Capris come in many cuts and colors, some of them will flatter you more, while others less. For intense activity, a tighter fitting capri, or
fitted capri as it were, will function better due to a reduced risk of tripping or catching on any particular equipment. Boot-cut capris are more flattering for very tall and slender ladies, while fitted capris help to elongate the appearance of your legs if you're shorter.
Fitted capris
Aside from the elongating effect the tight fit has on your legs, they also hide varicose veins in the upper legs. In the spring and summer, they're a good choice compared to longer leggings, because you'll stay cooler.
Boot-cut capris
Boot cut style, or "relaxed" capris have a more flattering effect on taller women. You'll get a different air flow through them as well, which may be preferable in very hot weather.
Boot cut capris are more difficult to match with shoes, due to their odd 70s curvature.