Dr. Peter Attia

I think I lifted far too heavy, far too often, and probably without enough coaching on technique. And so, you know, by the time I was 27, I had a devastating back injury. But it's one of those things that happened without any incident, right? Which is often the case, by the way, for a back injury. When you really blow out a disc in your back, it's not necessarily something you did in that moment.

I think I lifted far too heavy, far too often, and probably without enough coaching on technique. And so, you know, by the time I was 27, I had a devastating back injury. But it's one of those things that happened without any incident, right? Which is often the case, by the way, for a back injury. When you really blow out a disc in your back, it's not necessarily something you did in that moment.

It's usually something that's been built up from the past. So this injury I had at the age of 27 really was the result of years of... unnecessarily heavy axial loading, loading done with probably insufficient technique, you know, or technique that was at times sloppy and under fatigue, because I used to do a lot under fatigue, you know, I sort of believed in training under a lot of fatigue.

It's usually something that's been built up from the past. So this injury I had at the age of 27 really was the result of years of... unnecessarily heavy axial loading, loading done with probably insufficient technique, you know, or technique that was at times sloppy and under fatigue, because I used to do a lot under fatigue, you know, I sort of believed in training under a lot of fatigue.

And I think that that's a mistake. I think that training under very heavy load should not be done under great fatigue. Interesting. We'll talk about that as well.

And I think that that's a mistake. I think that training under very heavy load should not be done under great fatigue. Interesting. We'll talk about that as well.

And does it matter? Well, I think the second question is easier to answer than the first. I do think it matters. The why is probably multifactorial, and the why is just as important as the fact that it is. In other words, the fact that it's declining is both relevant for the fact that a very, very important hormone that has –

And does it matter? Well, I think the second question is easier to answer than the first. I do think it matters. The why is probably multifactorial, and the why is just as important as the fact that it is. In other words, the fact that it's declining is both relevant for the fact that a very, very important hormone that has –

incredible benefit to men and women by the way is going down and we have to come up with an answer to that right like so how do we address that do we address it medically where we replace that hormone exogenously meaning we give you that hormone directly or do we try to fix the underlying problem so if you want to do the latter you have to know what the underlying problem is now at the population level the best answer as to why testosterone levels are declining

incredible benefit to men and women by the way is going down and we have to come up with an answer to that right like so how do we address that do we address it medically where we replace that hormone exogenously meaning we give you that hormone directly or do we try to fix the underlying problem so if you want to do the latter you have to know what the underlying problem is now at the population level the best answer as to why testosterone levels are declining

And unmistakably, they are. So the data here are unambiguous. There's no debate on this fact. The debate is around the why. I believe that the best answer probably has to do with two things. One is increase in body weight and body fat specifically in men. and some combination of reduced quality of sleep and sort of disruption to sleep. So why are those two things relevant?

And unmistakably, they are. So the data here are unambiguous. There's no debate on this fact. The debate is around the why. I believe that the best answer probably has to do with two things. One is increase in body weight and body fat specifically in men. and some combination of reduced quality of sleep and sort of disruption to sleep. So why are those two things relevant?

So when you increase body fat, two things are happening. One is you're increasing inflammation and you are reducing the amount of testosterone that gets to stay in the form of testosterone because part of the testosterone gets converted into estrogen. So with body fat comes more of this process called aromatization or converting testosterone into estrogen.

So when you increase body fat, two things are happening. One is you're increasing inflammation and you are reducing the amount of testosterone that gets to stay in the form of testosterone because part of the testosterone gets converted into estrogen. So with body fat comes more of this process called aromatization or converting testosterone into estrogen.

So if you think about what those two things are doing, if you have more inflammation, that reduces your ability to make testosterone, and you have more capacity to turn the less testosterone you make into estrogen, the net result of that is both of those things are reducing your total pool of testosterone.

So if you think about what those two things are doing, if you have more inflammation, that reduces your ability to make testosterone, and you have more capacity to turn the less testosterone you make into estrogen, the net result of that is both of those things are reducing your total pool of testosterone.

If you couple that with lower quality sleep, and I'm not talking about over the last three years. I'm comparing like now to say 40 years ago. And what are all the reasons that people might have poorer quality of sleep now? I think there were many, but obviously phones and social media and just the stimulation of the world we live in probably plays a greater role in that.

If you couple that with lower quality sleep, and I'm not talking about over the last three years. I'm comparing like now to say 40 years ago. And what are all the reasons that people might have poorer quality of sleep now? I think there were many, but obviously phones and social media and just the stimulation of the world we live in probably plays a greater role in that.

Sleep is when we make these hormones, right? So we make follicle-stimulating hormone and luteinizing hormone at their maximum amount during sleep, and those are the hormones that are driving the production of testosterone.

Sleep is when we make these hormones, right? So we make follicle-stimulating hormone and luteinizing hormone at their maximum amount during sleep, and those are the hormones that are driving the production of testosterone.