Well being so young though which is good I would start with a serious full body stretching and exercise program if he is interested that will get him to start to develop good flexibility, mobility and strength.
You can go for sport combat systems but I would suggest the more Traditional Martial Arts to complete at least as a base from the below in list.
Where you will be taught allot more than just kick and punch under a true linage and sifu/instructor. Where you will undergo specific training through a proper syllabus / curriculum in effective fighting techniques (sport and self defense), conditioning and stretching programs movement and fighting strategy along with conditioning methods.
Traditional Martial Arts........
- Kung Fu San Soo
- Kung Fu Vovinam .
- Kung Fu Choy Li Fut
- Kung Fu Sanshou (or Sanda)
- Filopino Panantukan
- Wing Chun
- Karate Okinawan
- JiuJutsu
In all Traditional Martial Arts you cover the four fundamental combat zones of fighting... E.g.... kicks, punches, locks and grappling so on.
- Long Range
- Close Range
- Tackling Range
- Ground Range
Once you have covered one TMA as a base then just mix it up it will give you the fighting aspect needed if entering competition/tournaments etc.
Other fighting arts I like and encourage anyone to do are......
With Modern Muay Thai it lacks in the ground work area, as it’s more standup sport fighting by design.
Although it could be said its hard to find some places the teach TMA's altogether in some categories like Lerdrit or Boran which in my view are allot more interesting, in-depth, realistic, applies to more conditioning and is more a base and a long life process of refinement achieving more over the years in comparison to a sport derivative/branch.
You get much more training and fighting awareness in any TMA 100% that’s why to me they are more interesting to learn for personal hobby interest, where you can easily apply and adapt to a sport rule set in obeying them.
A MUAY THAI LERDRIT EXAMPLE FOR THE DIFFERENCE IN TRAINING APPROACH:-
