It's like 'used to'. It shows that it was quite a common activity in the past, but not any more. So, 'In the run up to the event, he would sit at his plans for hours, but now that it's over he likes to go for a run instead.'

Т - received your message, but oddly, I cannot reply! Oh well. So - you got this from a textbook? Interesting. Grammatically it is correct, I've just never seen this sentence before. :)

Mango's answer is good. I'd like to say though... it seems like a strange sentence to me, for some reason. May I ask where you found this sentence, Tanya?