exceed 60 mph, but athletes love accessories and there is a huge demand for the “next big thing.” The 2016 Rio Olympics have delivered.

It turns out that expensive tape, known as RV tape, just got an upgrade. It’s called Aeroswift Tape, and it’s covered in tiny rubber nodes that siphon air away from the body, allowing for a more aerodynamic stride. They look like the tiny wings on Hermes’ shoes, allowing runners to wedge their way through the air pocket. American Justin Gatlin is one high profile athlete who can be seen wearing 8 or more of these Aeroswift strips during many of his runs. It helped him earn silver in the 100m, but once again it’s worth noting he fell short of Usain Bolt, who was completely tape free (and, granted, about 14 feet tall).

The Judo AI Chat-Bot

The Israeli Judoku team introduced a new artificially-intelligent chat bot that can answer specific questions about other Judo athletes, providing strategies and best practice advice for each opponent. It’s trained to find weak points by analyzing all of the career performances of other athletes. If someone is weaker to tosses on one leg, for instance, it could retrieve that information and then leverage it to answer natural language questions from a coach or athlete doing their pre-battle homework.

Former Olympic Judo medalist Oren Smadja, who coached the Israeli men’s national team at the Rio Olympics, believes it proved its effectiveness during training, allowing them to get targeted advice without having to hire a team of Moneyball-style data quarks the way large franchise teams in the NBA, NFL, and MLB have. The Israeli team went home with two bronze medals for their efforts, and the sort of AI they developed will probably play an even larger role in the 2020 Olympics in Tokyo.

The Seamless Rowing Unisuit (& The Zika-Proof Warmups)

John Strotbeck is another former-Olympian-turned-startup-entrepreneur, and his Philadelphia-based company, Boathouse developed the most high-tech rowing suit worn in the games (not to mention long-sleeve warmups to protect from Zika-carrying mosquitos).

The actual competition unisuits are made from a single piece of high-wicking, ultrafine fabric. They us no seams, which minimizes the amount of drag during motion, and they’ve employed innovative sewing techniques to reduce bulk and prevent chafing. It’s also finished with an antimicrobial to reduce exposure to the bacteria in the water.

The design brings to mind certain controversial unisuits that premiered during the Beijing Olympics in 2008, when media outlets began asking if full-body suits gave swimmers a super-human advantage in the water. In fact, Boathouse actually started out by equipping swimmers. FINA, swimming’s governing body officially banned full body suits in swimming after Beijing, so Strotbeck pivoted to rowing, where the advantage isn’t as relevant.

Athletes like Michael Phelps may enjoy success with a traditional swimsuit, but there are still plenty of athletes looking for any advantage they can get, and as long as unisuits are legal for rowers, rowers will wear them and Boathouse will supply them.

And that’s why Olympic tech is so popular and so enduring: for athletes who accept nothing less than perfection, there’s more of a risk in not using whatever tool is out there than using it. Even if there’s little evidence to suggest that a cooling hood or a unisuit deliver any distinct advantage outside of the Placebo Effect. As far as we’re concerned though, it’s all pretty nifty.