We have a workout next week of 1/2 mile hill repeats on an 8% grade (~220 ft of elevation gain) with jog down recovery. I plan on doing at least 6, maximum 8 if I feel good. How fast should these be in relation to 5k pace/how hard should the effort be? My current 5k PR is 18:48 (~6:00/mile) and I run 45 mpw.
Just run baby.
You should do three at a pace of 90% max heart rate. When you start feeling lactat in your legs slow down. If you feel notting speed up.
8% grade is a helluva lot of incline. If that's really what your hill is, figure out what pace you would want to run on the flat and add 60-75 seconds per mile.
Bro dont worry about pace. Just run at an effort a very tad less than 5K and try to keep that consistently for all of the reps. If you slow down, you know its too fast.
You won't do 8 of those. 5-6 at most, unless you're jogging up as well as down. Aim for LT pace (5K pace is ridiculous if you want to do more than a couple), but really any pace faster than a jog is good.
Just noticed other poster said 5K effort, not pace, I misread. Agree with that.
Like others have said, run on effort and don't focus on pace. Just to put it in perspective though, running an 8:30 mile pace up an 8% incline is equivalent to your 5k 6 min mile pace on a flat road basically.....
What you want to do is get a Stryd and run the hills at a certain percentage of your critical power. Anything else is a guess and if you go by feel it's really easy to be too fast or too slow.