Real quick thanks you to guys and your crusade against >40" waist. Seriously, it’s what finally convinced me I was actually fat and unhealthy and not just a muscle bound freak.
I went from 0 cardio and 41" waist to able to run a 5k with a 37" waist (still cutting) while losing almost no strength as a 231 male (now 211) with a national qualifying total. If vagal tone is even a thing, I’m pretty sure I’ve improved mine as evidenced by my heart rate varying from 54bpm to 64bpm between inspiration and expiration as measured by the pulse ox on a vitals monitor.
My only vice is that I smoke a pipe (tobacco) once or twice a month. Since increasing my conditioning I have drastically increased my sensitivity to smoking such that I get dizzy and nauseated after less than half a bowl.
My question: Has increasing my vagal tone (again, a thing?) caused my new sensitivity to nicotine?
The vagus nerve is part of the autonomic nervous system that exerts parasympathetic control over various organs (including the heart). Your heart rate changes may be partially mediated through parasympathetic effects, as well as certain heart-specific adaptations to endurance training.
The parasympathetic nervous system uses Acetylcholine as its neurotransmitter, which acts upon acetylcholine (or “cholinergic”) receptors. There are two types of cholinergic receptors, muscarinic and nicotinic, the latter of which are named because they also respond to nicotine (particularly in the brain). Nicotine also has several actions on the sympathetic nervous system, and the combination of all these actions results in the stimulant effect observed by nicotine users.
With all that said, my understanding is that nicotine (particularly via smoking/inhalation) hits the bloodstream relatively quickly and has rapid action in the brain. I am not aware of evidence on sensitivity related to bodyweight or bodyfat, though it is plausible that your weight loss somehow altered the pharmacokinetics/pharmacodynamics at play here. However, nicotine does not seem to be distributed into bodyfat to a significant degree ( Nicotine Chemistry, Metabolism, Kinetics and Biomarkers - PMC ), so … I dunno?
PS - Congratulations on your weight loss and improvements in health markers! And yes … you should quit smoking
Thanks for the detailed summary and doctorly advice, Austin.
I guess I was thinking the effects of repeated conditioning stresses might make the parasympathetic system respond more robustly to stimuli, which is causing the (assumed) increase in heart rate variability as well as the increased sensitivity to dizziness and nausea from nicotine (but not the stimulating effects).
This is probably total nonsense, but since adding conditioning, I have found myself calmer and much slower to anger/anxiety/fight/flight. I couldn’t help but wonder if it had anything to do with switching from psych-up style always @10 lifting (sympathetic stimulating) to conditioning and “easier” lifting (parasympathetic stimulating?). Lol it’s probably just decreased NEAT from cutting calories and increasing activity.
Yeah, I don’t know … that’s kind of the opposite of what tends to happen in response to most repeated stimuli over time (outside of, say, pathologic pain states).
Whatever the mechanism, that sounds like a good thing!
