Sliding stones uses some muscles you may have forgotten but most of the exercise comes from sweeping. If you are doing it properly, you are sweeping very hard. You do this while moving with the stone during at least 80 feet of travel, which takes 10 to 15 seconds. During a game, which takes about two hours, you may do this some 50 or sixty times. Each time one of your teammates throws a stone at the skip's broom, the skip may ask you to sweep it.
Players have their own brooms and there are several kinds of brooms available.
Sweeping the ice in front of the stone makes it slide farther down the ice - and because a swept stone goes farther, it bends later. So sweeping is a means of controlling where the stone goes after it has been released. Usually as the number one - the lead. The lead stones, the two thrown by the number one player, are tremendously important to the evolving strategy of each end. Furthermore, the way the Lead helps sweep teammates' subsequent shots can make a tremendous difference in the team's success.