Query custom post type and reset query.

cpt-query.php

<?php
$args = array( 'post_type' => 'trainers', 'posts_per_page' => -1 );
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post(); ?>

	<?php the_title(); ?>

<?php endwhile; ?>
<?php wp_reset_query(); ?>