I am wondering if any of you have tried interval training, such as the
"Tabata" training described on Clarence Bass' and Richard Winett's websites.
 It seems to work for me if I do it infrequently, such as once a week.  If I
do it more often, I don't seem to improve.  I'm thinking maybe it's a bit
too structured (always 20 sec hard, 10 sec easy), and that a more varied
approach would be better.