Getting into running might start with tracking simple metrics, like time, distance, and pace. As runners advance, however, they often start to focus on more granular details to prevent injuries and improve performance. The Lumo Run ($99.99) is a clip-based fitness tracker you wear on your pants while you run to track advanced metrics that are usually reserved for more expensive gear. And when it comes time to assess your cadence, vertical oscillation, braking, pelvic drop, and pelvic rotation, the Lumo Run offers feedback on how to improve your form, including pre-run exercises. It doesn't support add-on heart rate monitors, and only works with iOS devices. But considering the price of other devices that track similar stats, the Lumo Run is a great value.

Design, Battery, and Stats

The Lumo Run is an oval pod that easily fits in a closed fist. It's about two inches long but only half an inch thick. One end has a little cap that flips back to reveal a micro USB charging port. A cable is included with purchase. A single LED illuminates in different colors to let you know when the device is charging, fully charged, and syncing.

The pod slips into a silicone clip that attaches to the back of your pants. It's water resistant, so you don't need to worry about sweat. Lumo also sells running capris and shorts with a specially designed rear pocket to hold the device if you don't like the clip.

On a full charge, the battery should last about a week, but it depends on how much and how long you run. The device requires an iPhone (5s or later) to set up and use, so Android owners are out of luck. You don't need to carry your phone with you when you run, except during an initial assessment. The Lumo Run can do almost all the tracking on its own, though you miss out on real-time coaching and GPS when you leave your phone behind. Similarly, you miss out on a few metrics if you run on a treadmill.

With your phone, the Lumo Run gives you a full running analysis, including time, distance, pace, splits, GPS mapped route, cadence, vertical oscillation (bounce), braking (change in forward velocity when you stop or "brake"), pelvic drop (hip dip), and pelvic rotation (hip swing). For those last five advanced metrics, the app has clear information about what they are, whether your readings are good or need improvement, and how to correct them. So if you don't know much about, say, hip rotation, the Lumo Run helps you learn.

Lumo Run on the Road

Getting started with the Lumo Run requires an iPhone for the initial setup and a ten-minute assessment run. If you planned a longer run, don't worry, you can continue running, and the Lumo Run will use just the first part for the assessment.

It helps to wear a pair of earphones during the assessment run to follow some audio instructions as you start and finish. There is no audio coaching during the first run. It only becomes available later.

At the end, Lumo syncs your run stats wirelessly to your phone, and the companion app provides you with a summary. The app gives you a lot of information, making it an excellent tool for runners who are at the intermediate level and want to improve, but don't necessarily have the knowledge or skills to know how to do so on their own. For example, my assessment told me to work on cadence, but it didn't end there. It explained what cadence is, that mine is low, and then suggested exercises I can do before a run to help me increase it.

The analysis and advice is the meat and potatoes, and it sets this device apart from other trackers. Running accessories and gear that track advanced stats usually assume the runner is experienced enough to know how to interpret their own data. And maybe if you spend $600 on a running watch (that's the price of the triathlete's bundle of the Garmin Forerunner 735XT), you can make sense of your own data. But Lumo doesn't make that leap.

See How We Test Fitness Trackers

As you use the Lumo Run more, it provides real-time audio coaching from your phone. At the beginning of a run, a voice reminds you what to do differently. In my case, I was told to work on increasing my cadence and to imagine I'm running through puddles, trying to make as little splash as possible. You might also hear audio cues that prompt you to focus harder if the skill you're trying to improve is slipping. You can customize some of the audio coaching features in the app. You won't get that kind of detail from most other running accessories.

The methodology for coaching is based on a five-percent increase model, meaning the advice should be fairly gentle. It's not going to push you run a four-minute mile, for example.

One major metric that's missing is heart rate. Lumo doesn't include any option to connect a compatible heart rate monitor. Many runners use heart rate data for training, so the fact that it's missing may be a deal breaker when deciding whether to buy the device.

Accuracy

To get a sense of the Lumo Run's accuracy, I completed a one-mile run on a familiar loop of road while wearing the Garmin Forerunner 620 ( at Amazon) and a HRM-Run heart rate monitor. This special heart rate sensor from Garmin has its own hardware for collecting advanced running metrics when worn in conjunction with a supported device.

The Lumo Run's calculation of one mile was 0.07-mile shorter than Garmin's. Lumo had my pace at 10:06, whereas Garmin clocked it at 10:58. Cadence and vertical oscillation were nearly identical between the two: 158 steps per minute with Lumo and 156 with Garmin, and 4.10 inches with both.

I was pleasantly surprised to see that the readings for cadence and oscillation were nearly identical, but the discrepancies between distance and pace were significant. Based on my knowledge of the route, I believe Garmin's distance was more accurate. As for pace, I would guess I was somewhere in between, more like 10:30.

While more expensive doesn't always mean more accurate, keep in mind that the Forerunner 620 bundle costs about $400, compared with the Lumo Run's $100 price tag. The 620 reports a whole lot data, though. It includes ground contact time, VO2max, estimated recovery time needed, and more. That said, it doesn't offer the same clear analysis and strength training suggestions you get from Lumo.

Conclusions and Recommendations

I enjoyed the Lumo Run more than I expected because of the specificity of its feedback. Data points are only as good as the choices we make because of them. Lumo helps you jump from information to action. If you're into running and want personalized information on how to improve and prevent injuries, the Lumo Run is an incredible device that doesn't cost too much.

More advanced runners will want the option to add a heart rate sensor, however, and the Lumo Run doesn't have that. It also doesn't give any advice about recovery time or provide insight on race time goals. Runners craving those in-depth stats need to open their pockets for a more expensive watch and HRM bundle, like the higher-end models in the Garmin Forerunner and Fenix series.

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