Walking 15 flights of stairs would be a daunting task for a person of any age, but that only serves as a nice warm-up for 80-year-old Roger Quindel.  Quindel does it every day, climbing up to his apartment in Milwaukee, Wisconsin. But he doesn’t stop there. Oh, no. The Army veteran, who served in Vietnam, logs 20,000 steps (almost 10 miles) each day, regardless of the weather, which can be unpredictable along the Great Lakes.  Quindel supplements his long walks with sit-ups, push-ups,