Mac and I got a chuckle from this line in the new coaching column in this month's Ultrarunning magazine:
"While doing back-to-back longs is both psychologically and physically necessary to prepare for a 100-mile effort, it is not essential..."
I don't bring this up to be the "Editing Police", but rather because I think it begs the question:
When training for a 100 mile effort, are back to back long runs necessary or not essential?
I have done 10-12 mile runs the day after a long run the previous day and several Long-Rest-Long efforts, but other than a couple of adventure weekends, I have never done back to back long runs in training.
There are several reasons for this, but the #1 is probably Lifestyle. My husband runs, too, and we have to divide the training time and not neglect the kids. In our house, that means I get Saturday, he gets Sunday. There is usually time for me to get in a run Sunday, but not an all day affair, especially now that Mac is training for ultras and spending hours on the trail every weekend. I am not sure where did he got that stupid idea, but I guess I have to oblige him his time. ;) Also, I am a full time working Mom, and even though I really enjoy being away from my kids (sometimes a little too much!), I still suffer from a good case of "Mommy guilt." I mean, I am supposed to spend at least a little bit of time with my kids each week, right?
Reason #2 is that I don't like back to back runs. I am a pretty tough cookie and I can make myself run when I am tired, but it is not fun. I don't expect every moment of training to be fun and I expect a few chunks of each race to be very un-fun. But I do not want to start a long run feeling crappy with the prospect of 3-4 miserable hours in front of me.
Reason #3 is that I feel that I can get everything I need out of a single long run, maybe more. In a 35 mile run, you will certainly have to deal with running on tired legs. You have to have mental strength to go out for another loop when you get back to your car at mile 22 or to keep going when everyone else calls it a day. And, if you were comparing a single 35 mile run to back to back 20 milers, the single run requires more attention to fueling, hydration, electrolytes (and chafing) and is more likely to make your GI tract "wonky" - all things that are good to have to deal with in practice.
Reason #4 is recovery time. After a long run (or hypothetically a back to back), I like an easy day. Not every ultrarunner does speed (a debate for another day!) but I try to get two "speed" workouts in a week, one on the track and one tempo or hills. I think the recovery after back to back (for me) would be great enough that two speed sessions would be extremely challenging and would put me at risk for major fatigue (which I seem to be prone to more than injury, but in others, injury would be a risk).
But all of this is just personal opinion and not really science. Many people thrive on back-to-backs, especially the high mileage guys. So what do you think - are back to back long runs necessary or not essential?