Skinny fat

Although I weigh 74Kg and am 180cm tall, I like many other cyclists are probably skinny fat.  The energy demands for most cyclists is glucose, and as a result I suspect we have a glucose burning engine.   This week I undertook a 3.5 day water fast (in a vain attempt to see if it would help PEM from covid), my experience was a miserable one.

The hunger side of things was fine, but although I ensured that I weaned of caffeine before the fast and drank plenty of water with minerals, I suffered with a constant headache and terrible insomnia on nights 2 and 3.   It’s day two after the fast, and I am still feeling weak and in some ways regret trying it.   I have however, concluded, that my negative experience was simply down to the fact that as a cyclist, I have a high carb diet, bread, potatoes, rice … yes, I eat lots of oily fish and nuts, but my body has never gone into Ketosis, and when it did during the fast, I suffered.

So, I am not wondering whether even us cyclists who do lots of exercise 3-4 days / week, need to be mindful of what percentage of our daily calories come from carbs as opposed to healthy fats and protein.

Keen to understand whether others have looked into this topic in more detail, or even adjusted their diet so carbs are not too high.  If so what was your experience.

Yes, I have tried fasted Zone 2 morning rides, but I am not sure whether a fasted Zone 2 ride for 2 hours will induce Ketosis, as you have only not eaten for 12 hours, and your energy demands for a Zone 2 2 hour ride will be less than 600 calories.

Were you still exercising when doing the fast ?

No.  I did a 45 minute zone 2 exercise on the morning of day one.

I think your negative experience is probably because a 3.5 day water fast is just about as brutal as it gets for a first time fast! Fair play though, you’re obviously not lacking in self discipline.

I have never done anything that long, but I have done extended periods (months) of low carb + 17/7 fasting (lunch + tea only). I hesitate to use the words ‘life changing’ but it did reset my whole approach to food – blood sugar regulation massively improved, sugar cravings gone, sweet tooth gone, food preferences completely changed. I’ve never had a problem with weight, so nothing changed there, although my bodyfat percentage definitely declined. I continued to exercise normally throughout, and suffered some truly epic bonks on the road bike. Was worth it though – I can easily do a 60 mile road club ride on a black coffee now.

These days I exercise 5 days a week, I usually eat 3 balanced meals a day between 7am – 6pm but try do skip breakfast a one day per week in order to get a decent fast in (17/7). I exercise more frequently now, so my nutrient demands are higher, otherwise I would fast more often. I usually do 2 gym sessions, 2 runs and 3 rides per week – 2 rest days. Thankfully all the changes from the initial period of more intensive fasting have persisted even after circa 8 years.

My advice would be try 17/7 or 18/6 for a few weeks and see how you get on. I wouldn’t worry about dropping carbs completely, as you will likely be down on calories anyway, but I certainly wouldn’t have carb focussed meals (e.g. a risotto or a pasta dish) you need to have balanced amounts of protein/fat/carbs otherwise you will get hungry by 2pm. Plus, if suffering from PEM you will need plenty of meat/fish/shellfish for the micronutrients anyway.

I think short periods without food (the morning fast) can be very effective, rather than going 100% low carb/no carb (even though I did both). Plus, just skipping food in the morning fits in perfectly with normal life. If you do a few hours on the bike during that time, then you will most certainly have burned though your carb stores before you have finished, then it’s just a matter of giving your body time to adapt.

The energy demands for most cyclists is glucose, and as a result I suspect we have a glucose burning engine.

Why do you think this is true? Won’t it vary widely depending on the type of riding you are doing and on individual physiology / training?

I know from experience I can do 3 hours gentle Z1/Z2 road riding without breakfast and without feeling hungry, but after a hard hour or two up and down hills I’d bonk without something to eat.

So I’m interested in whether that’s just your opinion or there is research to support it?

You haven’t said what you actually want to achieve.

Depending what you want, In addition to diet, consider doing some resistance training along with just the cycling.

There are a huge number of benefits and it’s not necessarily about getting hench etc.

What on earth is skinny fat?

If you’re worried about eg cholesterol, go see a doctor about getting bloods done.  Then perhaps a dietitian.

How old are you?

Skinny fat is being about a normal kind of size (or maybe a bit smaller) but body composition being characterised by a lot of fat and minimal muscle.

So you look normal wearing clothes but underneath it’s all love handles and moobs.

