Whole body routines are exhausting depending on the weight used. They are easy with light weights and exhausting with heavy weights. I use to bike a lot and even rode 500 miles in five days in the summer heat in Iowa. Endurance needs glycogen. Again it's a matter of of how hard you are pushing. A hard 5 mile run at OPTIMAL capability will be impossible on a low carb diet. Talking about being at your best for the run. I do understand that a high carb full of sugar is not healthy.
Do you feel you get really lean on your low carb diet? Many say they see the fat melt off.
You have to be in condition to do full-body workouts which can be up to 50 sets over 2 hours or so.
After a couple weeks you get used to it like anything else. There is a mental adjustment along with a physical adjustment.
If you are training heavy you may need longer rests between sets.
A routine like that done 2-3 days a week.
A mistake made by people doing full-body training is to just take their bro-split routine and trying to do it all in one day.
You don't do that!
A full-body routine should be in the range of 3-6 sets per bodypart, usually consisting of thighs, calves, chest, back, delts, biceps, triceps. Anywhere from 21-42 sets total spread over 1-2 exercises per bodypart. Compound exercises preferred.
The 3 hour full-body workouts for the Silver Age guys like Clancy Ross were pre-contest routines, not off-contest.
When I was doing Arnold bro-splits pre-contest many years ago it would be 20-25 sets a bodypart, 4-5 exercises per bodypart, doing say chest and back twice a week. So, that is 40-50 sets again over up to 2.5 hours in the gym.
That done 6 days a week!
Regarding fat, your body adjusts on keto. A new set point. Your ketone production adjusts. You don't just keep losing more and more fat until you disappear.
Interesting article excerpt:
https://www.doctorkiltz.com/cyclical-keto-diet/Ultra-endurance athletes may also thrive on conventional keto. Becoming keto-adapted actually helps the ultra-endurance athlete reach one of their most coveted goals: becoming ‘bonk-proof.’
Bonking is the word endurance athletes use to describe the point when your body uses up it’s glycogen stores, and switches to breaking down fat. For an athlete who is not keto-adapted, this means major physical struggle. But for an athlete whose body is adapted to CKD, the transition is easier. And there are already higher levels of ketones in the blood.
Ketones are a decidedly cleaner-burning fuel source than carbs when it comes to slow, steady energy production. [13] Ultra-endurance events are far too long to be sustained by the body’s glycogen (carbohydrate) stores alone.
