But less hard…
There isn’t one…
Although we exist in rhythms, your body isn’t too bothered about the 24 hour cycle (although your brain might be), the stress would be lower if sleeping between hard sessions…and thus potentially the quality better…
Looking at your current plan, you are some way off too many back to back hard sessions….
Seems to me you are always focused on over optimisation and constantly tweaking when just getting the basics right of regular volume, diet and sleep etc week in week out will see plenty of gains.
seems excessive.
I will take Mr normal, real world example of someone I coach now, probably about your standard, has 3 kids, one is 18mths old and businessman who travels a lot. he does 1 session a day, which is 2 swims, one technique and sprints one more aerobic based, also technical in focus. he does then 5 days split 3 run/2 bikes or occasionally vice versa in a bike block. we work every day knowing life will get in the way at some point anyway. no point scheduling a day off and he misses another. If he misses a day I reshuffle, so we get 2/2/2 most weeks.
of the runs 1 is always 45minutes but with some pickups, not speed work but I get him doing 30seconds harder focusing on an area of his form, them he will do one of intervals, usually target 10k pace ish. bike is one hard, and i change that from 1 min on/off best pace, 4min on/off best pace , over unders, russian ladders . Science behind it is just enough stimulus to steadily improve, and he really needs to do a hard bike/run each week to clear his head. nothing more 
I think 2 hard sessions total each week , 1 bike, 1 run + swims for me which should have a mix of intensities most sessions anyway, I prefer the take home sprints option every session.
I like to check my assumptions periodically, particularly when something new is presented to me.
I’d agree on getting the basics right, for me that is consistency and progressive overload, and the structure of training affects that. So, yes I guess I am digging into the nuances of stimulation and recovery.
@leahnp I don’t use TSS any more really, still tracked for bike. Vo2 and threshold are in the hard category for sure in any discipline. Lifting is a bit of a quandary, but if it’s a struggle then it’s hard .
Makes sense, particularly if you’re only doing six sessions a week.
6 sessions consistently is better than doing 9-12 and not completing them because its too hard and too frequent…and his times are pretty decent, 2:22ish oly last year, and not a “natural athlete” its just training 6 - 8 hours a week every week.
I’ve been using this approach as it helps me focus if I’m honest.
My hard sessions are all done in a 36 hour period.
Hard swim Monday AM - currently doing some VO2 max work 6 x 100m best efforts x 2
Monday PM is a long turbo - 90-120 mins in Z2
Tuesday AM is threshold run intervals
Tuesday PM is threshold or VO2 max turbo intervals.
Am finding the last rep or two is hard but doable
You have lost me.
Thats double hard, back to back days???
Maybe I need sleep.
I’ve moved on to quadruple days.
Day 1 short easy bike, short easy run
Day 2 Hard swim, hard bike, heavy lifting, hard run
Repeat, Repeat
Day 7 Recovery swim
Sounds good.
Treble whetherspoon days, might be a nice progression?
Had a nice beef casserole with half a can of Guinness in it.
I’ll drink the other half and might double up with a second can.
Thats a hard double day.
The other two are for the Rugby Saturday 
What for?
To ensure that the easy days really are easy, maximise gainz.
That’s achieved by self control, not beasting yourself the rest of the week.
when is it you think that you get fitter?
Is the answer ‘when you recover/sleep’ ? 
Ding ding
Certainly when you are inactive…
Geez, I must be the fittest bastard in the country right now then! 
With one important caveat my good man…
DOH !