Furball
Evil Scotsman
I was actually going to back myself for the marathon to answer the original question.With 5 years of intense training I think most people would be at least able to finish the triathlon/marathon, that's something that you really can just train for. You'd be slow as **** but you'd technically finish.
2013/14 in 12 months I went from physically not being able to run due to being post-op knee surgery to running the Berlin Marathon in under 3:45.
That's obviously nowhere near an elite time, but I had a look at my training log on Garmin recently to compare against my running this year and I was shocked at how little I trained for it compared to how I remember (the month prior to the run is hilarious in hindsight, I did one 22 mile run 3 weeks prior but apart from that it's a totally random collection of runs in the 8k-12k bracket.)
Particularly in the year post-op, I limited myself in how often I ran per week generally to 2-3 runs.
Now I'm running 4 times a week (and planning to go up to 5 post half-marathon to do a really aggressive 5k training block), I think with 5 years of properly structured training I would back myself to be capable of running a time which would at least qualify me for the Olympics.