I've noticed recently that my endurance seems to be quite bad (generally). I've noticed this when cycling, walking up hills while carrying a moderate weight rucksack and generally taking part in sports. I do indoor rock climbing several time a week (the outdoor times are when I notice my weakness walking) and can go for 2 hours on that but thats only really using very specific muscles. I have a hill I have to cycle up 2-3 times a week for classes (I'm first year student, 19 years old if it matters at all) and I stuggle up that while much older people will shoot past me.
What is the best way to increase my endurance in general? I'm not to worried about targeting specific activities to work on but if possible I would like to be better at cycling up that hill and also walking up hills carrying a load.
Sorry if I've left anything out/said somethings tupid, I don't really know much about exercise.
What's your story?