Hola, I've recently began been going to the gym again fairly regularly three or four times a week. I have a very basic routine starting with 20 minutes cardio followed by 4 or 5 resistance exercises (bench press, lat pull downs, thigh machine etc.) then finally 10 to 15 minutes more cardio as a cool down.
The whole routine takes a little over an hour, and I try to alternate which days I do muscle groups. You will find what works for you best, but if you’re like me and just want to tone up a little and lose some lbs then a simple exercise routine is probably the best from a practicality / benefit perspective.
While I know I *could* do far more, a few hours a week seems to be all I need to have a really positive effect on weight loss and overall fitness. For me going to the gym is a chore, so it needs to be quick and easy or I will simply find an excuse to not go
I do find that mixing up some weight and resistance training really adds benefit to the weight loss, and personally I find it much more varied and interesting than just plodding along on a treadmill for an hour.
From what I understand, just raising your heart-rate for a few hours a week alone has significant benefits, so mixing it up seems like the ideal solution with some weight training seems ideal (I have a Polar heart rate monitor, and my heart rate is generally just as high on weights as it is on cardio machines).
I'm sure you will get some good advice here though; there are some quite knowledgeable people who post on this forum.