By all means, LIFT HEAVY, but don't lack on the safety! They are 100% polyester so they have moisture wicking properties and anti-microbial performance. Both pockets are deep so your phone won’t fall out on the gym floor when leaning back on the incline bench. They have a two inch covered elastic waistband and drawcord. Double needle stitched hem as well so they are durable. Simply perfect for the gym or just lounging at home.