When I was training for a tri (olympic distance) a year ago, I did best lifting Monday and Friday (chest/should/tri and then Back and Bi’s, with abs both days) and then spending the remaining days (five of them) doing tri training. I ran tues/wed/thurs/Sunday and on wed I would swim as well and thursday would be a “brick” workout where you run/bike or bike/run. Everyone has different theories, but for me, I got most of my endurance from the running, and really focused on this as my primary sport. I didn’t do endurance on the lifting days and felt this was the best way to go about it…just get a HUGE protein/carb shake after the lifting. I tended to stay away from leg lifting then because I was recovering from an overuse injury and just couldn’t add in the extra load on my legs without pain. Now, however–I’m pretty much just running 5-10k’s and haven’t done much training for tris—and am lifting legs with much benefit.
Let me know what you think.