I have noticed that a lot of runners who have an April marathon are planning to PB attempt a half marathon in March.

I am thinking of running a half on the 3rd March but i am concerned that if i run 'eyeballs out'  the recovery time will have negative effect on my FLM training. The last thing i want is to be too fatigued leading up to and including FLM. 

Any advice would be welcomed.

Nothing wrong with a good hard HM in early March. Will be excellent training and the recovery tim shouldnt be too long. Just substitute one of your LSRs for the HM.

Will be a good work out for you

Thanks for the advice.

 I was chatting to a mate about the half. He was a bit sceptical, his reply was 'Do you want a half PB in March or a marathon PB in April?'

I will run the half flat out if i am feeling 100%. If not i suppose i could always run it at MP and push the pace in the last couple of miles.

Ooooh! Beware racing a 20-miler flat out close to London! That's an entirely different matter - it will take you 3 weeks to fully recover and in that time you'll have to be very careful you don't overtrain. You risk lowering your immune system and catching bugs. You can do it but only if you are prepared to back right off for a couple of weeks and maybe have several days of no running afterwards.

You're far better treating it as a training run and being able to carry on training afterwards. Doing it as say 10 miles slow, 10 miles marathon pace is fine and probably a good thing to do 3 weeks out.

Even 20 miles of marathon pace is too much unless your marathon pace is effectively jogging.

I'll be doing four or five 20 milers in the next few weeks (with a couple of 22 milers), as per my RW schedule, thought that was the whole idea?

I'm racing Wokingham flat out in my half this Sunday, see the Beginners thread to see Mike Gratton's reply to my question about it earlier today.  Don't think it will be a problem at all, good luck! 

very , very interesting

Rusty

can i ask you, as i see nothing on your profile

how used to running are you, how long have you been running

13 miles race pace, 20 mile race pace marathon run 6 weeks later.. depending on experience, ummm

I'd be careful

Even with my VAST experience HM's weeks before a full marathon i taper pace wise

anyway, that's what i think ,i know Windsurfin Susi, gosh , she's Fit, otther names i don't recognise

wishing you all the very best

micknphil-marathonlads.co.uk

My main aim is to PB at FLM(targrting 3.05), i ran 3.09 in 2006 (cool and damp conditions unlike last years heatwave).

recent training times have been very similar to  2006 so i am hopeful. 

i'm just not convinced that running a half flat out only takes a few days to recover from and that i would benefit more from LSR and MP type stuff.

Rusty

Running a HM flat out takes at least a week of recovery and probably more like 2 weeks! You are probably right that you'd be better doing LSR and MP, but some people need the confidence boost that a good HM time gives them. It's all personal choice.

Liz Yelling is running Silverstone flat out as part of her London prep.

Think I'll stick my 2p worth in if no-one minds

I would say an eyeballs out half in March is a good idea. As pointed out above, it's probably the best indicator of your marathon potential and as such provides a good way to determine the right pace for the marathon. In terms of recovery time, I think it very much depends how well trained you are and the sort of mileage you do on a regular basis. If you're doing high mileage and have been doing regular tempo runs then I think you'll be able to resume hard training by ~Thursday/Friday of the following week. The less well trained you are, the longer the recovery will take. Futhermore, as the half is done at race pace, by definition, a 13.1M tempo/threshold run, you'll provide a very strong physiological stimulus to boost your lactate threshold (LT). Think it's pretty much undisputed that the two most important determinants of marathon success are having a high LT and as much endurance as possible. For these reasons, I think you're better off racing a half and forgoing the LSR run for that week.

In terms of a 20M "race" pre-marathon. I'd agreed with Susie (and Pfitzinger and Douglas, and many other coaches for that matter) and think that it's too far to race. However, it can be an excellent venue for a marathon pace (MP) training run provided that you don't get carried away. Again, depending on how well trained you are, anything from 10-15M @MP can be an excellent session, with the benefit of mile markers, aid stations and "race conditions". All these factors lead to a great rehersal for the big day.  Again, expect to need a few days easy running after such an effort and try and choose a course that mimics the profile of the marathon so that you are using your legs muscles in the same way as you will during the marathon.

Good luck!