So, all going well you're enjoying your rest days.
- getting a massage
- going for a gentle walk or a mellow bike ride
- tai chi
Light physical activity on rest days helps you recover from your training days.
If you're training for the marathon (Canberra marathon is only 6 months away!) try an hour walk or bike ride or even some laps at the pool at this early stage of your training.
If cycling's your thing then a light jog or brisk half hour walk will help balance your leg muscles and help stretch out your hip flexors.Doing some intense circuits or heavy weight training get some flexibility in with stretching or something like tai chi or yoga.
If your exercise regime is varied and light you don't need a rest day at all so increase the intensity of one or two sessions.
Here's a link to some simple stretches you can do anywhere, even at the office.