For women with muscular -- also known as mesomorph -- body types, aerobic exercise helps keep body fat in check while building cardiovascular health and improving endurance. Mesomorphs tend to increase muscle mass faster than other body types. However, while an aggressive strength-training program for women mesomorphs may build more muscle than you want or need, light resistance training, in addition to a strong cardio routine, has long-term health benefits, regardless of your body type.
In addressing the common adage that women won't bulk up with weight training because of lower testosterone levels, the American Council on Exercise qualifies by pointing out that genetics also impact muscle development. Just as some men have a difficult time building muscle, some women bulk up much easier than others. For muscular women, the right cardio workouts can help limit muscle growth while retaining lean body mass. Check with your doctor before starting a new exercise program, particularly if you have a history of heart or orthopedic problems.
If your goal is to improve your fitness, manage your weight or live healthier, regular cardiovascular exercise gives you a solid base for meeting your goals. Moderate exercises such as walking, hiking, recreational bicycling and dancing enable you to burn calories and tone muscle. However, the higher the intensity and resistance, the more likely you are to add muscle mass. Step training or stair climbing, for example, may increase the size of muscles in your lower body. If your goal is to get fit without adding muscle, opt for moderate, lower-impact activities.
After age 30, inactive men and women lose muscle at a rate of 3 to 5 percent per decade, according to Dr. Len Kravitz and Chantal Vella, M.S., of the University of Minnesota. As you lose muscle, your metabolism decreases, as does your strength and stamina. After age 50, both men and women lose around 1/2 lb. of muscle per year. While cardio helps with the retention of muscle mass, resistance exercise provides long-term benefits, even for naturally muscular women.
Muscular body types benefit from resistance training. The American College of Sports Medicine recommends that adults perform resistance training two times a week. Use light weights, and perform one set of eight to 12 repetitions for each exercise to enjoy the health and endurance benefits of resistance training without bulking up. Consult with a certified personal trainer for help designing a fitness program that suits your needs and goals.