Sleep, blood sugar, and training load rolled into a long ride on a cold gray day. Your body has to pay the tab.
Beard Guy has been tired lately. Not the good kind of tired, where you finish a long run and collapse on the couch with a sense of smug satisfaction. The other kind. The kind where you wake up from a full night’s sleep and immediately want to go back to bed. The kind where a Tuesday afternoon feels like mile 20 of a marathon you didn’t sign up for.
He has a few suspects. New diabetes medication. A CPAP machine he’s still figuring out. A spring that keeps promising warmth and then ghosting everyone in Fort Wayne. Training that is technically happening but feels like running through wet concrete. None of these feel like the whole answer. All of them are probably contributing. That is the frustrating thing about fatigue: it rarely has one cause, which means it rarely has one fix.
Here is what Mad Anthony has observed from the booth.
The energy system is not one thing
Most people think of fatigue as a battery that runs down. You do stuff, the battery drains, you sleep, it recharges. Straightforward enough. Except the human body is running about six different batteries simultaneously, and they do not all recharge the same way or on the same schedule.
There is physical fatigue from training load. There is metabolic fatigue from blood sugar instability. There is neurological fatigue from poor or disrupted sleep. There is hormonal fatigue from chronic stress. There is emotional fatigue from carrying too much for too long. And there is the compounding effect that happens when two or three of these show up at the same time and start feeding each other.
Beard Guy is currently dealing with at least three. Which explains a lot.
Blood sugar and energy are the same conversation
If you live with diabetes or manage blood sugar through diet, medication, or monitoring, you already know this on some level. But it is worth saying clearly: unstable glucose does not just affect your health markers. It affects how you feel hour to hour.
When blood sugar swings high and then corrects, the crash that follows is not just a number on a CGM. It is a physical event. Your body registers it as stress. Your cortisol responds. Your energy craters. You reach for coffee or sugar or both, which starts the cycle again.
New medications can change how your body handles all of this. The adjustment period is real, and it is not linear. Some days feel fine. Some days feel like your body forgot how to regulate anything. That is not failure. That is physiology catching up to a change you made on purpose.
Beard Guy’s CGM adhesive has also been losing the battle with spring humidity and skin chemistry, which means the glucose data he would normally use to make sense of how he feels has been spotty at best. Flying blind during an adjustment period is its own kind of stress.
Sleep is not optional maintenance
CPAP therapy works. The research on this is not subtle. Treated sleep apnea improves cognitive function, cardiovascular health, metabolic regulation, mood, and athletic recovery. The catch is that the first few weeks are an adjustment, not a transformation. Your body spent years in a state of fragmented, oxygen-disrupted sleep. It does not immediately know what to do with a full, uninterrupted night.
The technical term for this is sleep debt. The experiential term is “why do I still feel terrible even though I’m supposedly sleeping better.” The answer is time. Not weeks. Potentially months before the full benefit of treated sleep shows up in how you perform and how you feel.
This does not mean the CPAP is not working. It means it is working on a timeline the body sets, not one that fits neatly into a training block.
What actually helps
The instinct when you feel this way is to push through it, or to do the opposite and completely back off. Mad Anthony would tell you the answer is neither. It is recalibrate.
Protect sleep above everything else. This is not negotiable and it is not soft. Sleep is when your body consolidates training, regulates hormones, processes glucose more efficiently, and does about forty other things your conscious brain does not get credit for. If the CPAP is still uncomfortable, that is a solvable problem. Work on it. The return on investment is enormous.
Eat in a way that keeps glucose stable, not just in range. For athletes managing diabetes, this means thinking about meal timing relative to training, not just carbohydrate totals. Fueling before a workout, recovering after it, and not letting four hours pass between meals while your blood sugar does whatever it wants are all part of this.
Train to how you actually feel, not how your plan says you should feel. Beard Guy’s training might look slower right now. His heart rate might be higher than usual at the same effort. His perceived exertion might be off. These are signals, not failures. The data is telling him something. The right response is to listen to it.
And give the adjustments time. Medication changes, CPAP adaptation, seasonal disruption to routine and mood: these are not small things. They are physiological events. Treating them like inconveniences and trying to train through them at full capacity is a good way to extend how long they affect you.
The compounding problem
Here is the part most people miss. Fatigue compounds. Poor sleep makes blood sugar harder to regulate. Blood sugar instability disrupts sleep architecture. Both increase cortisol. Elevated cortisol suppresses recovery. Suppressed recovery makes training harder. Harder training when you are already depleted increases fatigue.
You can enter this loop from almost any direction and it will take you to the same place: wondering why you are always tired and feeling like the answer is just “try harder.”
It is not. The answer is almost always “do less of the wrong things and more of the boring right ones.” Consistent sleep. Stable fueling. Easy days that are actually easy. Patience.
Beard Guy is working on all of it. Mad Anthony is watching the film and making adjustments.
If this sounds familiar and you are trying to figure out why your training feels harder than it should, that is exactly the kind of problem worth talking through. I work with athletes and active adults who want to feel better and perform better, whether you are chasing a finish line or just trying to get through the week without running out of gas.
Book a free 30-minute call at madanthonymultisport.com/booking.
Coach Tony Hampton is a triathlon and endurance multisport coach based in Fort Wayne, Indiana, with a growing focus on health and wellness coaching. He holds certifications through IRONMAN U, ESCI, Stryd Run Power, TriDot Pool School, and Precision Nutrition (PN Certified Master Coach).
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