Everyone's recovery time is different but the rule of thumb is that it takes a month to fully get over a big ride and be back to peak. If the 400 takes a lot out of you and you are shattered at the end, you might then find the 600 a bit harder going than if you'd had a bit more recovery. But you won't know until you try it and it is not an unreasonable thing to attempt.
FWIW I did a 400 this summer then a 600 two weeks later and it was fine
Hello everyone,
,My name is Will and i have been living in Switzerland for the last 20 years .I hope to be taking part in 2013 and am delighted to find this forum. Recovery time is indeed a very individual matter .I took part in a 600, 3 weeks before the LEL in 2009 and came away from this swiss 600(
www.radmarathon.ch) with a very swollen and painful knee,due to using too higher gears on a bike i didnt ride regularly.I thought at the time there was no way i was going to manage the LEL and would have had a good reason to call it off.However, after a couple of weeks the swelling went down and using a bike with a wider range of gears i managed to complete the LEL just within the time limit.I did the same 600 before the Paris brest last year and didnt feel at all incapacitated after the ride .I learnt a lot on that first LEL.The first thing i did before the paris brest was to invest in a hub dynamo and GPS. In 2009 i was luck enough to meet Martin who had a GPS and i followed his wheel for about 1100km. A soaked road sheet ,extreme tiredness and an unmarked route is an extra challenge for those who dont know the areas they are riding through.Ive read about riders going off the planned route and using main "A "roads to make up time. I wasnt sue where the A roads were,if i would miss controls and Im not sure about the ethos of such a practice anyway. That said, if you cycle 1400 km on main roads instead of the intended country lanes ,its still a long way to go.Hope to see you all there in 2013