So sometimes I swim a mile which takes 35-40 minutes in one session or I go do weights for 30 minutes and cross trainer for 30 minutes. After the swimming I feel more worn out.
But obviously the cross trainer and weights are for longer etc.
I am confused which one is the best all round exercise for fat burning and fitness etc? please help
Cross trainer will burn more calories if done to a high intensity. It isn't necessarily the length of time you spend on it, it is how hard you work. Look up 'high intensity interval training' and then give it a go :)