2 weeks is fine between 400s and 600s. Make sure you keep spinnng your legs in between also stretching and appropriate refuelling.
I have 12 days (hopefully) between finishing RAtN and my 600. That might be a push.
Assuming my RatN effort is as full value as my Audaxes, I have 15-16 days between RatN and a 400, then 2 weeks until the first 600.
The really scientific answer would lie in knowing the TSS values from every ride (and other strenuous activity you do) and then keeping track of your ATL, CTL and TSB values.
Knowing the TSS for each activity requires either a power meter and knowledge of your FTP, or an HRM and something that calculates HR-TSS.
TBH, you had me at power meter, data, and sexy graph!
Anyway. This is more than the vast majority of Audaxers ever consider, but it's the scientific basis behind fitness, fatigue and form - which are the essential parts of recovery.
Your post has given me some really interesting info to go with, thank you! I'm hoping to have a power meter by the new year, I'm trying to get my life together so I can start serious training, I need something more structured than my turning left out the office and seeing where I end up before riding home. But I also need to get my nutrition sorted too, currently my diet is a bit of a horror show, sure I'm loosing weight, but I'm probably eating too much chocolate, and there is a general lack of green in my diet.
I'm putting together a menu of training sessions, with say 5-8 different work outs, that I can pick each day. I know if I try to make a schedule of x on Monday, Y on Tuesday etc... I won't stick to it, life, and work will get in the way, but if I can just turn left out of the office, ride out the city and hit shuffle on a training session, I've more chance of sticking to it.
I agree with the above points about the recovery time being dependent upon how much you are generally riding (ie cycling fitness), and how intense the effort is to complete your rides.
I've been riding a lot this past year, with at least a 200km most weekends. I've found that I can ride consecutive weekends with the longer rides without ill effect, but paying attention to eating well and getting good sleep is preferable.
In July I did 3 200's in 8 days, with a 300 on the 13th day. I didn't really feel any ill effects of it, tho my arse was a bit sore by the end of the 300. But that could have been rectified had I stopped to put some cream on, rather than pushing on as it's only 60km to go...
In September I did an 11 day tour, with 10 consecutive days of 100+, varying from 117km to 167km, which included some crazy stuff, like the 40km fasted ride at -4°C, the 20km fasted ride in shorts (leg warmers got soaked when I left them outside my bivvi bag in the rain), it was a holiday so I wasn't really pushing it, but it's giving me a good base to build on.
On one instance I had a gap of 5 days between a moderate 450km ride and a 1000km ride. I don't think I was compromised in the latter ride.
Another factor is comfort on the bike. If you are not experiencing any discomfort after a ride, then it is much easier to sequence the rides close together.
Yeah, I learnt the hard way that any slight discomfort on a short ride is going to be amplified big time on bigger rides. Part of my training is going to involve fettling my bike to the point of total comfort, or as close as I can get to it. I'm hoping that in another ~5kg or so of weight loss I'll be able to fit into some better shorts than the ones I have now. Currently decathlon are about the only place I can go to get shorts that fit me.
J