At first it was extremely difficult to gain that initial impetus to roll out my yoga mat and do asana every morning, and then to abstain from eating breakfast for another stretch of time until I finished my pranayama exercises.  I started my experiment late because I had to finish my last week of work, but for a full ten days (including teacher training days), I managed to engage in at least one hour of yoga practice and one hour of other internal heat-producing exercises per day.  After the first few days, it became much easier to motivate myself to start, once the life-enhancing effects started to show up in my body as a feeling of lightness and increased energy.  The yoga practices almost completely erased my compulsion to eat out of stress rather than out of hunger, and it even had the unexpected result of making sweets much less appealing to me, as well.