Caused by a combination of genetics, lack of resistance training and bad diet

I definitely used to be skinny fat. I am now still a bit too fat but much better body composition.

Was worth it though – I can easily do a 60 mile road club ride on a black coffee now.

How exactly is this helpful for anything? This whole fasting thing completely baffles me, what’s the point?

What on earth is skinny fat?

I clicked thinking it would be about tyres.

I can’t imagine how a 3.5 day fast would actually be good for anyone, but particularly not if you are recovering from the effects of Covid. I have also never encountered the idea that “… The energy demands for most cyclists is glucose…”. All the reputable sources I’ve ever read recommend that cyclists need to eat a balanced diet with appropriate quantities of carbs, fats, protein, fruit and veg. I guess cyclists do have a “glucose engine” in some form, but so does every other human on the planet! I would also question the assumption that “… like many other cyclists are probably skinny fat…” unless you’ve had a scientifically rigorous body fat measurement. I’d suggest regular cyclists are actually far less likely to be “skinny fat” than non cyclists (because regular exercise will help maintain their muscle mass and a healthy body fat percentage).

Nutrition cannot be reduced to energy intake and expenditure. If you are recovering from illness, I think you want to give yourself the best chance by getting your essential vitamins and minerals and sufficient fuel for your daily energy expenditure. The best way to do that is to eat a healthy, varied diet of tasty food at regular intervals. That’s also a lot more enjoyable and psychologically easier than dramatically restricting your food intake.

This week I undertook a 3.5 day water fast (in a vain attempt to see if it would help PEM from covid),

I really don’t understand what led you to think undertaking a bit of “manorexia” would translate to sorting ‘PEM’ (actual Malaise or just lack of energy/exhaustion after exercise?). I can’t see how a water fast treats anything especially low energy/Malaise…

As you said you’re worried about your high carb diet (which I can relate to) look at adjusting your diet longer term but don’t just ditch food for 72 hrs. Cut down on/cut out bread perhaps as a first step? Do it for a couple of weeks and see how it affects things, perhaps bump up protein sources either meats or maybe nuts?

Out of interest what do you eat when riding/post riding?

I really don’t understand what led you to think undertaking a bit of “manorexia” would translate to sorting ‘PEM’ (actual Malaise or just lack of energy/exhaustion after exercise?). I can’t see how a water fast treats anything especially low energy/Malaise…

There’s a fair amount of evidence that fasting is beneficial for Long Covid because it promotes autophagy and healing in the body.

There is very little else available to treat Long Covid so these are some of the best tools we have.

On the OP’s original question, I would say going from a high carb diet to eating nothing is always going to be a struggle. I’d suggest intermittent fasting to begin with and cut carbs. From a low carb diet you’ll transition into longer fasts quite easily, and most of us eat far too many carbs to begin with anyway.

Long Covid reactions to fasting differ for everyone as well. Some experience a flare up in symptoms. That’s sometimes considered a herxheimer style reaction before they see improvement, but others can have less tolerance to the stress.

How exactly is this helpful for anything? This whole fasting thing completely baffles me, what’s the point?

It was an example of a marked change that I experienced after some months of intermittent fasting. It’s evidence of some material change within my body that was brought on by the fasting – better blood sugar regulation and/or a vastly improved ability to burn fat for energy (therefore smoothing blood sugar levels).

The point of fasting can either be a form of calorie restriction to lose weight (not my aim), or it can be something done to improve health/functioning of the body – that is that I experienced.

There’s a fair amount of evidence that fasting is beneficial for Long Covid because it promotes autophagy and healing in the body.

interested to see some of this evidence. Last I looked a while back there were a couple of fairly low quality studies that were interesting, but not what I’d call ‘evidence’.

There’s a fair amount of evidence that fasting is beneficial for Long Covid because it promotes autophagy and healing in the body.

There is very little else available to treat Long Covid so these are some of the best tools we have.

There’s a long covid FB group that’s focussed on using autophagy as a recovery aid. As well as fasting, it suggests the use of various foods or supplements that promote autophagy – extra virgin olive oil, resveratrol and a bunch of others. I used some of the suggestions and I think it helped, but it’s hard to know exactly what’s cause and what’s coincidence,  most of the ‘evidence’ I’ve encountered seems to be largely anecdotal and quite crude.

