A:AnswerThey will not fall out of your ear however to hear the bass notes clearly (which is why you pay the extra $$$ for premium earbuds) these need to stay snug in your ear so proper fit is key. The do move slightly when I am exercising so I periodically have to adjust but they never fall out. They come with multiple size earbuds to ensure it fits snugly.
A:AnswerYes, they come with silicone as well as "spongy" tips. The spongy tips WILL disintegrate of you sweat at all. The silicone tips won't but they also won't give you very good sound because they don't close your ear canal. They have the "wings" to hold them in your ear as well. These have may drawbacks not the least of which is the proprietary charger you have to take everywhere with you so shop carefully.