losing weight

Every winter I put on half a stone - then -when Spring breaks - after several false dawns - I get my saws, hooks, and other assorted cutting implements out and set about attacking the garden - the shrubbery - and the woods. Young trees I planted in my comparative youth i.e. twenty years ago or so - now need the attention of the high pruner which I  go armed with on my walks - stopping to prune up trees until the dogs make their boredom so obvious that I am forced to 'walk on.'  This work -I think -no I am sure - helps the tummy muscles and arm and shoulder muscles as it makes you stretch as you reach for the furthest offending branch.  Then of course there is acting as labourer (unpaid and bolshy) to my wife in the garden and carting all the rubbish which a winter of neglect has caused to accumulate to a bonfire -all this an attacking invasive laurel and ponticum in the shrubbery as well causes those pounds to begin to slip off. So now I leap gaily on the scales whilst -only a month or so ago - I avoided them.  The result is a loss of between three or four pounds to date and more - hopefully - to come.  Why is it I wonder that rich men spend a fortune on indoor gymnasiums and the like when all they really need are a few saws and hooks and a shrubbery and a garden to play in?