Training for a Long Distance Swim

Based on your previous posts, I'm guessing you are already comfortable swimming in open water?  That likely lowers the amount you need to practice it in.  That said, 8 miles is a LONG swim and you likely need some practice with getting used to being in salt water (I assume?) for that long.  Figuring out possible chafage issues, things like that.  

As for the preparation of getting ready for that long of a swim, I think I would still spend the majority of my time in the pool.

I did a 10K swim that turned out to be 7 plus... I increased my 2X weekly masters from 3 to 4K to 5K, longest I think was 5200 or so.  These were all in sets, I wasn't just swimming 5K straight.  Weekends, I bumped up the OW swim and did several 3 milers, some 4 milers and a 5 miler.  I definitely think you need some experience just swimming for the 2-3 hours that it's going to take.  Especially in salt water, as that can have all different kinds of effects on you, chafing, being able to feel your tongue, etc....  You don't need 8 miles, I'd say if you can do 6 you're fine (but if you really think it's going to be 10, then you might need 7+)

Most of my swims were so cal,. so the water was a bit murky.  Did have a heart in my throat moment when a large bottlenose decided to swim right underneath me...   But also dis a week's worth of training in Hawaii, seeing the bottom was not reassuring, especially knowing there are tiger sharks there (even though there are great whites at home), and all my training was basically  solo, no swim buddy or kayak support.  Lots of time to be in my head and see things that weren't there...

Making the transition from a 5K swim (if you've done one) to an 8 to 10 mile swim requires a change in your workouts. Since you are competing in both a Sprint and IM you probably plan on altering your training for them as well. So the key will be making the decisions on compromising to get a specific result.

To begin with, for me a sprint tri is equivalent to a 5K swim. It's been a few years, but I would train for a sprint and then switch over to just swimming 3 weeks before a 5K race (admittedly I am a swimmer). If you do that you could also easily switch back to do another sprint. But you are talking about another whole problem. I've never done anything longer than a HIM, but I have swum a number of marathon swims, including a few in rough ocean waters.

I know when I trained for HIM I didn't work on intervals because at that distance they would not do much for me other than expose myself to injury. However, I did a number of hard bricks. Marathon swimming is more akin to IM training as far as cardio fitness. A lot of it is maintaining focus training and on the swim. Efficiency is the key so focusing on form is critical during training and during the swim. However, when training for even my longest swims I always did intervals for part of the workout. I did this mostly to build strength for rougher ocean waters. In fact if I do another long rough swim I'd do more of them (and lift weights).

My marathon swim pace is very slow. I just dial in my tempo and just go, and go, and go . . . . It is a whole different kind of swimming than a 5K. It's also a lot different than swimming a 10K. I did my first 10Ks in the year before starting my long swims, and just swam them as a slow 5K pace. I learned a lot from doing this. However, I never learned how to race a 10K until I had a few long swims under my belt. So there is a good chance the trick for you is to find your swimming all day pace and make swimming at that pace a good chunk of your swim workout - but keep intervals as a part of every workout. As far as multi-sport training leading up to a long swim I found it very useful to extend my training sessions and do some intense intervals with out risking injury to my shoulders. I did this mostly with my bike up on a trainer working cadence, speed and heart rate to get the most out of my training time. Importantly by doing intervals on the bike or track, you'll be able to switchback quickly to multi-sport in preparation for your IM.

Which swim are you doing? Depending on which one it is, I might be able to give you some info on it. What is the expected water temperature? Will you be wearing a wetsuit? If you tell me what your current workout is in the pool I might be able to give you some suggestions. One thing I must warn you about is that training for marathon swims in my mind is very boring if you do all of your training in a pool. Be prepared for that. Frankly I hope to return to tris (probably just sprints) next year. The training is just so much more fun.

3mar,

1st, this is crazy talk!

2nd, for a training swim you could come up to Melbourne and do the "for fun" 3.75mi Bridge to Bridge swim, Sunday July 26th.  Heck I'd even volunteer to be your kayak escort!