A 2yo should really be active all day, exploring, jumping etc, a class is ok, but it is actually not the kind of physical activity that children necessarily need, they need to be able to toss things (socks in a bucket if inside) & boys even more so in many cases, although yesterday with my friend who has a 4yo boy & 2yo DD, it's the DD who is off exploring everywhere. 2yo really aren't made to sit still & play for in one position, they really are developmentally meant to be moving all the time.
One of the reasons that TV might seem to calm is that as it engages one part of the brain that pretty much blocks off the stimulation to other parts of the brain, you'd probably find that if you changed to an activity like throwing socks in a basket or crawling under & over chairs that you'd also get an improvement in his ability to cope too.