how many hard days a week?

I mean this would definitely break me (and probably most people) but it is hard to answer this without an understanding of your background.

If you're a real man, 7.

2 structured workouts and a long run. Easy days in between.

There’s a reason why 2 workouts + long run has worked best for most people for decades. Can some people handle 3 workouts a week? sure but they are rarely 15/5k types. almost always pure mid-d runners on lower mileage. there are many pro groups that use a 9 day training week:

EZ/EZ/Hard/EZ/EZ/Hard/EZ/EZ/Long

On the 7 day cycle, if you feel like you can get more out of yourself — an easy thing to do is add quality to the long run once or twice a month. Make it a long progression run where the last 20-40 mins are tempo pace.

3 with no long run or 2 with a long run

I personally don’t do long runs and I’ve gotten some pretty good results, but if you need a long run then I’d only do 2 workouts. 3 + a 90 Min LR is too much

What did your phase of training look like before this? And get rid of the fartlek. Just do the threshold and vo2 max and long run. I would guess the fartlek as well would be at 5k pace or faster so your hitting the same type of workout twice a week.

With the usual caveats regarding background, injury history, lifetime mileage and recent mileage, I'd say:

For someone who has worked up to it properly, and adjusts training mileage accordingly, I think this can work for a shorter period. Say one or two mesocycles or 8-12 weeks.

Beyond that, to accomodate three workout days I would keep the long run easy. And, better yet, make one of the workouts a hill session to reduce the mechanical load.

It's been a Hard Day's Night...

John, Paul, George and Ringo wrote:

It's been a Hard Day's Night...

And for the number, it's Eight Days a Week...

You only need 2 quality workouts per week to reach your optimum performance.

I would have done workouts on Tuesday, Thursday, Saturday.

If you want to keep the fartlek, I would consider doing it on saturday and adjust as you say. I would do a fartlek with some shorter repeats, hilly, etc to get something different there.

The long run, you can also adapt to how you feel. I do my "long" run (shorter than yours, but 75min) with a fast finish, but depending on how I feel. If I feel great, I do at least 15min progression M to T. If I feel heavy I can do just 5 min

So Tuesday Thresholds, being not to hard after the weekend

Thursday, I would ease down on the VO2 max, maybe biweekly VO2 max and biweekly some CV/10k. I personally am afraid of doing too much VO2 max. When closing in on races it is great to peak

Saturday fartlek