if ($_GET['content']=='exercises') {
    // opret forespørgsel
    $query = "SELECT * FROM tp_exercise";
    // send forespørgsel
    $result = mysqli_query($con, $query);
    // opret array til at gemme resultatet
    $json = array();
    // gennemløb resultater
		$i = 0;
    while ($row = mysqli_fetch_assoc($result)) {
			$muscle_query = "SELECT tp_exercise.id AS exercise_id, tp_exercise.name AS exercise_name, tp_muscle.id AS muscle_id, 
			tp_muscle.name AS muscle_name FROM tp_exercise_activates_muscle
				INNER JOIN tp_exercise ON tp_exercise.id = tp_exercise_activates_muscle.exercise_id
				INNER JOIN tp_muscle ON tp_muscle.id = tp_exercise_activates_muscle.muscle_id
				WHERE tp_exercise.id = {$row['id']}";
			$muscle_result = mysqli_query($con, $muscle_query);
      $json[] = array('Exercise' => array(
				'id' => $row['id'],
				'name' => $row['name']
        )
      );
			$muscle_i = 0;
			while ($muscle_row = mysqli_fetch_assoc($muscle_result)) {
				$json[$i]['Exercise']['activates'][$muscle_i]['muscle_id'] = $muscle_row['muscle_id'];
				$json[$i]['Exercise']['activates'][$muscle_i]['muscle_name'] = $muscle_row['muscle_name'];
				$muscle_i++;
			}
			$i++;
    }
    header('Content-type: application/json');
    echo json_encode(array('Exercises'=>$json));
  }