Thank you for the link! Anything sure is bound to be better than nothing, I limit my sessions to 1 hour but alternate between doing an hour of constant excercise at a slower speed (I'm a swimmer), and doing shorter burts of intensive excercise but then taking a minute or two break after 2 lanes.

Either way, I think it's easier to go for an hour 3 times a week, than doing half an hour each day. (would become a bit more pricey, and I'd lose the time of going to the pool and back each day. Not as easy to combine with other responsibilities imo)