Tim Don makes light of a simple but most important concept for beginner triathletes. But many find that the more we train consistently, the more 'anxious' we are when we actually do take a day off. We feel guilty. This shouldn't be the case, we have worked hard in the past 7-10 days and the body (and mind) need an almost complete break to rest and recuperate. If you are training too much and the routine is starting to get stale, perhaps take a few more days off as it's usually your mind telling you to 'stop!' so that your body can get the rest it needs to recover to make future gains.
Read what our forum member say about taking rest days