I didn't lie about their ages. The age limits can really vary here. For my eldest son's first half marathon the minimum age was 14. It was 16 for the second but I contacted the arrangers and they agreed to create a new age group.
I agree completely that distance increase should be very gradual and the hillwalking is a nice idea.
I have three teenage sons, two of which love to run. My eldest who was 14 last summer ran 2 half marathons no problem at all. He outruns me big time on our 5km tempo runs but enjoys training long with me because I keep his speed steady. He tends to start out to fast and crash, so my speed suits him for about 10km and then he speeds up towards the end.
My second eldest (14) also loves running and is really fast. He is a member of the athletics club but still enjoys running long with me because I keep a (slow) steady pace from the start. We three have signed up for half marathons for next year.
It's great that they do their speed sessions without me so they can get the best out of their short training distances but they use me to keep a steady pace when running long distances.
I have not experienced any problems with their training and as long as they are happy and injury free, I can't see any reason why teenagers can't run as much as they want to.
Running up the west coast of Denmark from the German border. The route is flat - sea to your left, countryside to your right, fair weather (neither too hot nor cold in the summer months - the winter can be a bit chilly) and good paths. Some of the route is through the national park. Wonderful nature - fantastic experience. I ran 70km of it last September and it was the best run I have ever experienced.
I ran Stockholm back in 2012. I would suggest bringing clothes for ANY weather type because it can really vary there. In 2012, it was 4°C and blowing a gale.
Despite the appalling weather, it is a lovely run that takes you through beautiful Stockholm. They say that it's hilly in places but I didn't think it was too bad and I live in a really flat area. There is just one bridge that you run twice that's uphill.
It is well arranged and there is a good atmosphere. I had a wonderful time and can whole heartedly recommend it.