Several research studies have demonstrated that boys and girls can gain muscle strength at approximately the same rate as adults.
Within the past several years, four youth strength training studies have been conducted. Certified strength instructors administered all of the research programs over a two-month training period.
Study One
The first study was conducted using teenagers. The training group consisted of 14 actively exercising participants (average age 14 years), and the control group consisted of 5 participants who did not exercise (average age 14 years). The exercise group trained three days a week for eight weeks using the following machines: leg extension, leg curl, leg press, decline press, pull down, incline press, low row and press down. The participants performed one set of 8 to 12 repetitions with each exercise, using slow movement speed and full movement range.
Results showed that the exercise group increased their lower body strength by 63% and their upper body strength by 33%. By comparison, the non-exercise group improved their lower body strength by 8% and their upper body strength by 4%. Both groups experienced a three-pound increase in body weight over the two-month study period. The exercises added four pounds of lean weight and subtracted one pound of fat, whereas the non-exercises added two pounds of lean weight and one pound of fat. Although the control group added lean tissue through normal growth processes, they did not improve their functional muscle strength.
However, the exercise group added twice as much lean tissue and made significant improvements in their functional muscle strength. It is noted that there were no injuries to any of the boys or girls who participated in this strength training program.
Study Two
This study involved 10 pre-adolescent boys and girls, with an average age of 10. All of the participants trained three days a week for eight weeks with the following machines: leg extension, leg curl, chest press, biceps curl and shoulder press. They performed one set of 8 to 12 repetitions with each exercise, using slow movement speed and full movement range. Results showed that the subjects increased their chest-triceps strength by 66%. They also made a four pound improvement in their body composition by adding three pounds of lean weight and losing one pound of fat.
Study Three
The largest study conducted included 57 pre-adolescent boys and girls, with an average age of 11. All of the participants trained three days a week for eight weeks with the following machines: leg press, compound row, bench press, torso-arm and rotary torso. They performed one set of 8 to 12 repetitions with each exercise, using slow movement speed and full movement range.
Results showed that these exercises increased their chest-triceps strength by 55%. They experienced a six and a half-pound improvement in their body composition by adding four pounds of lean weight and losing two and a half pounds of fat.
Study Four
The final study involved two groups of preadolescent boys and girls. The training group consisted of 14 exercisers (average age 11 years), and the control group consisted of 9 non-exercisers (average age 10 years). Unlike the previous studies, this exercise group trained only two days a week for eight weeks with the following machines: leg extension, leg curl, chest press, biceps curl and shoulder press. The participants performed 3 sets of 10 to 15 repetitions with each exercise, using slow movement speed and full movement range.
The results indicate that the exercise group increased their chest tricep strength by 64% and their overall strength by 74%. The exercises improved their muscle strength and body composition significantly more than the non-exercisers.
All four studies revealed significant strength improvements in 10 to 14-year-old boys and girls following eight weeks of sensible strength training. One of the most important outcomes of these four studies was the absence of any exercise-related injuries. It is therefore suggested that well-designed and well-supervised strength training programs are a safe and productive means for improving muscle strength and body composition in teens and tweens.
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Michael Cohen has more than 25 years experience as a personal trainer and is affiliated with top professional trainers, coaches and nutritionists. He consults with them daily.
