Its been my experience that you can over train with any form of exercise.
You can either exhaust your muscles or your whole body, but what your objectives are will determine you training and your definition of over training would then change as well.
If you're trying to build bulk in your muscles, then over training your muscles will not give you the results. pushing heavy weights are what you need to build them yes, but the growth only starts when you're resting and then your muscles get a chance to repair the tearing you put them through.
If you want to lose weight and tone, you'll be doing more reps and cardio, but doing them everyday will leave your body exhausted. sticking to a certain time limit each day and weekly schedule of training days helps you avoid over training. depending on your goals do different exercise for different body parts on different days. When you start feeling like your body can handle more, instead of increasing the time you train, simply change the exercise or the itensity at which you train.
Listen to your body is the key.