Products that measure and display our efforts can be slotted into three categories: metric senders; metric aggregators; and data crunchers. A sender (in my parlance) delivers a physical or biological metric: speed, power, cadence, heart rate, EKG, blood lactate, ventilation, hemoglobin, level of hydration.

A metric aggregator receives these signals and displays them real-time to you as you're training. It often adds a metric or two of its own, such as speed and location and the GPS is largely responsible for this.

The metric aggregator also remembers all this data and packages it into a file that is to be exported to Training Peaks, or Today's Plan, or some training log that archives and crunches the data, so that you and your coach can see your progress over time and decide what to do next.

Let's talk about that middle category, the data aggregator. And, honestly, what I just wrote above? It's already out of date. The display is no longer necessarily the device that remembers the data and packages it into an exportable file. I'll give you a couple of examples of this further below. Bear with me for now.

What are you using for this device class? Polar V800? Garmin 920XT or Edge 1000? This is a compelling product category, because we can divide this up in a number of ways also. Remember, this device gives you real-time data. It doesn't just report to your training log what you did, it's telling you what you're doing as you're doing it. How do you want that communicated to you?

Audio as a Powerful Data Delivery System

You can read it, of course. But, on your wrist? On the head unit of a bike? Or, as a heads-up unit, such as a Recon Jet? Does that about cover it?

Not even! What about audio? Consider KuaiWear, which we wrote about some months back during its Kickstarter campaign (image above). This is not simply a set of ear buds. It's a data aggregator. It not only prepares a file for export, like most other modern aggregators, it feeds you data real time. Just, it communicates its message to your ears instead of your eyes.

I can think of two ways that this would come in handy. Most obvious is in the pool. We have a real dearth of input when we swim. There's a pool clock and that black line on the bottom. That's it. Recon doesn't make a heads-up display for the swim goggle.

There are two other methods of communication: One is audio, the other is tactile. A Swimovate watch will vibrate at certain intervals, depending on what it is you want: at certain times, or laps, or a certain distance. This is a powerful device. It will vibrate in an open water swim when at a particular distance (if you want to swim a mile, it'll vibrate at the half-mile, telling you that you've reached the turnaround point).

Then there's audio. You think your earbuds are for music, at least when you're in the water. Nooooo. Let me ask you, who would you like to have coach you for a swim workout? Gary Hall, Sr.? Sheila Taormina? Andy Potts? Jan Frodeno? Daniela Ryf? Well, why not? A company like Kuai could send a script to any of these to be read and recorded with certain key phrases which include technique reminders. The phrases are cut and edited, producing workouts for any speed and leave interval. If it's a set of 100s on the 1:20, 1:30, 1:45, 2 minutes, you just edit the prompts – a bell in your ear for lap, every push off the wall, to tell you whether you're ahead, behind, or on pace – and a count as you enter each 50, 100 and so forth. Sheila's voice says, “5 seconds, 3, 2, 1, go” and it's off for another 100. “Ten down, 2 to go, in 3 seconds, 2, 1, go.”

The entire workout is audio, and you don't even need a pool clock.

Here's the second value. The pool clock is incredibly restrictive if you think about it. You can't do 100s or 200s with 10sec rest. You can only do them leaving on the 3min, the top, the bottom. Otherwise you'll lose track of the set. Let's say you want to have a fixed amount of rest in between efforts. Or, maybe the rest period is until your heart rate, or your blood lactate, drops to a certain point. You can't rely on the clock for this. You'll want a timer that starts when your chosen metric triggers the next leave. A Kuai device has an accelerometer in it. It'll speak to you when your lactate or heart rate has dropped to your target point and when you then push off the wall the accelerometer knows you've left and starts the clock.

At least two companies, Kuaiwear and Pear Sports, understand the power of the audio workout, certainly for swimming but while on land as well. I've offered to host workout libraries for each of these companies on Slowtwitch. Each is now busy lining up athletes to speak audio workouts, like podcasts, but better. These companies get it.

Head's Up Display: GPS on-board or not?

As you all know by now, a heads-up display is a compelling way to read and receive data and Recon's Jet (above) is a source for both visual and audio data prompts. With the device you can read, hear and speak. There is only one criticism with this device, and that is the battery life. Recon wants its device to have all its own functionality built in, which includes having a GPS inside and it's a fully-vested data aggregator.

SOLOS (below) is a nice glass, nice HUD, but has no GPS nor does it archive the workout and assemble a downloadable file. This data aggregator suffers from sports dementia. It remembers nothing. It relies on a BLE or ANT+ signal to give data to show you, but also to immediately offload that data to a smartphone and this is what generates the downloadable file.

The SOLOS also uses your phone's GPS. So, no camera, no GPS, and a less-powerful processor. It still gives you all the data you'll want from a Jet, just, it pulls in the GPS signal from your cell phone. This means the SOLOS would lose a lot of its functionality if your phone went dead, or if you forgot to bring it, or if it lost connectivity. But the SOLOS does expect to deliver 6 hours or more of battery life when it is introduced (6 months from now is the projection).

The Garmin Vario is another heads-up display, and while I've seen the SOLOS and the Jet, I've not yet seen the display on the Garmin. This device also does not have a GPS. It picks up the signal from the other Garmin unit you have (boy, Garmin assumes you're a loyal customer!).

The SOLOS looks like it will be a nice option for cycling (it's also lightweight), but less so for running if you don't want to bring your cell phone along for your run. The Garmin HUD can be used with your other compatible Garmin device.

Because the SOLOS (and one assumes the Garmin) does not use the heads-up display for data memory, or to compile the session into a downloadable file, its battery is not tasked with these duties. The Recon Jet seems to me much more powerful, much more feature-rich. The offset is the drain on the Jet's battery.

Before I get too wound up in the benefits of one of these products over the other, the only heads-up display Slowtwitch has ever tested in the field is the Recon Jet. We expect to have our electronics editor Tony Vienneau test the HUDs from SOLOS and Garmin (and 4iiii) and report on them here.