That said, jus the perception that you’re taking proactive steps towards recovery is positive in itself. Anyway, if anyone’s interested:

https://www.facebook.com/groups/recoverfromlongcovid

So I’m interested in whether that’s just your opinion or there is research to support it?

It’s rubbish.   Near all forms of cycling effort except all out sprinting rely on fat metabolism.   As you get into zone 4 you are switching to the max 90 minute glycogen supply you may have (assuming you are fully loaded) in a ratio proportionate to the effort.

better blood sugar regulation and/or a vastly improved ability to burn fat for energy (

How do you know this is the case rather than just you being comfortable riding slower than you would with some carbs?

A 3 1/2 day fast seems a bit of an odd way to kick off , but … what sort of diet do you normally OP? Tried anything to reduce the amount of carbs in that, or just gone straight to the fast.

This skinny fat thing – do you do any sort of training? Or just gentle cycling? No leg muscle from cycling?

Seems my post has divided opinion on the merits of fasting and limiting carb intake.   The dietary change is an attempt to see why I get terrible PEM 48 hours after a long ride.   Given I have the same symptoms on day two after my fast as I do after a long cycle ride, then I am beginning to think it could be a low blood sugar issue of some sort.  Eg, if I put myself into a Ketosis state, I then pay for it a couple of days later.  So maybe trying intermittent fasting and reducing the carb, might help balance insulin levels and enable me to become better at metabolising fat.   I don’t each sugary junk, or drink fizzy drinks, but a bowel of rice or a couple of slices of bread will cause an insulin spike.

Given my main cycling joy is prolonged multi day cycle touring, I don’t need a high glucose burning engine.  I need a slow burning diesel one.

To those who think fasting is rubbish, I would take a bit of time to read about Autophagy.  It’s very interesting.

Fasting is great. Regularly do 18:6 or 20:4. OMAD 24:1 a once a week or so. Much easier when fat adapted on a keto or carnivore diet.

the keto macros app is very useful (it’s a U.K app, has an avocado as a widget) Input your height, weight, age, and exercise level and it tells you how much fat, protein and carbs to eat to get into and maintain ketosis. Carbs are always 20g or less.

Forgetting the ketosis part.

Op doesn’t eat for 3.5 days and wonders why he feels a bit crap ?

Hardly a shock is it ?

Forgetting the ketosis part.

Op doesn’t eat for 3.5 days and wonders why he feels a bit crap ?

Hardly a shock is it ?

Yes, I’ll admit I fell into the trap of fasting based on the experiences of others who have done it.  They reported improved sleep, energy levels and mental clarity.  I didn’t and I learnt a lesson.

Aren’t you getting the PEM just because you’re beating yourself up – you desctibe yourself as skinny fat, i.e. no muscular bulk… I don’t know how long your long rides are, or the effort level, but if you don’t do much, then go out and do a long , long ride it’s very easy for that to have a big impact, and most people get DOMS on the second day? And that’s not a diet thing

They reported improved sleep, energy levels and mental clarity.  I didn’t and I learnt a lesson.

Them plans/books don’t sell them selves.

Influencers be influencing

Seems my post has divided opinion on the merits of fasting and limiting carb intake.

I don’t think it has. Most folk accept that there can be benefits to both of these.

There’s definitely something in it, although jumping straight into a 80 hour fast seems extreme.

I suffer from pretty bad CFS / long covid and one of the few things that definitely makes me feel better is eating very little. I feel like it’s because the effort of digesting food tires me out. I don’t have a scientific basis for that but my Garmin shows me that it definitely sends my stress levels way up.

I do 16:8 fasting every day and try to eat a very light lunch, salad and fish etc. Today, as it happens, I planned to go to a restaurant, but was feeling pretty bad, so I didn’t eat at all before 7pm (didn’t actually get out of bed til 3pm). I knew that otherwise, if I ate I’d just hit the wall.

I tried a 24 hour fast once, after tooth surgery, and felt surprisingly good that day and the next. I haven’t really been minded to do it again, although it is useful for days like today.

PEM is a result of mitochondria dysfunction  according to the science

i reckon i am fat skinny.

the thought of fasting sounds like a life not worth living.

ride bikes, drink beer, be happy.

I would literally sacrifice every penny I have to be able to ride bikes and drink beer again

Doesn’t the garmin measure stress from HR? After 16 hours unfed I’d expect the HR to move a bit when it gets some food.

