I challenge you to get 20 members to sign up in one week. Each of them need to creat a fitness challenge and challenge another person. Any challenge is eccepted, workouts, weight loss, biking, running, swimming hiking ect. Be creative, because the best wa... moreI challenge you to get 20 members to sign up in one week. Each of them need to creat a fitness challenge and challenge another person. Any challenge is eccepted, workouts, weight loss, biking, running, swimming hiking ect. Be creative, because the best way to stay fit is to challenge each other.