Does weight always drop if fuelling is inadequate?

Last year during SSB2, I suffered a lot from anxiety and irritiability after the workouts. I felt like I was not able to recover in time to handle even the Low Volume plan (I have now learned about periodising nutrition and am finding the workouts and post-workout periods to be fine).

In a discussion at the time, my friend had asked me if I was eating enough. To which I replied - my weight is not dropping, so I must be eating enough :man_shrugging:

So a year later, and still thinking about the issues I had encountered, I am wondering if it’s possible to under-eat on the bike, but also not lose any weight?

Surely if I was under eating, it would lead to weight loss over a period of weeks/months? Or is it possible that you can under eat during times when you need it, and compensate during times you dont, and that would result in weight holding steady but also causing me to experience the stress?

PS I have already identified other issues that likely caused/contributed to the stress but this question has lingered on my mind.

Yes, you can under fuel/eat on the bike and/or after a workout that could negatively affect the quality of workout or the workout the next day. You could also be eating the wrong things and/or at the wrong times that can additionally negatively affect your performance. Then, you could gain all those calories back by eating high caloric foods (fat) and be in calorie balance. Meaning, you can do everything wrong regarding eating but as long as you eat the amount of calories you burned during your workout and throughout the rest of the day, theoretically your overall weight would remain constant.


The best solution to this is to track calories using a free app. It sounds tedious but you get used to it very quickly and it’s helpful for weight loss AND for workout fuelling.

As already mentioned above, if you were to, say, just eat fat (extreme example but it makes my point) then you could easily maintain or even increase your weight but fat is not a good source of fuel, especially for more intense efforts.


This is one of those places where the calories-in, calories-out model does everyone a disservice. The thought goes that you can tell it’s balanced if your weight is stable, but this totally ignores the fact your metabolism is a dynamic system. The body can and will slow your resting metabolic rate if it decides energy is inadequate. You’ll get moody sleep/recover poorly, etc. There was a blog post I’d read by a female cyclist a month or 2 ago that when she had a dietitian analyze her food intake discovered she was underfueling by like 1000kcal per day (she felt bad for many months leading up to this). Under simplistic cico reasoning, that should not be possible without losing all the weight - and yet she was weight-stable for months.


Wow. A real eye opener, can’t believe I’ve been so slow on the uptake(:face_with_hand_over_mouth:) with this.

It’s only thanks to this forum and the podcast that I have stumbled upon the issue at all!

In Amber’s wise words…don’t diet on the bike!

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In my experience, this is 100% possible.

I recently got diagnosed with a pelvic stress fracture. MRI also showed changes in my bone marrow and muscles ‘indicating starvation’

I add been running and cycling about 11-14hours per week and accidentally under fuelling. yet my weight did not decline at all.

Having retrospectively analyzed energy intake i was down between 600-1000cals per day for at least 6 months.

That’s where i can 10000% agree with @gcarver - the body is dynamic.

Furthermore, just using your BMR + Exercise expenditure - is not necessarily the full picture. Your body composition matters AS lean tissue requires more energy than fat.

the IOC’s stance is 45cal/kg of lean tissue (so in other words ur total mass - body fat)

thus, 2 people, the same weight, age and height could have the same BMR but if 1 is 10% body fat and one is 23% body fat their energy requirements are very different.

Also - essentially as your body begins to think it’s starving (which happened to me) it slows your metabolic rate and starts to store fat (amazingly primitive!)

It is worth listening to anything you can find Trent Stellingwerf or Margot Mountjoy discussing this.

But yes, it is definitely not as simple as cals in / cals out.

It seems most athletes who become undernourished can actually improve body composition when they start to eat more. As I said, really worth listening to Trent Stellingwerf discuss this

Dukes et al is references: male mid distance runners having far less body fat than female gymnasts (who were minus approx 600cal) which is not what you’d expect! study below

this is a good podcast link ->


Calories in/calories out DOES apply, but most of us don’t have access to the tools necessary to calculate either of these components with any sort of precision.

Your body was likely adjusting the “out” side of the equation—BMR slows, NEAT decreases, etc., to balance the equation. The irritability and slow recoveries you report certainly suggest you were under eating.

I dug out this article I wrote a while ago, and I think it gives a pretty good overview of CICO!

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