Your post of article is insightful and I will do some online research to understand more of cortisol with sports. As for uphill running, I will need to plan, but unlikely so, because it may stress the knees too much.
If you are talking about the usual petallar tendon pain (front knee tendon just beneathe the knee cap bump) coz it is "something new that you are doing", can proactively pre-habilitate first by strengthening for 4-8 weeks the usual strengthening exercises for calves, shin, quads, hamstrings and glutes. Basically just strengthen everything lah....no harm one. All the exercises on youtube.
But one specific point that i'd like to emphasise more (and personally gone through a few niggles before) for faster speeds / sprinting / 200-400m stuff / etc is to train your TFL....as many runners or even cyclists neglect or arent even aware of such a muscle.
Can even start on basic forms of plyo and as usual slowly progress up, as it is explosive in nature hence relatively more beneficial esp for the shorter/faster intervals, particularly sprinting. Just see how sprinters train and the drills can liao, pretty explosive stuff even though it seems normal to them (their normal is maciam like our super-explosive movements liao)
Actually i can give a "middle milestone" update on my Sava R7 bike riding w/o bike fit. So now it's been like 3 weeks and tried most things that i'd be doing on it. Last night tried some pretty hard microintervals, till now i am feeling fine although muscularly late last night before i slept i quite felt the muscular fatique. This morning and now pretty ok but tonight i'll play it save and let the rest do the work for me, total rest night.
Till now, no joint pain muscular pain of any sorts that is related to the new bike.
I have a very high suspicion/belief that the strength training that i have been doing since i started running 2 years ago helps hecklots. The new aero position vs triceps strain even for > 30 mins (I already started training on foldie then etc, backpain neckpain all no issue.
Only did the simple fore/aft saddle positioning + saddle height with the only basic lemond method, i have yet to do the video analysis knee angle measurement with a graphical protactor and confirm via too low a seat height and slowly raising it 3-5mm increments until pedal stroke feels choppy ie it is slightly too high.
Also changed the stock PU saddle to a GUB 3D printed one (shd be passable, dont think i need a $675 Specialized Power Mirror), solved the issue of backside pain and a bit of numbness for > 1hr rides (i dont go for > 3hr rides and the longish weekend ones averaging 4 to sometimes 5-6hrs include lots of breaks). So i think more or less i have dialed stuff in to the point that it fits my current needs and that my current level of strengthen is able to tahan.
The only race that i forsee doing is T100 standard duathlon, which is "only" 32km (just under +300m elevation gain)....though such a format is that it's all guns go LT1 to LT2 range you are already warmed up just gun first talk later, nothing else.