For those on the hunt for more advanced training insights, picking up a dedicated heart rate monitor can help provide you with the answers you crave.
But with so many options at your disposal, acquiring a device that suits your training can be tough – especially if you're looking for one that can pair easily with your smartphone.
Read this: Best heart rate monitors for Strava
iPhone users will no doubt look to an Apple Watch Series 2 for a package that includes basic heart rate smarts, but if you're aiming to pick up on heart rate zones, overviews and more accurate information, locking yourself into a smart chest strap, pair of wireless headphones or even a headband can be a better choice to help you on your way.
Read on for our picks of the best heart rate monitors that can sync up with your iPhone.
Wahoo Tickr X
We at Wareable are big fans of the Tickr X, thanks in large part to its ability to store 16 hours of workout data without being tethered to your iPhone.
This means you can transfer all the data you've garnered once you've finished exercising, which can also include those pesky spinning sessions thanks to dedicated motion analytics. The companion app, meanwhile, isn't winning any awards for its complexity, but does allow for a breezy link-up with the strap and gives you a clean interface from which to control and view your workouts.
Wareable verdict: Wahoo Tickr X review
It's important to keep in mind that chest straps aren't for everyone, but the fact that Wahoo lets you run wild and free without having to take your phone is a big plus.
Like its older sibling, the Polar H7, the H10 is one of the strongest sensors out there. The iOS-friendly strap offers a modified design, adding silicone friction dots to help keep the strap in place, and is noticeably more comfortable to wear when exercising.
It uses the same ECG-style sensor that detects the electrical activity of the heart to deliver your BPM readings, though a fresh measuring algorithm and extra interference-preventing electrodes help improve accuracy even further.
What's handy about the H10 is the waterproof smarts, which mean you can take it for dips in the pool. And while its internal storage only allows for one training session, this is still a handy backup in case your iPhone loses power.
Hey, maybe you want to kill two birds with one stone and gain some heart rate metrics while also listening to your tunes.
Bragi's Dash isn't the only option in this area, of course, but for runners it solves a couple of long-standing issues. Firstly, there are no cables flailing around while you're trying to concentrate on your run – this is truly wireless. There's also enough storage to carry a solid amount of music, and the heart rate sensor is comparable to rivals.
Wareable verdict: Bragi Dash review
One negative is the lack of third-party app support, meaning you'll have to store your data in Bragi's own app, and no GPS also means you'll be taking your iPhone out for runs. But still, if you're set on picking up a pair of Bluetooth headphones and don't mind shelling out, the Dash earpieces are as good as it gets.
Moov HR Sweat
After it brought real-time coaching smarts to the original Moov and the Moov Now, the company's HR Sweat provides the next piece of the puzzle. The device is essentially a small circular sensor that sits inside a silicone case, which itself fits inside a sweatband.
This is still an optical sensor, but it works well for those who want to track data from the head. And according to the folks over at Moov, positioning the sensor to the high temples on the side of the head, where the skin is thinner and the blow flow is increased, also reduces sensor movement and makes for more reliable readings.
Like its siblings in the Moov stable, the HR Sweat is able to sync up with your iPhone to let you store workouts within its companion app.
Tracking your heart rate through a monitor is one thing, but the MyZone MZ-3 also allows you to gamify the process.
Whether you're running, swimming, cycling or even rowing in the gym, the device will take your readings and project them into a points system. This isn't as basic as simply rewarding high rates, either, with MyZone able to understand your effort levels and provide an accurate picture through its companion app.
This takes the great heart rate game a step further, too, by offering league tables, personal goals and challenges for you to take on.
Like the Wahoo Tickr X, the MZ-3 has storage for 16 hours of data, meaning your iPhone doesn't always have to come buckled along for the ride.
If you don't want the burden of a chest strap but you also don't feel comfortable wearing something on your head, or need a pair of headphones, the Scosche Rhythm+ is a heart rate monitor that can be strapped to your forearm or upper arm.
It uses the same optical, light-based sensors that you find on pretty much all wrist-based trackers, meaning there are some minor questions over accuracy, but it's a handy option for those who want to export data to the likes of MapMyRun on their iPhone.