There are quite secretive, but they've been around for long enough and are all on enough podcasts giving little snippets here and there over the years plus that one time Karissa Schweizer was uploading stuff to Strava when she first joined the group. From that and their social media you can get a pretty good picture of their training. Not interested in speculating about their being clean or not. There have been some fantastic threads on the training of Marius Bakken/the Ingebritsen's recently; it would be great if we could have a serious conversation about training methods without screaming at each other about doping - there's 1000 other threads already dedicated to that without this turning into the same two posters arguing about the CAS trial.
Marc Scott on the Sweat Elite podcast gave a very thorough run down on their fall training. The general philosophy - which you can hear GDS quoting Schumacher in one of her post race interviews (with Citius or LR?), is that "strength is speed." So long as you have a minimum speed foundation and turnover, then what matters is having the aerobic capacity that your kick isn't compromised by most race paces. So lots of tempo work, lots of mileage, and leave the specific sharpening until later. Fall training then, put together from various media.
They alternate between two different weekly structures. Different athletes say they double, 2-4 times a week for 20-40min. So throw those in there.
Week A
Monday
60-70min Easy
Tuesday
Long 40min easy warm up. Hill repeats - they don't look like they're straining too hard on instagram when doing these. It's a hill near Duniway Park in Portland that's maybe 200m long, 5-10% grade max. Then down from the hill to the track where they do not too hard track work with lots of jog recovery.
Wednesday
60-70min Easy
Thursday
Tempo - they like to go to a turf field near Portland airport - Delta Park. They do 10 miles of tempo in various combinations ranging from marathon pace to 10k pace.
Friday
60-70min easy
Saturday
60-70min easy
Sunday
"Structured long run" as they call it - 2hr long run, with the pace winding up every 30minutes, finishing a touch slower than marathon pace. They do this at a popular running/cycling spot in Portland which is a 3.5mile undulating loop with about 170m of climb per loop. The women can do 18-19 miles, 5+ loops, so nearly 1000m of climb. So though the paces are slower, with the length and the elevation change it is almost like a 2nd tempo.
Week B
Monday60-70min Easy
TuesdayHills and light track workout from Week A
Wednesday60-70min Easy
Thursday60-70min Easy
FridayThey go up to Sauvie Island (where Shalane Flanagan ran the "Tokyo" marathon since Tokyo got cancelled in her marathon spree in the fall) and do a road tempo. It's a pretty flat 12 mile loop. Looks like they just run straight 10 miles nonstop.
Saturday60-70min Easy
Sunday2hr long run. Not structured, at athlete's own pace.
Scott also said that the majority of the mens team don't use GPS watches except for long runs, they just run for time and put that time in "Jerry/Badger Miles" - 7min of running = 1 mile for men, 8min of running = 1 mile for women regardless of what pace is actually being run. This rule is there to disincentivize people smashing easy runs as they're meant to be for recovery. Workout distances count 1 to 1 their actual distance.
What makes this work? Minimizing the amount of track pounding while prioritizing recovery to maximize the amount of time that can be spent at or around threshold pace in any given week. It's more Lydiard influenced, but if you read some of the great threads recently on the Ingebritsen training, the idea of minimal interval work + max recovery + max threshold is what they do but in a much more deliberate and scientific way.
A massive variable that is often overlooked - the quality and the quantity of athletes in the group. Most pro groups are quite small with one "alpha" who is head and shoulders above the rest. E.g. team Boss with Emma Coburn, NB Boston with Elle Purrier, Josh Kerr at Brooks. So if the alpha is injured, sick, or just having an off day, the group loses a lot. BTC men's is spoilt for athletes who can push workouts and drive each other on. BTC women had enough depth that they could lose Shelby Houlihan, Kate Grace, and Colleen Quigley in a few months - most groups would find losing those 3 an irreparable loss. Yet BTC is left with Cranny (4:02/14:33/30:47 + US trials champ), Schweizer (4:00/8:25/14:26), GDS (1:58/3:56/14:31 - underrated range), Frerichs (world and Olympic silver medalist). The "least hyped" member of the team - Andrea Seccafien, is still a world and Olympic finalist who, leading from 2km out, absolutely demolished the likes of Hall, Kurgat, Dom Scott, Kurgat in a 10,000 last year before she joined the group.
If you've done track semi-seriously, you know how having a great training partner to drag you around is huge. Think about how much of a luxury it is having so many athletes who can carry a workout.
Hope people find this helpful.