Stupid question about exercise and weight loss

Bear with me folks…

I’m wondering about the timescales involved when calories get burnt when you exercise and when muscles repair post exercise. To use a simple example, let’s say I go riding and burn (according to whatever apps, gadgets etc) around 3500 cals. Now I’ve read that a deficit of 3.5k cals equates to roughly a pound in weight loss. Does that happen immediately or over a few days? Is there some rule of thumb split between calories/weigh loss during exercise and after?

Cheers

are you riding on the road or some kind of conveyor belt?

I don’t think that this is a stupid question at all, I would be very interested to know the answer myself. All I can find on t’web is that it takes 24-72 hours to break down, absorb and use the contents of a meal (link) but that doesn’t tell me how long it takes to get the fat out of the adipose cells that the body uses to store them in. The same article also says that there is a 24hr delay before you can see fat reduction after dieting and exercise, although that is dependent upon many variables. Maybe that answers your question?

If you are utilising fat to produce some of the 3500 cals, then it has to be processed at the time, otherwise you won’t get the energy.

The key thing is what proportion of the 3500 cals is actually from fat and not from glycogen stores or food, energy bars, malt loaf etc.

What happens afterwards and how your body ‘re-balances’ is probably far more complicated.

Matt

Certainly not a stupid question. For anyone active and trying to burn fat and still recover from a ride/workout, the answer is the Holy Grail!

What matt said, don’t eat anything, empty your glycogen stores and it’ll be fat and muscle getting burnt with immediate effect. You’ll still yoyo rehydrating and though.

Why does it matter, though?

Eat as little fat as possible,, eat less salt, eat 100/200g protein per day, carb up on unprocessed clean food, ride as much as you can, job done.

* unqualified interweb advice content. 🙂

Actually the myth about eating fat is in the process of being busted. The idea that you are what you eat is not necessarily true and actually a lot of the problems in recent years/decades is about our consumption of carbs and not fat, contrary to the anti-fat, pro carb propaganda we’ve been peddled over the last 30 years or so. The problem with the forms of carbs we often eat is that they cannot be used by the body so are converted to fat anyway (we’ve evolved to eat fat not carbs), so eating fat after exercise is not necessarily a problem. The key is what type of fat you eat.

Most of the problem of losing weight is nothing to do with exercise but how much we shovel down our throats anyway. We mostly eat too much. The human body is pretty efficient – it doesn’t need many calories to do things, so it is a pretty inefficient approach to use exercise only to burn fat – it can help, but in the space of a few seconds you can consume the calories it would take a number of hours of exercise to burn, so attack the problem at it’s source – restrict what you shovel into your gob! Easily said than done though, knowing what you have to do and doing it are two different things altogether.

My problem is two fold: portion control – I am good at not eating between meals, but I probably have double the portion size per meal than I should, and ‘letting go at the weekend’ – as soon as Friday comes around so do the beers, curries and those little treats!

Most of the problem of losing weight is nothing to do with exercise but how much we shovel down our throats anyway.

Hence why gastric bands work.

I agree, it’s not to do with too much fat, sugars, etc the obesity problem is largely that of portion-size. Plates and bowls are nearly twice the size they were 20 years ago, and food is more affordable.

You can’t out-exercise a bad diet, as they say.

Re portion size – so true. Was the biggest quick learning when i started trying to lose weight 30 months ago. I started with mfp and trying to keep to 1600cals by weighing out ‘portions’, latterly moving to 5:2 fwiw

1/ to start with you look at it on your plate and think ‘shit! Is that it? Have i mismeasured?’

2/ You quickly start to work out what foods are calories rich per g and which are filling while still being relatively calories poor. Lean protein, like chicken and white fish for example is ‘about’ a calories per gram. Red meat about 2-3 times that depending on fat content. Bacon about 5x unless you trim all the fat off, which defeats the point of a bacon sandwich! Bread about 100cals per slice……

3/ In a calories per bulk basis, vegetables are great.

If you track your food intake, you maybe surprised on how much you consume.
I like to snack, I wish I didn’t, but it costs so much in calories, that it hurts (with fat, I guess)
As above, we don’t need to eat as much as we think.

One interesting fact (well, I found it interesting) – when you lose fat, where does it go? Well, you breathe it out.

http://www.sciencedaily.com/releases/2014/12/141216212047.htm

i heard that lady of the radio, bit obvoius though isnt it were else would it go? and its not actuall fat its the leftover after youve used it to fuel your body.

