Iride01 

No. I realize I'm weak here in exact knowledge of what's happening. And I'm trying to tiptoe around the details hoping to stay out of trouble.

My point was that one of the reasons we get seemingly spectacular weight loss after some rides is that more of our energy came from muscle glycogen. Which will be repleted hopefully by the next ride and all that dramatic weight loss from the previous ride will be essentially nothing more than temporary water weight loss.

And I've been seeing more and more suggestions that although fat conversion to energy is going on all the time. When we get on a bike and just go for a short ride, we really didn't ride long enough to increase our fat conversion rate much. So the energy we use from that is also just going to be energy that at best results in temporary weight loss. If a person hydrates well during the ride, they may see no weight loss at all.

I was also trying to make the point that not every Calorie burned during a ride is going to come from entirely from fat being metabolized. And I really do suspect fat is never a overwhelming provider for that energy or Calories used. Unless perhaps we are talking about really long rides. Say maybe 4 or more hours.

In the OP's case, putting in maybe 6 hours a week riding a bike, it might easily take two weeks to lose just one pound of body fat. And at the time of his initial post, I think that is how long he's been at it for weight loss and trying to keep a Calorie deficit. But still, many other things are in play that determine when fat gets burned or if it's being replaced as quickly or quicker than it was burned. Tracking Calories in isn't quite the exact and consistent number that apps and tables make us believe they are.

MoAlpha

I agree with everything you wrote, but would still emphasize, perhaps unnecessarily, that every calorie the OP burns that isn’t replaced in his diet, no matter where it comes from, will cause him to burn a calorie of stored fat. …or muscle, but that’s a different story.

Iride01 

Certainly.

However allowing that the body will attempt to maintain a certain level of glycogen in the muscle tissue, then even a person on a Calorie restricted diet, even keto which really isn't keto any more IMO, will have some of the carbohydrates they consume used to rebuild that level of glycogen the body has determined it want to try to keep. And again, storage of that glycogen is 3 or 4 parts water to one part glycogen. And that seems to mean that weight loss via use of glycogen stores is just going to come back.

Not to mention that tracking of foods eaten for their Caloric content as well as other nutrition is always going to be suspect for how accurate that final daily figure is. So fats and carbs will be added to the body while all the numbers says that a Caloric deficit was made and we should have lost more weight.

I think most will agree that glycogen use is peaking when we ride at high aerobic and anaerobic levels. And to me that will suggest that if one is wanting to get the most weight loss benefit from cycling, then they'd should stay in the lower aerobic zones. And likely too, should try to schedule rides for more than a hours time I'd say 90 minutes or more at that low aerobic intensity to even begin to get a good exchange of Calories from fat actually due to the cycling activity and not just base metabolism.

While fat is being converted to energy all the time, the rate of fat conversion is fairly steady. And apparently it doesn't quicky change to accommodate sudden increase in need. So most of the additional Calories expended in the first 40 minutes or so of any bike ride is supposedly from use of glycogen.

And some of the more scientific places seem to back that up, but they speak in too many words I have to look up the meaning for, and about processes going on in the body that are well above my 9 grade biology class.

This is one I had open yesterday. Though it is probably more applicable to some of my other replies.

https://www.ncbi.nlm.nih.gov/pmc/art...2%88%BC100%20g)


And all this gets back to my recommendation for the OP is to schedule as many longer low intensity rides as is practical. Short rides aren't going to do much.

Also, I find that I tend to want to eat back more Calories in the days between rides than I expended if my rides are high intensity. For lower effort rides I don't have the urge to eat as much. I think this is a individual thing though. My stomach controls my eating more than my brain does. But the OP should try to figure out if that's a thing or not for him/her.





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RH Clark

I don't know what you mean by keto that isn't keto. You say the carbs consumed will go to rebuild glycogen. What happens when no carbs are consumed? Does a person in a high level of ketosis burn the same amount of fat that someone will burn who is not in ketosis for the same amount of energy expended? The question becomes, is the rate of fat conversion steady regardless of any metric except calorie intake VS estimated calorie expenditure. I stress estimated on both sides of the equation.

Isn't ketosis the very state the body goes into to burn fat? Why would either being in or out of a fat burning state have no effect on the amount of fat burned?

Carbonfiberboy 

I think this article is interesting:.
https://sportsscientists.com/2010/01...ss-part-3-fat/

Certainly riding more is preferable to riding less, but the harder one rides, up to 60-80% of VO2Max, the greater the rate of fat loss per hour. American zone 3 therefore would be the most productive of fat loss. If one only has an hour, ride hard, not easy - but see below.

My last two days: Sunday group ride on the tandem, 3' Z2, 30' Z2, 1:21 Z3, 12' Z4. Monday hiked in the mountains with a 20# pack, 4:34 Z1, 00:7 Z2. Between those two days I lost a pound, scale says it was fat and I gained muscle. Hiking is our secret for improving bike fitness. All that zone 1 and absolutely exhausted legs from the rough trail and elevation gain and it's anything but boring. The low HR hiking is partly due to the low cadence.

The OP's 10 mile rides would benefit from his riding as hard as he can for those 10 miles. OTOH, riding as hard as you can for 10 miles 5 days/week will mean learning how hard that can be and still being able to do it again the next day. A plan more likely to produce fat loss is simply to ride more hours. In my late 60s
early 70s, I got my best results from averaging about 100 miles/week, so whatever it takes to do that.

