From Ergo Log
If adolescents spend a couple of minutes each day doing squats without weights, they build up muscle mass, lose fat and their leg muscles become stronger. Japanese sports scientists discovered this when they got a group of teenagers aged 13-14 to do about one hundred body mass squats daily.
Sports scientists are in no doubt: strength training is healthy. But the jury is still out on what the optimal age is for young males to start doing strength training.
The researchers, who work at the Japanese National Institute of Fitness and Sports, suspect that 13-14 year-olds can start to benefit from strength training as long as they only use their own bodyweight as the load. They carried out their study, which was published in the Journal of Sports Science and Medicine, to test this idea.
The researchers did an 8-week experiment with a group of nearly one hundred boys, all of whom did sports at a high level and trained on average five days a week. Of the group, 58 just kept to their own training – the control group.
The experimental group was made up of 36 boys. Every day after school, 4-6 times a week, the researchers got the boys to do a short squat training session. The boys had to do knee bends with their own weight as the load, for a few minutes. The boys had to squat until their upper legs were parallel with the floor.
They did this at high speed: they did a rep every two seconds, and the aim was to build up to 100 reps without a break.
At the end of the eight weeks, the researchers noticed small but significant changes in the body composition of the boys in the experimental group. Their fat percentage had decreased by almost 1 percent and the muscle mass in their legs had increased.
MTQF = muscle thickness of anterior of thigh.
At the end of the eight weeks the boys in the experimental group were also capable of generating more strength on a leg-extension machine [KES]. Their sprint speed had not increased, but they could jump a centimetre higher.
“Our experiment may suggest a new line of approach to reduction of mental fatigue involving creatine”, the researchers conclude.
Neurosci Res. 2002 Apr;42(4):279-85.