I was wondering if it is safe for a healthy, athletic 14-year-old to participate in a full-marathon. He has a training program that he has researched and plans to follow. He currently is on a club swim team and rides regular 15-30 mile bike rides.
I have written on this topic before but it always bears revisiting when inquiries like this come in. The first clarification is one of what is “possible” versus what is “advisable”. COULD a 14 year old run a marathon? Yes, with the proper training program tailored to the individual and a long enough and gradual enough build-up period. I would never encourage a downloaded generic program for this purpose. These programs are intended for adults and do not consider the issues of training youth. SHOULD a 14 year old run a marathon? I do not advise it.
There is inconclusive evidence about true dangers or safety of really long runs or high mileage for youth runners. So the jury is still out. But the predominating opinions of the medical community and most youth coaches fall on the side of moderation and avoid excess (i.e. marathons).
Your son is doing the right thing for his age. He swims and bikes and though you don’t mention it I assume he also runs. This is good cross training and develops muscular balance. That is ideal for youth athletes. And though this is good cross-training it does not make him a good “runner” or marathoner. Training is sport-specific. To be a good runner you must run. To be a good cyclist you must bike. To be a good swimmer you must swim. To be a marathoner you must run. It is in that very issue that makes marathoning ill-advised for youth. The odds of injury will greatly increase.
So, I advise against having your son train and run a marathon though it can be done.
If he decides to go for it then:
He needs a tailored program designed for youth (contact me if you are interested).
He needs a long-term approach (24 weeks would be reasonable – but no 12 or 16 week wonder program is advised).
Perhaps he would really benefit from a high school running camp and learn about training.