As a Personal Trainer It’s my job to target the areas of the body where the clients want to be toned/built. In most cases, women want to be toned in the arms (especially triceps-the bingo wings), legs, stomach and bums. Men however usually want to build their muscles, especially in the arms, chest, and stomach. These might look like similar goals, but there is a major difference between toning muscle, and building muscle.
Toning Muscle- Toned muscles are muscles which are always slightly contracted, even in a relaxed state. To get a nice definition in the muscles, it is widely believed that completing 2-3 sets of 12-15 repetitions, using lighter weights, to be the standard way. Complete an entire body workout, with about 8-10 exercises in, and repeat around 3-4 times per week. You should change the workout about every 2 months. Performing more reps, with less weight also increases muscular endurance. Of course, eating a well-balanced diet and performing cardio exercises for fat loss goes in hand with toning muscle.
Building muscle- To build muscle, completing more weight with less reps is seen as the best way. Completing 4-5 sets of much heavier weights, with about 4-8 reps, is a great way bulk up. Good technique in all exercises are of course essential- for safety reasons and to ensure the correct muscles are being used. Eating good amounts of protein is key to building muscles, as they need the protein to help repair them.
So, the weight you lift and the number of reps and sets to complete depending on what you want to achieve in the final result. Personal Trainers are very handy when it comes to showing you how to target those problem areas.