You’ve decided to get healthier by doing some hiking. Your sports bras are at least seven years old, so what kind of new ones should you get?

Outerwear hogs folks’ attention when they plan for adventure travel, but the stuff closest to the skin often matters the most. While your worn cords might have gotten increasingly comfortable over the past decade, bras that are well used probably need to head into retirement.

Of course, if you’re more Kate Moss than Pam Anderson, even a not-so-sturdy tank top will do for a leisurely hike. But if what you’re carrying up top is more substantial, this becomes a more critical issue. “Breast movement isn’t bad; it’s the flopping that’s a problem,” explains Tomima Edmark, founder of HerRoom.com, an online intimate apparel company.

Edmark’s site offers the innovative “Bounce Test” feature: Videos that show a 36D model running in each of the “high-impact” bras for sale, so women can see how much movement to expect. Edmark’s standby suggestion is the Enell 100, which uses compression and encapsulation to make for a sturdy bust. Plus, wide straps and wire-free cups mean less chafing and jabbing.

For flatter gals, those comfort features will make the most difference. Same goes for wicking. Some even come equipped with antimicrobial linings, and a little stink-fighting might be nice in the woods.