Master Snyder offers weekly, after school classes at several schools in our area. He also has summer lessons and a day camp. We opted for lessons at the smaller of the two closest elementary schools. Tae Kwon Do is Malachi's "thing." That's not to say he is great at it, but it's where his body and brain are becoming strong and being trained. He's learning a lot about self-control and listening, which is very beneficial for him.
Xavier and Malachi both attended lessons for a few weeks, but it quickly became clear they just could not participate together. Since Xav also takes archery lessons, we decided to pull him from TKD and Mal started doing much better. Merrick is devastated that he never gets to do any of the things we find for the big kids. Hopefully, next year, or the following year, he'll be old enough for Tae Kwon Do.
Now, to participate, we did need to sign up for the school's after school program. TKD was not an included class, so there was a charge that we pay our instructor. We did need to be "official" with the school, though. We were welcomed and invited to participate in the activities that were offered on other days as well. When we arrive, the boys can, and often do, participate in the snack program right before everyone disperses to their activities.
Check with the local school districts or other in-the-know parents who might be able to fill you in on this type of Phys Ed option.