I have every Fall and Spring except this past one, well one did and one didn't, and the current one. We let both kids do Soccer and T-Ball at the Y this spring because the season is shorter with a lot less practices. The Y teaches sportsmanship that other sports seem to forget sometimes.
We have done soccer both Spring and Fall for the older girl several times. She enjoys it a lot but this past Spring was a recital year at the studio and there was just not enough time to do all the extra practices for both.
For a 6 yr. old I would expect 1-2 short practices per week. Perhaps about 45 minutes to an hour one or two evenings per week. Some parents tell the coach at the beginning they can only do 1 time per week. The games are usually on Saturday morning but there are the occasional Sunday games. We do BMX on Sunday afternoons so we don't do Sunday games unless they are the 4:30 ones and we are done racing.
For T-Ball the practices stopped once the games started and the games were on Mon, or Tues, or Thurs. So we could actually do both at the same time and not have lap over.
The reason we choose to do sports. I am morbidly obese. My hubby is too. The kids other grandparents are heavy but not too bad. The kids both will have a tendency to be sedentary and eat unhealthy so I wanted them to learn early on to be active.
Soccer is constant running when playing, T-Ball is more standing around waiting but requires more mental participation, trying to figure out what the batter will do and how to meet the challenge of being where the ball is going to be hit and getting the runner out.
BMX is riding bikes on a path that has hills, curves, plateaus, some jumps when they get older, etc...the power is totally in the hands of the rider, they decide how fast they go, where they choose to ride around the curve part, which strategy works to come in a winner.
We also have the older girl in several classes at the gym/dance studio. She does tap/ballet, Hip Hop, tumbling, and is on the show team. She stays busy 4 nights of the week going to an hour class with one night being for 2 hours. I work there also so she would be there anyway if she wanted to go.
The younger child has sensory issues and doesn't do very well with classes or sports if he can't be constantly moving plus the cost is very high if he's not going to get the full amount out of it. We wanted to put him in football but the cost is $100, $50 for entry fees and $50 for clothing/gear rental. If it were less expensive we would surely have him in it.
We did swimming lessons this summer and the kids really liked them. When the Y offers them again we will do them too.