By default for viewing latest activity on BuddyPress site you need to refresh whole page. User experience can be made better by making BuddyPress activity stream live like Twitter so that everytime any of your member posts anything can come visible for everybody instantly without even refreshing the page.
BuddyPress has a free plugin RS BuddyPress Activity Refresh, it automatically checks for latest activity like status, articles and comments and display them on the activity stream using JavaScript. By default refresh rate is 10 seconds but you change it from Dashboard -> BuddyPress -> Activity Refresh. Try it, this is the best plugin for making BuddyPress activity live.