One other thing I found when building up my distance was not to get too hung up on timing yourself, relax into it... if the body aches/hurts slow-down or stop.... if you feel good keep going... too much addiction to times will only result in you pushing your body when it doesn't fancy being pushed. Contrary to what my perverted PE teacher used to shout... pain isn't 'good'....! But as I said, he was a bit of a perv....
One other thing I found when building up my distance was not to get too hung up on timing yourself, relax into it... if the body aches/hurts slow-down or stop.... if you feel good keep going... too much addiction to times will only result in you pushing your body when it doesn't fancy being pushed. Contrary to what my perverted PE teacher used to shout... pain isn't 'good'....! But as I said, he was a bit of a perv....