Running

Here's a brain dump of what I've learned over a decade of running for fitness
Not everything on this page is running-specific but most of it is
I like running because it suits me and is the most efficient way of burning calories, but you may prefer other cardio

Advantages

Feel less tired
Sleep more soundly
Get ill less often and with reduced severity
- But flu will still knock you out for a week
You will want to eat more, which is fine as food is great and you're going to burn it all
Run for the bus without nearly dying, more stamina in general
Use the walking lane up escalators because standing is too boring
Improved tolerance of hangovers
Joints become much stronger
Improved blood flow everywhere, e.g. the brain which helps with thinking

Injury, where the bad part is you may have to give up cardio for a couple of weeks until it goes away
Cyclists who use the pavement will try to collide with you, so be vigilant
Can become a minor obsession

Get decent trainers, as you'll be using them a lot
- Tell the shop person what you're going to use them for
- If they try to sell you fashion trainers, go to a different shop. Avoid soles that look like they don't bend
- It's a good sign if they feel like you're wearing nothing at all
Sports bra is recommended if you're a girl
Hat and gloves when it's really cold or even a fleece
Don't forget your keys like that one time
- I bring my spare set without lots of keyrings so it doesn't jangle about as much
- Maybe keep them in a little bag so they don't eat their way through your pockets
Cheap 3/4 length jogging bottoms from Sports Direct are cool in summer and warm enough in winter

Listen to what your body is telling you, and err on the side of caution while you're still discovering what's normal for you
- Having to curtail a session due to some random niggle is frustrating, but better that than get injured
Always do your stretches
- These will help prevent injury
- Always do them when warm (I use the middle of a session)
- Don't bounce, hold for 10 seconds while you feel tension and then release
Most important stretch for runners is the calf stretch
- Calf injury is the most annoying and hard to shake off, you don't want it
I also recommend the thigh stretch
Groin stretch is good if you have a place to sit
Give your legs a good shake after stretching, I don't know what this does but it seems to help

Your first session will feel much easier than subsequent sessions
- This is because you are burning your liver's glycogen store, which is a cheap source of energy
- The glycogen store takes a few days to regenerate, during which time you'll find training to be harder
You are likely to feel muscle stiffness a couple of days after your first session
- Wait for the stiffness to go away (another couple of days) before continuing, it shouldn't come back
At first, the mechanism that transports fat from where it usually accumulates to where it's needed (the muscles) is very inefficient
- This will gradually improve over time

Read the rest of this page
Aim for 20 minutes 3 times a week
- At first you will only be able to run for a few minutes at a time, this is normal
- Stay out for the full 20 minutes even if you have to walk most of the way
- Over a few weeks you can build up to running the whole thing
Take it easy, the time to push yourself is after you feel bored with what you're doing, not before
If like me you're prone to fainting, bring an energy bar to eat after your session
- I favour McVitie's Digestives Snack Bar Hazelnut & Milk Chocolate
Remember to drink water but never force it down

Some like to go first thing in the morning, which I consider the height of masochism
I prefer the evening, so I can have dinner when done
- This also seems to improve my energy levels in the evenings when I'm not running

I think outside is better to begin with, as that way you have total control while finding your feet
- It's also free, and saves time if your route starts and ends at home
Treadmill makes it easy to monitor your pulse and progress
- And being a gym member gives you a spare shower to use if your boiler breaks in winter

Enter a race e.g. 5K in about 3 months, so you have the fear factor of not being one of those people who clearly did not train
- After the race, it's very easy to fall back into your previous lifestyle, so book another race and then take your holiday
Music helps alleviate boredom
- Have an inline volume control so you can turn it down when crossing roads
Sometimes I don't want to go, so I ask myself can I put one foot in front of the other? Then go

The /r/Fitness wiki has good info much like this page, if you can ignore its obsession with lifting
Couch to 5K
Paula Radcliffe's half-marathon training guide for beginners, not online unfortunately
- As per #Getting started, then escalate to 40 mins 3 times a week (Mon/Tue/Thu) plus a Saturday run of up to 70 mins
- One of the 40 min runs (Tuesday) should focus on fartlek or sprints, which will help improve your regular performance