Yeah very pleased, thought I'd take longer to progress from 5k to 10k so it was a nice surprise.
Wondering about trying my next couple short runs with a backpack to get used to it so I can carry a bit of water and a jacket if I start going longer. I didn't need water yesterday but I was happy to have a drink when I got in. I've got a vague idea of heading up onto the Downs maybe and doing a bit of off road for variety.
In general the recommendation is do more than 10% of what you did before, but it's not as simple as just saying that 5km to 10km is a 100% jump and therefore bad, it's got to be taken in context of the weekly load. If you're doing four 5k runs a week (for 20km in total) then making one of them 10km would only mean a 25% weekly distance increase. Dropping one of the 5k runs and replacing another with a 10k run would give you the same weekly load.
It's still not that simple. Doing 4x11km runs in a week doesn't mean that you can do nothing for most of a week and then run a marathon. Your body is going to need to build up getting used to the longer runs. If you can run 5k at a reasonable pace (you're talking about a 5min/km) then pushing on to 10k isn't that tricky.
In general, a large increase in individual run distance will come with an increased risk of injury. Plenty of people get away with going 5k to 10k, but some don't. I'm glad you got away with it.
As for drinks. It's personal. Some people can't do a 5k without carrying water. I'll do a 16km run without taking anything to drink, just make sure I'm hydrated before hand. For anything longer than that I'll take a 500ml hand bottle[1] with me. I prefer not running with anything on my back if I can help it.
But when I used to extend my commute in to work into a HM I used to have to take work ID/wallet/keys/etc with me and so I'd use a small running rucksack and take the hand bottle, when it was finished I'd stuff it in the backpack so I could do the majority of the route without having to hold anything.
Another alternative is something like an IsoGel or two. That way you can get some energy and a bit of hydration (rather than just a normal gel that is hypotonic[2] if not taken with some other fluids).
I could always get a drink shortly after finishing or, if I really needed it,
en route somewhere given my commute was into central London and I passed nearby to literally thousands of shops along the way.
1. Something like this:
https://www.wiggle.com/ultimate-performance-kielder-handheld-bottle-carrier2. Can never remember if its hypo- or hyper-, the one that means it'll make you more dehydrated.