Before revision: </ref></ref> +Numer alPerceived exertion rating6no exertion7extremely light89very light1011light12moderate13somewhat hard1415hard1617very hard1819extremely hard20maximal exertion CR-10 scale Borg later developed a CR10 scale.
After revision: +Numer alPerceived exertion rating6no exertion7extremely light89very light1011light12moderate13somewhat hard1415hard1617very hard1819extremely hard20maximal exertion CR-10 scale Borg later developed a CR10 scale.