Second last erg-week! Time to gear up for a r20 5 k next week :-)
4 x 6 minutes, r20, on 1 min rest
Quite a simple one. It's 24 minutes of work - most people will pull between 20-25 minutes for the 5k piece next week, so this is the right ballpark. Idea is to do the first piece at your target split for the 5km (what you would personally like to aim for) and then try to hold that across the next three - figure out if it's too ambitious, or too soft. In a piece like this the breaks are only vaguely physiological, but they are mentally useful as they help you to break it up. So they are there as a crutch, basically!
Suggested second session
2500, then 1500, then 1000 - all r20, with 1 minute rest between them.
It's a similar idea. It's 5000m total, but with some mental break rests. The reasoning for the breakdown is that's mentally how a 5k goes for a lot of people - relatively straightforward until 2500, then the horrible struggle of the next 1500, and then you are able to ramp it up and hang on for the last 1000m. So by practicing the three sections, you can be ready for it and prepare how to attack each one.