Looking on the internet deeply has found these results:

be involved in an activity is the most popular phrase on the web.

be involved into an activity 11 results on the web	be involved in an activity 12,620 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
... despite the accuracy of the grammar Social skills 6 and 7 relate to the ability of children to participate and be involved into an activity carried out in English.	Flow theory postulates three conditions that have to be met to achieve a flow state: One must be involved in an activity with a clear set of goals and progress. Discipline Policy: Members are expected to be involved in an activity of their choice while at the Club and to follow club rules. Children whose behavior is found�... Discipline Policy: Members are expected to be involved in an activity of their choice while at the Club and to follow Club rules. Children whose behavior is found�... to become very involved in something so that you do not think about anything else. take part (in something). to be involved in an activity with other people�...

be involved into an activity

11 results on the web

be involved in an activity

12,620 results on the web

More popular!

... despite the accuracy of the grammar Social skills 6 and 7 relate to the ability of children to participate and be involved into an activity carried out in English.

Flow theory postulates three conditions that have to be met to achieve a flow state: One must be involved in an activity with a clear set of goals and progress.
Discipline Policy: Members are expected to be involved in an activity of their choice while at the Club and to follow club rules. Children whose behavior is found�...
Discipline Policy: Members are expected to be involved in an activity of their choice while at the Club and to follow Club rules. Children whose behavior is found�...
to become very involved in something so that you do not think about anything else. take part (in something). to be involved in an activity with other people�...