[gullywhumper]

There's an efficient ratio between the drive and recovery. At 20spm a 1 second drive means 2 seconds on the recovery (so a full stroke is 3 seconds). Try rowing that rating at a ratio closer to 1:1 and you'll really notice the inefficiency. You couldn't do that for an hour and maintain a decent split. As power and rating increase, you want to maintain a ratio. I don't know if it's always 1:2, but there's still an efficient ratio. A similar idea might be being in the wrong gear on a bike. On flat ground with no wind, if you're in the wrong gear you might be able to pedal at a very high rpm, but you'll probably notice that you are not moving efficiently. So avoiding rushing the slide isn't as much about free speed or checking the boat, but being in the right gear. Definitely not a physicist - so maybe not the best analogy, and maybe I'm misremembering how my coaches had explained it to me.