I would like to chime in on this great thread both as encouragement to you guys to continue and to add another data point.
I used this "Time crunched, low mileage, Norwegian-Inspired" method in 2021-22 to run a 4:40.4 mile (track) and 17min 5k (road) at age 40 after taking 20 years off from competitive racing and dedicated running.
Those were the only two races I ran--the 5k in November 2021 and the track mile April 2022. After becoming fascinated reading about the Ingebrigsten and Bakken method, and how radically it differed from my HS and college "All-out, all the time" training, I decided to try it out myself and target a mile race at age 40 as a personal experiment/ curiosity project.
Background fitness: last college track season 2003. Racing weight 160 lbs. College coach system:
Vo2 max intervals on Tuesday (Huffing and puffing after each rep, long rests, basically as fast as you can complete each rep) example: 5x mile.
Shorter, faster reps on Thursday with long rests. Again, each rep as fast as possible. Example 10x 300m.
"Tempo" run on Saturday. 4 miles. AKA a 4 mile race for all but the top guys.
"Easy" runs Mon, Wed, Fri. 8-9 miles, getting to 6:00 pace and staying there.
Long run Sunday, 15 miles, 6:00 pace.
Minimal exercise 2004 to 2015--work, wife, kids, etc. = 200 lbs dad bod. Recreational cycling 2015-2020 (three to five times per week with fellow middle aged dads). Not competitive cycling like Sirpoc, but spirited MAMIL riding. No power meter, intervals, etc. Annual cycling mileage during these years: 2400, 4800, 2900, 3600, 1800, 4100. This got me down to 185-190 lbs and much better cardio fitness than the previous decade. During these years I would run 0-2 times per month, usually three miles progressing from 8:00 at the start to 6:00 by the end.
Decided to start the running project in earnest November 2020. Treadmill 3-4 nights per week. 4 miles at 8:00 pace. December 2020 increased to 5 times per week. Kept the same 20 mpw at 8:00 pace on the treadmill through March 2021. Bought a GPS watch with wrist HR March 2021 with the idea the point of this device is to LIMIT my pace and HR. Total mindset switch from my youth. By watching food intake, got under 180 lbs.
First outdoor run with watch late March 25, 2021: 4 miles, avg 7:47, HR under 150 bpm always. April was spent gradually increasing average run to 6 miles. The word "threshold" shows up in log for the first time April 27, 2021--4 x 2:00 with 1 minute rest at what I felt was "comfortably hard", around 6:00 pace. At this time I decided I had better define my paces better, so I ran an all out 1 mile time trial on May 3 in flats on a hardpacked dirt road--5:15. I then used the online Tinman calculator and plugged in 5:10 mile as the reference, figuring a race on a track in spikes was worth 5 seconds. Spent May to October 2021 trying to build gradually and avoid injury, eventually finding the regimen that fit my work/kids schedule:
Mon: Threshold
Tuesday: easy
Wednesday: OFF
Thursday: Threshold
Friday: easy
Saturday: easy
Sunday: "long" aka usually 10 miles; minimum 8, max 12miles.
My threshold sessions were most often intervals of 3:00 (min 4 reps, max 8), 4 x5:00, or 2-3x 10:00. The rest was ALWAYS 59 seconds--to make sure I kept the intensity low enough that instead of panting and wishing for more recovery as in my youth, I was raring to go by 60 seconds.
My easy runs were NEVER allowed to go faster than 7:00, usually above 8:00. I often did 10 x 6-8s hill sprints/bounds after these easy runs.
Long run usually averaged 7:00 pace.
The most important points about this training was how EASY it was, and the complete lack of DREAD. Unlike my youth, no need to get psyched up for the workouts, and no no need to dread the gut-busting next interval because there is no gut busting with this system.
Time for bed now, but if you guys are interested, I will post my exact log with workouts and weekly mileage.