Coincidentally, I just put myself on the waitlist for a Concept2, and this thread pops up. I've wanted to buy a Concept 2 for at least 15 years, and just haven't gone forward with it because of price. The past 2ish years, I've been actively looking for used, and can't ever find one reasonably near me. I finally decided I was ready to have my own erg in my house where I can use it any time I want. I rowed competitively in HS and college, though that was 20+ years ago, and the erg has always been my exercise happy place since then. A couple years ago we joined the Y, and I always head straight for the erg when I get there. COVID screwed up my gym trips, though I was never great about going because the kids make it much more difficult. We finally decided to put together a small home gym - rower for me, bike for my husband, some basic weights.
When I was going to the gym regularly, I was doing 3 days a week. My gym time was limited because it was before work, so I'd usually only have about 30 min to work out. I'd either do about 15 min of warm up + intervals then 15 min of weights, or 30min at a steady state. Every so often I throw in a race day - relaxed warm up then 2K all out. For intervals, it's really anything you want to do and you can convert any running or biking interval program for rowing. My only thing is I prefer going by meters vs time. I feel more motivated seeing meters click down vs time, and it makes me work harder because the harder I work, the faster it goes by. Just figure out your typical 500m splits for different intensities. Also, there are 2 types of races in rowing - there are sprints (typically 2000m) where boats race directly against each other. In head races, boats set out at staggered times and have to cover 4-10km, so you're rowing for an extended period of time and have to pace yourself to win without using up all your energy early. I mimic those for myself sometimes as well.
You can even compete in indoor rowing competitions. The CRASH-B erg sprints are held annually - I competed back in HS - and I'm considering training to go next year, just for some extra motivation.
