Now my thought. If they'd monitor his body temperature precisely they might find that the temperature is too low. That is dangerous. If he'd spread over the day would intake sugars, like glucose the body had immediate fuel to burn and body temperature would increase, the fatigues would decrease and he had more strength at the weights thereby increasing his fat burn, but in a healtier way.
What you think about that theory?
During a hard contest-prep diet, especially when carbs and calories are low, a lot of people do experience:
- low body temperature
- extreme fatigue
- poor training performance
- hunger
- reduced thyroid output / metabolic adaptation
- low muscle glycogen
So if Mike Sommerfeld says prep “kicks hard,” that’s not surprising. At very low body fat, the body starts defending itself: T3 drops, leptin drops, sympathetic nervous system activity goes down, and body temperature can fall. That low temperature is not necessarily acute hypothermia, but it’s a sign that the body is downregulating energy expenditure.
Your idea is: what if he took small amounts of glucose/sugar through the day to give immediate fuel, raise body temperature, reduce fatigue, and improve training so he burns more fat?
That could partly work, but I don’t think it’s the optimal version.
### Why your idea makes sense
Glucose/carbs can:
- restore muscle glycogen
- improve training performance and strength
- reduce perceived fatigue
- increase diet-induced thermogenesis slightly
- transiently raise body temperature via insulin, carbohydrate oxidation, and sympathetic
So if someone is training horribly and feels cold and weak, adding carbs **around training** can absolutely help. Many bodybuilders use intra-workout carbs like cyclic dextrin, Gatorade-style glucose, or rice-based shakes during prep for exactly this reason.
### Why spreading sugar all day is probably not ideal
If he constantly sips glucose all day, insulin stays elevated. That can:
- suppress fat oxidation
- reduce lipolysis
- potentially increase hunger later via blood sugar swings
- blunt the fat-loss signal he’s trying to create
Also, if those sugars are added on top of his current calories, the deficit shrinks. If they replace protein or fat, that could hurt muscle retention or hormones. So all-day sugar may not actually increase fat burn; it may just shift fuel preference toward glucose and away from fat.
### A better version of your theory
Instead of spreading sugar all day, I’d use carbs strategically:
- pre-workout carbs for strength
- intra-workout carbs for performance
- post-workout carbs for recovery
- occasional refeed days or higher-carb days to restore thyroid/leptin and body temperature
Monitoring morning body temperature is actually a useful low-tech marker. If it’s consistently low, that’s a sign the deficit is too aggressive or carbs are too low. But the solution is usually not constant sugar; it’s more total food, more carbs around training, better sleep, or a short diet break/refeed.
### Bottom line
Your theory has a real mechanistic basis: low body temp and fatigue in prep are signs of low energy availability and metabolic adaptation, and glucose can transiently help. But all-day sugar is probably not the best tool because it can blunt fat oxidation and make the final fat loss harder.
The smarter version would be: use glucose/carbs around training and monitor body temperature, strength, mood, and performance. If temperature is dropping too much, the answer is usually more food or a refeed, not constant sugar.
At 6% body fat or lower, the body is fighting back hard. That’s why he feels terrible. Some of that is normal for contest prep, but extreme cold and weakness can also mean the deficit is too aggressive.
If you hooked Mike Sommerfeld up to a research-grade continuous core temperature monitor and logged it into a spreadsheet, I think you’d see some clear patterns:
- Lower baseline waking temperature as prep deepens
- Blunted post-meal thermogenesis
- Drops on low-carb/low-calorie days
- Worse temperature recovery after training
- Possibly lower overnight minimums
That would be a real signal of metabolic suppression, and it might show up before he “feels” terrible.
But there are some practical and scientific issues.
### Core vs skin temperature matters
Continuous measurement sounds easy, but skin temperature is heavily confounded by room temperature, sweat, blood flow to skin, clothing, etc. It’s not a reliable proxy for metabolic rate.
