Many think of muscle maintenance throughout life as being aesthetically pleasing but at its finest, it has to do with maintaining a good metabolic rate and perfunctory body. Not many people are aware that starting at about 30 years, one will be losing between 3% to 5% of muscles per decade depending on the activity levels. Muscle loss is somewhat stealthy; understanding the ‘why’ might help drastically in reversing the process.
Use It or Lose It

Muscle isn’t the least expensive tissue to maintain; it consumes high energy. If you don’t use it, your body decides it is not good enough to support that extra weight or is of no use and starts breaking it down. The only way that makes your mind think, “I need that muscle,” is by regular use.
The Harm of Excess Sitting

Severely sedentary, the pace at which muscle breaks fastest. The longer you sit close to a desk or couch, the more likely you are going to suffer muscle atrophy. Breaking up your work by at least getting up and stretching or performing air squats any time within the day keeps those muscle fibers firing.
Not Consuming Sufficient Protein

Protein comes by way of course into the actual architecture for muscle. With age as well, equally our bodies become less astute, actually, in regards to the uptake of protein: indeed, it might be good to consume a higher amount of it from our 20s onwards. For example, attaching a source of good quality protein such as eggs, beans, or lean meat for almost each meal.
Hormonal Changes

Ageing brings with it naturally diminishing levels of hormones like testosterone and growth hormone, both which are responsible for muscle repair after an activity. While aging cannot be stopped, regular exercising and having a sound sleep can help keep these hormones at optimum levels.
Chronic Inflammation

The wrong diet, too much stress, and insufficient sleep create low-grade inflammation in the body, which can have an adverse effect on how signals in the body can build muscles. Proper water intake and consumption of unprocessed whole foods help combat damaging inflammation leading to muscle wasting.
Make Strength Training a Preference

Cardio is a good activity for the heart, but it’s not the best activity for maintaining muscle. You will need to do something that combines resistance—weights, resistance bands, or body weight. Go to fatigue at least two times weekly.
Vitamin D

It depended on vitamin D in muscle function and strength. Low levels of vitamin D have been associated with muscle weakness as well as being a fall risk among older persons. Reward yourself by spending a little bit more time in the sun or even discussing a possible supplementation time with your physician to save those muscles!
Sleep Quality

It is built in the gym and in sleep; basically, this growth hormone acts most’ because it is involved in repairing micro-tears realized through a workout. So if the body does not receive enough sleep because of chronic deprivation, then the muscle repair mechanisms get so difficult to catch up and will even lose muscle faster.
Staying Hydrated

Muscle tissue is on the average composed of 75% water. Muscle weakness and failure of the functionality required when damaged also occur with quite slight dehydration. An adequate supply of water means nutrients are supplied to muscle cells, as well as the elimination of metabolic wastes; this is probably just as beneficial to continue tissue health.