ive just started training again after about a 2 yr break, in that time i seem to have aquired a small beer belly and obviously lost the muscle. My aim is to get more muscular and loose the belly. I have a good healthy diet and have cut out the beers. In the gym i do about 20 mins on the treadmill then about 45mins on weights (focusing on different areas each time 3 times a week) then another 15 - 20 mins on the cross trainer or exercise bike.

 Does this sound like the right way to achieve my goals? am i doing things the wrong way round? should i split the weight / cardio into different days?

 Any advice welcomed.

I'd split the weights and the cardio - 35-40 mins of cardio is going to reduce the ability of the body to build muscle.

Thanks,

you mean split the weights and cardio into different sessions?

How much cardio is adequate to get properly warmed up for weights but not to overdo it and prevent muscle building?

Doing them on different days would be a good idea if you want to build muscle.  10 mins would be plenty to warm up.

Remember - if you're building muscle, do one part of the body, say the upper body on at one workout, and then do the lower body at the next one...otherwise you risk injury.  Your body needs time to recouperate between workouts, and so it's better not to do the whole body in one session.

It's Ok to do the whole body at one go if you only do it every other day.

Circuit training would also be a really good option.