I get up around 7.30am. I put on my uniform and go downstairs. I have a pretty normal breakfast -- Weetabix with milk -- but my other meals are not very normal, because of my mountain-climbing training. My mom has left the house at that stage. She's a community nurse, but she has gone back to college this year so that she can get paid more. My dad is in Saudi Arabia right now.

I cycle to school, which is on Carysfort Avenue. I'm in fifth class. We have a new teacher this year, Miss Baxter. She's nice. There are boys and girls in my class, but the girls aren't really friendly with the boys. My favourite subject is geography. I know a lot of countries, and not just from looking them up for my football. For little break at 10.30am, I eat broccoli. I eat it raw. I don't really like it cooked. Eating the broccoli was my uncle Ian McKeever's idea. I do all my training for the mountain climbs with him. He tells me that I need the broccoli for iron. I need extra oxygen in my blood, and I get that if I eat broccoli. Obviously the broccoli doesn't taste as good as a sandwich, but I feel better after I've eaten it. At the big break, I have brown bread with butter, fruit and some yoghurt. You're not allowed sweets in our school, but a bunch of people eat sweets right after school because there's a newsagent close by.

I finish school at half two. I cycle home through the park. It takes longer than it should because I talk to my friends on the way. When I get home, our au pair is there. Her name is Justina, and she's from Germany. I change out of my uniform and put on some tracksuit bottoms and a short-sleeved T-shirt. And I bring a rain jacket, in case it rains. I have an hour's break before Ian comes to pick me up for training. He's my godfather as well as my uncle.

I train every day. If it's raining, we still train, but if it's raining really hard I have this little exercise thing in my house which I can do. It's a cross-trainer. I like it because I'm not really panting on it, but it still makes me as tired as running.

The drive to Glendalough takes 45 minutes. In the car park, you can see a kind of a lake with a path around it. We run around the path, and when we're done with the path, we run up 30 steps. They're steep. I race Ian. He mostly beats me, but only just. When I am doing the steps he will say, "This is our last one," and then when I come down, he says: "This is our last one." He says this about four times more. I know it's not true, but I just need him to say it so that I can do it.

Running up steps makes you really fast. When I started training I used to be wheezy doing the steps, but not any more.

After that we go up Camaderry hill. It's a 45-degree angle hill, and it's about 400 metres. I don't think it's possible to run up it but we go as fast as we can. Ian runs with me. He can go much faster if he wants, but he does the same speed as me. In football I have a competitive spirit but in mountain climbing I'm not so sure that I do, because it's more about getting to the top and seeing all around you, all the views. But I still do it at a quick pace.

Then I go home, have a shower and do my homework. That takes about half an hour. After that I go on the cross-trainer for an hour. This is to build up my arm and leg muscles. I have the TV on and I listen to my iPod -- it has to be fast music.

My mom is home at that stage, and she cooks me a steak. I have broccoli with the steak, and I have also have this thing called liquid iron. It tastes disgusting, really bitter. It's brown but when it's a big dose it's black. My eyes water when I take it. It has iron in it, and I need loads of oxygen in my blood because of the altitude up a mountain. Children my age feel better at altitude than grown ups. I don't know why.

All I get to see of my friends is when I'm at school, and at yard time. I think they understand why I climb mountains and do all the training. But when I do just the cross-trainer instead of going to Glendalough, I have time for my friends. Yesterday I was playing tennis with them. When I came back from Kilimanjaro, the class gave me a big clap, and put a banner up saying 'Well Done Sean.' I go to bed at 9pm.

When I am on the mountain, it's a different life. When I climbed Kilimanjaro, we had to sleep in tents. It was very stuffy waking up in a tent, except when we got higher, and then there were icicles inside the tent. At the bottom of the mountain, in the tropical rainforest, it was sprinkling rain a lot there. But it was warm rain, and as soon as it hit the ground it evaporated. I saw bats and monkeys there. The monkeys woke me up in the morning. We'd wake at half six and leave around seven.

There is surprisingly good food on Kilimanjaro. They had this chef called Alex -- he's a sherpa -- and he gave us fried eggs. The sherpas carry massive things on their head climbing up and it's no problem to them. I don't know how they do it. They would go straight ahead of us, and when we'd arrive at the next place, all the stuff would be set up. Sometimes we'd sing as we'd climb.

I don't know if there were any snakes. There might have been, but I didn't see them; but I did see massive spiders. Even though I'm scared of spiders, I didn't scream -- I just tried to avoid them at all costs.

When we were climbing, the people didn't allow us to go very fast because the altitude would have affected us very badly. In Africa, they said: "Pully, pully, slowly, slowly", so we didn't go fast at all. We'd climb, and then have a break every three hours.

On the first day, the sherpas greeted us by doing a dance. We joined in with them. I like learning about their culture. I didn't get a headache with the altitude, but everyone else in our group did. When you're walking, you're better off not thinking at all. When I do this I am switched off and I can't feel my legs. They hurt a bit after Kilimanjaro. I was really tired just before I got to the top of Kilimanjaro, but when I got there, suddenly all of this energy started to surge through me. We stayed there for around 20 minutes and the air felt fine. It took us seven days to go up, and we sprinted all the way back down in one day. It was fun.

I like climbing mountains because you get to meet other people, and you see all the views -- and I like the snow. I'm never going to climb K2, even when I'm older. I just wouldn't want to do it, but maybe Mount Everest.

I'd like to be a movie editor when I grow up. I edit little short films on my computer and put music to them.

When I climbed Carrauntoohil I just felt like climbing more mountains afterwards. I think I'll always climb mountains. Why stop when I've just started?

Sean McSharry's climb to Mount Elbrus was sponsored by Crowne Plaza, Blanchardstown

- In conversation with Ciara Dwyer