Yes, it is good for kids to get exercise and play, you could probably get most of the benefit by buying a dog and a frisbee. i had a soccer team I was on (NE OHIO champs 2 years running) both when I attended school and briefly after in home school, that I quit for medical reasons as opposed to some limitation from homeschooling. Most kids, home-schooled or otherwise, do most of their play with their neighbors, I don't think I was socially stunted because I wasn't playing tag during recess but just at home after dinner. A homeschoolers summer vacation is no different then other kids, except of course most of us study year round or on weekends too. They have studied this, statistically the only social behavior homeschoolers tend to 'suffer' from is significant lower 'problem behavior' score, I guess our marked tendency not to be juvenile delinquents or bullies might be considered a sign of 'social awkwardness'.