There was something on the radio earlier this week about different types of fat. subcutaneous fat and visceral fat. The one that is more inside you get lost first but shows less on your body type, Now I wonder if it also shows less in weigh and hence will effect the answer to your question

When fat cells get emptied, they fill with water (unsure of to capacity or not). The fat that was stored in them has gone, because it’s been converted into energy, basically. So, in that sense, the fat goes right away.

But, your energy needs during exercise get met in lots of ways, from a variety of energy sources which includes fat cells. So in that sense, you don’t necessarily lose that weight in that instant, because your energy needs may be met in other ways.

Re portion size – so true.

Use a smaller plate, like a breakfast one instead of a lunch/dinner one.

It’ll look piled up too 🙂

One of the sunbsequent benefits of my new diet is the much smaller food bill, for me personally c.50% of what it was, for that reason alone your unlikely to get food producers/retailers supprting healthy food consumption.

Last year and this year I went through trying to loose a stone each time using what I feel is common sense and suitable for my own body.

First off try using a calorie tracking app for a week. It really surprised me where my calories were coming from and also, what appeared to be small portions were actually still quite large. I used that knowledge to gauge what I ate as I didn’t want to track everything for months.

I chose to aim for a relatively modest calorie reduction each day but for me the real effect came from what I did on days I cycled. Rather than carb load abit and eat a big breakfast pre ride. I’d eat the same as normal the night before, a small breakfast and then try to ride on the fewest calories possible. Sometimes skipping lunch but maybe one snack bar mid ride. Post ride I’d allow myself a larger than normal dinner.

This was following the process that food consumed post ride is efficiently stored to be burnt next time. As my system had few calories in it during exercise, I was forced to burn any fat. Each time I lost a stone in 2 months and kept it off.

If you are utilising fat to produce some of the 3500 cals, then it has to be processed at the time, otherwise you won’t get the energy.

Yes, of course! Sometimes I overcomplicate the issue and forget the simple mechanics.

What happens afterwards and how your body ‘re-balances’ is probably far more complicated.

This sounds interesting!

I’m wondering about the timescales involved when calories get burnt when you exercise

As most fat loss is breathed out as Co2, the amount you loose in exercise comes off pretty much straight away, I’d have thought?

It’s a bloody mystery.

On the calorie front, if you eat ‘well’, almost no matter what the portion size, you struggle to eat the ‘recommended’ calorie intake a day anyhow!

To the op – just play around, experiment, get a bit obsessive and you’ll eventually settle & realise what works for you. 🙂

Pretty much everything you “burn” as fuel ends up as carbon dioxide and water as they are the elements which make up fats and carbs, you may as well say you piss the fat as exhale it.

BTW what sort of exercise are you doing that’s burning 3500kcal? 😯

90kg man doing ‘vigorous’ road cycling at 14mph estimates at about 800 cals; same for mtbing. So a 4 hour ride is possibly a bit overestimated but not far off.

Some interesting stuff, thank you.

I suppose my question stems from looking at the exercise that I’m doing from purely a weight loss perspective. I have a regular 45 mile xc loop with around 2800 ft of climbing which I ride twice a week at present. Strava and MFP tell me I’m using up around 2700 cals each time and I am interested in making those count towards an overall weight loss. For the record I’ve dropped 7.5 kg (could do with losing another 10 unfortunately as well) in 2 months and as my fitness improves I’m looking to get the most out of each ride.

They already count to your weight loss, are you just eating them again the same day. I try these days not to over eat before or after execise, just let my body burn fat which seems to work so far.

i agree with @ Travis – if you track what you eat on your phone – plenty of apps out there, it’s much easier to see what you’re consuming in food but also exercise.

I’ve found that weighing myself throughout the day results in varying degrees of fluctuations. I seem to loose and gain weight throughout the day. Makes sense i suppose as you eat, sh*t and pi*s it out.

Which is why they always say weigh yourself at the same time every day….stick to a time and go with it.

Although i don’t agree with weighing yourself first thing in the morning since you’ve effectively fasted/dehydrated for 7/8 hours, you’re bound to be on the low side…

This is an interesting read.

I also want to loose some weight to make my trousers a bit loser. 🙂

My Garmin said I used a shade under 5000 calories on a 75 mile road ride today. Having had some cakes and sandwiches during the ride, then big dinner, beer and wine I suspect I’m no longer in calorie deficit 😳

I suppose my question stems from looking at the exercise that I’m doing from purely a weight loss perspective.

My understanding is that it takes the body around half an hour of aerobic exercise to use up its glucose and glycogen stores, and then it’s on to using up the fat. I’m guessing that some of this will be in the blood stream already, as well as some in the liver, and then you’re on to the stuff in the adipose cells. However, on not sure how that half hour estimate has been arrived at and it must be subject to variation, right?

