>Racing>20-miler in prep for marathon
You'll ruin your knees!
""...the truth that someday, you will go for your last run. But not today—today you got to run." - Matt Crownover (after Western States)
Abs of Flabs
The Floor Walker
However, at one point this book suggests doing those 20 mile training runs in the same TOTAL time as my goal marathon time (that would be 20 miles in approx 3 hours, or 9 min/mile). The rationale given for this is that it is good to get your body used to running for the total duration of time it will take you for the marathon... an interesting idea... However, it seems to me that when running 3 hours at 9 min/mile you will use very different posture/muscles than running for 3 hours (or a shorter duration) at 7:30 min/mile. So does this approach makes sense? (The counter-argument to this may be that you use speedwork to build muscle and use long runs to build bone-strength?)
I'm a big fan of the long run and do believe that it is beneficial to go really long and really slow. The main reasons are to teach your body to convert fat stores into energy, which is essential for the marathon especially in that last 10k when all your glycogen stores are depleted. I'm not an expert on this but I've read a lot on the benefits of the long run. Here is a link that I think explains it pretty well:
Good counsel from a number of posters here. And, while it may seem counter-intuitive, you actually lose weight faster running long runs slower. I generally do 3-20/21 milers before a marathon, but each one is a bit different. Yes, it is to get your body used to being on the road for a length of time (as has been discussed), but on the 2nd and 3rd 20-milers in particular I have different paces interspersed in the run--eg, alternating PMP+30 to 60 for, say, miles 1-7, then picking it up to PMP-30 for the next 4, then back down to PMP+30 to 60, perhaps for the balance of the run. On my third, I make sure my last 3-4 miles are done at PMP or PMP-20 to 30 seconds. This gets your body trained to running at pace when you are tired and have been on the road a while.
And, a comment on the distance. Personally, and I know no one here has advocated it, I don't run over 20 on my long runs (yeah, I mentioned 21 above, but that just kind of "happened"). When younger, my fastest was a 2:40:35 when running for the Marines, and we never ran further than 20. I think it gets counterproductive to go much further in training, as the return in conditioning is marginal. But, that's just my $.02.
Distance Running Tips
"If everybody throws in their $.02...but it's a "penny for your thoughts" ...somebody's got to be making some money on this deal...
Lynn: which 50 miler is this?