The other day i was sparring with a guy bigger than me and a guy the same as me. Both times I soon ended up in closed guard where I begin struggling to find something to do. If I try to stand up, they automatically reach for my legs to try for the sweep. It seems I don't have the leverage to try to trap an arm and attempt an americana. I'm pretty much stuck. My arms seem to be not strong enough to push their legs open to break the closed guard. It's as if the person can just wait the whole time. Any ideas/tips?