I've read a couple articles on elite distance Kenyan runners training recently. Despite the impression that the Kenyan runners train very hard...which they do sometimes...it seems they also do lots of very easy running. When you look closely at their easy running, you see that...for them...it's really, really easy...maybe only 60-70% of maximum heart rate. You can read one of the articles here.
In the past, I've tried to emulate their effort levels...just so I could see what it felt like...but I couldn't keep my heart rate low enough and still run. Today...I decided that no matter what I was going to run at 60-70% of max heart rate. But in order to do so...I realized I had to do a combo of walking and running. The 30/30 method above was just about right.
PM - F500 - 45mins alternating W25secs/R35secs...then a few exercises:
2x12 GHD sit-ups
2x30secs GHD back ext hold
17mins Steam Room
Seem to have recovered well from AM.