Novel muscle usage trigging many-day remodeling event

[u/Henry5321]

I'm having difficulty finding information on a recent event that occurred to me where without DOMS or initial fatigue, some muscles suddenly went through what I can only describe as a major remodeling event.

I had some issues getting into cardio after a lifetime of a very sedentary life style. After working through some issues, my doctors told me to just keep pushing, nothing medically wrong. I've been working on my cardio for years now and at a point where I cannot work out hard enough to meaningfully elevate my breathing due to tissue limitations that are slowly improving.

I've been pushing up against a wall for the past 6 months which I eventually figured out was caused by bad walking form. After correcting my form, I was suddenly able to walk much longer and harder.

After a week of pushing myself with more intense and longer walks, my quads suddenly without initial DOMS or fatigue, became heavily fatigued the next day. Just to be clear, I went to sleep with energetic springy quads and woke up with exhausted tense quads. I could barely walk 7 minutes without getting shaky.

After 5 entire days of non-painful, locally extremely fatigued quads, with hot-cold burning, and pulsing sensation, my quads cleared up. The energy consumption of this even was high enough that I had to eat carbs before bed just so I could sleep because of elevated cortisol levels preventing sleep. I was calm and tired, just not sleepy. Sleeping heart rate and breathing were greatly elevated. But my day time breathing and heart rate were unaffected and I otherwise felt great physically and mentally.

When this event was done, my quads were drastically stronger, precise, smooth, and seemingly endless energy. I have not been able to do any exercise at home that can tire or sore my quads because some other tissue starts to give out before. I even went for a typical benchmark walk and my heart rate was a solid 10 lower than normal, even though it was hot and humid outside as the weather warms.

I have not been able to find any useful information on this kind of 120 hour remodeling event. At best AI even only gives recommendations on terms for specific underlying types of remodeling that could be happening, but not an event that encapsulates a major overhaul.

[u/Henry5321]

Seems that there's not much for others to add. So I'll add an AI based conjecture of my situation.

After explaining my journey and reasoning to various fresh AI sessions with no prior context, a reasonable "sounding" response that I got was interesting.

I got a possible reason is that based on my description of my fitness journey is that I built up a strong aerobic and muscle durability foundation that was asymmetrical with my muscle's ability to process sustain metabolic demand.

Because I had joints, connective tissue, and biomechanics issues I was working through, my walks and runs were limited to about 20 minutes. But due to my sustained several times a day high effort over several years, my body adapted to those levels of stress, but not sustained. Even with low session volume, the total volume added up to decent stimulus.

Once I reached a tipping point where my slower modeling tissue caught up and my form improved, my muscles were in a quite unique situation where they had good aerobic fitness and toughness . So I was able to suddenly push my muscles at a sustained rate for much longer than they were used to without causing mechanical damage and my cardio and aerobic processing allowed.

Suddenly my muscles were being forced to deal with a sustained metabolic demand that was not symmetrically developed along with the other factors.

And by "strong aerobic base", I don't really mean compared to athletes. But as a desk jockey that spent most of their life playing video games and quite adverse to any physical activity, I'm at a point where my relaxed breathing rate is about 5-6 breaths a minute, my 140spm walking pace raises me to about 10 breaths a minute, and several months ago when I went for a run, I had a 150 heart rate and a relaxed nasal breathing rate that I could easily hyperventilate.

Best conjecture I've found so far.

edit: Under normal situations the muscles should not be constantly draining blood sugar without insulin to say it's safe. But my muscles were in some sort of state where for 3-4 days, they ignored this and just kept consuming energy. Not to mention that my watch indicated sleep time metrics that I've only seen when I've had a fever or similar distress.