To do it properly, you’d want something like:
- an ingestible core temperature pill
- a rectal or esophageal probe — not practical for daily life
- or at minimum a high-quality tympanic/oral thermometer taken under strict conditions
The ingestible sensor plus a data logger would be the “clinical research” version, but it’s expensive, uncomfortable, and probably overkill for prep.
### What the data would likely show
In a depleted state, body temperature is usually lower, especially in the morning. That’s partly due to:
- reduced T3/thyroid output
- lower sympathetic nervous system activity
- less diet-induced thermogenesis
- low glycogen and low insulin
- less total energy expenditure
If he then consumed glucose, you’d probably see a temporary rise in temperature. That doesn’t necessarily mean he’s burning more fat. It may just mean he’s burning more glucose and generating heat.
So the spreadsheet might look promising — temperature goes up after sugar — but you have to be careful interpreting it. A rise in body temperature after carbs is not the same as an increase in fat loss.
### A more useful version of your idea
Instead of constant sugar, the data could tell you when and how much carbohydrate is actually needed to keep temperature, performance, and recovery from collapsing.
For example, you could track:
- waking temp
- pre-training temp
- post-training temp
- post-meal temp rise
- evening temp
- sleep minimum
If waking temp drops below a certain threshold for several days, or if post-meal temp rise disappears, that might be a signal to increase carbs, take a refeed, or reduce training stress.
You could even combine it with:
- continuous glucose monitor
- heart rate variability
- sleep data
- training load
- subjective hunger/mood/fatigue scores
That would give you a much fuller picture than temperature alone.
### But would it change the outcome?
Honestly, I think it would mostly confirm what experienced coaches already suspect: at very low body fat, the body is running cold, tired, and metabolically downregulated. Strategic carbs around training and periodic refeeds help, but all-day sugar would probably blunt fat oxidation and make the final condition worse.
So your monitoring idea is cool, and in a research setting I’d love to see that dataset. But in the real world, I think the takeaway would be:
> Use the temperature trend to know when to pull back or refeed, not as a reason to sip glucose constantly.
That’s the smarter version of the theory.
If you hooked Mike Sommerfeld up to a research-grade continuous core temperature monitor and logged it into a spreadsheet, I think you’d see some clear patterns:
- Lower baseline waking temperature as prep deepens
- Blunted post-meal thermogenesis
- Drops on low-carb/low-calorie days
- Worse temperature recovery after training
- Possibly lower overnight minimums
That would be a real signal of metabolic suppression, and it might show up before he “feels” terrible.
But there are some practical and scientific issues.
### Core vs skin temperature matters
Continuous measurement sounds easy, but skin temperature is heavily confounded by room temperature, sweat, blood flow to skin, clothing, etc. It’s not a reliable proxy for metabolic rate.
To do it properly, you’d want something like:
- an ingestible core temperature pill
- a rectal or esophageal probe — not practical for daily life
- or at minimum a high-quality tympanic/oral thermometer taken under strict conditions
The ingestible sensor plus a data logger would be the “clinical research” version, but it’s expensive, uncomfortable, and probably overkill for prep.
### What the data would likely show
In a depleted state, body temperature is usually lower, especially in the morning. That’s partly due to:
- reduced T3/thyroid output
- lower sympathetic nervous system activity
- less diet-induced thermogenesis
- low glycogen and low insulin
- less total energy expenditure
If he then consumed glucose, you’d probably see a temporary rise in temperature. That doesn’t necessarily mean he’s burning more fat. It may just mean he’s burning more glucose and generating heat.
So the spreadsheet might look promising — temperature goes up after sugar — but you have to be careful interpreting it. A rise in body temperature after carbs is not the same as an increase in fat loss.
### A more useful version of your idea
Instead of constant sugar, the data could tell you when and how much carbohydrate is actually needed to keep temperature, performance, and recovery from collapsing.
For example, you could track:
- waking temp
- pre-training temp
- post-training temp
- post-meal temp rise
- evening temp
- sleep minimum
If waking temp drops below a certain threshold for several days, or if post-meal temp rise disappears, that might be a signal to increase carbs, take a refeed, or reduce training stress.
