Hi there,


Great job detailing your history. Based on my (similar) experience, it seems like you've reached a stage in life (age) where your body has undergone a shift in its ability to use stored fat as a fuel source. This is reflected in your weight gain and the noticeable decrease in performance during prolonged exercise over the past year. I've included some theories and potential solutions that might pique your interest in this paper I wrote with Phil Maffetone.


Best,
Paul

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https://athletica.ai/
https://hiitscience.com/

Note: I am NOT a doctor. Just a 55 year old athlete.

I think you are right to be concerned. 15 lbs of weight gain for a 29 yo male training and performing at a high level should be pretty hard to do. Could be normal depending on diet, but.... Certainly worth looking into when coupled with your performance changes...

Your thyroid is on the low end of normal...which does have some effect on metabolism and consequently weight gain.

What type of doctor is your primary care physician? I'd be looking for a good internal medicine doc preferably one with a sports background (not just a gp) to manage to case, and possibly seeking a referral to an endocrinologist.

I would probably limit intensive activity until you have a better read on what is (or is not) going on. Stay healthy, but limit stressors.

Good Luck.

This is easy. You ate more calories than you burned. Specifically from Dec to June to the tune of 50,000 excess calories. It makes sense that you wouldn't notice a change in activity levels or food intake levels as it's about 300kcal/d extra. This is as easy as eating or twice a week instead of once a week. The modern world makes it easy to over eat and under exercise. It's easy to see day to day changes but difficult to see long term changes. That pasta you make for dinner gets a little bit bigger, has a little bit more butter, a little more creamer in the coffee. Imperceptible differences day to day that amount to big differences over time.

Buck up and start counting calories. Weigh out food if you need to. Establish a baseline over a few weeks of what intake you need to maintain weight, then reduce that to a sustainable rate to lose weight if that's what you need. Your performance will likely drop off as calories are restricted, but once you refeed the performance will return and likely to a higher level (in running) as the weight is lower. Don't drop calories so low that you can't still train effectively.

Tl;dr-CICO

inb4 eating disorders---gaining 15lbs in 6 months is symptomatic of an eating disorder.

how tall are you? as mathamatics stated above, could be easy excess calories along with water retention of high sodium intake

Increased stress at home or work? Increased alcohol intake? Any major changes in diet? I’d definitely start counting calories. Also, did you get too lean and crash your testosterone levels?

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Let food be thy medicine...

Yeah I was wondering about T as well. A blood test for T might show something.

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https://www.strava.com/...tes/zachary_mckinney

From my personal experience, this sounds familiar, and pretty normal. Welcome to the fight. In my early 30’s I grew out of my skinny kid body, and could no longer eat and drink anything I wanted. I was racing at 138-140 pounds, and it seemed like over night, I was 145, and was struggling to stay under 150. If I did a lot of swimming or lifting, I ballooned up to 155-160. If I didn’t watch my diet, there were times I would hit 165. And weight really kills running time. One pound of weight gain equals about two minutes in marathon time. Once I hit 150, I never saw another sub 3:00 marathon. I’m over 60 now, and still fighting tooth and nail to stay under 160, and run well. If it was easy to stay thin and fit, the age groups wouldn’t thin out so much as we grow older. The fight is real.

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Athlinks / Strava

Thanks for sharing the article. I was curious to understand the shift that you mentioned, could you share more about the change to use stored fat as a fuel source and what that would mean?

Primary care doc is actually still in school so kept needing to consult with the attending doctor. Even though I live in a big US city, I've had trouble finding a primary care doctor who specializes in athletes. My searches seem to come up with orthopedic doctors for athletes or something similar.

It's a fair callout and I'm certainly open to counting calories to get a better understanding of my intake. The surprising thing was a quick shift in my body composition. To me these shifts in weight would suggest something bigger than diet alone for someone who has consistently been in a weight range on a fairly consistent diet. But it's worth understanding everything involved so will begin tracking and potentially consult nutritionist also.

I'm 5'9".

Stress levels relatively unchanged. Alcohol intake has actually decreased (0-1 drinks/week). Summer 2022 I was down to 130lb, then gradually rose to 135lb by Dec 2022. I did have testosterone tested a long time ago in 2017, I was at a normal level then, but haven't tested since.

If I were you I would seek out functional medicine and read about hpa axis dysfunction and adrenal fatigue. I think it is way more common in endurance athletes than anyone knows and conventional medicine will really not be too helpful as they will treat low thyroid or low T.

I would also consider taking some time off from training. Really turn off the Garmin and do nothing while you heal.

Sure. You lead off describing how you experienced a shift in both your ability to perform in your sport concomitant with fat gain. We have a central regulator in us called the HPA axis that regulates our stress (see figure). Stress comes in many forms (exercise, nutrition, life, etc). But ultimately in the year you describe, your ability to tolerate your stress was shifted (you reached your limit). Your fight or flight system (sympathetic) remained cranked up, and you couldn't go into the rest and digest phase any longer (parasympathetic). That resulted in an inability to recover, and over time, an inability to access to your stored fat as fuel to perform, seen as a metabolic substrate imbalance (bottom of figure). Insulin (but also cortisol and adrenaline) is the primary hormone involved.

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https://athletica.ai/
https://hiitscience.com/

Glad to know you'll at least try it. Body composition will change negatively when you gain weight unless you put in some effort to build muscle specifically. Gaining 10lb of fat and 5lb of muscle will still make your % body fat increase.

It's shockingly easy to think that you're eating consistently the same thing but drift over time. Pepperoni on a pizza easily adds 100cal to a plate of 2-3 slices. Spreading peanut butter a little bit thicker than yesterday. Using a smidge more olive oil on cooked veggies. Stuff that's too small to notice day to day, so it feels like you're doing the same thing you've always done. One noodle of spaghetti is like 5 calories. You'd never notice one extra noodle on your spaghetti. But one extra noodle at every weekly spaghetti meal has you eating 250 extra calories by the end of the year. You've got 21 meals every week where this drift can happen.

