I put in a nice and easy 10 miles today. The trails and mountain canyons are still packed with snow, so this time of year we get days like today, snow, rain, hail, sleet, sunshine, calm, wind, etc. So I used the radar to pick the best weather window and hit the bike path south of town and ran along the snake river for a while.
This is a fairly hilly course and the purpose of my run today was to get in a very easy "strength" run to build efficiency. I kept my heart rate well within zone 1-3. After a fun and fast SP5 run yesterday, my HR was really responsive today, so really needed to be aware to keep my effort in check. I call this a strength run because I used the most natural platform shoes I could, focusing on really good form so every foot step is strength building. My easy effort on all of the hills helps me develop crucial efficiency to prepare me for the mountains in the Summer and Fall.
I need to be able to run long mountain climbs, like the above photo, as efficiently as I can. Native American runners of the past would train this way by running up a hill and back with a mouth full of water. The challenge was to arrive back at the start with the water still in their mouth, forcing them to be as efficient as possible running up the hill.
Keeping my HR in check today accomplished the same thing over a long period of time over many hills. This will improve my overall efficiency, bump up my speed endurance across the board, and allow me to better manage my efforts in the mountains. This gives way to fatigue resistance and better energy and fueling efficiency on the really long runs.
Efficiency is the holy grail for ultra running - running faster, easier!