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McBleezy8 t1_ivcezad wrote

Though interesting the truth is not all substrates are created equally this is especially true for high functioning athletes that require X amount of energy for Y amount of time. Within skeletal muscles carbs can be utilized much faster than fat because the anaerobic conversion of glucose to ATP is more direct and involves less steps than oxidizing fat in the mitochondria. In addition to that fat cannot be taken up as efficiently into muscles during intense exercises. There’s a few reasons for that if anyone is interested I can detail those

Athletes being the key term here. For an average person not working out multiples X a day or numerous times a week the effects might be as negligible as this study claims.


yangYing t1_ivei7wt wrote

Sorry for a basic question, but - what is 'substrate'?


tjdux t1_ivelvmr wrote

In general, a substrate is a basic building block or underlying surface.

For this instance they are describing different forms of simple sugars that the human body can metabolize.

Carbohydrates are a basic sugar that the body can easily break down and use as energy, they are an example of 1 type of substrate in this convo. Biology has always considered carbs relatively "efficient" because the body doesn't need to change them to use their energy.

Another substrate would be created when the body converts fat cells into sugars that can be used by the muscles.

The overall point of the study is saying that the sugar the body converts from fat is just as powerful muscle fuel as pure carbohydrates for most people, except high level athletes.

Disclaimer, I'm just a guy who has done a lot of reading on nutrition and weight loss, specific to low carb diets.


lost_in_life_34 t1_ivd94cw wrote

Athletes have more mitochondria’s and more efficient ones?


dr_eh t1_ivdiq47 wrote

No they burn more energy and require faster repletion for high-intensity activities.


lost_in_life_34 t1_iveojps wrote

And they burn more energy cause they have more mitochondria in their cells due to training

Low intensity builds more mitochondria per cell and high intensity trains them to work better

For strength training more muscle mass means more mitochondria to burn fat


dr_eh t1_ivf0eaf wrote

Source? I'm curious how they measure # of mitochondria.


-Kibbles-N-Tits- t1_ivfbr69 wrote

“Low intensity” he’s specifically referring to zone two cardio, which every type of athlete has to do a lot of to maximize performance

Just look up “aerobic exercise and mitochondria”

I just picked one of the first ones there but yeah, google scholar will take you to better ones if you add stuff like meta-analysis or review to it

Idk if what they said about high intensity was true though


valleyof-the-shadow t1_ivcqywt wrote

Doesn’t the body going in to ketosis and you start utilizing fat for energy? We’ve been doing a high protein/ fat vegetable diet for a while and I was surprised at the increase in energy for workouts as well as the loss of a lot of body fat at the age of 60.


MrSarcastica t1_ivd33ok wrote

It says over a 24h period, so not likely to be in ketosis yet. Usually takes about 3 days for your body to go into full ketosis.


TheTiniestPeach t1_ive60fm wrote

Was I going into keto after fasting for 48 hours straight? What about intermittent fasting?


MrSarcastica t1_ive6god wrote

Fasting for 48 hours would put you into keto but you would be loosing musclemass in the process of getting there so I wouldn't recommend going that route. Intermittent fasting doesn't really put you into keto unless your also cutting out carbs.


-Kibbles-N-Tits- t1_ivfb3bs wrote

Coming from someone already thin and athletic, as long as you move a lot during your fast you’re going to lose a neglible amount of muscle/strength

Nothing noticeable at least


ladida- t1_ivev3yc wrote

I have seen a guy on YouTube who made a video about studies on intermittent fasting and these study do not support your view. They showed that you loose about as much muscles mass as any other diet.


MrSarcastica t1_ivgwcrh wrote

True like I said if you're not in ketosis you will lose muscle mass. If you're already in ketosis you will minimise you muscle loss. Keto is the only diet where you can actually lose fat and gain muscle at the same time.


ladida- t1_ivh6agj wrote

Intermittent fasting doesn’t equal an ketogenic diet afaik


MrSarcastica t1_ivh9wfy wrote

No it doesn't, but it'd often used while on keto to maximise effects of the diet.


TheTiniestPeach t1_ive76ut wrote

So fasting is a bad idea in general? Cus many people practice it. I feel like it also really helped me to lose weight and go from obese to overweight.


Strazdas1 t1_ivjr7jt wrote

>So fasting is a bad idea in general?

In a very generalized broad terms - yes. May be different for individual situations.

Long term habit change is what you want to do.


MrSarcastica t1_ive7f3g wrote

I mean fasting can definitely help if your only goal is to loose weight. But if you want to put on muscle as well I wouldn't be fasting for long periods.


osoALoso t1_ivf0hpc wrote

When I did keto I had more long term energy, but had a remarkable deficiency in explosive short Burst energy.

On my cheat days I was easily increasing bench press by 15 to 20 pounds in my reps and would bump my max by 35 or so pounds.

Speed in running was down but longevity was up.

Anecdotal but it's what I noticed on 6 months of keto.


dabeawbeaw t1_ivfregr wrote

I did keto recently for about 2 years. I definitely had more energy during my workouts. I went back on a regular diet and my workouts haven’t been the same so I decided to go back on keto. Not so much the high fat part but mainly lower carbs and more protein.


valleyof-the-shadow t1_ivghr7f wrote

That’s interesting. I tend to just eat meat, vegetables and fruit and a whole bunch of different herbals. All as natural and organic as I can afford. My grocery bill is about the same now that I’ve cut out all that processed stuff.


JohnConnor7 t1_ivc2dji wrote

Wut mean, they just found out the lag is 24 hrs? Can't read right now.


SurNihl t1_ivcb7j1 wrote

Study was saying switching to low carb, high fat doesn't tank your energy levels that day as some people believe. Total calories was kept the same for the study.

In my mind they seem to be saying one is just as good as the other, neither is superior.


Strazdas1 t1_ivjrhns wrote

Admittedly anecdotal evidence but doing the opposite - going from fat to carbs certainly increase energy levels, sometimes to the point where its hard to stay focused. Its not something i do very often but if i need a "boost" that day it certainly works.


cedenof10 t1_ivcc68q wrote

so is carbo-loading BS?


Meatrition OP t1_ivcccxl wrote

Even the exercise physician that discovered the carbo-loading phenomenon, and wrote a book on it Lore of Running, now thinks he was wrong. He also got Type 2 Diabetes. I have his new book Lore of Nutrition.


lost_in_life_34 t1_ivd98jd wrote

Carbs help at high intensity running but you can raise the thresholds at which the body still burns fat


Dobber16 t1_ivdt1rv wrote

Carbo-loading before long endurance exercises like a marathon or some other multi-hour cardio exercise has been proven to be helpful, not sure about normal exercise lengths of an hour or two, or other types of exercise


BullfrogRepulsive05 t1_ivceasz wrote

I mean we have glycogen stores in our muscle for about a day anyways right?

Edit: a day


HyperAad t1_ivdz6m4 wrote

>I mean we have glycogen stores in our muscle for about a day anyways right?
>Edit: a day

In muscles, we have for a long time depending on the activity and which muscle. It also depends on how well-trained you are. Liver glycogen is depleted after maybe two-three days for a sedentary untrained person. This is why you don't see a reduction in activity over 24 hours.


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