Quite often seated training is frowned upon due to the fact that most people sit way too much and it's not functional (whatever that means to you). However, because most people do sit too much is why it should be trained at least a bit. The problem is that we become "ungrounded" from our chairs (as well as ungrounded from the actual ground). I recall this happening to me in the 8th grade when I started to find it difficult to breathe while seated. At this point we are screwed. As we become more ungrounded and unseated, we become unstable (physically and probably mentally too). Our hip flexors, lower back extensors, and anterior necks start to kick in. Suddenly a simple task like sitting becomes uncomfortable and painful. Back and neck tension are the biggest complaints. Sitting is a part of life, but most of us (myself included) were sitting with improper muscle and breathing patterns. I recently had to "re-learn" how to sit and my PRI exercises completely changed my experience of sitting. Now that I can sit correctly, I can train myself in a seated position. In this exercise my knees are slightly above my hips (keeps my lower back relaxed) and the band keeps my hip flexors off. I keep my center of mass slightly to the left regardless of which arm I'm lifting with. Inhale at the bottom, exhale through the rep. You can "reference" your left heel and right arch as well.