MoAlpha

When carbs aren't consumed, glycogen is repleted (very slowly) by gluconeogenesis, an energy-requiring process whereby molecules principally derived from fat and protein are converted to glucose. The body can burn plenty of fat without being in a ketotic state. All it takes is energy restriction.

Iride01 

Well here again I'm going to be talking about things I don't know enough about to give you the detail. However the original Keto diet was very high fat. 90% of the Calories were from fat. Only a scant 4% for carbohydrate and 6% for protein.. However the diet was useful for certain things BITD, then 1920's. And might still be today. But for long term and realistic human consumption, I tend to think not.

Looking at the Keto diet today, they've included a list of items you should and shouldn't eat that actually have some healthy choices not unlike other diets. And for certain that list probably provides for somewhat less Calories from fat and more carbohydrates being allowed.

As to ketosis. I suppose it's how you define it.. Keto fans seem to think this indicates that fat is being converted to energy. However that is probably or almost always going on. Some refer to it as being when the ketones produced by fat being turned into energy are noticeable in the breath. Which many times occurs when energy from carbohydrate sources are insufficient and the normal fat conversion process has to ramp up production to meet the need of the body.

I don't see anything overwhelmingly appealing to forcing that to happen. Other than for some that can't seem to get it together for them on the other type diets. Maybe the challenge of getting to that state of ketosis keeps them involved enough to keep them scrutinizing their foods eaten. And therefore are eating at a Calorie deficit sustainably... for them. Otherwise, the newer emphasis of keto to include more vegetables that are nutrient dense is a plus. As well the lessening of the restriction on carbohydrates. However I'd not like the limitations that keto imposes for trying to maintain their idea of ketosis.

You don't have to be on a keto diet IMO to go into the ketosis state as described by the Keto fans. It probably happens to many of us when we cycle frequently enough to use up our glycogen and not let it get replenished between rides. I'm convinced I've been in ketosis on many occasions. And I don't restrict my carbohydrates.

I also don't think the keto diet makes anyone inherently better at converting fat to energy. As I said, that process is almost always happening. Just getting out there and riding at decent levels of exertion for longer times are going to improve ones ability to process fat at a faster rate.

But, I admit that this is just my opinion of how I interpreted the facts I've read. Not a fact in itself.

cyclezen

It's been said, key is discipline on your food intake. and when...
Lot of good discussion, but what it boils down to is you have to eat for the weight you want to be, if you want to be 170 lbs, then eat for that level _ and add in exercise/efforts which helps burn Kcalories. If you consistently keep your caloric intake at the maintenance level of the weight you want to be, you'll get there - down the road. BUT you also need to 'time' when you consume.
If you pile on calories at some close period before you rest, the body will recover as much resources as it can scrounge ... and find replacement for prior useage. Late food/snacks puts a complete hold on losing weight. And don;t let down or cheat...
already noted : 1 lb of stored body fat = approx 3500 Kcal , so that's at least 500 extra Kcal burned every day for a week. But given the body' ability to find replacement, the need to increase burn beyond 500 Kcals /day is important.
Also, don't go hard from the gun, give yourself at least .75 to 1 mile warmup at start of ride, slowly increasing effort, and same amount lowering intensity at end of ride to allow the muscles to recover and remove as must metabolic waste from the muscles - better recovery means better efforts the next day.
See my note to terrymorse below - affects your expectations of results from your daily ride...

Big numbers, terry. All my sources over the years come to 25-30 Kcal/mile for a moderate intense bike ride effort. Your number was closer to what one might use for a real 'runner' effort.
At my current weight/muscle/structure, a fairly intense 20 mi segment might have me using 800 +- Kcal. My usual harder 34 mi rides with climbing, maybe 1700-2000 Kcal. this at 145 lbs.(wish I could do more...but not happening at this time...)
Many of the current devices all seem to over-estimate Kcal burn...
Now if your Power meter is giving an accurate cummulative of watt/hr , a good approx Kcal burn can be estimated from that...
so for the OP, at 195 lbs, and lets say a good AVERAGE spd number for entire 10 miles is 11 mph (a little better than 10mph, per OP's numbers)
so that would come to 200-210 Kcals for the hour ride. and if he is putting in some stronger efforts and then slowing, will still come to the 11 mph, then 250 Kcal, tops...
That's roughly 60-70 watts avg.
That's for flatish ride, at sea level, only apparent wind.
Ride On
Yuri

Carbonfiberboy 

The word "keto" has been popularized to mean a diet which is low in carbs or perhaps I should say high in low-carb veggies, protein, and fat. Which doesn't mean what it used to mean, i.e. being in a state of ketosis where carb availability is well below what it takes to operate the human body and thus the body switches over to running on ketones rather than carbs. The real difference in fat burning there is that the brain is also running on ketones and it burns about 20% of one's total calories at rest. But if the question is, can athletes who are converting ketones to energy burn more fat than athletes who're on a normal diet containing carbohydrates, I think the answer is probably not, or at least not much more. Ketonic ultra-runners have to consume carbs during their run if they are attempting to keep up with runners who eat a normal diet, even though the effort level is mostly zone 1. Endurance athletes get really good at burning fat if they do enough long efforts.

The really good part about eating a "normal diet" is that one does not lose the ability to burn lots of carbs, which the ketonic athlete does. Thus normal dieters can operate their bodies in all the zones and stay in the upper zones for long periods of time as long as they keep the carb calories coming. Grand Tour stages are usually less than 5 hours long, just the length of a good hard training ride, in time if not in distance.