Of course, the youth strength training research programs are highly supervised, and this is indeed the key to safe and successful exercise experiences. For example, the South Shore YMCA in Massachusetts has run multiple strength training programs for children (ages 7 through 11) and young teens (ages 12 through 14) for the past 19 years with no injuries and very few dropouts. In fact, the attendance rate has consistently exceeded 90 percent, indicating that boys and girls respond favorably to well-conducted programs of strength exercise.

While some facilities have the advantage of using youth-sized strength training machines, children can attain excellent results with other types of resistance equipment including free-weights, elastic bands, medicine balls and Bow-Flex devices. Careful supervision, gradual progression and proper technique are the critical training components for children.

With respect to exercise progression, boys and girls should use a resistance that they can lift between 10 and 15 repetitions. When they complete 15 repetitions, the resistance should be increased by approximately five percent.

Proper training technique includes good posture, slow exercise speed, and full exercise range, as well as continuous breathing on every repetition. Fast reps, short reps, breathholding and squirming actions should be avoided.

Like adults, children should train all of their major muscle groups. Fortunately, this can be accomplished with about seven basic exercises. If appropriate weight stack machines are available, consider the following sequence of youth strength training exercises: (1) leg press for the front thigh, rear thigh and hip muscles; (2) chest press for the chest and rear arm muscles; (3) seated row for the upper back and front arm muscles; (4) shoulder press for the shoulder and rear arm muscles; (5) pull down for the mid back and front arm muscles; (6) trunk flexion for the midsection muscles; and (7) trunk extension for the lower back muscles. If dumbbells are used, the following exercise sequence is recommended: (1) dumbbell squat for the front thigh, rear thigh and hip muscles; (2) dumbbell bench press for the chest and rear arm muscles; (3) dumbbell row for the upper back and front arm muscles; (4) dumbbell press for the shoulder and rear arm muscles; (5) dumbbell curl for the front arm muscles; (6) bodyweight trunk curls for the midsection muscles; and (7) bodyweight trunk extensions for the lower back muscles.

Although one strength training session per week is sufficient, our research shows better results with two non-consecutive strength workouts on a weekly basis. Overweight boys and girls who do strength exercise in this manner average 2.5 pounds more lean (muscle) tissue and 3.0 pounds less fat every eight weeks of training.

Finally, most youth (overweight or otherwise) like strength training. However, they seem to like it even better when it is part of an overall physical activity program that includes lots of large muscle exercise such as low-organized games, relays, ball-handling skills, dynamic stretching and equipment utilization (hoops, medicine balls, wands, ropes, beanbags, etc.). One well-researched approach is to sandwich 20 minutes of sensible strength training between 15 minutes of game-like warmup activities and 15 minutes of similar but less vigorous cooldown activities. This provides a well-rounded program of muscular and cardiovascular exercise that is physiologically beneficial and psychologically interesting.