‘You go a-walking,’ he said. ‘Do for all love go walking up very steep heights — traverse the Rock from end to end — traverse it again and again on an empty stomach. You are an obese subject; your hand quiver as you go. You must weight sixteen or even seventeen stone.’
‘And to be sure I do sweat like a mare in foal,’ he reflected, sitting under the shade of a boulder, loosening his waist-band and mopping himself. 

Master and Commander – Patrick O’Brian