This question can be asked in a number of ways, substituting arms and thighs for any number of body parts. This is also a very loaded question and not an easy one to answer. The first thing is to understand what muscle tone really is. Muscle tone is simply the percentage of activity within a muscle group at rest. So when most people talk about toning up, they really mean something different from the true definition of muscle tone. What people are really looking for is better muscle definition. Better definition can be achieved by decreasing bodyfat percentage. Reducing bodyfat can be achieved by decreasing the fat content within your body, by increasing your muscle or a combination of the two.
There are several ways of decreasing the fat content within the body. Cardiovascular activity is probably the most effective if you are looking for fast results. Having a balanced diet is also a great way to drop fat from the body. Weight training also can indirectly assist with fat loss. Regular weight training boosts a person’s metabolism and over time that increase will result in fat loss.
Unfortunately, contrary to what many people think, it’s not possible to “replace fat with muscle” so while you are losing fat, you will need to do something in order to build up muscle. Muscles develop through resistance training. There are many forms including dumbbell training, machines and bands among others. If a person wants to have defined muscles then resistance training will be a key to their workout. It is important when training with weights that a person train at a moderate to high intensity in order to develop the muscles. This applies to men and women. Training with light weights and high repetitions only increases muscle endurance and does not develop the muscle in any significant manner.
Another important thing to note is the idea of spot reduction. When there is a specific bodypart that needs work, the only control you have is over developing the muscles in the area. A person cannot control where they will lose fat. Your body will decode on it’s own where and how it loses it’s fat. A good example would be a person seeking to lose belly fat. That person can do thousands of crunches a day but if they do not focus on fat loss, the person may develop muscles in the abdominal region but never see it through the fat.