Sennheiser Momentum Sport review – Wareable

Heart rate tracking from a pair of sports headphones was all the rage 7 years ago – but the Sennheiser Momentum Sport brings it back, this time in collaboration with Polar.

But the Momentum Sport is a product that fits a narrow subset of people.

And understanding where this fits is crucial. Why would you want a pair of heart rate-sensing headphones when there are plenty of decent running watches to buy?

It works well if you’re a gym goer who wants to record workout intensity without splurging on a watch.

But it’s not a natural fit for runners, because tracking runs via a smartphone can be a nightmare for GPS accuracy. And if you do classes, then wearing pair of headphones isn’t helpful either. So it’s not a form-factor for everyone.

But heart rate in the ear does make sense. For those working out in the gym, wearing a pair of headphones means you don’t need to purchase another device.

Then there’s the idea of accuracy. Wearing a watch while doing functional fitness is a good way to get duff accuracy, with all the flexing of the wrist, so the ear is a good place. What’s more, if you’re flinging weights around, watches easily get scratched.

But then there’s the price. $329/£279 is a big price tag for a pair of sporty headphones.

So does the Sennheiser Momentum Sport live up to the promise of truly accurate HR from the ear? We got sweaty to find out.

Design

I moved over from the AirPods Pro to Sennheiser Momentum Sport (SMS), and the transition in terms of design was underwhelming. The SMS is bulkier and more bulbous in the ear, so you need to do a little place and twist to get a good fit.

Once it was in it stayed put, and I didn’t need to go into the box to try any of the replacement buds.

I’ve done a serious amount of running in them, clocking up hundreds of kilometers, and the SMS buds have rarely felt loose.

But in all those miles, I’ve never got to grips with the control system for some of the advanced features.

There’s a host of on-device control, with double or triple taps on the left or right bud used for switching between ANC/anti-wind/transparency, skipping tracks or changing volume. It took ages to memorize them. And the sensitivity by default isn’t great, but you can up that in the settings.

But the lack of sensitivity is compounded by how easily it is to accidentally activate them while adjusting the fit, or as I found, even the act of chewing while wearing the Momentum Sport will cycle through the ANC settings.

The charging case is also a little large, and certainly no-where near as pocketable as the AirPods Pro.

Sound quality

As I always point out when I’m reviewing biometric headphones for working out, I’m an expert when it comes to the sports tech – but I’m no audiophile. But overall, I’ve been impressed with the sound quality of the Sennheiser Momentum Sport, and they sound as good than the excellent Apple AirPods Pro.

There’s a particular warmth to the sound and a delicacy of mid to high frequency, that you don’t always get with sporty headphones.

That’s backed up with a quick check of audio-focused headphones reviews such as the esteemed What Hi-Fi.

They also praised the separation and detail of the Sennheiser Momentum Sport, but did point out the audio didn’t excel at this price. So if you’re looking for top quality audio, you need to look elsewhere. However, you won’t find any that also track heart rate – so this is a unique proposition.

However, I found the audio experience to be as good as the AirPods Pro – and if you’re looking for a good workout partner, your choices for amazing audio are not plentiful.

I am partial to bass getting jacked up for workouts, but the sound here is even throughout. So you may want to look at the Beats Pro for more punchy block-rocking beats. There’s a bass boost pre-setting in the equalizer, which can be accessed via the Smart Control app. That was a nice boost. And you can set up Sound Profiles for different situations and locations. That means you can boost the bass in the gym if you want to.

Features

The Sennhesier Momentum Sport does have a pretty complete feature set, and in the interest of brevity and readability – our experiences are below:

Heart rate tracking: Read below for full testing, but accuracy was a mixed bag. No huge problems with steady runs, and the peaks of interval sessions were recorded well. However, I found some issues with accuracy in sessions that were hard to explain. So it’s not world-class heart rate tracking performance.

ANC: Active Noise Cancellation will block out background noise, and can be set to automatically turn off in some areas. It wasn’t as pronounced or powerful as the AirPods Pro, which feel like they can turn off the outside world, but does a good job of keeping audio clear. There’s also anti-wind, which is one of the better experiences I’ve tried. Each can be toggled from the app, or a triple-tap on the left bud.

