Go for a run or a swim? Which do you prefer for your fix of exercise?
In the last decade, running has gone from being the UK's fourth-most-popular participation sport to second place and is now set to overtake swimming as the nation’s favourite.
BBC Radio 4's Winifred Robinson asks former Olympic athletes Brendan Foster and Steve Parry to argue the case for their chosen sport.
First broadcast on You & Yours, BBC Radio 4, 18 January 2017.