Great input so far, I agree with all of the above. I had some old school Kreitler rollers back in the late 70s and early 80s, they really do help you with your balance and feeling how your body positioning effects your riding. Always felt as if I had worked harder during a roller session than on any ride, of a comparable time period and pedaling cadence. Now, I could not dream of riding on rollers, due to my Parkinson's Disease, and the balance issues it has in my case.

Only thing I can offer is to make sure you have some air circulation around and on you while doing a session. I remember that I could overheat quickly on rollers, since there isn't any wind from forward movement, or atmospheric conditions either. I just set up a fan ahead of me, usually a quartering cross wind setting, rather than head on into my chest and face.

Bill