At the end of the day there's only one reason anybody gains weight-because of a calorie surplus. The reasons why calorie burn and/or hunger change are numerous, but the fundamental cause doesn't change.

I can relate to this. From about 28-32 yrs old I was hitting it pretty hard and posting times just about the same as the original poster. Then I went through two years of nonstop injuries and just feeling off. Stress fractures, plantar fasciitis, hernia repairs, outpatient surgery for a hydrocele, some other weird ankle injury that landed me in a walking boot for a bit. Each time I would ramp back up after an injury, still get a decent result, and then hit another injury. It was a really good chriopractor who identified adrenal fatigue for me and put me on the right track. Kind of like no sh*t looking back that my body--esp my adrenal glands--could not handle the stress. At 32 I had an 18-month son and newborn twins who slept horribly. In a span of 3 months, I had the twins, started a new job, moved between Europe and US, and bought a house. The chripractor helped identify some vitamin deficiencies to address with supplements, did some weird (and painful) poking at my glands and stretches, made me be extra diligent about my diet (which was not horrible to begin with), and said I couldn't do anything that would get my HR above 120 bpm or something like that. If I was told to stop exercising completely I might have not stuck with the bigger treatment plan or lost my sanity. Anyways, after about 2 months I felt a lot better, essentially back to normal. Then just had to modify how I trained, including be more conscious of life stress and knowing when to tone training down. Had some of my best results at 41.

Now I've done it again though... Felt awesome last year and pushed it too hard. Have spent the past year up and down. Not with injuries, but just feeling like crap in workouts and unable to recover for a bit, then thinking like I've turned the corner, then having a solid workout or decent race, and then back to crappiness. I am just now accepting it might be adrenal fatigue and getting serious about treating it. This may all sound like no sh*t to some, but I am sure there are others here who can appreciate how hard it actually is to accept the situation and "turn off the Garmin". Training is sanity for many of us.

My symptoms before and now may be different than the original poster's. But I am sure adrenal fatigue manifests itself in many different ways. Just sharing my own experience in case anything resonates.

I can't speak to everything but it sounds familiar, albeit with a smaller weight gain for me.

I gained weight really suddenly after years of having the opposite problem — that is, not maintaining enough weight. I can tell you the month it happened too.

In my case I strongly suspect it's gut microbiome related.

I've had lots of tests (without being a hypochondriac) and none of them have pointed to anything really definitive.

I've been at a loss except for trying to be extra vigilant about my diet.

Given that some of the symptoms that the OP described may very well be signs of endocrine changes that would affect basal metabolism, it seems rather myopic to immediately focus solely on the kcal-in aspect without considering one of the two sources of kcal-out. In both of your posts so far, it's rather glaring that you've mentioned only ingestion and expenditure without touching on basal metabolism.

Because when it comes down to it, deficit/surplus = kcal ingested - (kcal burned + basal metabolism). The difference between kcal ingested and kcal burned can very well be constant, but there can still be a deficit (or surplus) when basal metabolism changes.

Proximal, not fundamental.

The more important question to answer is what is the underlying cause of the either metabolic or satiac change. With the other changes and marginal blood work, there is the possibility of the onset of several different metabolic or hormonal syndromes. These should be ruled out before assuming that it's simple a cico issue.

Literally ANYONE is a better choice than a med student / intern. I don't care if they are backed by an attending. Let someone else be their Guinea pig.

I don't know your insurance status, your financial status, or where you live. Every "big city" has internal medicine doctors. So, if you have the means to select and afford a decent doctor... Then find an Internal Medicine doctor with 20-30 years of experience (ie, age 50-55). Don't worry so much about the sports part, it isn't as critical as people like to think. Just find an internist. Look your options up on health grades, read some reviews and pick one. Go see them, tell them what's going on, and see what they say. Every decent internist should be aware of metabolic syndromes, over-training syndrome, and their cousins. You just need a doctor with a brain.

As questions. .. Ask "why" A LOT. Ask until until you understand. If they won't bother, if they get annoyed, pick a different one, and repeat. You aren't looking for someone to tell you what you WANT to hear (the truth sucks sometimes) ... You are looking for someone who cares and who will take the time to answer yiur questions to a depth that you are comfortable with.

Eta: there are a number of experienced physicians on this forum spread around the world. If you tell us where you live someone here might be able to give you a reference near you.

There. I bolded it for you. You are correct. More people should take note. It's one of the most important distinctions in CICO discussions.

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Dr. Alex Harrison | Founder & CEO | Sport Physiology & Performance PhD
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Yes, it could very well be a hormonal change causing lowered metabolism, but it also could be from increased intake. It's good to have voices with different opinions, and prior to my first post all nobody had suggested the possibility that OP is eating too much. I suggest it because it's far and away the most common reason people gain weight, and because people are famously unreliable at tracking calories. So when someone has unexplained weight gain the first and simplest place to look is intake. If OP is going down the road of endocrinologists and expensive doctors and testing, it's not going to hurt anything to track for a bit and look for patterns.

Proximal is a better word for this than fundamental, I had to look it up, it's def the right word. I don't think, though, that OP needs to rule out any possible metabolic issues before at least starting to track calories. It's free, easy, a little bit annoying, but in comparison to finding a doctor able to diagnose and treat any possible issue it's a no-brainer. At least do both concurrently.

If you train with a group or tri club, ask around and see if anyone knows a Dr. that has experience with endurance athletes.

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Let food be thy medicine...