Full austerity of allergy tests? Gluten sensitivity,, etc?

PEM is a result of mitochondria dysfunction  according to the science

Science doesn’t know for certain what causes PEM. There are competing theories and mitochondrial dysfunction is one of them (which fasting could help with through mitophagy). It could also be neurogical, immunogical, or metabolic. It could be any or all of the above. There’s a lot of complexity through the interconnected systems that is not well understood.

I’d question the OP’s assessment that it’s low blood sugar:

Given I have the same symptoms on day two after my fast as I do after a long cycle ride, then I am beginning to think it could be a low blood sugar issue of some sort.

You mentioned you did a zone 2 ride on day one. This is much more likely to be the culprit, fasted or not (fasting could add some extra stress).

Reading between the lines you don’t think this should trigger PEM, but sadly the pattern for many is the window of activity gets smaller each time you trigger it. As mentioned in the other thread, avoid it at all costs!

Doesn’t the garmin measure stress from HR? After 16 hours unfed I’d expect the HR to move a bit when it gets some food.

One of their main metrics is HRV (if supported by the device you’re using). People with Long Covid or CFS have a tendency to develop all kinds of sensitivities as their body is thrown out of balance. Anecdotally, the lowest stress levels I’ve seen this year were during a fast, and they stayed pretty low in the days afterwards.

interested to see some of this evidence. Last I looked a while back there were a couple of fairly low quality studies that were interesting, but not what I’d call ‘evidence’.

There’s certainly more than a couple. None of it is entirely conclusive, but it’s about as strong as the evidence for anything else we have, so if you’re stuck with Long Covid, what do you try? We’re yet to establish the exact cause and mechanism of Long Covid and without any treatment it’s probably a life long disease for many.

Fasting has been, and still is, a common practice for many cultures and civilisations throughout history.

I like many other cyclists are probably skinny fat.

This seems like a really weird assumption

Fasting has been, and still is, a common practice for many cultures and civilisations throughout history.

Sure, but that is overwhelmingly religious and cultural custom. It’s not scientific evidence that it actually has health benefits.

I thought “Skinny fat” was a phrase invented by juiced up social media influencers to sell steroids and growth hormones to normal healthy people who look, well, normal.

Pretty sure I first heard the term skinny fat from Michael Moseley describing himself donkeys years ago as some one who looks healthy and slim in clothes but actually has quite an excess of fat (especially visceral fat) and lack of muscle in reality. I think it was when he was first talking about him being pre-diabetic maybe?

Actually not uncommon in the general population, lack of muscle from inactivity allows a ‘sheath’ of fat hidden under clothes, so you don’t actually look big/fat/bulky.

There you go….

“I wrote the Blood Sugar Diet because I was diagnosed as a type 2 diabetic,” he said. “I was not particularly overweight, weighing about 86kgs and I didn’t look particularly fat, but that was because a lot of the fat I was carrying was internal. I was a TOFI, Thin on the Outside, Fat Inside. ‘

I do 16:8 fasting every day

Me too, although sometimes the 8 hour fast gets interrupted if I wake up for a midnight snack.

Actually not uncommon in the general population, lack of muscle from inactivity allows a ‘sheath’ of fat hidden under clothes, so you don’t actually look big/fat/bulky

That was my understanding too. Basically someone who eats badly but not too much in calorie terms and doesn’t do any exercise. So you don’t look obese but have more fat and worse fitness than first glance would suggest. I don’t understand what the OP means by the term though.

I don’t understand what the OP means by the term though.

Agreed. Have they actually been told they have a lot of visceral fat? I don’t agree that this is a problem rife amongst cyclists either.

If you eat a balanced and not excessive diet and cycle 3 times a week then I doubt you would be likely to have dangerous levels of visceral fat or a lack of muscle.

If OP is feeling unwell I would focus on improving the quality of the diet in terms of nutrients, stress levels, sleep, maybe look at gut health and add in fermented foods if you think your immune system is low.

Also PEM is not necessarily related in anyway to ‘skinny fat’ but CNS/post viral fatigue stuff and as on the other thread on PEM fasting is more likely to have a negative affect due to extra stress on the body than the benefits of it with an otherwise healthy person. You need rest and just healthy eating with PEM.