Stacking on the pounds too early is ill-advised but a controlled weights regime can improve an athlete's fitness and prevent injuries, Roddy Mackenzie writes.
When is it safe for children to lift weights as part of a programme to build strength and conditioning for sport? It is a question that has been debated by coaches for many years and still attracts conflicting views.
Many commercial health and fitness centres will not let children into the gym until they have turned 16. Yet the British Schools'
Weightlifting Championships, held in Manchester this month, held competitions at under-14, under-15 and under-16 level.
The Scottish Institute of Sport has led the way in high performance sport in Scotland since it was established in 1998 and finds itself, through its network of six area institutes, working with younger and younger athletes.
Gail Young, a strength and conditioning coach with the SIS and the Central Scotland Institute of Sport, works closely with some of Scotland's brightest young talent.
While not advocating that children under 16 should be lifting heavy weights, she sees distinct advantages in talented children following a strictly controlled and supervised strength and conditioning programme from as young as 12 or 13.
She emphasises that everyone is different and matures at varying rates but believes a programme of regular weight training can be hugely beneficial, in terms of overall fitness and injury prevention.
"Any strength and conditioning is done after consultation with a physiotherapist and it has to be done under supervision. There has to be a physical screening process, as all individuals are different and you have to cater to those different needs," she says.
"We can have tennis players coming to us with horrific shoulder injuries because of repetitive use. We need to change their training programme, so that it incorporates a strength and conditioning programme.
"We're not talking about lifting 100kg weights because, until they reach physical puberty, it will have no anaerobic training effect.
"If we get athletes at 18, it can take 12-18 months to teach them to be technically competent in the lifts that will lead to them gaining the strength they are looking for.
"What we try to do at the institute is prepare them so they are good to go for their chosen sport."
Even at the SIS in Stirling, no one under 16 is allowed into the gym, unless under the supervision of an institute coach. Sessions for young athletes can vary from 30-40 minutes to an hour, but the emphasis is on a good warm-up and strong technique.
A lot of work is done on lengthening the body and using wall bars and broom handles with weights sometimes as light as 5kg.
Athletes have to learn to control their own bodyweight before moving on to anything heavier at an older age group.
"The important thing is for us to catch an athlete young," Mr Young says.
"If we can get them at 12-13, they are like sponges and absorb all the information. It is a steady progression from there.
"If they come to us at the age of 18, they can be difficult to teach new things, as they are already set in their ways."
Three of Scotland's best tennis prospects - Caitlin Steel (15), Katie Gater (14) and Scott Lister (13) - are all working with Ms Young to improve their fitness.
"Everything is done in a very controlled manner and we teach them to train in a more holistic way and be open to new ideas," Ms Young says.
"We're not giving them anything they can't handle. If they can spend 20 hours a week hitting a ball on a court, then they can handle strength and conditioning.
"Look at young rugby players. Core strength work and stability can help them."
Ms Young concedes that gyms can be daunting to go into, especially if there is a 6ft4in shot putter or a judo player in there using weights. But strength and conditioning work does not have to be done in a gym, she says.
Equipment can be brought to the side of a tennis court, for instance, so that individuals still see it as part of their sport and not alien to it.
Ms Young knows that what is appropriate for young high performance athletes is different from what other children in Scotland may need to supplement their chosen sport.
"I'm a PE teacher by trade and there's no reason why children cannot work out in a gym while they are still at school, as long as they are under the appropriate supervision," she says. "There is a lot that can be done which will help them in sport, provided they learn the right techniques.
"The sports adults are doing recreationally now tend towards aerobics and gym work. For a lot of people, the traditional school sports of football, rugby and hockey are not something they play when they leave school. So preparing children for a life of activity that they can pursue when they leave school can only help.
"The general rule of thumb is that once individuals have gone through puberty, then they can get the benefits of a strength and conditioning programme."