I've seen one of your quick sketches, and I think that those 30" (second) quick sketches are the most loosest and fluidest I've seen so far. The 2 minute poses are fluider, while the 5 minute ones are basically your fluid. Why don't you please do 96 minutes of 60 second poses, in two days?? The reason why you could do this amout of drawing practice is because, it'll help you get that lively and energetic hand-drawn animator's line. For even more practice and inspiration, then please check out the Action! Cartooning by Ben Caldwell, Fantasy Cartooning, also by Ben Caldwell, and this book, Vanishing Point for Perpsective Drawing.
Hat's off to you, and I hope you'll find this completely, totally, and absolutely obliging and informative.