Hi Carolyn, and welcome to the forums! Great question. I’ve worked with athletes on long duration events in the past, but 600km is definitely a big distance. That’s impressive!
I think we can pull out some practices that may help you for this event. In any case, once you get beyond a certain time frame, it’s about that durability and grit, so if you have the capacity to keep making forward progress, you’ll come out of it pretty nicely. A 4 day block is a perfect way to prepare the body for something like this. I’ve done this before personally and with athletes, so good thinking building this into your training.
To your current plan, I would suggest incorporating some specific work into your routine. Like I mentioned before, at some point it’s more about just continuous movement rather than any particular % of max or threshold, so my general thought is to include specific components to those days that would suit your needs in the race. It sounds like there is plenty of climbing to be had in the event, so that would be an area to consider!
- Where do you gain the most climbing?
- Does any particular day stand out over the others?
- What are the climbs like? Long and shallow, steep and short, etc.?
With regard to the setup of the 4 days, I would recommend getting any quality/intensive work in early, so maybe day 1 you can include some top end or threshold work. Although you are going to be spending the vast majority of your time at a very sustainable HR in the race, we can always work on maintaining the feel of that top end work. So you might include some short efforts like 30/30, 40/20, etc. This can be done within a relatively long ride of 6-7 hours too.
Day 2 might include some long sustained efforts, near threshold or in the sweet spot range. You can do this in a structured way either with intervals built in, or just saving some bigger climbing miles until the last 2-3 hours of the ride.
Day 3 might be a long ride, but relatively flat, where you just log miles (this could be where you put in a huge volume of ~9 hours if you are thinking in that direction).
Finally, by day 4 you should be feeling the effects of this mini camp. I always feel like when we are coming to the end of these types of camps, that last day is kind of whatever you can do. You’re not going to have much quality to put out, so it’s again just another day to work on that durability to keep moving. Could be another long push of many hours. HR may be showing signs of fatigue by then too, so play it by ear.
After that, like you said, it’s proper hard recovery to allow the body to adapt.
Let us know what you come up with, and I’ll be looking forward to getting an update on the mini camp once you complete it!
Coach Ryan