Long Bike/Long Run Same Weekend vs Alternating Weekends

There is NO added physiological benefit to running on tired legs.  There IS added physiological benefit from running at a faster pace.

As for the schedule, do what works for you because the most important factor is to do the work consistently.

Similar to running2far, I would suggest a mid-week long run, a long ride Saturday but instead of a long brick I would just do a semi-long ride (about 50-80% of Saturday) on Sunday.

Shane

I try and get in my long runs during the week (Wed. or Thurs.) and do a long ride on Saturday and a brick on Sunday. 

Most of the time it doesn't happen as that pesky job I have gets in the way during the week.  I usually end up doing both long ride and long run on the weekends. 

What has worked best in the past for me is long runs midweek and long rides on the weekend with at least 48 hours rest between, 72 hours is better.

In times when I've needed to do both a long ride and long run on the same weekend, I always made sure to run on Saturday and ride on Sunday.  I never do a long run on tired legs. 

Define long run.

I did long ride on saturday, long run on sunday. Long run was never more than 2 1/2 hours and was usually done before my wife was out of bed. 

I'm another for long run midweek, long ride on the weekend. I did my long runs in the AM, even if that being out the door by 4:30 a.m.

Like JK said, there are no physiological benefits to running on tired legs. Besides, the tired legs (and other effects) you feel 24 hrs after a long ride are a lot different than those you feel immediately after a ride. Go into your long ride/brick and long run feeling good and recovered...you'll get the most out of it that way.

Of course, what works best time wise for you trumps everything else . Good luck !

why don't you try this: one week do your long ride on sat and your long run on sunday (or viceversa) and the next week do your long run mid week (wed/thurs) and do you long bike sat or sund.

Try to see which one allows you to do each session better and what method allows you to recover faster for the next session(s). the one that works best for you is your best choice

I am at the end of my first IM preparation and I tell you my opinion on that, coming from a solid experience on marathons.

I see 3 types of long runs you can do:

1) Long runs with last 5km in progression: good approach for "fast marathons";

2) Long runs as brick after long ride: in this case shorter runs than (1)

3) Long runs after a "though" week end, either after rides, races or whatever, trying to reproduce the fatigue of the Ironman. When I say "fatigue" I mean mental and phsyical efforts. For Ironman you should fight mainly against mental challange when you are tired.

I approached most of the times (3) in this year, doing on wednesday my long rides, saturday tipically running or triathlon races, sunday morning medium distance ride but at high intensity and sunday afternoon long runs.

This plan allowed me to be in a good shape for the long ride (after the swim you should be like that...) and pretty challanged at beginning of my long runs.