Every personal trainer agrees that you need to combine strength training, cardio and stretching for a balanced fitness routine. The good news is you can make some positive strides by spending only two half hour sessions a week if you do it wisely.
The key is to start with a brisk walk ( 10-15 mins.) and then follow it with the proper exercises that tone the body while keeping the heart rate up. You don't need to go to a personal trainer every time, you can do all the movement at home in any room with a little space. A few hours of instruction may be all you need.
This methodology applies to anyone who is not currently doing any routine exercise. If you are doing something but not getting results, unfortunately you're not doing what you need to. You may have adjusted to what you're doing and just need to change it up a bit. The best program in the world becomes less and less effective after a month or two. You can try the above program but extend the walk and add some extra strength moves. Still you don't need longer than 45 mins. a session. People laugh at how quickly I workout but at nearly 60 I think it's working.
Most of my clients come to me because they haven't found a program that works. They want to lose weight and look better and just be healthier. In my opinion most people are working inefficiently and getting discouraged with a lack of progress.. Doing less and sticking with it is better that doing more and giving up.