Swim Training.... 8 x 100m "Off" 2 Minutes

Sorry - great articles, as usual, but I don't understand the jargon! To swim "8 x 100m off 2 mins", what exactly does "off" mean in this context, or in terms of swim / recovery times ?

Intelligent Triathlon Training Replies:

8 x 100m off 2 minutes means starting each 100m every 2 minutes. So do the 100m swim, and then have the rest of the 2 minute cycle as recovery.

So if you did 100m in 90 seconds, have 30 seconds rest then swim again.

If you did it in 70 seconds, you'd have 50 seconds rest.

Hope that makes sense!