You could even combine it with:
- continuous glucose monitor
- heart rate variability
- sleep data
- training load
- subjective hunger/mood/fatigue scores
That would give you a much fuller picture than temperature alone.
### But would it change the outcome?
Honestly, I think it would mostly confirm what experienced coaches already suspect: at very low body fat, the body is running cold, tired, and metabolically downregulated. Strategic carbs around training and periodic refeeds help, but all-day sugar would probably blunt fat oxidation and make the final condition worse.
So your monitoring idea is cool, and in a research setting I’d love to see that dataset. But in the real world, I think the takeaway would be:
> Use the temperature trend to know when to pull back or refeed, not as a reason to sip glucose constantly.
That’s the smarter version of the theory.
I wondered if sugars in low dose could push up quickly the temperature and limit the fatigues. They also would have to measure the fat amount, daily. So, it is a combination of data anyway.
### Most reasonable continuous temperature sensor?
For practical daily use in an athlete:
1. **Core temperature pill**
- Ingestible sensor, e.g. CorTemp or e-Celsius.
- True core temperature, logs to a device.
- Gold standard for continuous core temp in field research.
- But expensive, requires replacement, gut transit time varies, not ideal for daily prep.
2. **Heat-flux skin sensor, e.g. CORE body temp monitor**
- Worn on the chest or upper arm.
- Uses heat-flux algorithms to estimate core temperature from skin temperature and heat flow.
- Not as accurate as a rectal/pill sensor, but validated well enough in athletes.
- This is probably the most realistic continuous option outside a lab.
3. **Ear/tympanic sensor**
- Infrared tympanic spot checks are okay if standardized.
- Continuous ear-canal thermistors exist, but they are awkward during training, sweat can affect them, and ear movement loosens contact.
- So “one at the ear” is reasonable for spot checks, but not the best for continuous logging during hard training.
So if I were doing this, I would use a **CORE-style heat-flux patch** for continuous trend data, plus a morning oral/tympanic spot check under controlled conditions. That combo is practical and gives you enough signal.
---
### Does low-dose sugar quickly raise temperature and reduce fatigue?
Small amounts of glucose or fast carbs can:
- raise blood glucose and insulin modestly
- increase carbohydrate oxidation
- increase diet-induced thermogenesis slightly
- improve central nervous system drive
- reduce perceived fatigue
- restore a little muscle glycogen
That often shows up as a small rise in core temperature and better training performance.
But the key word is **targeted**, not continuous.
If the sugar is low-dose and timed around training, it can:
- improve strength and volume
- reduce fatigue
- help maintain training intensity
- possibly preserve more muscle during prep
If it’s spread all day, even in low doses, you risk:
- chronically elevated insulin
- suppressed fat oxidation
- blunted lipolysis
- less total fat loss over time
So your instinct is right that glucose can push temperature up and reduce fatigue. The question is whether that translates into better fat loss or just better carbohydrate burning.
---
### Daily fat measurement
Methods like BIA/scales change too much with:
- hydration
- glycogen
- sodium
- gut content
- skin temperature
DEXA is more accurate but not practical daily, and even DEXA has hydration-related variation.
A better daily combo would be:
- morning body temperature
- continuous glucose monitor
- resting heart rate / HRV
- training performance
- hunger and fatigue scores
- waist circumference or skinfold trend
- body weight trend
That dataset would tell you very quickly whether low-dose glucose is helping performance and recovery without slowing fat loss.
---
### Bottom line
Your idea is actually a solid research-style concept:
- continuous core temp
- low-dose glucose pulses
- daily objective monitoring
- fat-loss tracking
But the practical takeaway would probably be:
> Use low-dose glucose around training, not all day. Let temperature, performance, and fat-loss trend decide whether it’s helping.
If his temperature is crashing and he feels destroyed, a small carb pulse before training might be exactly what he needs. But if his body temp rises yet fat loss stalls, then the sugar is just acting as a preferential fuel, not improving the actual goal.
