Sennheiser Momentum Sport: fitness tracking from the ear

I was a little skeptical of the $329.95 Sennheiser Momentum Sport earbuds. Other earbuds I’ve tested with heart rate tracking were fiddly. The workout tracking could be well-intentioned but a bit hit-or-miss in practice. So, I was pleasantly surprised that the Momentum Sport buds delivered what was promised — a simple way to view real-time fitness metrics without sacrificing sound quality.

Most fitness buds have extra bass, a more secure fit, and an emphasis on durability. The Momentum Sport have that, plus an optical heart rate sensor and temperature sensor. The pitch here is that the ear is actually a more accurate place to gather this kind of data than the wrist (which is technically true!). It also integrates with the Polar Flow app, giving you access to Polar’s training analytics, voice guidance, and coaching. In some respects, it works a lot like a chest strap… albeit one you can stuff in your ears and that plays music.

As a runner, my checklist for fitness buds is a bit different than everyday buds. They need to stay put in my ears, a good transparency mode is a must, they can’t be crap on windy days, and a lil rain can’t wreck them. The Momentum Sport gets high marks across the board.

Earbud fit is always tricky, but the Sport buds are a solid choice for working out. The buds are on the larger side, and I have smallish ears, so I didn’t find them as comfy as my favorite running buds, the Beats Fit Pro. However, I took them on several runs, and not once did they fall out of my ear.

I’ve had issues in the past with heart rate tracking earbuds because of fit. Good contact with the sensor is crucial, so a bad fit could mean getting wonky results — or none at all. It negates the whole point of in-ear metric tracking: better accuracy. I didn’t have that problem here. That makes this a neat alternative if you practice some sports that aren’t conducive to smartwatches or find chest straps uncomfortable, especially if you like working out to music — you can theoretically wear one less wearable to get your data.

Transparency and the Anti-Wind modes were great on my outdoor runs. I could still easily hear cars whizzing around me, but strong gusts didn’t drown out my tunes. I also took them on a miserable, rainy run with no issue. That said, I’d still check the weather before runs. These are IP55, a bit better than the typical IPX4 you see on buds, but a torrential thunderstorm could be a bad time.

For fitness tracking, I dug that you’re not limited to a proprietary companion app. If you’re in Polar’s ecosystem, it fully integrates with the Polar Vantage V3 watch. Without a Polar watch, you can also link the Sennheiser Smart Control app with the Polar Flow app on your phone. Then, all you do is launch a workout from Polar Flow and select it as your heart rate sensor of choice. It worked well when I tried it, and if you don’t have a fitness app you like, Polar Flow is a pretty comprehensive one! The downside is you’re not going to be wearing these all day, so your recovery insights aren’t going to be quite as good.

It also works with other fitness apps and smartwatches that support Bluetooth accessories. I checked and was able to pair it with Strava and Runkeeper — two of my more frequently used fitness apps. I also paired it to my Apple Watch Ultra 2 and was able to view my heart rate metrics from there as well. I appreciate it because it lets me go get my training guidance from the platform of my choice. When I tested the Amazfit Powerbuds Pro, a similar pair of fitness tracking buds, I had to use its proprietary companion app to get access to a lot of health features. That just added more clutter to my routine.

As for accuracy, it was within roughly 5 beats per minute of the Garmin Forerunner 165 Music paired with the HRM-Fit chest strap. Body temperature was more of a head-scratcher. For starters, it’s hard to test accuracy. It’s a safety hazard to run with a thermometer sticking out of my ear, and other wearables focus more on changes in skin temperature overnight. But I get why high-level athletes might value body temperature data. It’s just that for the average person, it’s overkill. You’ll get warmer when you work out. You’ll also probably notice when you start to overheat without needing to know your exact body temp.

On my everyday headphones, sound quality is the thing I care about most. With fitness buds, great sound quality is more of a bonus. I’ll tolerate a bit of tinniness so long as my K-pop anthems can get me through a run. Not an issue here! I’ve been running to a lot of Stray Kids lately and the thumpy, percussive MEGAVERSE sounds great on these buds. While the buds have great bass, the rest of it sounds great, too.

Battery-wise, you get about six hours of playback — that’s good enough for the average long run or race. The case holds an additional three full charges, and in normal usage, that should get you a good long while. I’ve been using these as my daily workout and commute headphones for the past two weeks. My case still has about 40 percent battery left.

One thing I didn’t love was the touch controls. You can customize them in the Smart Control app, but I found them too easy to activate while I was adjusting fit. This was despite the fact that I adjusted tap sensitivity lower. Still, having them is better than not during cold weather workouts when you’re wearing gloves.

At $330, these are expensive, but you are technically getting a chest strap and headphones in one. My Beats Fit Pro were about $180 on sale, plus I currently use the $150 Garmin HRM-Fit as a chest strap. (Though you can get chest straps for about $80-$100.) That’s about the same cost.

In the past, my issue with fitness tracking earbuds was that they didn’t make my life easier. The finicky fit meant it took longer to get going. I didn’t want any additional training features from buds when I was already using other fitness apps. The Sennheiser Momentum Sport aren’t promising too much — just good sound and an alternative way to measure your heart rate. That’s all I want from fitness buds.