Whether you need a rest day during your training weeks will be different for every person.  

For a brand new athlete, we'd say definitely taking scheduled rest days would be important. For a more experienced athlete, it's probably not necessary.  

That said, the bottom line is that it's really all about listening closely to your body.  If you feel really exhausted, beat up, even bordering on an injury -- absolutely, please do take a day (or several) to get back to feeling good. 

Pushing through extreme fatigue and/or injury is something we strongly discourage. If you are feeling unwell, or if you have physical niggles or even pain, please rest and assess your situation. If pain or feeling unwell lasts for more than a couple of weeks, please see a sports-specific physiotherapist or athletic therapist to determine the root cause and extent of the problem, and figure out with them how to fix it (and whether you should continue training in the meantime).

But it's not required to have a full day off every week to make good solid progress and to stay injury free!  

If you're following our training plan as it's written, staying in Zone 2 during your Zone 2 workouts (and not giving into the temptation to go faster when long slow training is prescribed), then there's no reason you should ever feel over-trained. So, if you feel good, keep going!