$r['find_everyone'] = mysql_query('SELECT * FROM `user`');
while($their = mysql_fetch_assoc($r['find_everyone']))
{
$r['their_new_health'] = ($their['health'] - 10);
mysql_query('UPDATE `user` SET `health`=\'' . $r['their_new_health'] . '\' WHERE ID = ".$their["id"] ."');
}