Women's Maidenform MSPTBK Sport Bikini Panty (Bozetto Blue/Black 5)

Great choice for those working in outdoor/hot/humid environments, like construction, law enforcement, park rangers, military, etc. They fit well and breathe wonderfully, so even if you're sweating like crazy, you're still comfortable. They also move well with your body as you climb scaffolding, ladders, or hills, drag gear around, stand, squat, etc. They have no lines and fit great under a uniform, workwear, or coveralls. I've only worn them for outdoor work so far, not at the gym, but I imagine they'd work well there too. They stay put and don't ride up, chafe, or have tight elastic. Easy to wash/dry by hand if necessary - good for camping & road trips.