What is Toning ( strength training)*
Toning (a definition)
There are only 2 things that you can do with your muscles. You can make them:-
    - Grow larger and/or stronger
    - Shrink smaller and/or get weaker
    i.e. your lifestyle can either strengthen or weaken your muscles. In this
    section, the term toning is used to denote strength training.
If your goal is to see your muscles, then your goal isn't toning .... it's losing body fat. And,
whether you're a man or woman, wanting to grow larger muscles or become slimmer, you'll use the same kinds of exercises  and training techniques. The difference lies in a) the weights, reps and sets you do and b) how many calories you consume (more if you're building muscle, less if you're trying to lose fat).
Spot Training
Often people say thing like "I want to tone the back of my arms, so I'm going to do some triceps exercises." It is important to make it clear that exercising your triceps is not going to get rid of the fat around your triceps, which is what keeps you from seeing the muscles. In order to see your
muscles you will need to reduce your calories, lift weights and perform some cardiovascular exercises. If you do this diligently,  you will lose body fat, but you cannot determine when or even if the fat over any particular (exercised) area will go.  i.e. Spot training is not possible.
The benefits of toning your body
    -    The more muscle you have... the more calories you burn each day.. the
         higher your metabolic rate.
    -    Strengthened muscles and connective tissues which helps you perform
         better (in daily a/ physical activities and reduces risk of injury.
    -    Preserve muscle mass as you age. We naturally lose muscle over time,
         unless we lift weights.
    -    Stronger bones.
    -    You'll improve your flexibility, stability and balance.
    -    Improved esteem
    -    Improved muscle definition
How do you improve your muscle definition?
This simple answer is to lose body fat. To lose body fat you need 3 key elements: i) regular cardiovascular exercise, ii) consistent strength training for all your muscle groups and iii) a healthy, low-calorie diet.
Is it possible to get 'too big'?
Whatever your goal or gender, don't be afraid of heavy weights! It takes a lot of hard work to build muscle, men can find it difficult and if your female there is even less cause for concern; as women don't have enough testosterone to develop them naturally with only the aid of weights.

* Always consult with a doctor or other healthcare professional before embarking on any exercise programme.