I started on this, after not running for at least 3 years, and gaining 50 lbs. I could skip right to week 4 - so your milage may vary. If you want to get in sha

I started on this, after not running for at least 3 years, and gaining 50 lbs. I could skip right to week 4 - so your milage may vary. If you want to get in shape, throw in strength training and most importantly, a good diet. But cardio is important. I had high blood pressure, got winded after walking up stairs, etc. more or less fixed that after 3 months with cardio.