Congrats to the wife. So many fast runners are a part of this thread. Motivating!
Boring question for everyone, considering all the stories and accomplishments of late by runners here.
What about a four month block of only HIT for my hard days (30 sec to 1 min ints)? Almost exclusively on steep inclines. I never get injured going up. Rest of training will be around 9 hours/week of very slow jogs through the countryside.
My focus the past few years has been HM and marathon . I'm burned out of TH, tempos, and MP runs here with the dogs ( bitten twice ) and the unforgiving terrain. The area is great for casual runs and I enjoy easy days. In the past, pace motivates me during hard sessions but when I'm going hard through constant big rollers and seeing TH pace +30 seconds on the watch, it demoralizing. No races here probably until next year because Covid has finally come to SE Asia and good time to experiment.
My twig legs might benefit from short HIT training. Could start to look like a runner which would be cool. I'm always looking around me at races thinking, wow these guys sure look fast and intimidating compared to my skinny legs and bulky upper. Doubt 4 months would change my body composition much but maybe a little.