Body temperature tracking: The SMS can also biometrically track core body temperature during runs. This is really unique and a nice data point to add to the tracking within Polar Flow, although as I’ll explain, I’d like to have seen more information on recovery and rehydration.

Qi charging and IP55: They’re rated as splash resistant, so rain and sweat won’t bother the SMS. And you can charge the case wirelessly, too.

Battery life: Sennheiser boasts 5.5 hours from each earbud and a full 24 hours from the case. I was impressed by battery life, and didn’t get caught out in weeks of use, even if I’d not used them for a while. There’s a handy red LED to prompt you to charge the case, too.

Heart rate accuracy

To workout with the Sennheiser Momentum Sport, you need to pair it up with a workout app.

Polar Flow is the obvious choice because the device is a Powered by Polar partner, so you get loads of extra data by using the app.

However, you can just patch the Momentum Sport into Strava or whatever workout app you fancy, simply by adding them as a Bluetooth heart rate sensor.

Polar Flow is a decent app for fitness and sport tracking – but it’s quite complex and could do with a lick of paint.

We used the Momentum Sport in the gym to track sessions, but for testing, mostly out on the road for running. That offered us a good platform to test baseline heart rate accuracy on steady runs which should perform well – most sports watches handle this with ease.

But let’s be clear, the Sennhesier Momentum Sports aren’t a natural bedfellow for runners. First up, if you don’t have a watch for running, what are you even doing? Secondly, tracking runs in smartphone apps using your phone’s GPS is a recipe for wonky data, and we didn’t get one accurate distance tracked by the Polar Flow app.

That’s nothing to do with the Sennheiser, it’s the position of our phone when running, but just don’t use this set up for runs.

But it still gave us chance to test the heart rate sensor against a Garmin HRM-Pro chest strap – and the results were mixed.

Questionable accuracy

We tracked the heart rate across a number of runs with varying intensity, and the sessions were generally reported well. I compared steady run data, and found generally good levels of accuracy, with little peaks matching up between the Garmin HRM-Pro and Sennheiser Momentum Sport.

I also took it out for some hill repeats sessions, and the peaks of the intervals, and the rest stops matched up between the earbuds and the chest strap.

But on most runs we could find periods where the Sennheiser HR just did its own thing. In the example above, there were some odd outages. And in another run, after walking briefly through an overgrown path, the next 5 minutes of data was around 10bpm lower.

But as you can see above, the general shape of the chart matches well.

So the Momentum Sport has the potential to track the intensity of your sessions well, but has a propensity for unreliability – and that’s been borne out by other testers I’ve spoken to.

I”ve seen some reviews that have pasted the SMS for accuracy, but I’ve had to look quite hard to find large problems. It’s certainly not a gold standard performance – if you want that then stick with a chest strap. But if the form factor fits your gym sessions and lifestyle, and you’re not obsessed with your HR performance, then you can venture here and get decent quality data.

Temperature data

While you can see heart rate data in any app, you need to use Polar Flow for temperature data. But the accuracy here didn’t convince me at all.

I also completed a hot run, including hill repeats, and saw no change in temperature from the SMS. See below.

And another run actually saw my body temperature fall, over an hour’s run, in the summer. Can that be right?

So there are question marks over the reliability – and the usefulness.

While temperature data appears among your other stats nicely, we’d like to have seen more analysis of it within Polar Flow – and there was little in the way of context. It would be neat to see some advice for recovery or rehydration, but it feels like another stat with little meaning.

Polar Flow

Polar Flow does have more content on the intensity of workouts, and data from the SMS will be rated in terms of training benefit, Training Load and Cardio Load.

It’s a good place for workout data, although I do find navigating it baffling – even after years of testing different devices.

Using the Momentum Sport won’t populate Polar Flow entirely, so elements of sleep tracking will be blank. So it never feels like an amazing experience, if you don’t have other Polar devices on the go.

But if you do cardio workouts regularly enough, it will show your Cardio Load data on the calendar screen and diary.

The good thing about the Momentum Sport is that while they are powered by Polar algorithms, you aren’t beholden to the app in any way. While it might suit a subset of users, you can use most apps – including Strava – to track your workouts.