Muscle Questions

kateowp

At maintenance caloric intake, what happens when muscles are no longer being used (imagine a weight lifter who spent a month or two lying on a sofa accurately eating her TDEE)? Do the muscles get smaller? Softer? Look the same but just get weaker? Without a caloric deficit (or super endurance cardio), will the body “eat” unused muscle? Is it correct that you can make existing muscle stronger (by working out) without making muscle bigger (eating more to build muscle)? If that is correct, are the main reasons to build muscle (instead of merely strengthening existing muscle) its fat burning property and the way it looks? Finally, I think that “toning” means strengthening muscle without trying to increase muscle size/bulk- is this what it means? Why do some people say “toning” is a myth?

SHBoss1673

At maintenance caloric intake, what happens when muscles are no longer being used (imagine a weight lifter who spent a month or two lying on a sofa accurately eating her TDEE)? Do the muscles get smaller? Softer? Look the same but just get weaker? Without a caloric deficit (or super endurance cardio), will the body “eat” unused muscle? Is it correct that you can make existing muscle stronger (by working out) without making muscle bigger (eating more to build muscle)? If that is correct, are the main reasons to build muscle (instead of merely strengthening existing muscle) its fat burning property and the way it looks? Finally, I think that “toning” means strengthening muscle without trying to increase muscle size/bulk- is this what it means? Why do some people say “toning” is a myth?

Unused voluntary muscle will seek the size that is needed for functional use. So if you've been training a muscle (group) hard, and then stop, there will be a reduction in both size and strength.
That being said, at maintenance, if you continue to be active and use your body functionally, then it will be a slow process. Depending on the muscle and how much daily use it receives you can delay any noticeable reduction by months just by staying active and keeping those anabolic hormones active (testosterone, HGH, IGF...etc.).

A muscle that was in heavy use will have some of it's size attributable to glycogen and water storage, these will reduce rather quickly if the muscle is allowed to begin catabolism, so in the first 6 weeks you'll lose up to 20% of the size, after that, it's a slow burn to lower the muscle's size and functional strength (again assuming regular activity to keep your hormone levels up).

Ever see someone who breaks their wrist or leg? After they take the cast off, that limb is usually 20 to 30% smaller than the other. This is a dramatic effect since immobilization and constriction will drastically reduce muscle quickly, but it's the same concept, just on a slower scale.

Now, if you want to keep a decent shape in the muscle (maintain) you can work that group 1 to 2 times a week and you should be able to keep it relatively stable (assuming you weren't at the very tip top of your genetic ability to grow that muscle). When my workout cycle is moved from weight training heavy to High Intensity heavy (about every 8 weeks I switch it up) I usually do 1 day of full body weight training and 1 day of light (relatively speaking) weight training for the large muscle groups. This leaves me 4 days of the week to work my HIIT (of which I pick 3 and use 1 day as a cardio day) and of course I usually take the day after my full body off as a recovery day.

kateowp

Thanks for your reply! So when unused muscles shrink (great cast example!) does the body process that previously stored energy as fuel? Is that why some people say that unused muscle turns to fat?

Sheila_Ann

bumping...great ?'s!

Martucha123

If muscle goes away then your TDEE lowers
your body don't need to repair it so it needs less calories...

but no, muscle can't turn to fat directly, simply even though you think you eat TDEE you are overeating as your body does not use a lot of calories to repair muscle

but the process is very very slow, my SO went 10 years ago! from playing soccer semi pro to playing 1 a week and his legs are almost as big as they used to be, even though he is significantly slower and weaker

SHBoss1673

Thanks for your reply! So when unused muscles shrink (great cast example!) does the body process that previously stored energy as fuel? Is that why people say that unused muscle turns to fat?

Ahh, I have no research suggesting any particular metabolic pathway for catabolized muscle. I would assume just using deductive reasoning that it would be catabolized as amino acids, and used in the citric acid cycle or used to build other protein based tissues. But the rate of break down is so slow compared to normal daily metabolic needs that it wouldn't give any noticeable increase in daily energy. I would assume something on the order of a couple of grams a day unless you were in a severe caloric deficit (so a few dozen calories a day would be my guess not enough to effect overall weight).

While research proves that fat cannot turn into muscle (there is no way to do this directly, in order to build muscle you need certain proteins, fat does not have these proteins and they are not proteins that the body can build without having the correct amino acids that are only found in existing protein, not fat). Research also proves that protein can, in fact, be converted to energy and thus, stored as fat. In other words, the conversion from muscle to fat is possible, though not very quick, or simple for the body to do.

kateowp

In other words, the conversion from muscle to fat is possible, though not very quick, or simple for the body to do.

Perfect sense! Thanks!