I very recently graduated (on my 53rd birthday) and then almost immediately went on holiday to the Canary Islands. I was quite worried as it's hilly and warm - not the conditions I have learnt to run in - and was unsure if I'd be able to stick to the 3 runs a week.
On the first proper day we went to the Barranco de Guayadeque (stunningly beautiful) and began to walk 6 or 7k up the valley. I have been known to be a bit of a moaner on a walk that starts with a hill, but this time I set the pace! Marched up the hill - and loved it! My husband was absolutely astonished (and thrilled) as this was the first time he'd seen the impact of C25K! After the up, and lunch, a brisk walk down. The change on stamina, fitness and lung capacity in a little over 9 weeks is completely amazing.
I ran when I could (and had my first failure of having to stop before the end of a run), but I think that was hydration, so a valuable lesson learned. And there were many stops in hillside towns where I wasn't able to run (I live in flat as a pancake country), but I was able to walk, and walk, and walk.
Got back, and next day went to the park for my run, I was worried I wouldn't make it as I hadn't run for nearly a week, but I did and all is good. The positive benefits of C25K are incalculable, and the fitness is transferable.