I know a lot of people who are afraid of lifting weights. There's a fear of getting 'too big' or 'too muscular' if one starts down the road of free weights and resistance training. The fact is, you won't. What will happen, is you will discover a whole new way of training that will give you as much a cardio workout as it will muscular.
Yes there are some very big and muscular people who do weights as well but in order to get to a certain size you would have to be eating in excess of 4,000 plus calories a day and be lifting heavy, heavy weights, up to twice a day.
So don't worry about adding in a little resistance work to your workouts. If you're eating the recommended daily amount, you won't hulk out. I recommend doing something every other day to push your body and mix up your routine.
I also hear people say 'I just want to tone up'. Toning up, is a combination of muscle building and fat burning. This is what achieves that look wherein you can see the muscle beneath the skin. What you're really doing is building the muscle up and cutting the fat down. The best way to do this is with high intensity interval training or HIIT for short. After just 30 minutes, you can rev your metabolism to burn fat and pump up your muscles to achieve hypertrophy (a good thing).
Also, the full body movements are a great way to develop your coordination by encouraging multiple muscle groups to work together at the same time which I believe is a better way to train as opposed to isolating individual muscle groups. If you are going to isolate, I recommend using free weights over machines as they promote good form and stability.
I hope this has helped dispel any myths about weight training. If you found this useful, feel free to share and pop back for more health and fitness advice.