> Few Dutch people don lycra to get out on their bike, preferring to ride to work, the shops or the pub in whatever clothes they think appropriate for their final destination.

> Of course, the cycle paths lend themselves to sauntering along in summer dresses in a way a death-defying, white-knuckle ride in rush-hour traffic does not. It is also partly because of this that people don't need showers at work to be able to commute by bike - it's a no-sweat experience.

So, reading with some context clues, the answer is "not long enough to work up a sweat."