Inserting records with C #

I am adding records in C # ASP.NET with SQL Server, the problem is that I do not know how to declare the checkboxes so that when I select one or more they are registered in my table. Here's what I have: The sex and age table are the checkboxes.

SqlConnection conn = new SqlConnection(@"Data Source=(local);Initial Catalog=System;User ID=sa;Password=17383");

cmd=new SqlCommand("insert into Personal(nombre, work, gender, age)values ("+this.txtname.text+",'"+this.txtwork.text+....(**Here I do not know how to add the checkboxes because they are several**));

This is my board