I've found that the first run is always tough but once it's over the rest follow with not too much of a struggle. My pace is snail like but....I keep going. But my next but one run is 20 minutes with no "first" run. How will I do that? Should I walk 5 minutes in my own time then use laura's five minute walk to run 3 and walk 2 before running 20? Or just trust in the program?