What is the best age to start kids in judo?

People often ask me at what age should they start their kids in martial arts. I will occasionally take kids as young as 3-4 as long as the parents know that a) I’m not babysitting, and b) their kids won’t really get too much out of it until they are older. Here are some basic guidelines as to when to start kids. 

• 3-4 year olds can usually warm up with the class and do some specific exercises, but most lack the physical coordination to do more complex drills. They lose interest quickly and often don’t get much other than fun from class. They tend to enjoy randori (sparring) games and do well against age and size-matched opponents. If I have a 3-4 year old, I tend to let them do however much of whatever they can until they start to lose interest, then let them go play in the corner. The goal with this age group is to get them to have fun so that they will tell their parents, “I love judo! I want to do judo again next year!” 
• 5-6 years old is when the little kids’ soccer and teeball leagues start, so there is a lot they can do athletically. Around age 6 seems to be the optimum age for beginning judo classes, but there is a lot of variability in physical and cognitive maturity around this age. With this age group the goal is still to have fun but within the structure of the class.
• 7-8 year olds are more competitive, more coordinated, and do better at randori, but some still don’t tolerate repetitive drills very well. They understand rules and structure better but get distracted and get into the same mode as the younger students. 
• 9-12 year olds can do drills and complex skills, but still enjoy the games-based approach. 
• Around age 13 (again there is a lot of plasticity in their maturity), we switch kids into the adult class. They are usually big enough, coordinated enough, and competitive enough to do well in a drills and randori based approach.