Posted: 14/02/2014 at 21:41
Sounds really sensible - I prefer a 25:5 minute ratio on flattish courses, otherwise it's all effort based depending on the terrain - i.e, walk the ups, run the downs and jog the flats.
120 is low, I train using the Maffetone 180-age+5 which gives me a training max of 142 - but, if you're happy at that level then good news, you should be firmly in the aerobic zone at that level
one thing I found from doing lots of this sort of training last year was that I found it REALLY hard to run for an extended period as I was so used to taking walk breaks! So, this year I'm trying to run for long, extended periods at a low HR, (sub 142 for me)
you you also might want to look at nutrition a bit, eating smaller, more often - look for 300-ish calories an hour. I find 100 cals every 20 minutes easier than one block of 300 an hour! Drip-feed it in, you should be able to digest food at the pace/effort you are running