If you like the idea of bringing heart rate training into the water but don't fancy wearing a chest strap to do it, Instabeat is here to make it happen from your swimming goggles.
The wearable device is slipped around one side of your existing goggles and can take heart rate measurements from the temple via an optical HR sensor. From a small light that appears on the lower bottom right of your goggle lens, you can see your current heart rate zone.
Essential reading: Best waterproof fitness trackers to buy
The idea is that with the ability to view your heart rate zones in real time, swimmers will be able to pace themselves better in long distance sets and optimise recovery in shorter sprint sessions, ultimately to offer more efficient training sessions.
Once you're done with your session and you've synced the device with the companion app (iOS only, Android is coming), you will be able to see additional insights and metrics including pace per 100m, lap time, total distance, active versus rest time, and swimming stroke for each lap thanks to the onboard motion sensors.
Instabeat is also introducing its own proprietary metric that it's calling BEATS, which measures your workout's total effort independent of time or distance. This insight is designed to give you a baseline to make it easier to compare your workouts.
A long time coming
We first heard about Instabeat and its quest to smarten up swimming way back in 2013. That's when it successfully raised its target crowdfunding goal on Indiegogo to build the ambitious swim wearable.
"This is the most complex product I've ever worked on. Its ability to fit on most goggles and faces while being accurate and waterproof was a vectorial challenge," said Jawbone co-founder Alexander Asseily who has partnered with Instabeat's founder Hind Hobeika to bring it to life. It's taken eight years of research and development to get Instabeat built and according to Hobeika, it's not been easy.
"For starters, water, chlorine, salt make every design more difficult and this is a de facto requirement for a swimming product," she said.
"On top of that, we were adamant on having a product that would fit on any swimming goggles and on any face. Designing with so many variables is extremely complex. We started by working with a human factors expert that digitized the different goggles and different head shapes to get to a first 'theoretical' design.
"We then started iterating experimentally. For each design, we had panels of people with different head shapes come to the pool with us, and swim (including flip turns and push offs) with 11 different goggles, to make sure the product was comfortable and did not cause any leakage. It took 250 people to get to a design that we considered successful enough to move forward with manufacturing.
Essential reading: Incus is a swimming wearable built for triathletes
"During these swim panels we were also testing for heart rate accuracy against a Garmin chest belt, and collecting data for our automatic motion detection data that are displayed on the app post-workout."
With the recent arrival of Form, a swimming wearable that builds swim tracking into a pair of swim goggles, Hobeika and her team opted against building something that would be integrated into a pair of goggles.
It took 250 people to get to a design that we considered successful enough to move forward with manufacturing
"We did consider it, but after talking to multiple swimmers, we realised it wasn't the best approach," she said. "Swimmers changed their goggles every few months due to fogging and leaking, and they said they would be very reluctant to purchase an expensive pair.
"The other thing was that once swimmers find a pair that works for them, they are pretty resistant to change them. I met people who bought the entire inventory of a goggle that they were going to discontinue so they had enough for the rest of their swimming days. I also met another guy who told me 'please don't touch my goggles, I am married to them.
"So we decided our best course of action was to design a product that would be adaptable to most swimming goggles."
Putting the heart first
The focus on heart rate is an interesting one as there is no debate from swim coaching quarters about the benefits and value of HR data over more distance-based metrics. But Hobeika believes there were very good reasons to put heart rate at the forefront of the device.
Read this: Best waterproof smartwatches to buy
"Heart rate data allows swimmers to understand whether they are training from a metabolic or cardiovascular standpoint," she explains. "In other terms, heart rate is the most reliable indication of how the body is responding and adapting to the intended training program.
"Heart rate in swimming, as for any other sports, allows improved recovery, lower risk of overtraining, and monitoring progress. We chose to develop a product focused primarily on heart rate for a few reasons. One relates to perceived versus real effort. That insight is more challenging for swimming than other sports due to water and the horizontal body position. Knowing your heart rate removes that uncertainty.
"We also found that fitness swimmers find motivation in knowing their effort level, and become more engaged in their swim. They tend to push themselves harder than they would without the real-time heart rate feedback."
Away from heart rate, Instabeat does record other swimming metrics, which aren't offered in real-time as you're swimming, but are viewable in the companion app. There were also some metrics that didn't make the cut for good reason according to Hobeika.
"We chose to leave out strokes as it's challenging to get them accurately solely from the head motion," she explained. "We also believe more in intuitive healthy eating than having the ability to count calories burned."
Time to smarten up those goggles
After the years it's taken to get the wearable properly fit for the pool you can now get your hands on it. It's available from Instabeat's website for $249. That is $50 more expensive than Form's smart swimming AR goggles, though you will be able to bring those additional smarts to the goggles you already own and have been putting through big swim sessions already.
We've got one to put to the test, so look out for full verdict on the swimming wearable over the coming weeks.
How we test