Bootstrap row reset query example.

bootstrap-wp-query-reset.php

<?php
/*
Template Name: Trainers Template
*/
?>

<div class="trainers-grid">

	<?php
		$args = array(
			'post_type'      => 'trainers',
			'posts_per_page' => -1,
		);
		$wp_query = new WP_Query( $args );
		
	if ( $wp_query->have_posts() ) : ?>
	
	<div class="row trainers-grid-row">
	 
	    <?php $count=0; ?>    
		<?php while ( $wp_query->have_posts() ) : $wp_query->the_post(); ?>
	 
		<div class="col-sm-4 trainers-thumbnail">
			<?php 
			if ( has_post_thumbnail() ) { // check if the post has a Post Thumbnail assigned to it.
			  the_post_thumbnail('full', array('class' => 'img-responsive'));
			} 
			?>
			<div class="title"><?php the_title(); ?></div>
		</div>
	    
	    <?php $count++; ?>
	 
	    <?php if ($count==3 ||$wp_query->found_posts==0) : ?>
	 
	</div>
		
	<div class="row trainers-grid-row">
		 
		<?php $count=0; ?>
	 
	    <?php endif; ?>
	    <?php endwhile; ?>
	 
		<?php else : ?>                
		    <h3>Sorry but there are no portfolio items.</h3>
		<?php endif; ?>
		 
		<?php wp_reset_query(); ?>
	
	</div>

</div><!-- trainers-grid -->