Today's main "set" was 1x400m IM as 2x200IM (I did not feel like doing 100 continuous of each). Also 1x200m hard as 50/50/50/50 fly-free.
Also I timed 25 underwater dolphin (with a lot of rest before each) just to get an idea of how long I am holding my breath. With fins 19 seconds. Without fins 29 seconds. So as suspected, duration is not that long. Some thoughts on with and without fins. With fins, is faster, but oxygen consumption is more. Without fins, I am working less hard per kick, but need more kicks to get to the other side even though cadence is almost the same (maybe a bit faster without fins). I would have a tough time holding my breath for 30 seconds at the effort level of using fins (and I would go further). Without fins, can last longer due to less workload per stroke
These are the fins I am using:
I don't feel there is a risk at 25m for me, but maybe there is. I am not saying it is easy either. Before I do the 25m, I usually do 50m of easy kicking to shunt blood to the legs (vs arms) and then take a decent rest first.
Jason, what am I am doing screwed up on my back that is making it hard to kick on my back dolphin kicking at the surface? Is there a trick? do you keep your core and hips slightly under water (vs at surface) and just have your chest/head.arms at the surface?