I was scared too. So scared that I run 25 min instead of 20, and then added 5 more min run after 5 min walk. Choose your pace wisely and you will feel great about yourself! Now I just finish w6d3 - 22 min run and then added 10 more min run after 3 min walk. This is my win strategy - low pace! I will go for speed when I complete the program.