Chris Kresser: I don’t think they’re necessarily the same thing, although I agree with you that they’re both probably signs of HPA axis dysregulation.
The first one, energy crashes or symptom exacerbation on weekends or during holidays, what those share in common, of course, is that the patient is not required to participate in their normal daily routine. They’re periods of rest or leisure. I think what can happen when we’re in a kind of hyperactive stress response is that we, in the course of our normal days and when we’re at work or we’re stressed, we’re getting ready to go to work and we’re dealing with all of the things that we have to deal with on a day-to-day basis, many of us are probably caffeinated in an attempt to cope with that, and all those things activate the fight-or-flight response, and that leads, as you know, to the production of stress hormones like cortisol and even adrenaline. That can sort of help us to manage and get through the day, but that has a cumulative effect over time, and where that can really show up is on days that we don’t have to step up to that level and where the fight-or-flight response isn’t activated and we don’t have the additional hormonal support of cortisol and adrenaline and noradrenaline and we’re just operating more in a kind of parasympathetic state. That’s where the body can just really kind of put the brakes on and really slow down and rest because it senses that it has the opportunity to do that, and those other hormones that would get in the way of that kind of response are not present.
If you think about it just from a kind of evolutionary or survival perspective, if you’re under threat, like if … I don’t know. If we use an example where, let’s say, you’re running away from a threat, maybe it’s a predator or it’s a rival tribesperson or something like that, your body is going to marshall all the resources it possibly can to help you survive that immediate threat, but as soon as that threat has passed, you could collapse in exhaustion, and that’s, I think, a similar kind of principle here with your number one.
Number two, I think, is a slightly different issue. There are cycles of sleep and wake. This is part of the normal circadian rhythm. We go through these different stages of sleep. The various stages have recently been revised, but there’s still recognition that there are different stages of sleep, some lighter and some deeper. And so if someone is awakened by an alarm clock or something else when they’re in a stage of deeper sleep, then it may be more difficult to wake quickly than if they’re in a stage of lighter sleep. There is some physiological explanation for why that happens. As to why that might be worsened in the case of HPA axis dysregulation, I’m not certain, but definitely if someone is tired and stressed and needs more sleep, it’s possible or plausible that when that sleep is interrupted they feel worse than someone would if they’re overall well rested.