Underwear / Briefs for treadmill running?

Hi friends,

I would request for you to suggest me which brand and particular type is recommended as underwear / brief while exercising. My current one is very loose and i never bothered ever.

I heard that in long run if i wear lloose under wear while running exercising problems relating to prostate may arise.

Pls share your thoughts. I am on the larger / heavier size. Pls suggest accordingly.

Sincerely looking from your suggestions.

I am from Delhi .

Thank You