Using dumbbells, or free weights, in your exercise program yields benefits such as strengthening and toning targeted muscles and muscle groups. Using dumbbells may also increase your muscular and cardiovascular stamina and endurance. However, you must use dumbbells properly to reduce your chance of injury. Factor in poundage, the number of repetitions and your overall health and exercise experience when choosing dumbbell weights. Consult your doctor before beginning any new weightlifting or other exercise regimen.
Form and Technique
If you've never used dumbbells before, it's best to start with lower weights so you can adjust to the shape of your dumbbells, become accustomed to holding them in your hands during exercise and learn proper form and technique before advancing to heavier weights. Practice an exercise like an overhead shoulder press without weights, then with light weights. You'll notice that the exercise itself is more difficult, and that you need to engage more muscles to help you lift that weight. Concentrate on holding your stomach in and using good posture and body mechanics lifting a 2- to 3-pound dumbbell to start.
Poundage for Beginners
Beginners should use light dumbbells to prevent injury or strain to muscles and joints, ligaments and tendons. If the dumbbells feel light to you, increase your number of repetitions or sets. For example, a beginner should start with 2- to 3-lb. dumbbells in each hand and perform up to 12 or 15 repetitions of exercises like single-arm rows, lateral raises, upright rows, hammer curls, biceps curls and triceps extensions. For increased focus and intensity, perform two to three sets of each exercise or exercise circuit.
Power vs. Endurance
Your dumbbell weight requirements will depend on why you're strength-training -- whether you're lifting weights for increased strength and endurance, for example, or for power. Women lifting to increase muscle mass and strength, the Brian Mac Sports Coach website advises, can use free weights between 5 and 8 pounds, while men can use 8- to 10-lb. dumbbells to start. Build up to about 15 repetitions with the lighter weights. Gradually increase your poundage over three to four weeks until you're lifting 10- to 15-lb. weights if you're a woman and 12- to 20-lb. weights if you're a men. The higher the weight, the fewer your reps, with a maximum of between eight and 12.
Men and women who want to tone their muscles but not add bulk should keep their dumbbell weight lower than higher. For example, two to three sets of 10 repetitions using a 5-to 10-lb. weight provides enough resistance to engage the muscles without experiencing the tearing of muscular fibers that results in increased muscle mass, according to the Brian Mac site.