Researchers at Cleveland Clinic wanted to test how well four popular wearable devices measured heart rate, which is involved in a formula that calculate how many calories a person is burning while they exercise. They hooked 50 healthy adults up to an electrocardiogram (EKG), the gold-standard test for measuring heart activity, and compared the results to heart rates obtained by Fitbit Charge HR, Apple Watch, Mio Alpha and Basis Peak. They also assessed a chest strap. The researchers measured everyone at rest, then walking and jogging on a treadmill.

The chest strap monitor was the most accurate, nearly matching the EKG with 99% accuracy—both technologies capture electrical activity coming from the heart. Of the wrist wearables, Apple Watch was about 90% accurate, but “the other ones dropped off into the low 80s for their accuracy,” says Dr. Gordon Blackburn, one of the study’s authors and director of cardiac rehabilitation at Cleveland Clinic.

Accuracy also went down as intensity increased. “What we really noticed was all of the devices did not a bad job at rest for being accurate for their heart rate, but as the activity intensity went up, we saw more and more variability,” Blackburn says. “At the higher levels of activity, some of the wrist technology was not accurate at all.”

Measuring heart rate from the wrist is convenient, but it comes with some disadvantages. “All of the wrist technologies are looking at blood flow,” Blackburn says. “You need to have good contact between the photosensing cells; as a person is exercising more vigorously, there’s more bounce, so you may lose some of that contact.”

For a person without health problems using a wrist-worn device to track heart rate, “it probably isn’t putting them at any risk,” Blackburn says. “Our concern is for patient populations that have health problems that can be aggravated by getting to too high of an intensity.”

“Fitbit trackers are not intended to be medical devices. Unlike chest straps, wrist-based trackers fit comfortably into everyday life, providing continuous heart rate for up to several days without recharging (vs. a couple hours at a time) to give a much more informative picture of overall health and fitness trends,” Fitbit representatives said in a statement, adding that their internal tests showed an accuracy rate of 94% [or a margin of error that was about 6%.]

This article originally appeared on Time.com.

A new report has determined just that. The study, part of the Gallup-Healthways State of American Well-Being Series, assigned an "Active Living" score to cities based on factors like walkability, bike-ability, the quality of the public transit system, and availability of well-maintained parks. The researchers looked at a total of 48 medium to large cities.

Boston nabbed the highest score, followed by San Francisco (unsurprisingly—have you seen that city’s hills?) and Chicago. New York City and Washington, D.C., were awarded fourth and fifth places, respectively.

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So, how do these locales' high scores translate to real-life health perks? Well, for one, the residents of the top five cities have significantly lower rates, on average, of a handful of diseases (from diabetes to high cholesterol to depression) compared to people living in cities with low scores. They also have higher rates of exercise and eat more fresh produce.

The bottom line: While leading an active life is possible no matter where you live, it certainly doesn't hurt to have protected bike lanes and lots of green space for outdoor rec. The top five cities make sticking to healthy habits just a little bit easier.

Velvety Nude

In rosy nudes (think your lips, but better). Spotted on the Herve Leger runway, the look is "universally flattering" says Troy Surratt, a makeup artist and the founder of an eponymous line. "It lets you fake fuller lips." He suggests using a lip-toned liner to draw a bit past your natural lip border, then topping with a liquid lipstick.

We like (from top): Bare Minerals Gen Nude Matte Liquid Lipcolor in Famous ($18, bareescentuals.com); Obsessive Compulsive Cosmetics Lip Tar in Dash ($16, nordstrom.com); Hourglass Opaque Rouge Liquid Lipstick in Lovesick ($20; sephora.com); Kat Von D Everlasting Liquid Lipstick in Lovesick ($20, sephora.com).

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Matte Plum

One swipe of this vampy hue will change your whole look. Make sure you're precise—dark lipsticks can get messy. "Prep with a lip balm," says Surratt. "Use a lip brush to apply color, then go in with a lip liner in the same shade to clean up edges."

We like (from top): Oribe Lip Lust Creme Lipstick in The Violet ($42, net-a-porter.com); Urban Decay Vice Lipstick in Jawbreaker ($17, sephora.com); Burt's Bees Lipstick in Orchid Ocean ($9, walgreens.com); Laura Mercier Velour Lovers Lip Colour in An Affair ($28, lauramercier.com).

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Glossy Red

A classic red lip is always chic, but this year's take is extra lovely thanks to its high shine factor. "Apply a matte red first," says Surratt, "to make the gloss on top look much stronger." Stash it in your bag; you'll need to reapply.

We like (from top): Essence BB Lipgloss in Heartbreaker ($4, essence.eu); YSL Vinyl Cream in N.411 Rhythm Red ($36, yslbeautyus.com); Cle De Peau Beaute Radiant Liquid Rouge in 17 ($48, neimanmarcus.com); MAC Versicolour Stain in Resilient Rouge ($25, nordstrom.com).

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Creamy Pink

Bright pink in the fall? A thing! This hue wakes up any complexion. "Opt for one with coraly undertones," says Surratt. For a smoothing effect, use foundation as a base, then reapply lip color, advises makeup artist Sonia Kashuk, founder of Sonia Kashuk Beauty. "Blot color until it's a stain before adding the final layer," she adds.

We like (from top): Cover Girl Colorlicious Lipstick in Spellbound ($6, amazon.com); Lancome L'Absolu Rouge in 317, Pourquoi Pas ($32, nordstrom.com); Kiko Milano Gossamer Emotion Creamy Lipstick in Shade 124 ($12, kikocosmetics.com); Nuance Salma Hayek Moisture Rich Lipstick in Shocking Lotus Pink ($10; nuancesalmahayek.com).

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Or DIY your own shade!

Mix these with your favorite lipsticks or apply on top for a unique color…