My understanding is that it takes the body around half an hour of aerobic exercise to use up its glucose and glycogen stores, and then it’s on to using up the fat. I’m guessing that some of this will be in the blood stream already, as well as some in the liver, and then you’re on to the stuff in the adipose cells. However, on not sure how that half hour estimate has been arrived at and it must be subject to variation, right?

So I’m assuming that using energy gels etc throughout a ride just prolongs this initial process and limits the opportunity to burn fat? That’s useful information for me, and pretty illuminating, although perhaps a bit bloody obvious when you think about it! 🙂

You weigh less in a morning because you’ve been burning fat for 6/8 hours and not eating. I find it the best time to weigh myself as later will be variable due to whatever you do through the day eat/exercise. You will be slightly under hydrated but consistently so if you otherwise keep your pee as clear as possible which is rule #1 for me.

don’t forget your hormone levels e.g. cortisol/HGH ratio

…So I’m assuming that using energy gels etc throughout a ride just prolongs this initial process and limits the opportunity to burn fat?

If you’re exercising to lose fat then yes, exercise semi-fasted and only drink water during the exercise.
You’ll have to start on low duration exercise say about 30 minutes, but build this slowly and your metabolism will adapt over a few months.
If you combine this with a calorie deficient diet structured around low GI carbs and regular (4-5 a day) small protein/veg based meals you will lose weight in a maintainable manner and become leaner/fitter 🙂

You shouldn’t be specifically targeting fat loss though, its calories you want to burn and if you create a deficit then the fat will be lost anyway. If you exercise semi-fasted and only drink water then you can only exercise at fairly low intensity (or for short periods as you burn up your glycogen stores) – that’s good for training your body to better use fat as fuel source but not for fat loss. You’re better off riding at higher intensities and for longer and using a lot more calories (obviously without wolfing down gels/cake/haribo) but some on-the-bike refueling is fine.

…that’s good for training your body to better use fat as fuel source but not for fat loss

You won’t “burn” fat during exercise until your body has been adpated to use it effectively

….You’re better off riding at higher intensities and for longer and using a lot more calories

where do these calories come from if you haven’t pre adapted your body to use fat as fuel?

It’s why many people “give up” on losing weight, they think an hour or so of exercise needs carb loading before, a few sports drinks to “get through it” and a recovery drink afterwards – net calories balance, probably few hundred in the fat bank.

You have to do the semi-fasted mid intensity exrecise regime before you can go and “smash it” or you’ll either be munching down sugar snacks after 1/2 hour or bonking badly.
Metabolic training is as much a part of becoming fit as the physiological and psychological aspects, and probably the part most people understand the least.

Agree with hilldodger, yesterday I had a banana and kiwi smoothie (with water) and a litre of water pre ride, did 50 miles @19.5mph with just water, then a egg sandwich(daughter was testing out some new camping gear) and a tarka dhall for dinner.

No need for extra “energy” food plenty in reserve with my 10kg of lard to burn!

There is an easier way, ditch the cardio and hit the weights. You use a shed load of calories repairing your muscles and weights are a good way to do that damage. Use big muscle groups (quads, glutes, hamstrings) and work to failure, weighted squats are good for this, find the weight you need for your 10 rep max and do 5 sets of that 4 times a week. You’ll barely be able to walk but you’ll lose weight. If you want to do cardio do hard, short stuff, 1 hour in the morning working at threshold with no fuel bar an espresso is very good for this.

And good, just eat less of it and try to eat clean not processed stuff, try and avoid carbs after 6pm as well. Don’t need to complicate it more than that

+1 to dropping the gels and energy drinks.

Diet aside, and if you don’t already, can I suggest throwing a few weight training sessions into your week? Fill an old duffelbag with sand and throw that around for half an hour (lots of guides on the internet on how to make and train with one). It will help with the weight loss.

And indeed, cut out the food during a ride. I can do 100 road miles at 16mph solo on water, a banana and a sarny at 75 miles, anything under 2 hours, arguably 3 you can do without any food at all.

Personally I found calorie counting apps to have a downside. Tendency to become obsessive about it, coupled with the number of people on there who clearly have disordered eating. The problem also with very calorie-restricted diets is that once you’ve lost the weight, you start eating more “normally” and then you will put it back on again. Changing the type of food you eat is as important as things like sensible portion sizes. It takes around 2-4 weeks for your tastebuds to get used to eating food with less sugar/salt, for example. Calories are not all equal, and we process energy from different foods in a different way. For example, we now know that fructose is metabolised in the liver, not by the digestive system.