Muscles may be built with any weight of dumbbells. If you have lesser weights, you may compensate by doing more repetitions and sets. However, if you want to improve your strength and endurance, bigger weights, such as 40-pound dumbbells, are a wonderful choice. You don't have to rush it, though. Start with less than your maximum weight and work up gradually. The majority of people can lift their body weight without excessive effort. Some men in their early 30's who are healthy enough to engage in physical activity regularly can lift over 100 pounds. The average woman in the same age group can lift about 50 pounds. But experts agree that the best way for most adults to build muscle mass is through resistance training. Research shows that lifting weights helps us lose weight, reduce our risk of disease, and prolong our lives. Weight training builds muscles faster than eating food does. So instead of eating several small meals throughout the day, try having a large meal with plenty of protein and fiber-rich foods like fruits and vegetables. This will help you feel full longer which will prevent you from overeating. It's important not to strain yourself when lifting heavy objects. Do only enough repetitions to fatigue but not to exhaustion. Take a rest between sets, and make sure to eat and drink after each workout. These activities will help restore your energy so that you can do more repetitions next time.