I’m training towards my first IM (FL) coming up in a couple months. I consider myself a reasonably strong age grouper but IM will definitely be new territory for me. This season I’ve gone 4:27 HIM on very good run fitness (1:17 open 1/2 mary), 2:08 Oly, and 36:30 open 10K. Running is my strongest sport but I’ve been focuse on the bike for the last couple months and got to thinking about using a run/walk approach. I know it can be effective (sub 2:30 marathons) but I’m wondering if anyone here has intentionally used (planned and executed) a run/walk for IM and been satisfied with the results. As of right now I figure if I pace the bike properly I should be able to run 3:30 or better. My 2hr long runs are currently at ~7-7:10 pace without being particualrly difficult. If I’m going to run/walk I need to start integrating it into my training now though. I’m thinking that walking 30sec every other aid station might be a reasonable plan. I could care less about what others think about me not running the entire course. All I’m concerned with is what will get me to the finish fastest.
You are definitely a strong runner and i assume that this is your best discipline so i would focus on setting yourself up on the bike where you have not blown out your legs and at a relatively easy pace could pass a lot of people on the run. Regarding walk/run strategy I find that walking all the aid stations works for me to make sure I consume all the drink/gel/food instead of spilling it but also it keeps me fresh and emotionally helps with looking forward to each aid station in order to get that few seconds of working different muscles. Make sure though to designate exactly where you will start and stop walking (start at first table and start running at last aid station flag) otherwise later in the race your will be tempted to walk just a little bit longer and longer each time. I do not incorporate walk/run into my training for IM, only for Ultra’s in which case I do a 5min run 1min walk for runs over 25 miles. This is all just from my own personal experience and opinion.
On my first IM (IMWI 2005) I thought I would probably be walking the aid stations per advice from Rich Strauss, whose plan I was using at the time. Like you I thought I should train like that as I have found in standalone marathons and training that if I do stop late in the race (such as at an aid station) I find it tough to get running again. (not as fast as you, my marathon PR is 3:45) I’m not sure how much, if at all, the couple of long runs where I incorporated a walk break helped. In fact I found it frustrating and think it made the training run tougher. I wouldn’t worry about incorporating it into training.
What did help was to be strict that as soon as I passed the last table I would start running again. No matter what. And I would not walk anywhere outside of the aid station, no matter what. In my second IM (Vineman) I did the same strategy. Except - after the first couple - I realised that these aid stations were much shorter than IMWI. Still, that was the plan and I stuck to it.
I once heard Jeff Galloway explain his run/walk strategy and one thing he emphasized was that you have take the walk break from the beginning for the walk break to be helpful. If you wait until you are already tired, your running muscles don’t get the benefit of the walk break. All that to say - walk only at the aid station and just enough to be sure you take in nutrition and don’t walk a step past the last table.
A little more background - I ran 2:53 at Boston in 2006 for only my 2nd marathon. I’ve been training/racing with a power meter on the bike this season and am 100% confident that I can pace the bike appropriately to run well so I’m not so much concerned about struggling on the run. I’m also doing a 2.4/112 race rehersal aquabike at Chesapeakeman in a few weeks which should help me nail down my bike pacing. I think I can ride a respectable bike and run 8min/mile continuous but I’m wondering if regular periodic walks of 20-30sec every 10-15min would allow me to stay fresher, get in the fluids/nutrition, and clock a faster overall marathon. Seems to be some good evidence that if I plan and execute it properly I’ll come out ahead. I dont necessarily feel the need to practice this a lot in training but I’ll definitely try it a couple times and see ow it goes.
Proper bike pacing doesn’t show up on the bike. The tale of proper bike pacing at ironman is told on the run. So saying you’ve been training with a powermeter doesn’t necessarily mean anything good or bad.
Go for an 8 mile run at chesapeakeman after the aquabike, I know a couple of people who have done this. That’s one loop of the run course. If you can run your pace, then you are all set to go. Whatever pace and walk / run ratio you can manage then you can be confident that you’ll hold it in Florida.
My two cents (and worth every penny) is that practicing your race day execution in terms of nutrition, liquids and pacing is just about all you need o be doing between now and race day. Find out on your own if a walk / run strategy off the bike is faster than a run only strategy. Find out on your own how fast you can bike and still get down the alotted calories. Find out on your own if those calories are then enough to hold you for a marathon.
Everything anyone says is guessing, all you have to go on are anecdotes; you won’t know until you try.
Your background and aerobic training says how fast you CAN go. But your execution is what determines how fast you WILL go.